Effects Of Inbreeding Research Articles

Selfing in epiphytic bromeliads compensates for the limited pollination services provided by nectarivorous bats in a neotropical montane forest.

Abstract. Plants with specialized pollination systems frequently exhibit adaptations for self-pollination, and this contradictory situation has been explained in terms of the reproductive assurance function of selfing. In the neotropics, several plant lineages rely on specialized vertebrate pollinators for sexual reproduction, including the highly diverse Bromeliaceae family, which also displays a propensity for selfing. Thus far, the scarce evidence on the role of selfing in bromeliads and in other neotropical plant groups is inconclusive. To provide insights into the evolution and persistence of self-fertilization in the breeding systems of Bromeliaceae, we studied four sympatric epiphytic species from the genus Werauhia (Tillandsioideae) in Costa Rica. We documented their floral biology, pollination ecology and breeding systems. We estimated the contribution of selfing by comparing the reproductive success between emasculated flowers requiring pollinator visits and un-manipulated flowers capable of selfing and exposed to open pollination across two flowering seasons. The studied species displayed specialized pollination by nectar-feeding bats as well as a high selfing ability (auto-fertility index values > 0.53), which was attained by a delayed selfing mechanism. Fruit set from natural cross-pollination was low (<26% in both years) and suggested limited pollinator visitation. In line with this, we found a very low bat visitation to flowers using video-camera recording, from 0 to 0.24 visits per plant per night. On the contrary, the contribution of selfing was comparatively significant since 54-80% of the fruit set from un-manipulated flowers can be attributed to autonomous self-pollination. We concluded that inadequate cross-pollination services diminished the reproductive success of the studied Werauhia, which was compensated for by a delayed selfing mechanism. The low negative effects of inbreeding on seed set and germination likely reinforce the persistence of selfing in this bromeliad group. These results suggest that selfing in bat-pollinated bromeliads may have evolved as a response to pollinator limitation.

Reproductive traits in Pura Raza Española mares manifest inbreeding depression from low levels of homozygosity.

Inbreeding depression is a genetic phenomenon associated with the loss of fitness and mean phenotypic performance due to mating between relatives. Historically, inbreeding coefficients have been estimated from pedigree information. However, the onset of genomic selection programs provides large datasets of individuals genotyped using SNP arrays, enabling more precise assessment of an individual's genomic-level inbreeding using genomic data. One of the traits most sensitive to issues stemming from increased inbreeding is reproduction. This is particularly important in equine, in which fertility is only moderate compared to other livestock species. To explore this further, we evaluated the effect of inbreeding on five reproductive traits (age at first foaling (AFF), average interval between foalings (AIF), total number of foalings (NF), productive life (PL) and reproductive efficiency (RE)) in Pura Raza Español mares using genomic data. Residual predicted phenotypes were obtained by purging these traits through the REML (wgResidual ) and ssGREML (gResidual ) approaches in reproductive data of 29,847 PRE mares using the BLUPF90+ program. Next, we used pedigree-based (Fped ) and ROH-based genomic (FROH ) inbreeding coefficients derived from 1018 animals genotyped with 61,271 SNPs to estimate the inbreeding depression (linear regression). Our results indicated significant levels of inbreeding depression for all reproductive traits, with the exception of the AIF trait when Fped was used. However, all traits were negatively affected by the increase in genomic inbreeding, and FROH was found to capture more inbreeding depression than Fped . Likewise, REML models (ssGREML) using genomic data for estimated predicted residual phenotypes resulted in higher variance explained by the model compared with the models not using genomics (REML). Finally, a segmented regression analysis was conducted to evaluate the effect of inbreeding depression, revealing that the levels of genealogical and genomic homozygosity do not manifest uniformly in reproductive traits. In contrast, the levels of inbreeding depression ranged from low to high as homozygosity increased. This analysis also showed that reproductive traits are very sensitive to inbreeding depression, even with relatively low levels of homozygosity.

A 15-year longitudinal study of search-and-rescue dogs identifies the musculoskeletal, integumentary, and gastrointestinal systems as commonly affected.

