Suffolk Sheep Research Articles

Modelling growth in Suffolk and Charollais sheep populations using random regression models and validation of constrained polynomial correlation values

Random regression modelling has been used across multiple animal species to model longitudinal data. The random regression model for growth accounts for the genetic correlation between measures of the same trait over time and the wide environmental variability in growth, but this requires adequate weight records across the age range. However, contemporary management practices in sheep in the United Kingdom generally focus on growing lambs and neglect mature weight recordings. This study examined modelling strategies for growth data in Suffolk and Charollais sheep, provided by the Agriculture and Horticulture Development Board, with polynomial random regression modelling with many early life weight recordings but limited weight recordings in mature animals. Two methods were employed to model the data. In Method A, missing mature weight records were predicted for those animals that did not have a recorded mature weight. The animals were sorted into groups based on the identity of their sires and the year in which the animal was born. Mature weight values were predicted within each group with a multiple regression model. The dataset, including predicted values, was analysed with random regression models using polynomials and simple linear regression for animal and permanent environmental (PE) effects. In Method B, the dataset with missing mature weight records was analysed using a random linear regression animal model with random animal and PE effects. Due to problems of convergence because the parameters were close to the boundary space, fixing the correlation between the intercept and slope of the Legendre polynomial at different levels was investigated. The heritability values resulting from the model with a fixed correlation between intercept and slope parameters at 0.5 for the Suffolk dataset resulted in heritability values ranging from 0.2 to 0.5 from 1 to 619 days of age. Corresponding estimates for the Charollais dataset ranged from 0.18 to 0.49 from 1 to 640 days of age. For the Suffolk data, the genetic correlations ranged from 1.00 to 0.08 between weight at day 1 to weight at day 619, while for the Charollais, the correlations ranged from 1.00 to 0.05 from 1 to 640 days of age. Validation procedures were undertaken using a multitrait approach to examine the estimated breeding values when the correlation between the intercept and slope are fixed at different levels. The results indicated that fixing the correlation at 0.5 gave the most appropriate estimates for the Suffolk and Charollais datasets.

Effect of Zilpaterol Hydrochloride and Zinc Methionine on Growth, Carcass Traits, Meat Quality, Fatty Acid Profile and Gene Expression in Longissimus dorsi Muscle of Sheep in Intensive Fattening

Zilpaterol hydrochloride (ZH) redistributes ingested energy and improves feed efficiency by increasing muscle mass and reducing fat in sheep and cattle carcasses in fattening; however, by increasing lipolysis and reducing intramuscular fat (IMF), it can affect meat quality in terms of the attributes of tenderness, juiciness, taste and color; in contrast, Zn methionine (ZM), due to its lipogenic effect, can improve meat marbling without affecting production efficiency. In the current study, 36 male Suffolk sheep were used (25 ± 0.58 kg live weight, LW) to evaluate the supply of ZH and ZM on growth, carcass traits, meat quality, fatty acid content and expression of genes which regulate the deposition of fatty acids (FA) in IMF. A completely randomized design was used, with factorial arrangement of 2 × 2 ZH (0 and 0.2 mg kg−1 LW) and ZM (0 and 80 mg Zn kg−1 dry matter, DM). The results showed that ZH increased (p < 0.05) carcass yield, compactness index and chop eye area and decreased greasing (p < 0.02). The content of ether extract in meat increased (p < 0.05) in sheep with ZM plus ZH, and in sheep with ZM (p < 0.01). ZH (p < 0.05) reduced (p < 0.02) the meat’s color index L*, a*, b*, C* and H*. The content in IMF of stearic (C18:0) and arachidic (C20:0) FA was reduced (p ≤ 0.05) by the effect of ZH, but the palmitoleic (C16:1), eicosatetraenoic (C20:4n6) and conjugated linoleic FA were increased (p ≤ 0.05) by the effect of ZH. ZM increased (p ≤ 0.05) palmitoleic (C16:1) and conjugated linoleic FA; the ZH interaction with ZM increased (p ≤ 0.05) linoleic (C18:2 c 9 c 12), linolenic (C18:3 c 9c12c15) and eicosatetraenoic (C20:4n6) FA. The ZH interaction with ZM influenced (p ≤ 0.05) the total saturated fatty acids (SFA), unsaturated fatty acids (UFA) and polyunsaturated fatty acids (PFA). ZH increased (p ≤ 0.05) the relative expression of mRNA from the enzymes lipoprotein lipase (LPL), hormone-sensitive lipase (HSL), glycerol -3-phosphate acyltransferase (GPAT1) and diglyceride acyltransferase (DGAT1). ZM increased (p ≤ 0.05) the relative expression of mRNA from the enzyme gene acetyl-CoA carboxylase (ACC) and HSL, monoglyceride lipase (MGL). The ZM interaction with ZH increased (p ≤ 0.05) the relative expression of mRNA genes of the enzymes HSL and ACC. It was concluded that ZH improved feed conversion (FC), increased yield and reduced fat in carcasses; ZM increased IMF in Longissimus dorsi. ZH and ZM influenced the FA composition, reduced the SFA and increased the UFA and PFA; both additives also influenced the relative mRNA expression of genes involved in fatty acid metabolism.

