Genetic relationships between steer performance and female reproduction and possible impacts on whole herd productivity in two tropical beef genotypes

2014 ◽  
Vol 54 (1) ◽  
pp. 85 ◽  
Author(s):  
M. L. Wolcott ◽  
D. J. Johnston ◽  
S. A. Barwick ◽  
N. J. Corbet ◽  
H. M. Burrow

Steer growth and carcass composition, and female reproductive performance have been identified as key aspects of productivity by breeders of tropically adapted beef cattle in Australia. Research has also demonstrated that traits describing meat quality and feed intake and efficiency are of economic importance to Australia’s beef industry. The present study aimed to determine genetic relationships of traits describing steer growth, feed intake and efficiency, carcass composition and meat quality with female reproductive performance in two genotypes of tropically adapted beef cattle. Female reproduction traits describing outcomes of first (Mating 1) and second (Mating 2) annual matings and lifetime reproduction (averaged over 6 matings) were analysed for 1020 Brahman (BRAH) and 1117 Tropical Composite (TCOMP) females. Steer traits were available for 1007 BRAH and 1210 TCOMP half-sibs of the females evaluated for reproductive performance, and measurements of liveweight and body composition for 1025 BRAH and 1520 TCOMP bull progeny of the same females were included in the analysis. Results demonstrated that selection to increase steer carcass weight and eye muscle area and decrease carcass fat depth would have no significant unfavourable impact on female reproductive performance for both genotypes. Measures of liveweight, eye muscle area and P8 fat depth in young BRAH bulls, however, were only moderately correlated with steer carcass equivalents (rg = 0.28 to 0.55) and results showed that selection on the basis of bull measurements alone may negatively affect female lifetime annual calving rate (rg = –0.44 to –0.75) if both were not included in a multi-trait genetic evaluation and considered when making selection decisions. More favourable (lower) net feed intake in BRAH steers was genetically associated with lower Mating 1 weaning rate (rg = 0.76) and higher days to calving (rg = –0.50), although this did not significantly affect lifetime annual calving or weaning rate (rg = 0.10 and 0.29, respectively). For TCOMP, higher steer carcass P8 fat depth was unfavourably genetically associated with female Mating 2 weaning rate (rg = –0.76), although these relationships were not as strong for weaning rate at Mating 1 or when averaged over the animals lifetime (rg = 0.43 and –0.13, respectively). Lower (more favourable) shear force (a measure of tenderness) also displayed a significant genetic association with higher (less favourable) Mating 1 days to calving in TCOMP and, while standard errors were high, tended to be unfavourably associated with other measures of female reproduction evaluated for the present study. Steer growth, carcass composition, meat quality and residual feed intake and female reproduction could be improved simultaneously if measurements describing both are included in a multi-trait genetic evaluation. Results of the present study also showed that expanding female reproduction traits to include descriptors of first and second mating outcomes, as well as lifetime reproductive performance, would allow a fuller account to be taken of genetic relationships of male traits with female reproduction.

2014 ◽  
Vol 54 (1) ◽  
pp. 60 ◽  
Author(s):  
M. L. Wolcott ◽  
D. J. Johnston ◽  
S. A. Barwick

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.


2010 ◽  
Vol 50 (4) ◽  
pp. 315 ◽  
Author(s):  
M. L. Wolcott ◽  
H.-U. Graser ◽  
D. J. Johnston

This study aimed to examine the impact of early weaning on residual feed intake, and other production and carcass traits, in a group of cattle subjected to early or conventional weaning treatments, but otherwise managed as contemporaries. Shorthorn (n = 140) calves were randomly allocated by sex and sire to early and conventional weaning treatments. Early weaned animals (n = 69) were weaned at an average of 123 days of age and 145 kg liveweight, while conventionally weaned steers and heifers (n = 71) were 259 days old at weaning and 273 kg. Following conventional weaning, animals were managed as contemporaries through backgrounding, and entered feedlot finishing at a mean age of 353 and 408 days for heifers and steers, respectively, for finishing and feed intake testing. At the conclusion of feed intake testing hip height was measured, and animals were ultrasound scanned to assess fat depth, eye muscle area and percent intramuscular fat. Early weaned animals were significantly lighter (P < 0.001) than their conventionally weaned contemporaries, when weighed at conventional weaning. The weight difference observed at conventional weaning of 19.4 kg between treatment groups persisted throughout the experiment, with significant (P < 0.05) differences of 17.1, 15.6 and 15.8 kg at feedlot entry, and the start and end of the feed intake test period, respectively. Weaning treatment also approached significance for daily feed intake (P = 0.06), with early weaned animals tending to eat less than their conventionally weaned contemporaries (daily feed intake = 11.6 and 12.0 kg, respectively). Weaning treat\ment did not significantly affect feed efficiency whether measured as residual feed intake (P = 0.64) or feed conversion ratio (P = 0.27). None of the other traits measured were significantly affected by weaning treatment. These data showed that early weaning, as implemented for this experiment, resulted in animals that were lighter than their conventionally weaned contemporaries through backgrounding and finishing. Weaning treatment did not, however, influence feed efficiency or the post-weaning growth and carcass composition traits measured for this experiment.


