Selection for increased muscling is not detrimental to maternal productivity traits in Angus cows

2018 ◽  
Vol 58 (1) ◽  
pp. 185 ◽  
Author(s):  
L. M. Cafe ◽  
W. A. McKiernan ◽  
D. L. Robinson
Keyword(s):  
Body Composition ◽  
Live Birth ◽  
Muscle Area ◽  
Eye Muscle ◽  
Weaning Weight ◽  
Myostatin Gene ◽  
Beef Cow ◽  
High Line ◽  
Breeding Cycles ◽  
Selection For

The aim of the present study was to assess the effect of selection for increased muscling on maternal productivity of a temperate beef cow herd. Cows of predominantly Angus breeding were selected using visual muscle score (1–15 scale, where 1 = lightest and 15 = heaviest muscling) into low- and high-muscled animals, and mated to Angus bulls with low or high muscularity. Initially, low-muscled cows were mated to low-muscled bulls to create the Low line, and high-muscled bulls and cows were mated to create the High line. On discovering that some High cattle carried the myostatin (821 del11) gene, a second High line was created to distinguish between cattle with no copies of the myostatin gene (High line) and those with one copy (HighHet line). Data from 12 breeding cycles, consisting of 2003 joining records, and 1713 resulting weaning records were analysed to assess maternal productivity. Cows from the three lines were similar in weight (547, 548 and 550 kg, P = 0.9), but varied in body composition – from Low to High to HighHet cows, muscling traits increased and fatness traits decreased (all P < 0.001). Compared with Low cows, High cows had a 4.4 units higher muscle score, 10% higher eye muscle area and 21% less fat, and HighHet cows had a 7.1 units higher muscle score, 17% higher eye muscle area and 45% less fat. There were no significant effects of selection for increased muscling on live birth or weaning rates, or weaning weight (all P > 0.1). Dystocia levels of Low and HighHet maidens or cows did not differ significantly, but High maidens or cows had less dystocia (P = 0.013). Low, High and HighHet cows weaned 218, 225 and 216 kg of calf/cow joined.year, indicating similar maternal productivity.

Genetic relationships of female reproduction with growth, body composition, maternal weaning weight and tropical adaptation in two tropical beef genotypes

2014 ◽  
Vol 54 (1) ◽  
pp. 60 ◽  
Author(s):  
M. L. Wolcott ◽  
D. J. Johnston ◽  
S. A. Barwick
Keyword(s):  
Body Composition ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Female Reproduction ◽  
Muscle Area ◽  
Eye Muscle ◽  
Weaning Weight ◽  
Igf I ◽  
Age At Puberty ◽  
Tropical Adaptation

The genetic relationships of female reproduction with growth and body composition, tropical adaptation traits and maternal weaning weight (descriptive of genetic potential milk production) were estimated in 1027 Brahman (BRAH) and 1132 Tropical Composite (TCOMP) females. Female reproduction was evaluated at puberty, as outcomes of the first and second annual mating periods (Mating 1 and Mating 2, which commenced when females averaged 27 and 39 months of age, respectively), as well as annual averages over up to six matings. Traits evaluated included age at puberty, Mating 1 and 2 pregnancy rate, weaning rate and days to calving, and lifetime annual calving and weaning rate. Traits describing growth and body composition (liveweight, hip height, ultrasound-scanned P8 fat depth and eye muscle area, subjective body condition score and blood IGF-I concentration) were measured in the animals as heifers (at ~18 months of age), and again at the start of Mating 2. Traits describing tropical adaptation included coat-length scores in both genotypes and, in BRAH, buffalo fly lesion scores. Previously reported analyses of these data identified heifer IGF-I and coat and buffalo-fly-lesion scores as potential genetic indicators for age at puberty in BRAH. The results of the present study found that exploiting these relationships would have no unfavourable genetic consequences for later female reproduction and, in some cases, may be indicators of female reproduction, when evaluated as outcomes of Matings 1 or 2, or as lifetime annual calving or weaning rates. For BRAH, heifer liveweight was a genetic indicator for Mating 1 weaning rate (rg = 0.70), and, while standard errors were high, there were also positive genetic correlations of heifer hip height, eye muscle area and blood IGF-I concentration with Mating 1 weaning rate (rg = 0.61, 0.58 and 0.43, respectively). For TCOMP, significant genetic relationships of heifer growth, body composition and tropical adaptation traits with female reproduction were virtually absent, suggesting that there is less opportunity to identify earlier in life measures as genetic indicators of reproduction for this genotype. Higher maternal weaning weight was significantly genetically related to lower lifetime annual weaning rate (rg = –0.50) in BRAH, and with lower Mating 2 calving and weaning rate (rg = –0.72 and –0.59, respectively) in TCOMP, which will need to be considered when making selection decisions that affect genetic milk in these genotypes. Importantly, the results presented revealed no strong genetic antagonisms of heifer growth and body composition traits with female reproduction, suggesting that selection could be undertaken to improve these simultaneously.