Recessive mutation for low fibre curvature in the wool of sheep

Two mating experiments suggest a recessive gene for lustre in the birth coat of the lamb and low fibre curvature of the yearling fleece. Suffolk sheep normally have high wool fibre curvature, but a sire was found that had very low fibre curvature (21.0°/mm). In the first experiment, no lambs were born with a lustrous birth coat among the initial progeny from this sire (n = 32). Fleece samples at weaning (70.0°/mm) and yearling shearing (67.6°/mm) had high fibre curvature with no sign of segregation. All second-generation progeny of this sire (n = 4) were born with a lustrous birth coat, yet none survived to lamb shearing. Breeding was discontinued.In a second experiment, two male lambs were born with lustrous birth coats and low fibre curvature at weaning (29.0°/mm, 20.8°/mm). First generation progeny (n = 17, n = 18) from these sires showed no evidence of lustre of their birth coat, with fleece samples that were relatively high in fibre curvature at weaning (43.1°/mm, 43.8°/mm) and yearling (43.4°/mm, 45.4°/mm) respectively. When one sire was crossed back to the ewe progeny of both (n = 10) there was strong evidence for segregation of lustre of the birth coat. Lustrous lambs (n = 9) had low fibre curvature when shorn at weaning (21.0°/mm) in comparison with lambs (n = 8) with a wild-type birth coat (46.5°/mm) (P < 0.001). Fibre curvature had increased at yearling shearing of those recorded as lustrous at birth (41.6°/mm) but remained significantly lower (P = 0.001) than those that were recorded as wild-type (56.9°/mm). There was also a large difference in medullation between the two phenotypes, where the lustrous birth coat was associated with greater medullation in the fleece at weaning (54.5 %) and again as yearlings (22.5 %), compared with wild-type progeny (9.5 % and 4.0 %) respectively. There was no difference between birth coat types for weaning weight, yearling weight or fibre diameter variation at either age of fleece sampling. Fleece weight was considerably lower (P = 0.001) for yearlings that had lustrous birth coats (1.22 kg) than those with wild-type birth coats (1.76 kg), and though there was no significant difference in fibre diameter at this age, fleece samples taken at weaning were around 3 µm finer in wild-type lambs (P = 0.008). These results suggest a recessive gene for low fibre curvature was segregating in this population.

High-energy diet modify rumen microbial composition and microbial energy metabolism pattern in fattening sheep

Higher dietary energy is often used to achieve better animal performance in mutton sheep production. Notably, changing the diet formula affects rumen fermentation and the microbiota of ruminants. In this study, we investigated the effect of dietary energy on rumen fermentation and ruminal microbiota in fattening sheep. Fifteen 2-month-old white-headed Suffolk sheep (♂) × Hu sheep (♀) crossbred lambs were randomly divided into three treatments based on the dietary energy of the feeds fed: 8.67 MJ/kg (Low energy (LE); n = 5), 10.38 MJ/kg (standard energy (CON); n = 5), and 12.31 MJ/kg (high energy (HE); n = 5) groups. After 70 days of feeding, sheep were slaughtered and the ruminal fluids were collected and analyzed to determine fermentation parameters. Microbiota was determined using metagenomics sequencing. Notably, the microbial cell protein (MCP) and butyric acid concentrations were significantly high in the HE group. Metagenomic sequencing revealed that ACE and Chao indexes of the HE group were significantly decreased. Four genera among the major classified taxa across all the kingdoms differed in relative abundance in the three dietary energy levels. The relative abundances of Prevotella_brevis, Succiniclasticum_ruminis, Prevotellace-ae_bacterium, and Lachnospiraceae_bacterium were significantly correlated with rumen fermentation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis further revealed that a high-energy diet increased lipid metabolism of microbiota. The Carbohydrate Active enzymes (CAZy) gene, which participates in energy metabolism, was upregulated, while genes regulating plant cell wall degradation were downregulated in the HE group. These results suggest that a high-energy diet had minimal influence on the rumen fermentation pattern but altered the composition of the rumen microbiota, enhancing microbial lipid metabolism and limiting crude fiber metabolism. The findings of this study provide scientific evidence of the effect of dietary energy on ruminant fermentation and fattening sheep production.

