A large proportion of genetic variation in cow and ewe body composition is independent of yearling composition

Published online: 14 March 2023 OnlinePublCommercial beef and sheep producers have adopted using condition score for management of cows and ewes to maximise productivity. Significant premiums are being paid for bulls and rams with higher-fat breeding values based on young animal measurements, with the aim of increased resilience in adult female progeny. Aims. The aim of this study was to quantify the relationship between adult body condition score and young muscle and fat and also the genetic variation in condition that is independent of yearling traits. Methods. Published genetic parameters for four large data sets from Angus and tropically adapted cattle, and composite and Merino sheep were used to partition genetic variation in adult condition that is associated with, or independent of, young composition measures. Key results. One genetic standard deviation in young muscle or fat was associated with approximately just 0.1 adult body condition scores. Approximately ¾ of the genetic variation in adult body condition score (BCS) is independent of genetic variation in young weight and composition traits. Conclusions and implications. Producers need to be careful with premiums paid for bulls and rams with superior yearling composition traits with the aim of changing adult BCS. The best way to achieve this is for seedstock breeders to record and report breeding values for cow and ewe BCS.W. S. Pitchfor

Mode of inheritance of triacylglycerol fatty acids in beef adipose tissue

Subcutaneous adipose tissues were biopsied in 67 Jersey, Limousin and Jersey x Limousin calves at the age of 9-10 months.All calves were grass-fed in a single management group and biopsied from the same anatomical site. Triacylglycerol fatty acids were extracted and analysed by gas-liquid chromatography. Genetic effects of heterosis, additive and maternal variances were estimated to investigate the mode of inheritance of fatty acids, Sex and genotype differences were also examined. Heifer calves had significantly higher proportions of palmitoleate, total monounsaturated fatty acids, desaturase enzyme activity index and lower stearate than bull calves. Genotype differences were observed:Limousin calves had the highest proportions of palmitate and total saturated fatty acids, while Jersey calves had the most palmitoleate and desaturase enzyme activity index. The mode of inheritance of palmitate, stearate, desaturase and elongase enzyme indices was by dominance. Myristate, palmitate and total saturated fatty acids showed significant additive genetic effect. The study showed that triacylglycerol fatty acids are heritable. Hetero-sis can also be exploited in reducing the percentage of saturated fatty acids in beef by crossbreeding Limousin and Jersey cattle

Statistical methods for analysis of multi-harvest data from perennial pasture variety selection trials

Variety selection in perennial pasture crops involves identifying best varieties from data collected from multiple harvest times in field trials. For accurate selection, the statistical methods for analysing such data need to account for the spatial and temporal correlation typically present. This paper provides an approach for analysing multi-harvest data from variety selection trials in which there may be a large number of harvest times. Methods are presented for modelling the variety by harvest effects while accounting for the spatial and temporal correlation between observations. These methods provide an improvement in model fit compared to separate analyses for each harvest, and provide insight into variety by harvest interactions. The approach is illustrated using two traits from a lucerne variety selection trial. The proposed method provides variety predictions allowing for the natural sources of variation and correlation in multi-harvest data

Single nucleotide polymorphisms in the bovine leptin gene and their association with carcass and efficiency traits, and endocrine profiles, in female Angus cows

One hundred and fifty female Angus cattle were genotyped for the bovine leptin gene SNPs UASMS1, UASMS2, E2FB and E2JW. Net Feed Intake (NFI) Estimated Breeding Values (EBVs) and E2JW SNP data was also acquired from 169 Angus cattle that originated from Trangie Research Station, NSW, and were selected for a divergence in feed efficiency. The E2JW SNP was associated with NFI, NFI EBV and P8 fatness. The UASMS1 and UASMS2 SNPs were associated with circulating leptin concentrations. These particular associations have not been reported previously but similar associations have reported in North American studies. The inconsistent associations suggest that these SNPs are not good candidates for marker-assisted selection for NFI. Also, the investigation of associations with endocrine profiles that reflect body composition such as leptin, requires genotyping of a larger number of Australian cattle than was possible in this experiment

Genetic relationships among yearling fertility, body composition and weight traits in tropically adapted composite cattle