The genetics of cow growth and body composition at first calving in two tropical beef genotypes

2014 ◽  
Vol 54 (1) ◽  
pp. 37 ◽  
Author(s):  
M. L. Wolcott ◽  
D. J. Johnston ◽  
S. A. Barwick ◽  
N. J. Corbet ◽  
P. J. Williams
Keyword(s):  
Body Composition ◽  
Body Condition ◽  
Body Condition Score ◽  
Genetic Correlations ◽  
Muscle Area ◽  
Eye Muscle ◽  
Weaning Weight ◽  
Mating Period ◽  
Lactating Cows ◽  
Condition Score

The genetics of cow growth and body composition traits, measured before first calving (pre-calving: in females before calving following their first 3-month annual mating period, at an average age of 34 months) and at the start of the subsequent mating period (Mating 2: on average 109 days later), were evaluated in 1016 Brahman (BRAH) and 1094 Tropical Composite (TCOMP) cows. Measurements analysed were liveweight, ultrasound-scanned measurements of P8 and 12/13th rib fat depth and eye muscle area, body condition score and hip height. Traits describing the change in these from pre-calving to Mating 2 were also included in the analysis. The maternal genetic component of weaning weight was estimated from weaning-weight records on these cows, their steer half-sibs and their progeny generated from up to six matings (n = 12 528). Within pregnant cows at pre-calving, BRAH were significantly lighter, leaner at the P8 site and taller than their TCOMP contemporaries, and these differences were also significant at Mating 2. There was a genetic basis for variation in growth and body composition traits measured at pre-calving and Mating 2 in BRAH (h2 = 0.27–0.67) and TCOMP (h2 = 0.25–0.87). Traits describing the change from pre- calving to Mating 2 were also moderately heritable for both genotypes (h2 = 0.17–0.54), except for change in hip height (h2 = 0.00 and 0.10 for BRAH and TCOMP, respectively). Genetic correlations between measurements of the same trait at pre-calving and Mating 2 were consistently positive and strong (rg = 0.75–0.98) and similar for both genotypes. In lactating cows, genetic correlations of growth and body composition traits with their change from pre-calving to Mating 2 showed that when animals had low levels of P8 and rib fat at Mating 2, change in eye muscle area was an important descriptor of genetic body condition score (rg = 0.63). This was supported by moderate genetic relationships, which suggested that lactating cows that were genetically predisposed to lose less eye muscle area were those that ended the period with higher P8 fat (rg = 0.66), rib fat (rg = 0.72) and body condition score (rg = 0.61). Change in liveweight, body condition score and, in particular, eye muscle area was significantly related to the maternal genetic component of weaning weight (rg = from –0.40 to –0.85) in both genotypes, suggesting that cows with higher genetic milk-production potential were those with the propensity for greater loss of these traits over the period from pre-calving to Mating 2. These results showed that for tropically adapted cows, the change in eye muscle area from pre-calving to Mating 2 was a more important descriptor of body condition at Mating 2 than was change in fat depth, and that higher genetic milk-production potential, measured as maternal weaning weight, was genetically related to higher mobilisation of muscle, and therefore body condition, over this period.

The effect of different dietary protein levels in the rearing phase (from 60 kg) on body composition and reproductive performance of gilts

1996 ◽  
Vol 1996 ◽  
pp. 143-143
Author(s):  
M C Cia ◽  
S A Edwards ◽  
V L Glasgow ◽  
M Shanks ◽  
H Fraser
Keyword(s):  
Body Composition ◽  
Reproductive Performance ◽  
Large White ◽  
Muscle Area ◽  
Eye Muscle ◽  
Protein Levels ◽  
Fat Reserves ◽  
Low Protein ◽  
Protein Diets ◽  
Real Time Ultrasonography

Low protein diets have been proposed as a way to enhance fat reserves and reduce liveweight gain in breeding animals of very lean genotypes. The objective of this study was to examine the effect of different protein levels on daily gain, body composition and reproductive performance of gilts.At 118 (sem=0.28) days old, 54 genetically lean gilts ((Landrace x Large White) x Large White) were allocated, considering firstly age and secondly weight, between three treatments with different dietary lysine:energy (g/MJ DE) ratios: High (0.9), Medium (0.6) and Low (0.3), fed twice daily at 2.9 x maintenance energy. Animals were weighed weekly and backfat thickness (P2) and muscle depth values were also taken. Eye muscle area measurements were taken by real time ultrasonography (Aloka 500) at the end of the experiment At 160 days of age, puberty was induced by administration of exogenous gonadotropin (PG600).

Indices of cellular development in muscles of lambs are influenced by sire estimated breeding values and pastoral nutritional system

2006 ◽  
Vol 57 (6) ◽  
pp. 651 ◽  
Author(s):  
P. L. Greenwood ◽  
G. E. Gardner ◽  
R. S. Hegarty
Keyword(s):  
Muscle Growth ◽  
Genetic Selection ◽  
Inverse Association ◽  
Semitendinosus Muscle ◽  
Eye Muscle ◽  
Weaning Weight ◽  
Breeding Values ◽  
Sire Group ◽  
Selection For ◽  
Estimated Breeding Values

This study examined influences of sire (n = 9) estimated breeding values (EBVs), sire-group (Muscle, Growth, and Control), and nutrition (low and high quality and availability pasture) from birth to slaughter at ~8 months of age on indices of muscle cellularity and transcriptional and translational capacity in 56 castrate lambs. Effects of nutritional systems to 8 months of age were greater, overall, than those due to EBVs or sire-group. Amount of DNA increased with increasing EBV for post-weaning eye muscle depth (PEMD or Muscle EBV) in longissimus but not in semimembranosus and semitendinosus muscles, while Muscle EBV also had an inverse association with concentration of DNA. Protein to DNA and RNA to DNA were related positively to Muscle EBV, the associations being strongest for the semitendinosus muscle. Post-weaning weight (PWWT or Growth) EBV correlated positively with the RNA to DNA ratio and, among high but not low nutrition lambs, was inversely related to concentration of muscle DNA, whereas post-weaning fat depth (PFAT or Fat) EBV was correlated positively with RNA concentration. Overall, the magnitude of effects of sire-group was less than for sire EBVs, presumably due to differing selection pressures for muscling, fatness, and growth. High nutrition lambs had more protein to DNA than low nutrition lambs in the longissimus and semitendinosus muscles, but not in the semimembranosus muscle. In low compared with high nutrition lambs, concentration of DNA was greater in the longissimus and semitendinosus muscles. Total amount of DNA was reduced by more in low compared with high nutrition in the longissimus and semimembranosus than in the semitendinosus, and amount of protein was reduced by more in low compared with high nutrition in the longissimus than in the other two muscles. We conclude that genetic selection for eye muscle depth in sheep has differing effects on cellular characteristics of the longissimus, semimembranosus, and semitendinosus muscles, and has greater effects on muscle cellular characteristics than genetic selection for post-weaning weight or fat depth.