2020 ◽  
pp. 1-28
Author(s):  
H.Q. Li ◽  
B. Wang ◽  
Z. Li ◽  
H.L. Luo ◽  
C. Zhang ◽  
...  

Abstract This study was undertaken to evaluate the influence of rumen-protected folic acid (RPFA) on slaughter performance, visceral organ and gastrointestinal tract coefficients, and meat quality in lambs. Sixty-six lambs from 120 Hu ewes were selected based on body weight and maternal diets, and then assigned to six groups using a randomized block experimental design in a 3 × 2 factorial arrangement. The first factor was folic acid (FA) as RPFA in the maternal diet (0 mg/kg [M0F], 16 mg/kg [M16F] or 32 mg/kg [M32F] on dry matter basis). The second factor was FA in the lambs’ diet from weaning until slaughter (0 mg/kg [OC] or 4.0 mg/kg [OF]). The results indicated that the addition of 16 mg/kg FA to the maternal diet increased pre-slaughter weight (PSW), dressing and meat percentage, the reticulum and omasum coefficients, length of the jejunum and ileum, tail fat and perirenal fat coefficient and a* value of the meat color. The addition of RPFA to the lambs’ diet increased PSW, dressing and meat percentage, eye muscle area, abomasum weight, weight and length of the small intestine, but reduced the coefficients of tail fat. A M×O interaction was observed for the weights of heart, lungs, rumen and total stomach, weight and coefficient of omental fat and the GR value. Collectively, RPFA in the maternal and lambs’ diet improved slaughter performance and meat quality by stimulating the morphological development of the gastrointestinal tract and the distribution of fat in the body.


1963 ◽  
Vol 3 (10) ◽  
pp. 249
Author(s):  
RM Seebeck

Variations in the cross-sectional area of eye muscle of carcasses cut between the tenth and eleventh ribs were investigated, using 105 Hereford and 51 Angus steers aged 20 months. These cattle consisted of three groups, born in successive years. At constant carcass weight, statistically significant differences in eye muscle area were found between breeds and between years. Breed and year differences were also found in eye muscle area with width and depth of eye muscle constant, so that there are limitations to the estimation of eye muscle area from width and depth measurements. A nomograph is given for estimating eye muscle area from width and depth for Hereford and Angus cattle, when all animals are reared in the same year and environment. The use of eye muscle area as an indicator of weight of carcass muscle is discussed.


2014 ◽  
Vol 43 (2) ◽  
pp. 147-153 ◽  
Author(s):  
MS Rana ◽  
MA Hashem ◽  
S Akhter ◽  
M Habibullah ◽  
MH Islam ◽  
...  

The research was conducted to study the effect of heat stress on carcass characteristics and meat quality in indigenous sheep. Nine sheep were divided into three groups which were almost similar in age, sex and weight. Three groups were divided as zero hour (T0), four hours (T4) and eight hours (T8) heat exposure to direct sunlight. During experimental period temperature–humidity index (THI) value was calculated as 27.09 which indicated T4 and T8 groups were subjected to heat stress condition for at least four hours and eight hours respectively every day. Slaughter weight, body length and heart girth had no significant difference among the treatment groups. Dry matter, ash and ether extract had no significant difference (p>0.05) among the treatment groups but crude protein were increased with the increase of heat stress from T0 to T8 group (p<0.05). Drip loss was increased (p<0.05) in non-exposure group than treated groups but there is no significant result (p>0.05) found in pH and cooking loss. Carcass weight and eye muscle area had no significant difference (p>0.05) among the treatment groups but dressing percentage was decreased with the increase of time in heat treated groups (p<0.01). Significant difference (p<0.05) were found in weight of heart, kidney, lung + trachea and pluck between control and heat treated groups. The significant difference (p>0.05) in empty gut was found in gut with content and gut fill in heat treated groups. It can be concluded that heat stress had significant changes on carcass characteristics and meat quality of indigenous sheep.DOI: http://dx.doi.org/10.3329/bjas.v43i2.20717 Bang. J. Anim. Sci. 2014. 43 (2): 147-153


