Carcass Characteristics

The importance of carcass characteristics and meat quality were recognized equally a priority for improvement,27 and several breeds followed the pb of the American Angus Association and began collecting carcass data as early every bit 1974.

From: Animal Agronomics , 2020

Pasture-finished beef production in the s

Matt Poore , ... Sarah Blacklin , in Management Strategies for Sustainable Cattle Production in Southern Pastures, 2020

Carcass characteristics of steers from dissimilar brood types

Carcass characteristics and rib section parameters of the same steers harvested at the end of the winter grazing periods are shown in Tabular array 10.5. In general, the data demonstrated the expected differences between the beef breeds, a dairy breed, and a nontraditional beef breed: the beef breeds had more fat, greater ribeyes, smaller KPH (kidney, pelvic and center fat), and less bone.

Table ten.v. Carcass characteristics from steers of unlike breed types at the cease of winter grazing (Apr/May).

Breed type Live BW (lb) Carcass Wt. (lb) Dressing (%) Skeletal maturity Lean maturity Marbling score Fat thickness, in. REA (sq in.) KPH (%)
Angus 974 510 52.4 A50 A50 307 0.19 ix.2 0.92
Brangus 938 502 53.v A50 A50 283 0.16 ix.four 0.89
Holstein 1098 547 49.7 A60 A60 293 0.07 8.0 1.17
Pineywoods 670 352 52.five A60 A60 293 0.07 8.1 i.75

REA, ribeye area; KPH, kidney, pelvic and heart fatty.

We are unaware of whatsoever other published carcass data with regard to Pineywood (Criollo) cattle. Of these cattle harvested at the end of the winter grazing flow, Pineywoods had the greater KPH every bit a percent of the nine–eleven rib section than any other breed type. They also had a lean percent that was greater than the beef breeds and similar to Holstein. Their percent fat was intermediate, and pct bone was similar to Angus and Brangus.

Carcass data obtained at the cease of the summertime grazing period after a yearlong finishing menses followed a similar pattern as the data obtained after the winter grazing season (Table ten.6). As expected, greater carcass weight, marbling scores, ribeye area, and KPH were observed as an issue of increased maturity (18–19 months of age). Even greater carcass weight, ribeye expanse, and marbling score would be expected if the steers had remained for another wintertime grazing season. However, many pocket-sized producers in the Gulf Coast region cannot retain steers for a 2nd winter, as they already have a new group of steers starting the yearlong finishing period subsequently weaning (October).

Tabular array ten.6. Carcass characteristics from steers of different breed types at the end of summertime grazing (September/Oct).

Breed blazon Live BW (lb) Carcass Wt. (lb) Dressing (%) Skeletal maturity Lean maturity Marbling score Fat thickness (in.) REA (sq in.) KPH (%)
Angus 1145 621 54.2 A50 A50 372 0.27 x.4 1.xxx
Brangus 1137 646 56.9 A50 A50 420 0.31 10.six 2.50
Holstein 1200 635 53.0 A50 A60 350 0.04 8.seven 1.75
Pineywoods 754 421 55.8 A60 A60 360 0.10 9.eight 3.00

REA, ribeye area; KPH, kidney, pelvic and heart fat.

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Biology and regulation of carcass limerick

P.Fifty. Greenwood , F.R. Dunshea , in Improving the Sensory and Nutritional Quality of Fresh Meat, 2009

2.vi Genotypic influences on carcass composition

Domesticated ruminants and pigs have been selected for traits including survival and reproductive capacity, growth rate, muscularity, yield of meat, and eating quality characteristics including intramuscular fat content. In this section nosotros provide a brief overview of furnishings of breed, quantitative selection, single genes with large furnishings, and of gene markers, on carcass characteristics in livestock. Nosotros also refer to recent research in sheep that has used estimated breeding values for growth, muscling and fatness to assess genotypic furnishings within differing production environments. More specific details of genotypic effects are provided in Role II ( Capacity nine to xiii Chapter 9 Chapter x Chapter 11 Chapter 12 Affiliate 13 ) of this book, and the reader is also referred to earlier reviews of the genetics of carcass and quality traits of pork (Sellier, 1998; Rohrer, 2001), sheep meat (Banks, 1997; Thompson and Brawl, 1997) and beef (Marshall, 1999; Cundiff, 2006).

Highly selected livestock, such as European cattle breeds, display productive advantages in more temperate climates inside highly managed systems, whereas tropically adjusted animals such as Bos indicus cattle and various sheep and goat breeds have the capacity to survive and produce in hotter and/or more boiling environments in which other types perform poorly. For example, Bos indicus breeds survive well in the tropics and produce a high proportion of lean beef from their carcass, although they do produce somewhat tougher meat than Bos taurus cattle (Thompson, 2002).

Substantial genotypic advantage conferred by using specific breeds of livestock may be captured by the apply of pure-bred herds or flocks (for instance, Dorset 5 Suffolk sheep: Beermann et al., 1995), terminal sires (for example, Piedmontesev Wagyu-sired cattle: Greenwood et al., 2006a), or within blended herds comprising animals with divers proportions of genetic cloth from specific breeds or genotypes. Industry-based convenance and selection programs within and across improved breeds of livestock utilise quantitative choice techniques and progeny testing to improve traits of interest such as growth, muscling, fatness, marbling, survival and reproduction. Increasingly, these programs are looking to incorporate furnishings of factor markers into their data bases (Nicholas, 2006).

Examples of breeds or genotypes of livestock with more farthermost carcass characteristics include:

•

European breeds of cattle that are late-maturing and display high degrees of muscling, in some cases associated with mutations resulting in non-functional myostatin and extreme levels of muscling, for example, Belgian Blue and Piedmontese cattle (Bellinge et al., 2004);

•

Wagyu and Hanwoo cattle from Japan and Korea, respectively, that produce highly marbled beef (Pethick et al., 2004);

•

Texel sheep which have a mutation in the myostatin gene that causes translational inhibition of the mRNA into myostatin, resulting in high muscling (Laville et al., 2004; Clop et al., 2006);

•

Callipyge sheep, which have a mutation which, when present in heterozygous offspring that inherit the mutation from their sire, produces extreme muscling, especially of the hindquarters, but which is associated with extremely tough meat (Freking et al., 2004);

•

Pietran pigs that have loftier levels of muscling (Sellier, 1998).

The virtually farthermost furnishings of specific genes on carcass characteristics upshot in double muscled cattle and the Callipyge sheep phenotypes. Although mutations for these genes result in increased muscularity, their specific causes and effects differ substantially, as summarised in Table 2.5.