Published Online: 6 April 2012 OnlinePublContext. Reproduction is an economically important trait in both males and females; however, the relationships between fertility and body composition traits are little researched, but essential to breeding programs, as they will help inform selection decisions and allow the greatest opportunity for genetic gain. Aims. Estimate genetic and phenotypic correlations between male and female yearling fertility traits and investigate their relationship with yearling body composition traits, which have an effect on the attainment of puberty. Methods. Genotype and phenotype data were obtained from a tropical composite commercial cattle population and imputed to 27 638 single nucleotide polymorphisms. A series of univariate and bivariate linear mixed models using a genomic relationship matrix were run to estimate genetic parameters, genetic and phenotypic correlations for a series of male and female fertility and body composition traits. These parameters were then compared to help understand the genetic relationships. Key results. Scrotal circumference was favourably genetically correlated with weight (0.34), fat traits (0.06–0.24), muscle (0.24) and heifer days to calving (−0.32). Heifer days to calving was favourably correlated with muscle (−0.18) but not fat traits (0.11 to 0.21). The genetic correlations between heifer days to calving and sperm morphology traits were generally unfavourable (−0.32 to 0.25). Sperm morphology traits were favourably genetically correlated with fat traits (−0.84 to 0.31) and muscle (−0.61 to 0.31) but not weight (−0.15 to 0.09). Conclusions and implications. Yearling sperm morphology traits were unfavourably correlated with heifer days to calving, indicating that they are not good candidates for indirect selection on improving female fertility in the herd. A different trend was found for yearling scrotal circumference and heifer days to calving, identifying it as a good candidate for indirect selection of heifer fertility as it is easy to measure and heritable. The genetic correlations estimated between composition traits with male and female fertility traits allow breeding programs to make an informed selection decision to optimise genetic gain across all traits.M.L. Facy, M.L. Hebart, H. Oakey, R.A. McEwin and W.S. Pitchfor

SNP associations and genetic-parameter estimation for nose and hoof pigmentation in Corriedale sheep

Published Online 7/6/23 OnlinePublContext. Quantity and quality of both meat and wool are important for selection programs of the dual-purpose Corriedale sheep. In Corriedales, black pigmentation of nose skin and hooves is preferred as part of the breed standard. However, within the breed, pigmentation can vary from none to complete pigmentation. Aims. The aim was to discover single-nucleotide polymorphisms (SNPs) and genes associated with nose and hoof pigmentation and to estimate genetic parameters of nose and hoof pigmentation, wool traits and meat traits. Methods. The phenotype and genotype data on Corriedale lambs (n = 764) produced from 44 sires (12 studs) and 300 ewes in 2017–2019 were used in this study. Lambs were slaughtered at 6–7 months of age. Nose pigmentation and hoof pigmentation were scored on a five-point scale, where no pigmentation was scored 0 and complete pigmentation was scored 5. Wool-and meat-quality traits were measured, including greasy fleece weight, fibre diameter, weaning weight, hot standard carcass weight and intramuscular fat percentage. The lambs were genotyped with the GGPOvine50K SNP chip. A genome-wide association study (GWAS) was conducted. Genetic parameters and bivariate analyses were estimated using ASReml-R. Results. The lambs had a mean nose-pigmentation score of 3.69 and hoof-pigmentation score of 4.12. The nose pigmentation (h2 = 0.58) and hoof pigmentation (h2 = 0.51) were highly heritable and highly correlated (rG = 0.73). The GWAS identified a genome-wide significant SNP (OAR19_33278780.1) associated with nose pigmentation (q-value = 0.04). This SNP is positioned in a known pigmentation gene, melanocyte-inducing transcription factor (MITF ). The same SNP was the sixth-most associated SNP for hoof pigmentation but did not reach significance level. OAR19_33278780.1 also had a significant effect on back conformation and weaning weight. Conclusions. The results of these analyses have provided information and an understanding of the genetics for pigmentation of nose and hooves in Corriedale sheep. Implications. Nose and hoof pigmentation are highly genetically correlated with each other, but with no negative effects on production traits.J. E. Aldersey, M. S. Khatkar, P. J. Blackwood, C. E. Blackwood, J. M. Pitchford, H. Gordon, S. C. Welsh and W. S. Pitchfor

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome