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Temperament measures have been correlated to ADG and DMI in feedlot cattle. However, most of these experiments evaluate intake at the pen level, rather than within the individual animal. Moreover, some of these relationships are often investigated using an average temperament score (either over time or numerous measures) rather than a single measure of temperament. The objective of this experiment was to examine relationships between temperament measures and performance in individual beef steers based on initial temperament scores. Steers from one source (n = 105) were randomly allocated to 4 pens in 2 weight blocks. Steers were fed a common TMR 3 times each day at approximately 0700, 1000, and 1400 for 70 d. Individual feed and water intake (WI) were measured daily using an Insentec feeding system. Body weights, exit velocity (EV), and chute score (CS) were measured every 14 d. Exit velocity was measured over 1.5 m; CS was measured by the same trained observer and reported on a 1-4 scale, where 1 is calm and 4 is wild. Animals were assigned an EV and CS ranking based on initial measures. Chute score ranking was assigned according to the first measure. Animals 1 SD above the EV mean were ranked as a 2 and animals 1 SD below the mean were a 0, with animals between ranking a 1. Lower ranks are indicative of calmer temperament. Dry matter intake, ADG, G:F, and WI were split into 5 periods (d 0-14, 14-28, 0-28, 28-70, and 0-70). Data were analyzed using the MIXED procedure of SAS where the model included main effects of EV and CS; block was used as a random effect. There was no effect of EV or CS on DMI or WI for any period (P ≥ 0.90). There were no treatment effects for periods d 0-14, 14-28, or 0-70 (P ≥ 0.72). From d 0-28, steers with a CS of 2 or 3 had a increased ADG and G:F (P = 0.04) compared to steers with CS of 1 or 4. From d 28-70, steers with an EV of 1 had decreased ADG and G:F (P ≤ 0.05) compared to steers with EV of 0 or 2. Chute score may be more important for measures during early periods in the feedlot. Additionally, because each temperament measure related to performance in a different manner, this data supports the concept that CS and EV measure different underlying traits. [ABSTRACT FROM AUTHOR]

The objectives of this study were to estimate variance components, genetic parameters, EBV, accuracies, and rankings for nine ultrasound and carcass traits in a multibreed Angus-Brahman population using three genomic-polygenic models and one polygenic model (PM). The genomic-polygenic models used the complete GeneSeek GPF250k SNP set (GPM), top 5% SNP (GPMR1), and 5% SNP evenly spread across the genome (GPMR2). Yearling ultrasound traits were weight (UW), ribeye area (UREA), backfat (UFAT), and percent intramuscular fat (UPIMF). Carcass traits were slaughter age (SLA), hot carcass weight (HCW), ribeye area (REA), backfat thickness (FAT), and marbling score (MAR). The 9-trait GPM, GPMR1, GPMR2, and PM contained fixed contemporary group, age of calf (ultrasound traits only), sex of calf, and direct heterosis effects, and random animal and residual effects. Variance components and genetic parameters were computed using AIREMLF90. Comparable heritabilities were obtained with GPM and PM for UW (GPM: 0.54 ± 0.05; PM: 0.51 ± 0.05), UREA (GPM: 0.36 ± 0.03; PM: 0.34 ± 0.03), UFAT (GPM: 0.12 ± 0.02; PM: 0.11 ± 0.02), UMPIMF (GPM: 0.34 ± 0.03; PM: 0.30 ± 0.03), SLA (GPM: 0.59 ± 0.07; PM: 0.61 ± 0.06), HCW (GPM: 0.58 ± 0.06; PM: 0.52 ± 0.07), REA (GPM: 0.48 ± 0.04; PM: 0.45 ± 0.05), FAT (GPM: 0.41 ± 0.05; PM: 0.30 ± 0.05), and MAR (GPM: 0.56 ± 0.07; PM: 0.51 ± 0.08). Additive genetic correlations between pairs of ultrasound and carcass traits were all between -0.31 and 0.81. The highest positive additive genetic correlations were between UW and UREA, UW and HCW, UW and REA, UREA and HCW, UREA and REA, UFAT and FAT, and between HCW and REA. The largest negative additive genetic correlations were between UREA and UPIMF, UFAT and SLA, UFAT and HCW, UPIMF and REA, and between REA and MAR. High similarity existed among predicted EBV and accuracies from GPM, GPMR1, and GPMR2 as well as high-rank correlations for sires, dams, and progenies. This indicated that the two reduced genotype sets were appropriate alternatives to the complete GPF250k set for genomic-polygenic evaluation and selection in this multibreed Angus-Brahman population. High EBV variability existed among animals of all Angus and Brahman percentages, and no specific breed composition was overwhelmingly better or worse for any of the nine traits. This indicated that optimization of genetic progress through selection in multibreed Angus-Brahman populations should be based solely on genetic merit regardless of breed composition. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a common disease in dogs, with multiple risk factors, including a complex genetic pattern. The origins of cartilage degeneration in canine and human OA are still poorly understood, and fundamental questions regarding the precise molecular nature of this complex disease remain to be answered. The objective of this study was to identify QTL for OA in a dog model of the condition. A genome-wide scan was undertaken to identify QTL associated with this disease. An experimental canine pedigree was developed for linkage analysis by crossbreeding dysplastic Labrador Retrievers with unaffected Greyhounds. We used 100 dogs from this pedigree, including backcrosses to both parental lines and F2 individuals. At necropsy, the hip joints were examined macroscopically and a score (ranging from 0 to 4) was assigned to describe the degree of cartilage degeneration. A set of 342 microsatellite markers were genotyped on 100 dogs. Interval mapping was performed using the QTL Express package. To adjust for the effect of age of the animal at the time of necropsy, the age at necropsy was included in the model as a covariate. Estimates were obtained for the additive and dominance effect of the putative QTL at that location. Chromosome-wide significance thresholds for each trait were determined empirically by permuting the marker data. Five chromosomes were identified to harbor putative QTL for necropsy score. The recent completion of the canine genome sequencing has facilitated the comparison of the dog genome with the human genome, allowing the further investigative analysis of canine QTL. The region on CFA18 flanked by markers AHT130 and FH2429 and identified in our study to harbor putative QTL is syntenic with 11q12.2-q12.3 region on the human chromosome 11, where a primary hip OA susceptibility locus was fine-mapped. Similarly, the region on CFA19 between markers FH2279 -Ren91I14 is syntenic to human 2q14.2-2q21.1, region identified as linked to an OA locus segregating in different human populations. This indicates that the genetic mechanism underlying hip OA in dogs may have similarities to human OA and the dog model would greatly improve our ability to identify candidate genes for further investigation. [ABSTRACT FROM AUTHOR]