DIGESTIBILITY, RUMEN FERMENTATION, RUMEN MICROBIOTA, AND LIPID PEROXIDATION IN SHEEP SUPPLEMENTED WITH LIPOIC ACID

Lipoic acid (LA) reduces oxidative stress and stimulates the immune system. However, data on its use in ruminants is limited. The objective of this study was to determine the effects of LA supplementation on free radical production, rumen variables, and feed digestibility in sheep fed high-grain diets. Nine rumen-cannulated Suffolk sheep were randomly assigned to three treatments: control (LA0 ), no LA inclusion; supplementation of 10 (LA10) mg LA kg-1 body weight (BW); and supplementation of 20 (LA20) mg LA kg-1 BW. In situ (ISDMD) and in vitro (IVDMD) degradation of dry matter and ruminal variables were evaluated. Total bacteria (TB), cellulolytic bacteria (CB), and protozoa (P) were also determined. Thiobarbituric acid reactive substances (TBARS) were evaluated in blood samples at the beginning and end of each experimental period. The ruminal variables and IVADDM were analyzed using a PROC GLM model with a repeated 3 × 3 latin square design, while means were compared using pairwise Tukey tests. LA supplementation did not affect (p 0.05) the ruminal variables under study. LA modified (p 0.05) ISDMD at 4 h in LA10, while no differences were found in terms of IVDMD among the treatments. The LA dose of 10 mg kg-1 BW increased CB (p 0.05) and decreased TB (p 0.05). TBARS differed (p 0.01) among the treatments and evaluation periods and were higher (p 0.05) 15 d after administration. In conclusion, LA supplementation in sheep had an antioxidant effect, reducing oxidative stress 15 d after administration, with slight differences in the ruminal variables evaluated.

Ultrasound evaluation of biometric and Doppler parameters of kidneys in sheep in the prenatal and postnatal periods

The aim of this study was the ultrasound evaluation of kidneys in sheep fetuses during consecutive weeks of pregnancy and of lamb kidneys in the first two weeks after delivery. To evaluate the fetal kidneys, 20 single-pregnancy Suffolk sheep were examined. In the postpartum period, the kidneys were examined in 10 ewe lambs and 9 ram lambs. B-Mode ultrasound was used to assess the length, width and thickness of the kidney, as well as the thickness of the renal parenchyma and the renal cortex. Vascular haemodynamics was assessed with color and pulsed Doppler in renal, segmental and interlobular arteries. Fetal kidneys were visualized from 53 ± 2.00 days, and corticomedullary differentiation was observed from the 10th week of pregnancy onwards. All fetal kidney biometric parameters increased significantly in the following weeks of pregnancy. The width and thickness of the kidneys were greater in male than in female fetuses (P < 0.05). The left kidney was thicker than the right kidney (P < 0.05). An interactive effect of gestational age, fetal sex and kidney location on kidney width, kidney thickness and renal parenchyma thickness (P < 0.05) has been demonstrated. All the biometric parameters of the kidneys differed significantly between the first and the second week of life of the lambs. The thickness of the renal cortex was greater in the ram lambs (P < 0.05). However, the length, width and thickness depended on the location of the kidneys (P < 0.05). An interactive effect of age, sex and kidney location on kidney width in lambs was demonstrated (P < 0.05). In the fetal renal artery, peak systolic velocity (PSV) and end-diastolic velocity (EDV) were significantly lower than in lamb kidneys in the first few days of life. In turn, the PSV/EDV and resistance index (RI) in fetal kidneys were significantly higher than that in newborn lambs. In lambs, PSV, PSV/EDV, RI and PI in the renal artery were significantly higher than that in the segmental and interlobular arteries. Regardless of the location of the arterial vessel, significant differences were noted between the Doppler indices in one-week and two-week-old lambs. The obtained results may be useful in establishing reference values for biometric and hemodynamic ultrasound parameters of sheep kidneys during the fetal and neonatal period. Assessment of the renal cortex is especially of great clinical importance. Increased echogenicity and reduced thickness may indicate certain pathological processes in the kidney. The results of Doppler indices indicate that the postnatal renal haemodynamics depends on the age of the lambs and the location of the renal vessels. Therefore, these factors should be taken into account in the assessment of renal arterial blood flow in lambs.

Identification of Y-SNPs within ovine MSY region and their association with testicular size

The screening of genomic variations within the male-specific region of the mammalian Y chromosome (MSY) is one of the most effective ways to investigate paternal evolutionary history and identify molecular markers related to male fertility. The current study was to identify single nucleotide polymorphisms (SNPs) within single-copy genes of the ovine MSY, and confirm whether they are associated with testicular size. A total of 21 Y-specific gene fragments were successfully amplified to screen Y-SNPs in 956 rams across nine sheep breeds. Three Y-SNPs, including SRY16: g.88 A > G in South African Mutton Merino sheep, ZFY16: g.146 C > T in Suffolk and South African Mutton Merino sheep, and EIF2S3Y2: g.77 C > G in Hu and Tan sheep, were identified using DNA-pooled sequencing and PCR restriction fragment length polymorphism (PCR-RFLP) methods. The investigation of the global distribution for three Y-SNPs showed that the C allele of ZFY16: g.146 C > T co-segregated with haplogroup y-HC, and the C/G allele of EIF2S3Y2: g.77 C > G co-segregated with haplogroup y-HA/y-HB1 in Hu sheep according to data mining from a previous study. In addition, association analysis revealed that ZFY16: g.146 C > T had a significant effect on yearling scrotal circumference in Suffolk sheep, and EIF2S3Y2: g.77 C > G was significantly associated with testicular and epididymis weight in Hu sheep (P ≤ 0.05). The current study concluded that Y-SNPs were associated with testicular size in specific sheep, which provides valuable candidate makers for selecting elite rams at an early age.

LBSUN310 Developmental Programming: Gestational Bpa Treatment Leads To Pancreatic Beta Cell Compromise

Abstract Developmental exposure to endocrine disrupting chemicals (EDC) such as bisphenol A (BPA) have been shown to be associated with many metabolic defects in humans. Studies in animals have documented detrimental effects of fetal exposure to BPA on metabolic variables such as insulin resistance, adiposity, and cardiac function. For instance, developmental exposure of sheep to bisphenol A (BPA), a ubiquitously present EDC, causes insulin resistance and compensatory hyperinsulinemia but the underlying mechanism of it is not fully understood. To determine if pancreatic hyperplasia or hypertrophy contributes to the hyperinsulinemic status and the ontogeny of these effects, pregnant Suffolk sheep were administered daily subcutaneous injections of BPA (0. 05, 0 .5 or 5 mg/Kg BW) in corn oil from days (D) 30-90 of gestation (term 147 days). Controls received corn oil during the same period. Pancreas were taken at Day 65 and 90 of gestation from control and 0.5mg/kg BPA (environmental exposure level)-treated female fetuses, and control and prenatal BPA-treated female offspring at 2 years of age (all 3 doses) during synchronized follicular phase of the cycle. Immunohistochemistry was used to determine beta cell number, size, and islet insulin content. In addition, to determine if the pancreas was fibrotic, islet collagen content was determined by Picro Sirius red staining and whole pancreas collagen content was measured with scroll collagen assay. Data were analyzed by ANOVA (Y2) and Students's t-test (D65 and D90), and magnitude of response by Cohen's Effect Size analysis. Findings showed large magnitude reduction of islet insulin content at day 65, significant decrease in islet insulin and beta cell count at D90 along with large magnitude decrease in pancreas/fetal weight. In contrast, in the Y2 sheep prenatal BPA treatment induced a large magnitude decrease in beta cell count (0. 05mg/kg dose group), a large magnitude increase in islet insulin content (5mg/kg dose group) and large magnitude increase in islet collagen content (all 3 BPA doses). The decrease in insulin in the D65 and D90 sheep along with the decrease in beta cells and pancreas/fetal weight at D90 indicates adverse developmental impact of BPA exposure on pancreatic beta cell differentiation. Increase in collagen accumulation in Y2 sheep likely contributes to the beta cell loss reflected as decrease in beta cell number seen in 0. 05 mg/kg dose of BPA. Absence of beta cell loss in 0.5 and 5mg/kg dose in the face of increased collagen is consistent with the nonmonotonic responses these EDCs manifest. Taken together, these results highlight the risks posed by developmental exposure to BPA on beta cell function and the corresponding risk for beta cell loss as animals age. Supported by NIH R01 grants ES016541 and ES030374 Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Novel Therapy for Acquired Tracheomalacia with a Tissue-Engineered Extraluminal Tracheal Splint and Autologous Mesenchymal-Derived Chondrocytes.

Introduction Acquired tracheomalacia (ATM) is characterized by a loss of structural strength of the tracheal framework, resulting in airway collapse during breathing. Near half of the patients undergoing prolonged invasive mechanical ventilation will suffer tracheal lesions. Treatment for ATM includes external splinting with rib grafts, prosthetic materials, and tracheal resection. Failure in the use of prosthetic materials has made reconsidering natural origin scaffolds and tissue engineering as a suitable alternative. Objective To restore adequate airway patency in an ovine model with surgically-induced ATM employing a tissue-engineered extraluminal tracheal splint (TE-ETS). Methods In the present prospective pilot study, tracheal rings were partially resected to induce airway collapse in 16 Suffolk sheep ( Ovis aries ). The TE-ETS was developed with autologous mesenchymal-derived chondrocytes and allogenic decellularized tracheal segments and was implanted above debilitated tracheal rings. The animals were followed-up at 8, 12, and 16 weeks and at 1-year postinsertion. Flexible tracheoscopies were performed at each stage. After sacrifice, a histopathological study of the trachea and the splint were performed. Results The TE-ETS prevented airway collapse for 16 weeks and up to 1-year postinsertion. Tracheoscopies revealed a noncollapsing airway during inspiration. Histopathological analyses showed the organization of mesenchymal-derived chondrocytes in lacunae, the proliferation of blood vessels, and recovery of epithelial tissue subjacent to the splint. Splints without autologous cells did not prevent airway collapse. Conclusion It is possible to treat acquired tracheomalacia with TE-ETS without further surgical removal since it undergoes physiological degradation. The present study supports the development of tissue-engineered tracheal substitutes for airway disease.

Combinatorial treatment of brain samples from sheep with scrapie using sodium percarbonate, sodium dodecyl sulfate, and proteinase K increases survival time in inoculated susceptible sheep

The agent of scrapie is resistant to most chemical and physical methods of inactivation. Prions bind to soils, metals, and various materials and persist in the environment confounding the control of prion diseases. Most methods of prion inactivation require severe conditions such as prolong exposure to sodium hypochlorite or autoclaving, which may not be suitable for field conditions. We evaluated the efficacy of a combinatorial approach to inactivation of US scrapie strain x124 under the mild conditions of treating scrapie-affected brain homogenate with sodium percarbonate (SPC), sodium dodecyl sulfate (SDS), or in combination followed by proteinase K (PK) digestion at room temperature. Western blot analysis of treated brain homogenate demonstrates partial reduction in PrPSc immunoreactivity. Genetically susceptible VRQ/ARQ Suffolk sheep were oronasally inoculated with 1 g of SPC (n = 1), SDS (n = 2), SDS + PK (n = 2), and SPC + SDS + PK (n = 4) treated brain homogenate. Sheep were assessed daily for clinical signs, euthanized at the development of clinical disease, and tissues were assessed for accumulation of PrPSc. Scrapie status in all sheep was determined by western blot, enzyme immunoassay, and immunohistochemistry. Mean incubation periods (IPs) for SPC (11.9 months, 0% survival), SDS (12.6 months, 0% survival), SDS + PK (14.0 months, 0% survival), and SPC + SDS + PK (12.5 months, 25% survival) were increased compared to positive control sheep (n = 2, 10.7 months, 0% survival) by 1.2, 1.9, 3.3, and 1.8 months, respectively. Treatment did not influence PrPSc accumulation and distribution at the clinical stage of disease. Differences in mean IPs and survival indicates partial but not complete reduction in scrapie infectivity.

A Study of Combined Genotype Effects of SHCBP1 on Wool Quality Traits in Chinese Merino.

SHCBP1 (Shc SH2-domain binding protein 1) is a member of the Src and collagen homolog (Shc) protein family and is closely associated with multiple signaling pathways that play important roles during hair follicle induction, morphogenesis, and cycling. The purpose of this study was to investigate SHCBP1 gene expression, polymorphisms, and the association between SHCBP1 and wool quality traits in Chinese Merino sheep. The SHCBP1 gene was shown, by qPCR, to be ubiquitously expressed in sheep tissues and differentially expressed in the adult skin of Chinese Merino and Suffolk sheep. Four SNPs (termed SHCBP1SNPs 1-4) were identified by Sanger sequencing and were located in exon 2, intron 9, intron 12, and exon 13 of the sheep SHCBP1 gene, respectively. SHCBP1SNPs 3 and 4 (rs411176240 and rs160910635) were significantly associated with wool crimp (P < 0.05). The combined polymorphism (SHCBP1SNP3-SHCBP1SNP4) was significantly associated with wool crimp (P < 0.05). Bioinformatics analysis showed that the SNPs associated with wool crimp (SHCBP1SNPs 3 and 4) might affect the pre-mRNA splicing by creating binding sites for serine-arginine-rich proteins and that SHCBP1SNP4 might alter the SHCBP1 mRNA and protein secondary structure. Our results suggest that SHCBP1 influences wool crimp and SHCBP1SNPs 3 and 4 might be useful markers for marker-assisted selection and sheep breeding.

Transcriptome-metabolome analysis reveals how sires affect meat quality in hybrid sheep populations.

Crossbreeding improves and enhances meat quality and is widely used in sheep production; however, the molecular mechanisms underlying the meat quality of various crossbred sheep remain unknown. In this study, male Southdown, Suffolk and Hu sheep were crossbred with female Hu sheep, and the transcriptomes and metabolomes of the longissimus dorsi muscle of the F1 generation were sequenced to explore how different sire breeds affect meat quality. The results showed that 631 differentially expressed genes and 119 significantly altered metabolites contributed to muscle development characteristics and meat quality-related diversity (P < 0.05). These genes and metabolites were significantly enriched in lipid metabolism pathways, including arachidonic acid metabolism and PPAR signaling. Several candidate genes were associated with muscle growth, such as MYLK3, MYL10, FIGN, MYH8, MYOM3, LMCD1, and FLRT1. Among these, MYH8 and MYL10 participated in regulating muscle growth and development and were correlated with meat quality-related fatty acid levels (|r| > 0.5 and p < 0.05). We selected mRNA from four of these genes to verify the accuracy of the sequencing data via qRT-PCR. Our findings provide further insight into the key genes and metabolites involved in muscle growth and meat quality in hybrid sheep populations.

Determine the vertical ground reaction forces and knee mechanics with different gait inclinations in the sheep model.

Our current understanding of knee mechanics and anterior cruciate ligament (ACL) function is predominately based on data recorded during simulations of clinical examinations or the application of nonphysiologic loads and motions. These methodologies provide little information on knee and ACL mechanics during activities of daily living (ADLs). Additionally, researchers have not directly measured knee kinetics, knee contact pressures, and ACL forces, and it is unknown how these parameters change with different activities. This study quantified the effects of activity level on vertical ground reaction forces, knee kinematics, and joint and ligament forces during in vivo motions. Five female Suffolk sheep were walked twice weekly on a treadmill during level (0°), inclined (+6°), and declined (-6°) gait for 12 weeks. Electromagnetic (EM) trackers were surgically implanted onto the left distal femur and the left proximal tibia, and in vivo motions were recorded for all activities. Following sacrifice, the in vivo motions were applied to their respective knees using a serial robot with a multi-axis load cell. In vitro simulations were repeated to measure (a) total knee forces, (b) contact pressure maps, and (c) ACL-only forces. Declining the gait surface led to increased posterior translation during the swing phase and decreased flexion at hoof-strike, decreased medial contact pressure at push-off, decreased ACL force at hoof-strike and increased ACL force at push-off. This study established a system that can be used to examine knee mechanics and ACL forces during ADLs for different knee states to define design requirements for ACL reconstruction techniques.

Cervical immune activation during the luteal phase may compromise subsequent trans-cervical ram sperm transport†.

Worldwide, cervical artificial insemination using frozen–thawed semen yields low pregnancy rates. The only exception to this is in Norway, where vaginal insemination with frozen–thawed semen yields pregnancy rates in excess of 60% and which has been attributed to the specific ewe breed used. Our previous work demonstrated differences in cervical gene expression at the follicular phase of the estrous cycle in ewe breeds with known differences in pregnancy rates. In this study, we characterized the cervical transcriptome of the same ewe breeds [Suffolk, Belclare, Fur, and Norwegian White Sheep (NWS)] during the luteal phase, as an optimal environment at the luteal phase could better prepare the cervix for sperm migration through the cervix at the subsequent follicular phase. High-quality RNA extracted from postmortem cervical tissue was analyzed by RNA sequencing. After stringent filtering, 1051, 1924, and 611 differentially expressed genes (DEGs) were detected in the low-fertility Suffolk breed compared with Belclare, Fur, and NWS, respectively. Gene ontology analysis identified increased humoral adaptive immune response pathways in Suffolk. Increased expression of multiple immune genes supports the presence of an active immune response in the cervix of Suffolk ewes, which differentiates them significantly from the other three ewe breeds. Inflammatory pathways were upregulated in the Suffolk, resulting in higher expression of the potent pro-inflammatory cytokines. Therefore, higher levels of pro-inflammatory cytokines indicate unresolved inflammation in the cervix of the low-fertility Suffolk breed that could contribute to reduced cervical sperm transport in the next follicular phase.

The Mechanism of Heat Stress Resistance During Spermatogenesis in Turpan Black Sheep.

Heat stress can affect the reproductive function of livestock and cause harm to animal production, which can seriously damage the economic interests of livestock producers. Therefore, it is important to explore the effect of heat stress on reproductive function to improve livestock production. In this study, the experimental animals Turpan black sheep and Suffolk sheep were selected as controls, each with 10 sheep, and the reproductive physiological performance was measured in Turpan, China from April to August when there was no heat stress to strong heat stress. The results showed that the sperm density, vitality, and kinematic parameters of Suffolk sheep were significantly lower than that in Turpan black sheep (p < 0.01) after heat stress, while the sperm acrosome malfunctions and DNA damage were significantly higher in Suffolk sheep (p < 0.01). In addition, the endogenous levels of reproductive hormones and oxidative stress indicators in the blood of Turpan black sheep were stable before and after heat stress treatment, while Suffolk sheep showed different degrees of fluctuations. There was no significant difference in testicular histomorphology between the two after heat stress treatment. However, Suffolk sheep showed a significantly decreased number of spermatocytes after heat stress treatment (p < 0.05). It was found that during meiosis, the proportion of cells in the meiotic zygotene stage of Suffolk sheep was significantly higher than that of Turpan black sheep. To investigate the mechanism of normal spermatogenesis in Turpan black sheep under heat stress, we performed RNA-Seq analysis on the testis. The results showed that there were 3,559 differential genes in Turpan black sheep before and after heat stress, with 2,118 up-regulated genes and 1,441 down-regulated genes. The enrichment analysis of GO and KEGG showed that the differential genes are mainly involved in cellular component organization or biogenesis, cell cycle process, mitotic cell cycle process, meiotic cell cycle process, double-strand break repair and Rap1 signaling pathway, Ras signaling pathway, Cell cycle, signaling pathways regulating pluripotency of stem cells Oocyte meiosis. Genes related to spermatogenesis, SYCP2, TDRD9, BRDT, CEP120, BRCA1, etc. were significantly up-regulated in Turpan black sheep after heat stress. In summary, our results showed that the up-regulation of genes involved in spermatogenesis protects the normal production of sperm in Turpan black sheep under HS, thereby achieving normal reproductive function.Our research systematically elucidated the mechanism of heat stress resistance during spermatogenesis in Turpan black sheep and provided potential possibilities for the subsequent breeding of new heat-resistant breeds.

Assessing Population Structure and Genetic Diversity in US Suffolk Sheep to Define a Framework for Genomic Selection.

Long-term sustainability of breeds depends on having sufficient genetic diversity for adaptability to change, whether driven by climatic conditions or by priorities in breeding programs. Genetic diversity in Suffolk sheep in the United States was evaluated in four ways: 1) using genetic relationships from pedigree data [(n = 64 310 animals recorded in the US National Sheep Improvement Program (NSIP)]; 2) using molecular data (n = 304 Suffolk genotyped with the OvineHD BeadChip); 3) comparing Australian (n = 109) and Irish (n = 55) Suffolk sheep to those in the United States using molecular data; and 4) assessing genetic relationships (connectedness) among active Suffolk flocks (n = 18) in NSIP. By characterizing genetic diversity, a goal was to define the structure of a reference population for use for genomic selection strategies in this breed. Pedigree-based mean inbreeding level for the most recent year of available data was 5.5%. Ten animals defined 22.8% of the current gene pool. The effective population size (Ne) ranged from 27.5 to 244.2 based on pedigree and was 79.5 based on molecular data. Expected (HE) and observed (HO) heterozygosity were 0.317 and 0.306, respectively. Model-based population structure included 7 subpopulations. From Principal Component Analysis, countries separated into distinct populations. Within the US population, flocks formed genetically disconnected clusters. A decline in genetic diversity over time was observed from both pedigree and genomic-based derived measures with evidence of population substructure as measured by FST. Using these measures of genetic diversity, a framework for establishing a genomic reference population in US Suffolk sheep engaged in NSIP was proposed.

L’implantation de fragments méniscaux autologues enveloppés par du fascia induit la régénération du fibrocartilage en cas de pertes de substance méniscales sévères chez le mouton : étude histologique et biomécanique

IntroductionCurrently, various studies have been reported to regenerate the meniscus tissue in a large defect after partial meniscectomy using biological or synthetic scaffolds with or without fibrochondrocytes. However, the clinical utility of those treatments has not been established as of yet. HypothesisPurposes of this study were to develop a sheep model to evaluate feasibility of this new surgical strategy to treat the irreparable meniscus injury, and to test the hypothesis that implantation of autogenous meniscal fragments wrapped with a fascia sheath may significantly induce fibrocartilage regeneration in a large meniscal defect in the sheep model. Methods and methodsTwenty Suffolk sheep were used. In each animal, an anterior 10-mm width of the right medial meniscus was resected. Then, the animals were divided into the following 2 groups. In Group I, the defect was enveloped with a fascia from the left thigh. In Group II, the resected meniscus fragmented into small pieces was grafted into the defect. Then the defect was enveloped with a fascia. In each group, 5 of 10 sheep were used for histological and biomechanical evaluations, respectively, at 12 weeks after surgery. ResultsIn Group I, the defect was incompletely filled with thin fibrous tissues, while fibrocartilage tissues rarely regenerated in the tissue. In Group II, all defects were completely filled with thick fibrocartilage tissues, which were richly stained with the safranin O staining. Both the gross and histological observation score of Group II was significantly (p=0.0005, p=0.0005) greater than that of Group I. Concerning the cross-sectional area of the regenerated tissue, Group II was significantly (p=0.0002) greater than Group I. In the biomechanical evaluation, the maximal load and the linear stiffness of the meniscus-tibia complex were significantly (p=0.0015, p=0.0283) greater in Group II than in Group I. DiscussionsImplantation of autogenous meniscal fragments wrapped with a fascia sheath significantly induces fibrocartilage regeneration into a large meniscal defect in the sheep model. Level of evidencenot applicable; Controlled Laboratory Study, Experimental in vivo study.

159. Modelling growth in Suffolk sheep with insufficient mature weight records for polynomial random regression models

159. Modelling growth in Suffolk sheep with insufficient mature weight records for polynomial random regression models

124 The Effect of Innate Immune Receptor Activation on Differential Breed Responses to LPS in Sheep

Abstract While studying breed differences in immune response of peripheral blood mononuclear cells (PBMC) to Haemonchus contortus (Hc) antigen, RNA sequencing revealed that St. Croix (STC) PBMC upregulated expression of NLRP3 compared to PBMC from Suffolk (SUF) sheep. Nod-like receptor pyrin containing domain 3 (NLRP3) is a cytoplasmic pattern recognition receptor (PRR) with a wide array of agonists, such as PAMPs, DAMPs, ATP, bacterial product, and viral products. Stimulation of the NLRP3 inflammasome results in proteolytic activation of IL-1b and IL-18, cell pyroptosis, and classically, the induction of proinflammatory responses. Common activation of this pathway can be achieved by stimulation with liposaccharide (LPS) which binds and activates a toll-like receptor-4 (TLR4) pathway, causing production of proinflammatory cytokines. Interestingly, NLRP3 has been recently implicated as an early initiator of IL-4 production in response to helminth antigen. Thus, the objective of this study was to determine differences in breed responses to LPS and the role of NLRP3. To test this hypothesis, PBMC were collected from STC and SUF sheep and cells were incubated with LPS only, LPS in combination with pharmacological inhibitor of NLRP3 (MCC950), or complete media for 3 hrs. Gene expression of PBMC exposed to LPS revealed that Inflammatory linked genes IL-1β (P &amp;lt; 0.001), TLR4 (P &amp;lt; 0.001), TNFα (P &amp;lt; 0.001), NFκB (P &amp;lt; 0.001) were upregulated in STC PBMC. Treatment with MCC950 in combination with LPS, reduced inflammatory gene expression in STC PBMC to the level of SUF PBMC (P &amp;gt; 0.05), thus ablating inflammatory responses in STC PBMC. These data reveal a deficiency in NLPR3 function in SUF sheep and have been confirmed by SNPs found in that gene that have been predicted to alter NLRP3 protein structure.

Personalized Strategy for Animal-Assisted Therapy for Individuals Based on the Emotions Induced by the Images of Different Animal Species and Breeds.

Simple SummaryIn this study, we hypothesized that the personalized strategies for the animal-assisted therapy (AAT) could be improved by selecting animal species and breeds for individuals (persons) according to the emotions induced in the persons by different animal species and breeds. To our knowledge, this study is the first in the area in which the FaceReader technique has been applied to improve the methodology of AAT, which could be the first step to avoiding and/or minimizing stressful situations during a person’s contact with an animal. To implement the aim, the images of different animal species (dogs, cats, pigs, sheep, and horses) and various breeds of those species were used. This study showed that the animal species is a significant factor in the intensity of the ‘neutral’ and ‘happy’ emotions as well as valence. In addition, animal breed is a significant factor in the intensity of the emotion ‘happy’ and valence. Finally, in this study, we obtained results that could be used as a personalized strategy for improvement of the AAT and to help the individuals select a pet.The aim of this study was to apply the FaceReader technique to select the animal species and breed for a personalized AAT based on the emotions (‘neutral’, ‘happy’, ‘sad’, ‘angry’, ‘surprised’, ‘scared’, ‘disgusted’, and ‘contempt’) induced in the persons (18–64 years old) by the images of different animal species and breeds. To implement the aim, the images of different animal species (Canis familiaris, Felis silvestris catus, Sus scrofa domesticus, Ovis aries, and Equus caballus) and their breeds (dogs: Australian shepherd, pug, Labrador retriever, Doberman, miniature schnauzer, beagle, three mixed-breed types, Yorkshire terrier, Cane Corso, Samoyed, and Chihuahua; cats: British shorthair, Himalayan cat, three mixed breed types, Siamese cat, Sphynx, and Bengal cat; horses: Norwegian Fjord, Exmoor pony, Andalusian, and Friesian; pigs: Vietnamese pot-bellied and Kunekune; sheep: Herdwick sheep and Suffolk sheep) were used. This study showed that the animal species is a significant factor in the intensity of the emotions ‘neutral’ and ‘happy’ as well as valence, and the animal breed is a significant factor for the emotion ‘happy’ intensity and valence. The obtained results could be used as a personalized strategy for improving AAT and helping the individuals to select a pet.