1996 ◽  
Vol 1996 ◽  
pp. 143-143
Author(s):  
M C Cia ◽  
S A Edwards ◽  
V L Glasgow ◽  
M Shanks ◽  
H Fraser

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).


Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1836
Author(s):  
Masoumeh Naserkheil ◽  
Abolfazl Bahrami ◽  
Deukhwan Lee ◽  
Hossein Mehrban

In recent years, studies on the biological mechanisms underlying complex traits have been facilitated by innovations in high-throughput genotyping technology. We conducted a weighted single-step genome-wide association study (WssGWAS) to evaluate backfat thickness, carcass weight, eye muscle area, marbling score, and yearling weight in a cohort of 1540 Hanwoo beef cattle using BovineSNP50 BeadChip. The WssGWAS uncovered thirty-three genomic regions that explained more than 1% of the additive genetic variance, mostly located on chromosomes 6 and 14. Among the identified window regions, seven quantitative trait loci (QTL) had pleiotropic effects and twenty-six QTL were trait-specific. Significant pathways implicated in the measured traits through Gene Ontology (GO) term enrichment analysis included the following: lipid biosynthetic process, regulation of lipid metabolic process, transport or localization of lipid, regulation of growth, developmental growth, and multicellular organism growth. Integration of GWAS results of the studied traits with pathway and network analyses facilitated the exploration of the respective candidate genes involved in several biological functions, particularly lipid and growth metabolism. This study provides novel insight into the genetic bases underlying complex traits and could be useful in developing breeding schemes aimed at improving growth and carcass traits in Hanwoo beef cattle.


2018 ◽  
Vol 58 (1) ◽  
pp. 145 ◽  
Author(s):  
K. A. Donoghue ◽  
S. J. Lee ◽  
P. F. Parnell ◽  
W. S. Pitchford

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.


Author(s):  
C M Yates ◽  
A Cuthbertson ◽  
M G Owen

1. Increased leanness is an economic objective of nearly all breed improvement programmes. Predictions of lean concentration can be used in an index of performance or can be used to select animals for slaughter.2. Predictions of carcass composition from ultrasonic measurements of fat and muscle depths are currently used to aid the selection of animals for breeding and slaughter. Recent developments allow muscle area to be measured using B-Mode pulse echo real-time ultrasonic scanning machines. These machines produce a two-dimensional image of a cross section through the animal, from which measurements may be taken.3. There is a need to estimate for the live animal the benefits of including eye muscle area in the prediction of carcass composition but few data are available to estimate this directly. Therefore the potential benefit of including such measurements in the prediction of carcass composition has been evaluated using measurements taken on the cut surface of carcasses


Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 954 ◽  
Author(s):  
Safa’ M. Hatamleh ◽  
Belal S. Obeidat

This study considers the impact of dried distillers’ grain with solubles (DDGS) in diets of lambs. Randomly; 27 lambs were distributed to one of three diets. Diets were: a control diet (CON; n = 9), a 125 (DDGS125; n = 9) or a 250 g/kg DDGS (DDGS250; n = 9) of dietary dry matter (DM). The lambs were fed using these diets for 91 days. To assess carcass traits; five lambs were randomly selected at the end of the study. No significant differences were detected in intake and digestibility of DM; crude protein and fiber. Average daily gain did not differ among diets. Carcass characteristics did not differ among diets. With the exception of shear force and redness, which were greater in DDGS250 than in DDGS125 and CON diets, meat quality parameters were unaffected. Eye muscle area decreased in DDGS125 than in DDGS250 and CON diet. These results demonstrate that the feeding of lambs on DDGS at 125 or 250 g/kg DM did not have any impact on growth. These diets only had a simple effect on the characteristics of carcass and meat quality. These results suggest that it would be suitable to introduce these feeds into sheep nutrition in the future.


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