Maternal body composition in seedstock herds. 4. Genetic parameters for body composition of Angus and Hereford cows

2018 ◽  
Vol 58 (1) ◽  
pp. 145 ◽  
Author(s):  
K. A. Donoghue ◽  
S. J. Lee ◽  
P. F. Parnell ◽  
W. S. Pitchford
Keyword(s):  
Body Composition ◽  
Body Condition Score ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Fat Percentage ◽  
Muscle Area ◽  
Eye Muscle ◽  
Life Traits ◽  
Condition Score ◽  
Over Time

The genetics of body composition traits measured before calving and at weaning in the first and second parities were evaluated in 5975 Angus and 1785 Hereford cows. Traits measured were liveweight, body condition score and hip height and ultrasound scanned measurements of subcutaneous P8 and 12/13th rib fat depth, loin eye muscle area and intramuscular fat percentage. Corresponding yearling measures on these animals were obtained for analyses of relationships between yearling information with later-in-life traits. There was moderate genetic variation in all body composition traits measured at pre-calving and weaning in Angus (h2 = 0.14–0.59) and Hereford (h2 = 0.14–0.64) cows. Genetic correlations between measurements of the same trait at pre-calving and weaning were consistently positive and high in both parities for both breeds, indicating animals were ranking similarly for the same trait measured over time. Genetic correlations between measurements of different traits were generally consistent over time (pre-calving and weaning) in both breeds, indicating genetic relationships between traits were not changing significantly over time. Genetic correlations with corresponding yearling measures of body composition were consistently positive and high for the first parity, and lower for the second parity. The results of this study indicate that genetic improvement in body composition traits in cows is possible, and that body composition information recorded at yearling age is a reasonably good predictor of later in life performance for these traits.

Genetic parameters for terminal sires estimated using data of progeny from Border Leicester × Merino ewes

1995 ◽  
Vol 46 (4) ◽  
pp. 703
Author(s):  
PA Kenney ◽  
ME Goddard ◽  
LP Thatcher
Keyword(s):  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Muscle Area ◽  
Eye Muscle ◽  
Bone Length ◽  
Selection For ◽  
Using Data ◽  
Omental Fat

Three and a half thousand lambs from Border Leicester x Merino ewes mated to 133 sires from five Poll Dorset, one White Suffolk, one Siromt, two Meridale and four Merino studs were slaughtered, their carcasses halved and one side divided into six primals. Subcutaneous fat was dissected from all six primals, and bone from only the three rear primals. There were four slaughter groups: average slaughter weights of 30 and 35 kg for ewes and 35 and 45 kg for cryptorchids. Heritabilities and phenotypic and genetic correlations for all traits measured (>50) are published in an appendix. Where comparisons were available, estimates were similar to those for purebred animals. Genetic parameters for various assessments of fat were similar except for channel and omental fat. The GR fat depth was the best predictor for total subcutaneous fat, cannon bone length for total bone, and eye muscle area for total soft tissue. Carcass weight and GR appear to be the most important measurements for use in selection for breeding of sires for the prime lamb industry. Slaughter weight and fat depth at the C site could be used as suitable alternatives on live animals. Production of lean meat is not likely to be increased greatly by including measurements other than liveweight and GR in a selection index. Of the other measurements bone length and eye muscle measurements showed most promise.

The effect of different dietary protein levels in the rearing phase (from 60 kg) on body composition and reproductive performance of gilts

1996 ◽  
Vol 1996 ◽  
pp. 143-143
Author(s):  
M C Cia ◽  
S A Edwards ◽  
V L Glasgow ◽  
M Shanks ◽  
H Fraser
Keyword(s):  
Body Composition ◽  
Reproductive Performance ◽  
Large White ◽  
Muscle Area ◽  
Eye Muscle ◽  
Protein Levels ◽  
Fat Reserves ◽  
Low Protein ◽  
Protein Diets ◽  
Real Time Ultrasonography

Low protein diets have been proposed as a way to enhance fat reserves and reduce liveweight gain in breeding animals of very lean genotypes. The objective of this study was to examine the effect of different protein levels on daily gain, body composition and reproductive performance of gilts.At 118 (sem=0.28) days old, 54 genetically lean gilts ((Landrace x Large White) x Large White) were allocated, considering firstly age and secondly weight, between three treatments with different dietary lysine:energy (g/MJ DE) ratios: High (0.9), Medium (0.6) and Low (0.3), fed twice daily at 2.9 x maintenance energy. Animals were weighed weekly and backfat thickness (P2) and muscle depth values were also taken. Eye muscle area measurements were taken by real time ultrasonography (Aloka 500) at the end of the experiment At 160 days of age, puberty was induced by administration of exogenous gonadotropin (PG600).

scholarly journals Fine mapping of porcine chromosome 6 QTL and LEPR effects on body composition in multiple generations of an Iberian by Landrace intercross

2005 ◽  
Vol 85 (1) ◽  
pp. 57-67 ◽  
Author(s):  
C. ÓVILO ◽  
A. FERNÁNDEZ ◽  
J. L. NOGUERA ◽  
C. BARRAGÁN ◽  
R. LETÓN ◽  
...  
Keyword(s):  
Body Composition ◽  
Leptin Receptor ◽  
Receptor Gene ◽  
Chromosome 6 ◽  
Nucleotide Polymorphisms ◽  
Fat Percentage ◽  
Muscle Area ◽  
Eye Muscle ◽  
Coding Regions ◽  
Narrow Region

The leptin receptor gene (LEPR) is a candidate for traits related to growth and body composition, and is located on SSC6 in a region where fatness and meat composition quantitative trait loci (QTL) have previously been detected in several F2 experimental designs. The aims of this work were: (i) to fine map these QTL on a larger sample of animals and generations (F3 and backcross) of an Iberian×Landrace intercross and (ii) to examine the effects of LEPR alleles on body composition traits. Eleven single nucleotide polymorphisms (SNPs) were detected by sequencing LEPR coding regions in Iberian and Landrace pig samples. Three missense polymorphisms were genotyped by pyrosequencing in 33 F0, 70 F1, 418 F2, 86 F3 and 128 individuals coming from the backcross of four F2 males with 24 Landrace females. Thirteen microsatellites and one SNP were also genotyped. Traits analysed were: backfat thickness at different locations (BFT), intramuscular fat percentage (IMFP), eye muscle area (EMA), loin depth (LOD), weight of shoulder (SHW), weight of ribs (RIBW) and weight of belly bacon (BBW). Different statistical models were applied in order to evaluate the number and effects of QTL on chromosome 6 and the possible causality of the LEPR gene variants with respect to the QTL. The results support the presence of two QTL on SSC6. One, at position 60–100 cM, affects BFT and RIBW. The other and more significant maps in a narrow region (130–132 cM) and affects BFT, IMFP, EMA, LOD, SHW, RIBW and BBW. Results also support the association between LEPR alleles and BFT traits. The possible functional implications of the analysed polymorphisms are considered.

scholarly journals Meat quality and the calpain system of feedlot steers following a single generation of divergent selection for residual feed intake

2001 ◽  
Vol 41 (7) ◽  
pp. 1013 ◽  
Author(s):  
M. B. McDonagh ◽  
R. M. Herd ◽  
E. C. Richardson ◽  
V. H. Oddy ◽  
J. A. Archer ◽  
...  
Keyword(s):  
Feed Intake ◽  
Shear Force ◽  
High Efficiency ◽  
Subcutaneous Fat ◽  
Residual Feed Intake ◽  
Divergent Selection ◽  
Muscle Area ◽  
Eye Muscle ◽  
Single Generation ◽  
Selection For

Residual feed intake (RFI) is calculated as the difference between an animal’s actual feed intake and its expected feed intake based on its size and growth over a specified test period. Following a single generation of divergent selection for postweaning RFI, Angus steers and Angus × Hereford, Angus×Poll Hereford and Angus × Shorthorn crossbred steers born in 1996 and 1997 were fed in a feedlot. Cohorts of steers were slaughtered at the same age and had attained similar (P&gt;0.05) final liveweights: 467 kg for steers selected for low RFI (high efficiency; HE, n = 91) and 459 kg for steers selected for high RFI (low efficiency; LE, n = 98). The HE and LE steers had similar (P>0.05) carcass weight (247 and 244 kg), dressing percentage (53.1 and 53.2&percnt;) and eye-muscle area (58.9 and 60.3 cm 2 ). The HE steers had slightly less subcutaneous fat over the rib than the LE steers (9.2 v. 10.1 mm, P&lt;0.05), and there was a trend towards less fat over the rump of HE steers (11.5 v. 12.1 mm, P = 0.10). For meat samples taken from the M. longissimus dorsi (LD) there were no differences (P>0.05) between the HE and LE steers in content of intramuscular fat (5.4 and 5.3% fresh weight), marbling scores, meat colour and fat colour. There were also no differences (P>0.05) between HE and LE steers in shear force and compression values for samples of LD aged for 1 day (4.6 and 4.6 kg shear force, 1.45 and 1.44 kg compression), or for 14 days (3.8 and 3.5 kg, 1.36 and 1.32 kg). Myofibril fragmentation index (MFI) measures the breakdown of these structural elements which occurs as an initial step in the process of protein degradation and meat tenderisation. MFI was lower (i.e. less fragmentation; P<0.05) in LD samples from HE steers than from LE steers, both in samples aged for 1 day (67.7 v. 72.5 units) and in samples aged for 14 days (87.8 v. 91.1 units). The rate of decline in MFI between 1 and 14 days post slaughter was similar in the LD samples from both lines of steers. There were no differences (P>0.05) between HE and LE steers in the activity of m-calpain and &micro;-calpain in LD immediately after slaughter (HE steers: 1.9 and 2.3 units, LE steers: 1.8 and 2.1 units). The level of calpastatin in LD from the HE steers was 13% higher than in the LD from the LE steers (5.2 and 4.6 units respectively, P<0.05). Rate of myofibril fragmentation was positively correlated (P<0.01) with the ratios of both m-calpain and µ-calpain to calpastatin, but not (P>0.10) with levels of either calpain or calpastatin. A single generation of divergent selection for RFI produced differences in calpastatin and myofibril fragmentation that may, with on-going selection for low RFI, negatively affect meat tenderness.

Corrigendum - Genetic parameters for terminal sires estimated using data of progeny from Border Leicester × Merino ewes

1995 ◽  
Vol 46 (4) ◽  
pp. 703
Author(s):  
PA Kenney ◽  
ME Goddard ◽  
LP Thatcher
Keyword(s):  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Subcutaneous Fat ◽  
Muscle Area ◽  
Eye Muscle ◽  
Bone Length ◽  
Selection For ◽  
Using Data ◽  
Omental Fat

Three and a half thousand lambs from Border Leicester x Merino ewes mated to 133 sires from five Poll Dorset, one White Suffolk, one Siromt, two Meridale and four Merino studs were slaughtered, their carcasses halved and one side divided into six primals. Subcutaneous fat was dissected from all six primals, and bone from only the three rear primals. There were four slaughter groups: average slaughter weights of 30 and 35 kg for ewes and 35 and 45 kg for cryptorchids. Heritabilities and phenotypic and genetic correlations for all traits measured (>50) are published in an appendix. Where comparisons were available, estimates were similar to those for purebred animals. Genetic parameters for various assessments of fat were similar except for channel and omental fat. The GR fat depth was the best predictor for total subcutaneous fat, cannon bone length for total bone, and eye muscle area for total soft tissue. Carcass weight and GR appear to be the most important measurements for use in selection for breeding of sires for the prime lamb industry. Slaughter weight and fat depth at the C site could be used as suitable alternatives on live animals. Production of lean meat is not likely to be increased greatly by including measurements other than liveweight and GR in a selection index. Of the other measurements bone length and eye muscle measurements showed most promise.

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