Table ii.5. Comparison of characteristics of Callipyge sheep and double-muscled cattle

Callipyge sheep Double-muscled cattle
Specific crusade Uncertain (DLK-i involved) Myostatin (GDF8) mutation (non-functional myostatin)
Location of single nucleotide polymorphism(s) Ovine Chromosome 18 Bovine chromosome 2 (Ovine chromosome 2) i
Genotype resulting in mutant phenotype Heterozygote with mutant allele inherited from sire (polar overdominance) Homozygous for mutant allele (heterozygote has intermediate phenotype)
Phenotypic expression Primarily postnatal Prenatal and postnatal
Location of muscle hypertrophy Hindquarter and loin More generalised
Myofibres of affected muscles (cf. normal) No hyperplasia Hyperplasia
More blazon 2X More than type 2X
Far less type 2A Less blazon 2A
Less type 1 in some affected muscles
Type 2 hypertrophy May have blazon 2
Hyperplasia hypertrophy depending on mutation and genetic background of cattle
More glycolytic More than glycolytic
Predominant machinery in enhanced musculus growth Reduced protein degradation (more calpastatin) Increased protein synthesis
Meat quality (cf. normal) Much tougher, pale Similar or more tender, stake
1
Mutation in Texel breed of sheep which affects translation into myostatin protein.

Recent studies take assessed the use of sires with a range of Australian sheep breeding values (ASBVs) for muscling (eye muscle depth), fatness (subcutaneous fat depth) and growth (postal service-weaning weight) on a broad range of commercial, cellular, and biochemical measures (Tabular array ii.6). Furthermore, associations of ASBVs with factors including historic period, live weight, carcass weight, gender of offspring, and nutrition have also been assessed (Hegarty et al., 2006; Warner et al., 2007). This approach to understanding influences of quantitative selection for traits differs from previous single-trait selection line studies by assessing effects across a continuum of breeding values for a trait (for case, muscling), while accounting for effects of convenance values for other associated traits (for example, growth and fatness). Among the numerous experimental, single-trait pick lines are those for growth rate or weaning weight (Thompson et al., 1985a,b,c; Parnell et al., 1986; Oddy and Sainz, 2002), fatness (Abdullah et al., 1998), muscularity (Cafe et al., 2006c) and net feed efficiency (Arthur et al., 2004).

Table ii.six. Effects of increasing the estimated breeding values of sires for post-weaning eye-muscle depth (PEMD) on major growth and carcass characteristics of lambs

Unaffected Positively afflicted Negatively affected
Mail-weaning LWG A Slaughter weight (0.59 kg) A
Carcass EMD (0.61 mm) A Carcass C-fat depth (–0.136 mm) A
Conformation score (0.03–0.85) A B
Carcass protein (0.037 kg) B
Four hindquarter muscles (0.021 kg) B
Radius, ulna lengths C Proportion of lean in carcass (0.015) C Proportion of bone in carcass (–0.022) C
Bone mid-shaft width C Carcass musculus to bone ratio (0.20) C
RNA:DNA in muscle (0.351) D DNA concentration in muscle (–10.2 μg/g) D
Poly peptide:DNA in musculus (24.9) D
Total protein in muscle (1.29 yard, semimembranosus) (3.17 chiliad, longissimus) D
% blazon 2X myofibres (0 to 2.fourteen) E % type 2A myofibres (0 to −1.29) E
Cooking loss Connective tissue seam thickness (219 μm) F Muscle fascicle width (–0.27 mm) F
Longissimus shear force One thousand Longissimus International monetary fund% (–0.11) Chiliad
Meat color (L,a,b∼) G Overall consumer liking (–1.32) G
A
Hegarty et al. (2006a);
B
Hegarty et al. (2006b);
C
Cake et al. (2006);
D
Greenwood et al. (2006c);
Due east
Greenwood et al. (2006b), range indicates musculus × EBV interaction;
F
Allingham et al. (2006);
G
Hopkins et al. (2005). ∼ Colour assessed approximately 24h after slaughter and thirty–twoscore min after cutting.

(adjusted from Hegarty et al., 2006c). Regression coefficients are provided for each trait significantly affected (P<0.05) by PEMD within multifactor analyses

Copyright © 2006

Use of sires with greater ASBVs for muscling (eye muscle depth) increased slaughter weight and proportion of lean while reducing subcutaneous fat depth and the proportion of bone in the carcass (Tabular array 2.6). This results in an increase in carcass conformation score and the muscle-to-bone ratio (Block et al., 2006), which is consistent across ages ranging from 4 to 22 months (Warner et al., 2007). This reward of high muscling breeding value and the growth advantages due to high sire ASBV for postal service-weaning weight were maintained within low and high nutritional systems. In dissimilarity to increased muscularity at whatsoever given weight that is generally associated with large mature size within breeds and strains of sheep (Black, 1983; Beermann et al., 1995), offspring of sires selected using ASBVs for centre muscle depth had reduced mature weight, which was particularly associated with the skeleton (Warner et al., 2007).

Increasing sire breeding values for muscling likewise increased the percentage of type 2X (fast glycolytic) myofibres (Greenwood et al., 2006b) and connective tissue seam thickness (Allingham et al., 2006), and reduced the percentage of type 2A (fast oxidative–glycolytic) myofibres (Greenwood et al., 2006b). Furthermore, the intramuscular fat content (Hopkins et al., 2005) declined, and there was a reduction in consumer acceptance of meat (Hopkins et al., 2005) with increased breeding value for muscularity. These latter findings are consistent with those for pigs genetically selected for greater eye muscle area, which also has agin consequences for eating quality associated with an increasing proportion of fast glycolytic myofibres (Rehfeldt et al., 2000; Fiedler et al., 2004). They advise that continued genetic selection for muscling should incorporate eating quality characteristics and may likewise demand to include myofibre characteristics inside indexbased genetic selection programs if acceptable eating quality is to be maintained while increasing meat yield. It was likewise axiomatic that site-specific genetic choice for increased muscling has differing affects across different muscles (Greenwood et al., 2006b,c), with implications for compositional and eating quality characteristics (Hegarty et al., 2006).

Marking-assisted selection has been made possible through the development of molecular technologies that let identification of specific gene markers or unmarried nucleotide polymorphisms (SNPs) for commercially of import traits. A detailed history of developments in the search for Dna markers is provided by Nicholas (2006). The search for SNPs in ruminants was enhanced by development of the bovine gene map, which was made possible through the identification of quantitative trait loci (QTL) using microsatellite markers on specific chromosomal regions, the development of linkage and radiation-hybrid maps roofing a large proportion of the genome coupled with loci physically mapped using in situ hybridisation, and the use of Location Database (LDB) to integrate this information. Identification of markers in or near specific genes has been possible using fine-mapping of QTL, although identification of the causative quantitative trait nucleotide (QTN) has occurred infrequently due to difficulties in their identification, equally detailed by Nicholas (2006).

Deoxyribonucleic acid sequencing of the bovine genome and the appearance of large-scale, high throughput detection and SNP genotyping now allows for genome-wide studies to decide the clan of SNPs with commercially important traits (Hawkin et al., 2004). Differential expression of genes using, in particular, microarrays containing many thousands of genes, is also used as a means of identifying of import genes (Lehnert et al., 2006a,b, 2007) and gene networks (Reverter et al., 2006) that regulate development of carcass tissue traits and their response to the surround. More than recently, these developments have immune for expression QTL (eQTL) studies to exist undertaken in which microarray profiling is integrated with loftier throughput SNP genotyping to let for a detailed molecular phenotype to be quickly linked to a genome region responsible for a specific trait (Lehnert et al., 2006b).

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Quality Evaluation of Meat Cuts

Liyun Zheng , ... Jinglu Tan , in Figurer Vision Engineering science for Food Quality Evaluation, 2008

one Introduction

Currently meat quality is evaluated through visual appraisal of certain carcass characteristics, such every bit marbling (intramuscular fat), muscle color, and skeletal maturity. Although the visual appraisal method has been serving the meat manufacture for many years, the subjective evaluation leads to some major intrinsic drawbacks, namely inconsistencies and variations of the results in spite of the fact that the graders are professionally trained ( Cross et al., 1983). This has seriously express the power of the meat industry to provide consumers with products of consistent quality, and subsequently its competitiveness.

As there is always a desire from the meat industry for objective measurement methods, many research efforts have been devoted to developing instruments or devices. Ane obvious and popular approach is to measure the mechanical properties of meat every bit indicators of tenderness, with the most well known perhaps being the Warner-Bratzler shear-forcefulness instrument. For cooked meat, the shear strength correlates well with sensory tenderness scores (Shackelford et al., 1995); yet, such a method is not practical for commercial fresh-meat grading.

To overcome this problem, ane of the near promising methods for objective assessment of meat quality from fresh-meat characteristics is to utilise computer vision (Brosman and Sun, 2002; Lord's day, 2004). Recently, applications of reckoner vision for food quality evaluation have been extended to food in many areas, such as pizza (Sun, 2000; Lord's day and Brosnan, 2003a, 2003b; Lord's day and Du, 2004; Du and Sunday, 2005a), cheese (Wang and Lord's day, 2002a, 2002b, 2004), and cooked meats (Zheng et al., 2006a; Du and Dominicus, 2005b, 2006a, 2006b). However, for fresh meats, research began in the early 1980s. For case, Lenhert and Gilliland (1985) designed a black-and-white (B/W) imaging system for lean-yield estimation, and the application results were reported past Cantankerous et al. (1983) and Wassenberg et al. (1986). Beef quality assessment past image processing started with the work past Chen et al. (1989) to quantify the marbling area percentage in six standard USDA marbling photographs, and later on McDonald and Chen (1990a, 1990b) used morphological operations to dissever connected muscle tissues from the longissimus dorsi (LD) muscle. For quality evaluation of other fresh meat, such as pork and lamb, early studies were performed past Kuchida et al. (1991) and Stanford (1998). The composition (fat and poly peptide %) of pork were analyzed based on colour video images (Kuchida et al., 1991) and video-image analysis was also used for on-line classification of lamb carcasses (Stanford, 1998). Since so, inquiry has been progressing well in this area.

To develop a calculator vision system (CVS) for objective grading of meat quality, several steps are essential. Although the existing human grading system has many intrinsic drawbacks, any new systems designed as a replacement must still be compared with the man organisation before they can exist accepted. Furthermore, the existing human grading system is qualitative, whereas the quantitative characteristics that contribute to the human being grading are not ever obvious. Therefore, it is necessary to search for image features that are related to human scores for marbling abundance, muscle colour, and maturity – and, eventually, official grades such as USDA grades. Moreover, to improve the usefulness of the grading system, new instrumentally-measurable characteristics are needed to enhance the power of the grades in predicting eating quality, such as tenderness.

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Nutrition and Feeding Management to Alter Carcass Limerick of Pigs and Cattle

Virgil W. Hays , Rodney L. Preston , in Low-Fat Meats, 1994

Ii Impact of Energy Level

The most common and readily demonstrated furnishings of nutrition on carcass characteristics relate to biologically available energy (e.g., metabolizable free energy) intake relative to intake of other essential nutrients. In pigs the metabolizable energy intake, the poly peptide (essential amino acids) intake, and protein-to-free energy ratio in the diet have marked effects on carcass composition at a standardized trunk weight. The related effects of protein and energy are not unproblematic. Backlog protein may be utilized almost as efficiently as carbohydrates for energy purposes. This is credible from the estimated energy values of feedstuffs (National Research Council, 1984, 1988b; Ewan, 1991) and the rates of body weight proceeds and fat deposition on high protein diets as reported by Wagner et al. (1963). The metabolizable free energy values of the high protein ingredient soybean meal are very similar to those of the high-carbohydrate ingredient corn (iii.15 vs iii.25 and three.76 vs iii.84 Mcal/kg for cattle and pigs, respectively). The differences are somewhat greater in terms of net energy values. For beef cattle the net energy values (Mcal/kg) for gain are 1.48 and 1. 55 for soybean repast and corn, respectively; and for pigs the respective net energy values are 1.96 and 2.58.

If adequate free energy in the form of carbohydrates or fat is not provided, the creature will utilise protein for free energy purposes at the expense of protein accession. These interrelationships are exemplified in pigs by studies of Cunningham et al. (1962) equally summarized in Table I. The low level of feeding (1.60   kg/day) of the low protein diet was inadequate in protein or energy for maximum protein retentiveness. At this level of feeding, protein was being used for energy purposes. Additional protein resulted in some increase in total protein deposition, but a lesser increment in protein intake in combination with increased energy intake (higher feeding level) resulted in an even greater increase in protein retention.

Table I. Effects of Diet Restriction and Protein Intake on Free energy and Poly peptide Utilization in Pigs

Protein level:
Feeding level:		 Low
Low		 High
Low		 Low
High
Trial one
  Feed intake/day (m) 1600 1600 2450
  N intake/twenty-four hour period (g) 31.2 53.1 47.8
  Dig. Energy/day (cal.) 4836 4698 7311
  N retention/day (g) x.iii 14.3 sixteen.6
  N retention (%) 33.0 26.nine 34.4
Trial 2
  Feed intake/day (grand) 1630 1640 3220
  Daily gain (1000) 284 243 755
  Feed/gain 5.82 6.95 4.40
  Loin eye area (sq. in.) 4.33 iv.24 4.fourteen
  Carcass protein (%) fifteen.2 15.6 14.six
  Carcass fatty (%) 38.4 37.7 forty.0

Adapted from Cunningham et al. (1962).

In pigs, the furnishings of energy intake on performance and carcass composition may be illustrated by varying the total feed intake (restricted vs advert libitum feeding) or by varying the metabolizable energy density of the diet (by substituting fat for carbohydrate or highly digestible carbohydrates for more than fibrous materials). In cattle, this is accomplished primarily by varying the ratios of provender and concentrate feeds. Either method of varying energy intake volition influence body composition.

Examples of the effects of feed brake on functioning and body composition in pigs are presented in Tables Two and III (Braude et al., 1958; Greer et al., 1965). Moderate restriction of feed intake results in a relatively modest but meaning improvement in feed efficiency but a rather marked reduction in rate of proceeds. Fat in the carcass is reduced substantially equally measured by thickness of backfat or pct intramuscular fatty in the longissimus muscle. Note that intramuscular fat is reduced to a much greater extent, on a per centum basis, than is external fatty cover (backfat). Information technology is well established, equally illustrated in these two tables, that restriction of feed intake will upshot in a higher ratio of lean to fat in the carcass. In barrows fed ad libitum, 92.five% or 85% of ad libitum intake, Leymaster and Mersmann (1991) as well found that fat deposition was decreased; whereas poly peptide intake even on the lowest feeding level was near acceptable and rate of protein degradation was minimally affected. To limit fat deposition, the diets should be formulated so as to limit only the energy intake, and free energy should non be express to less than that required for maximum lean tissue degradation. The added price of labor and/or automated feeding devices involved in restricting full feed intake, the added costs associated with slower rates of gain, and the low premiums paid for the improved carcasses do not encourage restricted feeding in the U.S. In some countries, however, it is rather common to restrict the feed intake. In those countries practicing restricted feeding, either labor costs are relatively lower, feed costs are relatively college, or the premiums for leaner carcasses are relatively greater than in the U.South.

Tabular array 2. Furnishings of food Brake on performance and carcass Characteristic of Pigs

Body weight (kg)
14.5 to 54.5
54.5to xc.viii		 Ad lib
Ad lib 		Feeding level
Advertisement lib.
2.95   kg		 To calibration a
To scale
Feed intake (kg/day) 2.65 2.47 2.14
Daily gain (g/mean solar day) 676 640 563
Feed/gain 3.92 3.86 3.81
Backfat (cm) iii.92 3.71 3.50
Depth of longissimus (cm) four.41 4.52 4.43
Width of longissimus (cm) 7.51 7.75 vii.64
a
908 g/day initially plus 45 for each 1.36   kg increment in trunk weight to a maximum of two.95   kg.

Adapted from Braude et al. (1958).

Table Iii. Furnishings of Restricting Corn Base Diets on Performance and Carcass Characteristics of Pigs

Feeding level
Per centum of advertisement libitum 		100 85 70
Trial one
  Feed intake (kg/day) 3.xv 2.44 ii.06
  Avg. daily proceeds (kg) 0.77 0.61 0.51
  Feed/proceeds 4.09 iv.00 4.04
  Ham and loin (% of carcass) 35.9 38.0 38.4
  Backfat (cm) 3.78 3.40 3.22
  Fatty in 1. dorsi (% of D.Grand.) 20.vii fourteen.3 15.iii
Trial 2
  Feed intake (kg/24-hour interval) 2.61 ii.11 1.eighty
  Avg. daily gain (kg) 0.lxx 0.55 0.45
  Feed/gain 3.73 3.84 4.00
  Ham and loin (% of carcass) 37.1 38.6 39.4
  Backfat (cm) 3.73 3.61 3.28
  Fat in ane. dorsi (% of D.M.) 16.iv 13.0 xi.iv

Adapted from Greer et al. (1965).

Free energy intake by pigs may be altered either by adding fibrous feeds to the nutrition to reduce energy density or adding fatty to the diet to increase energy density. Animals tend to voluntarily adjust feed intake to satisfy energy needs. Pigs eat more feed per twenty-four hours if the dietary energy density is diluted (added fiber) and eat less feed when fat is added to the diet. Withal, the adjustment oft is not of sufficient magnitude to totally compensate. The data in Table IV (Wagner et al., 1963) show that pigs fed the lower energy diets consumed 14.6% more feed than did those fed the higher energy diets, and this was sufficient to most compensate for the divergence in energy density (17.5%). Pigs on the loftier energy diet consumed only 3.half dozen% more energy per day. Within the same poly peptide level, substituting fat (x%) for soybean hulls resulted in a 9 to 11% increment in backfat thickness and a 32 to 34% increment in intramuscular fat.

Table IV. Effect of Dietary Free energy and Protein Levels on Performance and Carcass Characteristics in Pigs

Energy (Mcal ME/kg)
Protein (%)		 three.12 a
25		 ii.93 a
13		 3.59 b
25		 3.52 b
13
Feed intake (kg/mean solar day) two.08 2.52 1.82 3.11
Energy intake (Mcal ME/day) 6.50 seven.39 half-dozen.54 vii.43
Poly peptide intake (g/solar day) 520 327 458 285
Average daily proceeds (thou) 929 929 754 835
Feed/gain three.23 iii.41 two.63 2.72
Backfat (cm) 3.15 3.30 three.43 iii.67
Longissimus fat (%) c vii.ix 12.6 10.4 xvi.9
a
Diets formulated to contain 0.950 Mcal productive energy per kg.
b
Diets formulated to contain 1.15 Mcal productive energy kg.
c
Percent of dry affair.

Adapted from Wagner et al. (1963).

The effects of restricting energy intake by adding fibrous feeds to the nutrition are illustrated in Table V (Merkel et al., 1958a,b). Ground corn cobs or alfalfa meal were used to dilute the metabolizable energy content of the nutrition. Diluting with corn cobs resulted in a half-dozen.five and 34.4% reduction in backfat thickness and intramuscular fat in the longissimus, respectively; but, it too resulted in a 10% reduction in charge per unit of gain and a 44.ix% increment in feed required for unit of measurement of gain. The aforementioned corporeality (three.90 vs 3.85   kg) of the non-cob fraction of the diet was required per unit of gain; however, the composition of the gain was altered. Reducing energy intake past reducing level of fat, by increasing level of fiber, or by restricting full feed intake will increase the lean-to-fat ratio every bit measured by backfat thickness, intramuscular fat levels, lean cut yield, or chemical analysis of the total carcass.

Tabular array V. Effect of High Fiber Diets on Functioning and Carcass Characteristics of Pigs

Detail Nutrition
High concentrate High fiber
Corn cobs 30% Alfalfa 53%
Average daily gain (yard) 645 581 399
Feed/gain 3.85 5.58 6.98
Backfat (cm) iv.29 4.01 ii.97
Fat in longissimus (% of D.M.) xv.1 ix.nine 10.9

Adjusted from Merkel et al (1985a.b).

Altering weight gain and trunk limerick during the growing stage can be more practical in cattle than in pigs because of their efficient utilization of gristly feedstuffs. Energy intake can be restricted to a level below that required for a high rate of fat synthesis, while at the same time maintaining adequate intakes of protein, minerals, and vitamins to assure maximum muscle growth. This is accomplished by feeding a diet consisting of a high fodder-to-concentrate ratio or allowing animals to graze on pasture forages with simply mineral supplementation.

Reid (1971), Preston (1971), Marchello and Hale (1976), Thonney et al. (1981), Nour et al. (1983a,b), and Old and Garrett (1987) concluded that in cattle fed to usual market grades (22–30% fat), plane of nutrition did not bear upon the last carcass fat level if compared at equal trunk or preferably carcass weights. Preston (1990) concluded that the major affect of increasing plane of nutrition on growth of cattle, big or pocket-sized mature size, is to increment charge per unit of proceeds and improve feed efficiency. While apparent carcass fat and marbling (intramuscular fatty) increase and retail yield subtract in cattle fed diets high in grain (high plane of nutrition), when adjusted for greater carcass weight, these differences become very small or nonexistent. Big-frame cattle need to be fed for maximum rate of gain (high grain diets) to heavier weights to achieve a similar caste of marbling every bit modest-frame cattle before reaching an age that negatively impacts tenderness and overall consumer acceptability. When interest on investment, yardage, and other stock-still costs are considered, in that location is little to be gained in "growing" large-frame cattle on roughage-type diets especially when the energy price of these diets is near equal to or higher than in high grain diets (Amer et al., 1994).

There is non universal agreement on the influence or lack thereof of airplane of nutrition on carcass composition of cattle (Byers, 1982; Williams et al.,1983). This indicates that factors other than plane of nutrition are interacting to produce variable results. Limit feeding of a full-bodied diet from 243 to 342   kg body weight followed by ad libitum feeding of a concentrated diet to 505   kg resulted in steers with less fat thickness but somewhat more than marbling every bit compared to steers continuously fed the concentrated diet ad libitum to the same final trunk weight (de la Torre et al., 1993). These authors ended that "programmed" feeding can be used to alter carcass composition but at the expense of reduced feed lot performance (rate of gain and efficiency of gain). Keele et al. (1993) reported that decreases in fat content of the carcass and increases in the days required to accomplish a given carcass weight were increased as dietary energy was decreased. Evidently these two factors, energy content of diet and rate of proceeds, are related. Together, however, they deemed for only 20% of the variation in carcass fat; whereas, carcass weight accounted for 55% of the difference in carcass fatty.

Marbling can be influenced by plane of nutrition or systems of feeding (Lofgreen, 1968; Hedrick et al., 1982; Bennett, 1988). However, airplane of nutrition and cattle blazon (mature size) as well change feed lot performance and last carcass weight. Owens et al. (1993) postulated that plane of nutrition may change mature size of cattle. Thus as concluded by Preston (1971), in that location is little human relationship between plane of nutrition and marbling contained of carcass weight.

As with pigs, carcass composition of cattle can be influenced by energy concentration of the nutrition, but the divergence in energy level must exist of such magnitude that charge per unit of proceeds and efficiency of feed conversion will be affected to such an extent that it may be economically impractical nether present grading and pricing weather. If high roughage feeds are sufficiently less costly, their utilise in cattle may justify the reduced performance, peculiarly when much of the body weight proceeds may exist acquired on pasture or other depression cost forages.

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DOUBLE-MUSCLED ANIMALS

Southward. De Smet , in Encyclopedia of Meat Sciences (Second Edition), 2014

Carcass and Meat Quality

The largest merit of double-muscled animals lies in their superior carcass characteristics ( Table i). Because of the slower rate of fat deposition, slaughter maturity is delayed. Inversely, animals of this genotype tin exist finished to higher slaughter weights. Dressing proportion is significantly increased (approximately 5%) compared to normal animals because of the reduced digestive tract and the lower weight of pare and organs. At similar historic period or weight, carcasses of double-muscled animals have higher proportions of lean meat and lower proportions of fat and bone. Although prominence is mostly given to the muscle hypertrophy in describing the double-muscled condition, the reduced development of the fat tissues is relatively much more than distinct. The size but not the number of the fat cells is decreased. The reduction in bone proportion is more moderate. The muscle hypertrophy and the fatty and bone hypotrophy are general but not uniform throughout the body. Specially superficial muscles and the hindlimbs compared to the forelimbs are most affected, but differences between studies as to the relative muscle hypertrophy are noticed. Basic of the limbs are shorter and thinner according to the same gradients observed for the muscles. The muscle to bone ratio is maximal at the level of the shoulders and the thigh where the hypertrophy is also most visible. At a comparable level of subcutaneous fat cover, a lower overall carcass fatty content is establish for double-muscled compared to normal animals. The nonuniform muscle hypertrophy and greater conformation in general results in a different size and shape of about meat cuts and in a higher proportion of more expensive cuts. In commercial practice, this effect of conformation and carcass cutability may add together essentially to the deviation in carcass value of double-muscled animals, irrespective of the deviation in lean meat content. The combination of increases in dressing proportion, carcass lean content, and upgrading of some cuts may yield a difference in the proportion of high value cuts on a live weight basis that amounts to more than a quarter for pure-bred double-muscled compared to normal cattle.

As mentioned above on the genetic determination, the myostatin-deficient status leads to an increment in muscle fiber number (Table one). The contractile differentiation during the outset two-thirds of gestation and the metabolic differentiation of aerobic oxidative metabolism during the concluding third of fetal growth are delayed in double-muscled fetuses. A higher proportion of glycolytic muscle fibers at the expense of oxidative and oxido-glycolytic fibers are thus constitute at birth and throughout life in double-muscled cattle. Most reports indicate no major changes in the muscle fiber dimensions, and slightly lower equally well as higher fiber sizes have been reported. Hence, the relative area of type IIB fibers is increased and the overall muscle metabolism is more glycolytic.

The more than glycolytic muscle cobweb blazon results in a faster muscle pH fall postmortem in double-muscled animals, whereas ultimate pH values are generally non different. Concomitantly, the meat is paler, illustrated by college CIE 50? values (Table one). A lower ratio of CIE a?/b? values corresponds to a less red colour tint in line with reduced levels of myoglobin. The higher rate of glycolysis early postmortem, in combination with the increased muscle mass, also leads to slightly higher muscle temperatures postmortem, and consequently an increased degree of protein denaturation. This is expected to touch on water-holding capacity unfavorably. However, data on several measures of water-holding capacity take been variable. Slightly college drip and purge losses are generally plant, simply lower, unchanged as well equally higher cooking losses have been reported. Differences in color and water-holding chapters in comparing with changes in other traits are relatively moderate.

With respect to meat tenderness and palatability in general, literature concerning double-muscled cattle are coherent on most but not all points (Tabular array 1). Meat tenderness and tenderisation are complex phenomena determined by a number of factors. The content and nature of connective tissue content together with the postmortem weakening of the myofibrillar and cytoskeletal network are considered the well-nigh important factors, provided that no extreme muscle shortening occurs during rigor development. No divergence in sarcomere length in meat of double-muscled animals is observed under normal slaughtering conditions. A large reduction (approximately 25%) in musculus collagen content in double-muscled animals is reported in almost all studies. The perimysial connective tissue network is thinner, but the nature of the perimysial collagen in terms of solubility and crosslink concentrations on a collagen tooth basis is not affected. The much lower content of connective tissue explains the upgrading of lower quality cuts to more expensive cuts, allowing for a larger and more homogenous distribution of high quality meat throughout the carcass. In muscles with a low content of connective tissue, like the Longissimus, the positive effect of double muscling on tenderness may exist mitigated by reduced myofibrillar and cytoskeletal protein degradation that normally occurs during the tenderisation procedure. Double-muscled cattle accept consistently lower µ-calpain, calpastatin, and cathepsin levels in the Longissimus, associated with changes in protein breakdown and in line with the reduced in vivo protein turnover. Total proteolysis and tenderization during full ageing seem to be lower in double-muscled animals. Even so, observations in the Longissimus indicate that proteolysis occurs at a faster rate early on postmortem in double-muscled beef animals, consistent with the more glycolytic muscle cobweb blazon and the earlier rigor development. Data for other muscles on enzyme activities and postmortem proteolysis are very scarce. The overall effect on shear force values is variable, depending on the muscle studied and on the time/temperature treatment of the meat. Across studies and muscles, shear force values of raw meat accept always been lower due to the lower collagen content. The literature shows that cooking meat for 1   h at 75   °C, the recommended standard preparation method for shear forcefulness determinations, yielded college values for double-muscled animals, but not in all studies. Considering of extensive solubilization of collagen, this process of shear force determination can be regarded as a measure of myofibrillar toughness, but is not necessarily a adept indication of overall tenderness. The college myofibrillar toughness of double-muscled animals as a result of reduced proteolysis is apparently just reflected in higher shear force values in heated low-collagen muscles in some studies. Indeed, taste panel tenderness evaluations on cooked meat practise always bear witness college tenderness ratings, although the do good may be lower for muscles low in connective tissue. Hence, in full general meat from double-muscled animals is more tender. Meat of double-muscled animals is peculiarly suited for raw consumption or after short fourth dimension heating only, culinary training methods prevalent mainly in Western and Southern Europe. Regarding other gustatory modality panel parameters, lower juiciness, and beef flavor ratings have been reported, in line with the lower intramuscular fat content.

The meat composition in double-muscled animals is changed co-ordinate to the altered carcass composition. The meat protein content is higher and, because of the lower collagen content, protein quality in terms of essential amino acids content is improved. The intramuscular fatty content is approximately 25% lower when compared to normal counterparts. Differences in fat acid composition in dissimilar fat depots take also been reported. In intramuscular fat, the triacylglycerol content is greatly reduced equally a result of the lower fat deposition, whereas the phospholipid content is only slightly lower in line with the bottom amount of jail cell membranes of the more glycolytic muscles. Accordingly, the contents of saturated and monounsaturated fatty acids are significantly reduced, whereas the contents of polyunsaturated fatty acids are similar or slightly reduced. Consequently, the molar proportions of polyunsaturated fatty acids are significantly higher and those of saturated and especially monounsaturated fatty acids are lower. The ratio of intramuscular polyunsaturated to saturated fatty acids is thus college in meat from double-muscled animals. Like but less marked changes are to exist expected in other fatty depots. There are also indications for alterations in the n-6 and northward-3 polyunsaturated fat acrid metabolism, based on differences in the proportions of the long concatenation fatty acids resulting from elongation and desaturation of linoleic and linolenic acrid. The content of conjugated linoleic acids is similar relative to the sum of fat acids, but is lower on musculus weight basis. Meat oxidative stability of double-muscled and normal animals has not been properly compared now, only in that location are no indications for large differences.

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DOUBLE-MUSCLED ANIMALS

S. De Smet , in Encyclopedia of Meat Sciences, 2004

Carcass and Meat Quality

The greatest merit of double-muscled animals lies in their superior carcass characteristics. Considering of the slower rate of fatty deposition, slaughter maturity is delayed. Conversely, animals of this genotype can be finished to higher slaughter weights. Dressing yield is significantly increased compared to normal animals because of the reduced digestive tract and the lower weight of skin and organs. At similar age or weight, carcasses of double-muscled animals have higher proportions of meat and lower proportions of fat and bone. Although prominence is more often than not given to the muscle hypertrophy in describing the double-muscled condition, the reduced development of the fatty tissues is relatively much more distinct. The size, only not the number, of the fat cells is decreased. The reduction in bone proportion is more moderate. The muscle hypertrophy, and the fat and os hypotrophy, are full general but not compatible throughout the body. In detail, superficial muscles and the hind limbs, compared to the fore limbs, are most afflicted, simply differences between studies regarding the relative muscle hypertrophy are noted. The bones of the limbs are shorter and thinner according to the same gradients observed for the muscles. The muscle-to-bone ratio is maximal at the level of the shoulders and the thigh, where the hypertrophy is also most visible. At a comparable level of subcutaneous fat cover, a lower overall carcass fatty content is found for double-muscled compared to normal animals. The nonuniform muscle hypertrophy, and the more than blocked conformation in general, results in a different size and shape of most meat cuts and in a higher proportion of more expensive cuts. In commercial practise, this effect of conformation and carcass cutability may add substantially to the difference in carcass value of double-muscled animals, irrespective of the difference in lean meat content. The combination of increases in dressing yield and carcass lean content, and upgrading of some cuts, may yield a difference in the proportion of high-value cuts on a live weight basis that amounts to more 25% for pure-bred double-muscled cattle compared to normal cattle.

As already mentioned regarding the genetic determination, the myostatin-deficient condition leads to an increase in muscle fibre number. The contractile differentiation during the start ii-thirds of gestation, and the metabolic differentiation of aerobic oxidative metabolism during the final third of fetal growth, are delayed in double-muscled fetuses. A higher proportion of glycolytic muscle fibres, at the expense of oxidative and oxido-glycolytic fibres, is thus found at birth and throughout life in double-muscled cattle. Virtually reports signal no major changes in the muscle fibre dimensions, and slightly lower every bit well equally higher fibre sizes accept been reported. Hence, the relative area of type IIB fibres is increased and the overall muscle metabolism is more glycolytic.

The more glycolytic musculus fibre type results in a faster muscle pH fall post-mortem in double-muscled animals, whereas ultimate pH values are by and large not different. Concomitantly, the meat is paler, as illustrated past higher CIE Fifty* values. A lower ratio of CIE a*/b* values corresponds to a less carmine colour, in line with reduced levels of myoglobin. The higher rate of glycolysis early on post-mortem, in combination with the increased muscle mass, besides leads to slightly higher musculus temperatures post-mortem, and consequently an increased degree of poly peptide denaturation. This is expected to bear upon water-holding capacity unfavourably. However, information on several measurements of water-property capacity have been variable. Slightly higher drip losses are more often than not found, but lower, or unchanged, also as higher cooking losses have been reported. Differences in colour and water-holding chapters in comparing with changes in other traits are relatively moderate.

With respect to meat tenderness and palatability in full general, literature data concerning double-muscled cattle are coherent on most but not all points. Meat tenderness and tenderization are complex phenomena determined past a number of factors. The content and nature of connective tissue, together with the post-mortem weakening of the myofibrillar and cytoskeletal network, are considered the most of import factors, provided no extreme musculus shortening occurs during rigor development. No divergence in sarcomere length in meat of double-muscled animals is to be expected nether normal slaughtering weather. A large reduction in muscle collagen content in double-muscled animals is seen in almost all studies. The perimysial connective-tissue network is thinner, but the nature of the perimysial collagen in terms of solubility and crosslink concentrations on a collagen molar basis seems little affected. The much lower content of connective tissue explains the upgrading of lower-quality cuts to more expensive cuts, allowing for a larger and more than homogenous distribution of loftier-quality meat throughout the carcass. In muscles with a depression content of connective tissue, such every bit the longissimus, the positive effect of double muscling on tenderness may be absent owing to a relatively more important contribution of myofibrillar and cytoskeletal protein degradation during the ageing process. Double-muscled cattle have consistently lower μ-calpain, calpastatin and cathepsin levels in the longissimus, associated with changes in protein breakdown and in line with the reduced in vivo protein turnover. Data for other muscles on enzyme activities and post-mortem proteolysis are very scarce. Both the changes in enzyme activities and protein concentrations during tenderization observed in the longissimus indicate that proteolysis occurs at a faster charge per unit early post-mortem in double-muscled beef animals, consistent with the more glycolytic muscle fibre type and the before rigor development. Total proteolysis and tenderization during full ageing seem to be lower in double-muscled animals. The overall issue on shear forcefulness values is variable, depending on the muscle studied and on the time/temperature treatment of the meat. Across studies and muscles, shear force values of raw meat have always been lower, in view of the lower collagen content. The literature shows that cooking meat for 1 hr at 75 °C – the recommended standard preparation method for shear force determinations – yielded higher values for double-muscled animals, but not in all studies. Considering of all-encompassing solubilization of collagen, this procedure of shear forcefulness determination tin be regarded every bit a measure of myofibrillar toughness, but information technology is not necessarily a skilful indication of overall tenderness. The college myofibrillar toughness of double-muscled animals, as a outcome of reduced proteolysis, is apparently reflected in higher shear force values just in heated low-collagen muscles in some studies. On the other hand, taste panel tenderness cess on cooked meat always show college tenderness ratings, although the benefit may be lower for muscles low in connective tissue. Hence, in general, meat from double-muscled animals is more tender. Meat of double-muscled animals is particularly suited for consumption raw or later on only short-fourth dimension heating – culinary preparation methods prevalent mainly in western and southern Europe. Regarding other taste console parameters, lower juiciness and beef flavour ratings have been reported, in line with the lower intramuscular fat content.

The meat composition is changed according to the altered carcass composition. The meat protein content is higher in double-muscled animals and, considering of the lower collagen content, protein quality in terms of essential amino acids content is improved. The low intramuscular fat content has already been mentioned. Differences in fat acid composition in different fat depots have likewise been reported. In intramuscular fatty, the triacylglycerol content is greatly reduced as a result of the lower fat deposition, whereas the phospholipid content is only slightly lower, in line with the smaller corporeality of cell membranes in the more glycolytic muscles. Accordingly, the content of saturated and monounsaturated fat acids is significantly reduced, whereas the content of polyunsaturated fat acids is smaller or slightly reduced. Consequently, the molar proportion of polyunsaturated fatty acids is significantly college and that of saturated and especially monounsaturated fatty acids is lower. The ratio of intramuscular polyunsaturated to saturated fatty acids is thus higher in meat from double-muscled animals. Similar simply less marked changes are to be expected in other fat depots. There are also indications of alterations in n-6 and n-iii polyunsaturated fatty acrid metabolism, based on differences in the proportions of the long-chain fatty acids resulting from elongation and desaturation of linoleic and linolenic acid. The content of conjugated linoleic acids is like relative to the sum of fatty acids, merely is lower on a musculus weight footing. Meat oxidative stability of double-muscled and normal animals has not been properly compared at present, but there are no indications of large differences.

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Historical perspectives of the meat and creature industry and their relationship to animal growth, body limerick, and meat technology

Steven M. Lonergan , ... Dennis N. Marple , in The Scientific discipline of Beast Growth and Meat Technology (2nd Edition), 2019

Introduction

At that place are pregnant relationships between the regulation of animate being growth and torso composition and meat quality traits of domestic animals. Animal growth traits and carcass characteristics take dandy influences on the value of the alive animate being for both breeding value and retail meat value. Therefore it is important to sympathise growth and development concepts when management decisions are made for livestock product systems.

This book volition provide fundamental scientific discipline-based concepts likewise as practical and practical concepts from prenatal growth to postnatal growth of cattle, sheep, and pigs. This volume is unique, as information is too presented that relates growth and development traits to the carcass value, meat retail characteristics, meat processing, and meat storage traits that are important at the wholesale and retail markets.

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Innovative uses of aromatic plants as natural supplements in diet

E. Christaki , ... P. Florou-Paneri , in Feed Additives, 2020

Biological properties of aromatic plants (functional foods) nutrigenomics

The addition of effluvious plants and their derivatives to livestock nutrition is an interesting tool for providing supplements with biologically agile compounds. These reveal considerable properties such as antimicrobial, antiviral, antifungus, antioxidant, antiinflammatory, and immunostimulatory (Diaz-Sanchez et al., 2015; Adaszynska-Skwirzynska and Szczerbinska, 2017; Ribeiro dos Santos et al., 2017). Subsequently, the apply of aromatic plants due to their valuable compounds is fundamental for successful development of novel, healthy foods, the functional foods. These foods across their nutritional effects accept demonstrated benefits to the human organism by improving the land of health or well-being. They may reduce the gamble of chronic diseases such as cardiovascular, neurodegenerative, bone metabolism, cancer and may detect application for the treatment of respiratory and inflammatory disorders, allergies and diabetes (Prescott and Saffery, 2011; Ismail and Imam, 2014). Accordingly, the involvement of the dietary use of the compounds of aromatic plants as functional ingredients or nutraceuticals has been enhanced by the recent advances in genetics. In relevant studies, an interaction between dietary components and the genome has been highlighted, which is mandatory to impact metabolic pathways and homeostasis in the human body. Hence, a new concept the "nutrigenomics" has been revealed. The nutrigenomic actions exerted by the effluvious plants could be a preventive arroyo for optimizing health, delaying chronic disorders or minimizing their intensity or severity, since many diseases have a genetic predisposition (Simopoulos, 2010; Ismail and Imam, 2014; Carrasco Lopez, 2015; Pavlidis et al., 2015; Elsamanoudy et al., 2016).

Modes of action

Although the precise modes of action of the phytogenics are not elucidated yet, studies have shown their beneficial furnishings on productive animals, apropos growth performance, carcass characteristics, and meat quality. Generally, the benefits of effluvious plants and their essential oils depend greatly on the diverseness and number of effluvious compounds responsible for their biological activities, their synergistic effect, the origin of the plants, the inclusion level in the nutrition and their pharmacokinetics ( Franz et al., 2010; Diaz-Sanchez et al., 2015; Gadde et al., 2017; Sanchez-Vidana et al., 2017).

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ELECTRICAL STIMULATION

C.Due east. Devine , ... I. Richards , in Encyclopedia of Meat Sciences (2nd Edition), 2014

Electrical Stimulation Parameters

Any electric electric current above a sure threshold will stimulate muscles, and for this reason stunning or immobilization currents can take a beneficial effect on tenderness by also accelerating glycolysis. The current flow is dictated by the applied voltage and carcass characteristics such every bit pelt cover, animal size (determining resistance) and fatness (potential insulation), and contact area (in particular reduced contact with shin). All the same, in commercial situations where loftier voltage ES is used, large peak current flows occur (east.g., in excess of 2  A superlative per carcass). In situations where many carcasses are stimulated simultaneously on the same electrode system, very sophisticated power supplies, delivering up to 60   A full, are needed for the pulsed currents and currents are non necessarily shared as between carcasses. Evolution of new systems for sheep/lambs and beef in Australia using short pulse widths and moderate voltages use segmented electrodes to ensure that each electrode only contacts ane carcass at a time. This allows computer-controlled electronics to give a precise, but adaptable current to each carcass to match the requirements of a particular carcass type (Figures 2 and 3a,b). The current pulses in these systems apply very rapid rise times that appear to provide a greater stimulation result with lower peak current to give very effective results (Box ii).

Box 2

Meat characteristics following ES. Color (redness (a*), color stability at 630/580   nm, shear forcefulness (N), pH, predicted temperature at pH half dozen.0 (°C), for the 1000. longissimus of electrically stimulated (800   mA, pulse width 0.5   ms, height voltage of 300   V, xv   Hz, for 60   s) and nonstimulated lamb carcasses (40 per treatment). Chilled at iv.2   °C. All values are predicted means (south.eastward.d.)

Trait Stimulated a Nonstimulated due south.east.d.
Initial loin pH vi.34a half-dozen.79b 0.04
Predicted temperature at pH 6.0 24.8b 13.9a ane.50
Shear forcefulness (N) at 1-solar day aging 36.0a 44.0b ii.40
Redness (a*) seven.70a vii.00a 0.32
Color stability (630/580   nm) three.20a 3.00a 0.14

Source: Adapted from Toohey, E.Southward., Hopkins, D.50., Stanley, D.F., Nielsen, S.G., 2008. The touch on of new generation pre-dressing medium-voltage electric stimulation on tenderness and colour stability in lamb meat. Meat Science 79, 683–691.

a
Stimulation treatment was at a electric current of 800   mA with a pulse width of 0.5   ms for elapsing required. Ways followed by the same alphabetic character in a row are not significantly different (P=.05).

Voltages used vary from 32 to 3600   V (historically). The value specified might exist that of the top or the rms (root mean square) voltage, or in some cases the average over the full time. The rms voltage is the effective value or heating chapters of a waveform. For a sine wave, the rms value is the peak voltage divided by v2. For 1130   V peak, l   Hz, the rms voltage is 800   V. Withal, for many derived (nonsinusoidal) waveforms the rms may be quite different and ineffective. For one version, termed the Meat Industry Research Institute of New Zealand (MIRINZ) waveform, every seventh one-half-sine wave of a 50   Hz sine moving ridge is used and the rms voltage is the acme voltage divided by v14. Figure 5 illustrates the meaning of the different terms used to describe voltages and waveforms. Defining a waveform with a frequency (expressed in Hz) is likely to lead to defoliation unless the waveform is too defined in terms of shape, elapsing, and pulse spacing. Foursquare waves also tin exist used and may be unipolar or bipolar and practical equally discrete pulses or fifty-fifty every bit pulse trains.

Figure 5. Terms used to describe pulses and waveforms illustrated by sinusoidal (a and c), one-half sinusoidal (b) and square moving ridge pulses (d). In (a) there are 50 sinusoidal cycles per second (100 one-half sine wave pulses); tiptop and rms voltages are indicated. The pulses in (b) are obtained by cutting out one-half-sinusoidal pulses, which in this case gives 10   ms duration pulses, 14.28 pulses per second, with the aforementioned peak voltage. The pulse width (marker) and space between pulses give the marker-to-space ratio used to specify a single repetitive bicycle, with the polarity of pulses and the number of cycles per second required to complete the description. The waveforms (b) and (c) both take the same period (inverse of frequency) and summit amplitude, just have dissimilar shape characteristics. Foursquare wave pulses (d) tin can have variable widths depending on the characteristics desirable, and simply a particular stimulation waveform is shown here.

Extensive research in Australia especially in sheep and lambs has demonstrated that ES systems must be validated and optimized to ensure effective operation – in other words mere application of electricity does not guarantee a satisfactory upshot. In instances where this does not happen or organization monitoring is not employed ES tin be relatively ineffective. In some situations with multielectrode systems, lights are used to signal when each electrode is operating, to limit ineffective ES. Although whatever stimulation increases dpH/dt, information technology is but optimum parameters (elapsing, meridian voltage, and pulse characteristics) that increment the fall ?pH significantly. Information technology is probable where ES is not regarded as effective or useful the resultant ?pH has not been sufficient.

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Artificial Insemination and Embryo Transfer in Sheep

C.F.B. SHIPLEY, , ... J.R. HUNTON , in Electric current Therapy in Large Animal Theriogenology (Second Edition), 2007

Marker-Assisted Selection

The use of genetic markers for the identification of animals carrying a specific gene is known every bit mark-assisted selection. Economically important major qualitative genes such every bit those for fecundity (Booroola-FecB; Thoka), wellness (scrapie resistance), growth and carcass characteristics (Callipyge), and sexual activity take all been recently identified in sheep. The Booroola, Callipyge and male person-specific genes have additionally been isolated later identification by molecular techniques. Genetic markers let individuals to exist screened for specific genes that may not be expressed (fecundity genes in males) or before phenotypic expression is unremarkably observed in expressing animals. This advantage is nearly pronounced if marker-assisted selection is combined with ET and manipulation, and embryos can be screened for the presence of specific genes before they are transferred. Future developments should include the evolution of screening methods by which an embryo'south genetic makeup could be determined through noninvasive methods. Marker-assisted option volition play an increasingly important role in livestock selection equally more than genes and gene markers are identified.

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