The effect of prolactin (PRL), β-lactoglobulin (β-LG), and κ-casein (CSN3) on milk yield was estimated in an East Friesian dairy sheep population from Old Chatham Sheepherding Company, New York. Genotypes were determined by PCR amplification followed by digestion with HaeIII and RsaI for PRL and β-LG, respectively, and by PCR amplification for CSN3. Monthly milking records and pedigree information were used to evaluate the effect of each polymorphism on milk yield. Results indicated that PRL genotype had a significant effect on milk yield. Ewes carrying one A allele produced 110.6 g more milk per day than ewes with no A alleles. There was no statistical difference between ewes with only one A allele and ewes with 2 A alleles. No association among polymorphisms at the β-LG and CSN3 loci and milk yield was found. The results presented in this study indicate that the PRL gene is a potential marker that could be used in selection programs for improving milk yield in dairy sheep. [ABSTRACT FROM AUTHOR]

Skin and hair coat play important functions in maintaining homeostasis and thermoregulation for cattle, which can affect all modes of heat loss. Our objective was to investigate the effect of hyperthermia experienced in utero during late gestation on postnatal hair length, skin properties, and thermoregulation. Pregnant dams were heat stressed (n = 41) or actively cooled (n = 41) for the last ∼56 d of gestation and gave birth to heifers that were in utero heat stressed (IUHT) or in utero cooled (IUCL), respectively. Hair samples and skin tissue biopsies were collected from neck and rump locations at birth (d 0), 1 wk after weaning (d 63), and at 12 mo. Hair samples were also obtained at 4 and 8 mo. Skin tissue was stained with hematoxylin and eosin to visualize morphology. Hair length (short and long hairs, undercoat and topcoat, respectively), stratum corneum (SC) area, SC thickness, epidermis thickness, sweat gland (SWT) number, SWT cross-sectional area, SWT average size, sebaceous gland (SEB) number, SEB cross-sectional area, SEB average size, and sweat gland depth were assessed. Respiration rate, skin temperature, sweating rate, and rectal temperature was measured weekly from d 7 to 63. Additionally, thermoregulatory patterns were measured every 4 h over a 36-h interval beginning 4 d after weaning. Data were analyzed using PROC MIXED in SAS with a main effect of in utero treatment with location and time points analyzed separately. No difference in hair parameters were detected at d 0 or 12 mo. At d 63, IUHT heifers had longer average hair length (14.8 vs. 13.8 ± 0.2 mm, standard error), shorter undercoats (9.3 vs. 10.4 ± 0.3 mm), longer topcoats (19.6 vs. 17.1 ± 0.3 mm), and a greater difference between topcoat and undercoat (10.1 vs. 7.0 ± 0.4 mm). At 4 mo, IUHT heifers had longer average hair lengths (26.1 vs. 22.2 ± 1.0 mm) and longer topcoats (36.9 vs. 33.9 ± 1.1 mm), and at 8 mo, IUHT had longer average hair lengths (17.9 vs. 16.2 ± 0.6 mm), relative to IUCL. At d 0, IUHT heifers had more (13 vs. 9 ± 2 glands) but smaller average sized SEB (neck: 1,636 vs. 2,238 ± 243 µm 2 ; rump: 2,100 vs. 3,352 ± 379 µm 2 ) and reduced SC area (79,243 vs. 169,419 ± 13,071 µm 2 ). At d 63, IUHT had fewer SEB (11 vs. 15 ± 2 glands), smaller SWT (0.16 vs. 0.23 ± 0.02 mm 2 ), fewer SWT (16 vs. 23 ± 4 glands), and deeper SWT (0.5 vs. 0.4 ± 0.03 mm). At 12 mo, IUHT had greater distance from the skin surface to the most superficial SWT (0.016 vs. 0.015 ± 0.0004 mm), shorter distance to the deepest SWT (0.031 vs. 0.033 ± 0.001 mm), and smaller SWT (81.1 vs. 108.9 ± 10.8 µm 2 ), relative to IUCL. When measured both weekly and hourly, IUHT heifers had higher rectal temperature and sweating rate. Overall, in utero hyperthermia triggers long-lasting hair and skin adaptations, possibly leading to differences in postnatal thermoregulation., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)