A longitudinal study followed search-and-rescue (SAR) dogs for 15 years to determine the incidence of health events and whether factors of deployment during 9/11, breed, or sex altered the risk of specific events. 150 SAR dogs: 95 dogs deployed to the September 11 terrorist attack sites and 55 SAR dogs not deployed. Each year, a survey was sent to the handler to collect health information until the dog died or the handler withdrew from the study. The reported health events were then categorized according to the body system affected and etiology. Incidence risk rates, with 95% CIs, were calculated for the most common types of health events. Incidence rate ratios were calculated stratified by deployment status, sex, and breed and significance assessed. 1 or more health event was recorded in 96 of the 150 enrolled dogs. The most affected systems were the musculoskeletal (31%; CI, 24 to 39), integumentary (22%; CI, 15 to 29), and gastrointestinal (20%; CI, 14 to 26). The health events were most commonly reported as inflammatory (45%; CI, 37 to 53) and degenerative (28%; CI, 21 to 35) in nature. There were no significant differences in incidence of health events based on deployment status to the September 11, 2001, terrorist attacks. Additionally, there was no significant effect of breed or sex on incidence of health events. To improve the health and longevity of SAR dogs, disease prevention and management programs should focus on reducing the health problems involving the musculoskeletal system as well as the integumentary and gastrointestinal systems.

Evaluation of Sheep Colostrums According to Time after Lambing by Brix Refractometer Method and Color Scoring

The aim of the study was to determine the effects of breed and post-lambing time on sheep colostrum quality. In this study, colostrum samples taken at different times after lambing from 4 different sheep breeds (Tuj, Awassi, Morkaraman, Akkaraman) raised in Turkey were compared using Brix refractometer and color scoring. The sheep included in the study were placed in different paddocks according to their breeds. In the first week after lambing, a total of 7 colostrum samples were collected from each ewe, every 12 hours for the first 3 days and on the 7th day (mature milk sample). According to the data obtained from the study, it was determined that colostrum quality was affected by breed and milking duration (p&lt;0.05). Brix values of colostrum in the first and second milking were found to be higher in the Akkaraman breed than in the Morkaraman breed (p&lt;0.05). Additionally, it was determined that the color score decreased over time after lambing and this decrease was statistically significant (p&lt;0.05). In conclusion, since the quality of sheep colostrum varies depending on breed and time, the quality of the colostrum to be fed for lamb health and performance must be determined in advance

Genetic diversity of three consecutive selective breeding generations in Pseudobagrus vachellii (Actinopterygii: Siluriformes: Bagridae)

Pseudobagrus vachellii (Richardson, 1846) is a commercially important freshwater fish species in China. To understand the effects of artificial breeding on the genetic diversity of three consecutive P. vachellii breeding populations (F1, F2, and F3) since 2012, a genetic analysis was conducted using polymorphic microsatellite markers. The mean allele number, expected heterozygosity, observed heterozygosity, and the polymorphic information content from generation F1 to F3 decreased from 7.75 to 5.63, from 0.77 to 0.63, from 0.83 to 0.77, and from 0.72 to 0.58, respectively. Analysis of molecular variance showed greater genetic divergence within the three generations (93.67%) than that among the generations (6.33%), and the overall differentiation level was moderate. Additionally, the lowest genetic differentiation was between F2 and F3 (Fst = 0.0484), and the highest was between F1 and F3 (Fst = 0.12864). Inbreeding occurred in each generation and was the highest in generation F3. Structural analysis showed that the three P. vachellii generations were most likely divided into two different genetic clusters. Although genetic diversity declined slightly in the mass selection lines after three breeding generations, overall genetic diversity was maintained at a relatively high level. To minimize the loss of genetic diversity and inbreeding in the subsequent breeding process, a moderate number of parents can be used for each generation. Information regarding the genetic diversity and structure of the selective P. vachellii breeding generations obtained in this study will be useful for future broodstock management and selective breeding programs.

Relatedness and genomic inbreeding in a sample of Timor ponies

Timor ponies (TP) were first shipped to Australia in the early 1800s and were highly valued as transport and pack animals, which resulted in TPs contributing to the development of Australian horse breeds. Today, while the exact number of TPs in Australia is currently unknown, there has been recent interest in establishing a domestic breeding program for Australian TPs. The aim of this study was to evaluate the relatedness of a sample of TPs, as well as provide estimates of genomic inbreeding levels to better inform the feasibility of using these animals as founders for a domestic breeding program. Hair samples from each horse were genotyped using the Illumina 80K Infinium Equine genotyping array and data were analysed using PLINK v1.90b7, KING 2.3.2 and R v4.3.1. The results illustrate that there are distantly related and minimally inbred horses within the sampled TPs. Lengths of the ROH segments also indicated that recent inbreeding events are likely to only have occurred in a third of the horses. Overall, these results are promising for the success of a domestic TP breeding program; however, considering the low number of domestic TPs known to reside in Australia, there would certainly still be substantial benefits to incorporating additional TPs either directly from Timor or from areas in Australia that are believed to contain wild descendants of TPs.

Teat morphology across five buffalo breeds: a multi-country collaborative study.

The buffalo (Bubalus bubalis) is a species of worldwide importance, raised to produce milk, meat, and hides, and often used as a working animal in rural contexts with low access to hi-tech solutions. In the present study, 100 lactating buffaloes (50 primiparous and 50 pluriparous) of five popular breeds were recruited to characterize and compare teat morphology. In particular, the focus was put on the Nili Ravi, Mediterranean, Egyptian, Bulgarian Murrah, and Azeri buffaloes raised in Pakistan, Italy, Egypt, Bulgaria, and Iran, respectively. In all countries, a longitudinal cross-section ultrasound was obtained before the milking to measure teat parameters at individual level: overall, teat canal length (TCL) averaged 24.13mm, teat diameter (TD) 30.46mm, cisternal diameter (CD) 17.80mm, and teat wall (TW) 7.12mm. The most variable trait across breeds was TCL which was positively correlated with CD and TD and negatively with TW, regardless of the teat position (front/rear or left/right). A strong negative correlation was found between TW and CD (- 0.43). The analysis of variance revealed that the fixed effect of breed significantly affected all the traits except TD. In fact, Bulgarian Murrah, Azeri, and Egyptian buffaloes presented the greatest estimate of TCL, whereas NR the smallest (14.70mm). The TW was maximum in Nili Ravi, Egyptian, and Mediterranean buffaloes, with estimates equal to 8.19, 7.59, and 8.74mm, respectively. Nili Ravi also showed the greatest TL (82.39mm). In terms of CD, the lowest least square mean was that of Mediterranean buffaloes (12.14mm). Primiparous and pluriparous buffaloes differed in terms of TD, TW, and TL, with older animals presenting the highest least square mean. In terms of position, instead, significant differences were observed for TD, CD, and TL when comparing front and rear teats, as left and right teats did not differ. Teat anatomy includes a set of heritable morphological features and is therefore breed-dependent. Differences presented in this study could be attributed to the divergent breeding objective and selective pressure across the five breeds; e.g., in some cases such as Mediterranean buffalo, selection for decades was oriented to improve milk production and milkability and achieve optimal conformation for mechanical milking. A better understanding of the mammary gland anatomical descriptors can be informative of the history of a breed and could provide useful insights to guide possible selection.

Effects of inbreeding on fertilization, growth and survival in the tetraploid Pacific oyster Crassostrea gigas

Effects of inbreeding on fertilization, growth and survival in the tetraploid Pacific oyster Crassostrea gigas

Sequence-based population structure, relatedness, and inbreeding estimates for forensic autosomal STR markers

Population data have become available for sequence data to aid forensic investigations and prepare the forensic community in the move towards implementing NGS methods. This comes with a need for updated population genetic parameters estimates to allow DNA evidence evaluations using sequence data. Initial work has been done on a small sample and here we expand this work by providing estimates of population structure and relatedness for autosomal STR data generated by sequencing technologies. We also discuss the effect of inbreeding on forensic calculations and discuss why the use of genotypic-based estimates may be preferred over allelic-based estimates.

Does Keeping Cows for More Lactations Affect the Composition and Technological Properties of the Milk?

This study investigated differences in the raw milk composition and technological properties between cows with different numbers of lactations. In total, 12 commercial herds were visited within a period of 12 weeks. On each farm, milk samples from five young cows (lactations 1-2) and five older cows (lactation ≥ 3) were collected. For each farm, milk samples from the young cows and the older cows, respectively, were pooled. The pooled milk samples were analyzed for gross composition and technological properties. Using principal component analysis (PCA) to assess the overall variation in milk quality attributes and the potential clustering of milk from young cows and older cows, respectively, an effect of breed, but no clear effect of lactation number, was observed. In contrast, one-way ANOVA showed higher plasmin activity (p = 0.002) in pooled milk from the older cows, whereas plasminogen-derived activity (p = 0.001) and total proteolysis (p = 0.029) were higher in milk from the young cows. Likewise, orthogonal projections to latent structure discriminant analysis (OPLS-DA) showed higher plasmin activity in milk from older cows, whereas younger cows had higher plasminogen-related activity and higher total proteolysis. To conclude, except for plasmin and plasminogen-related activities, there were no major differences in the composition and technological properties between milk from older cows and young cows.

Milk microbiome in the first month of lactation and at weaning from ewes supplemented with zinc pre- and postpartum.

Mastitis is an important disease with economic and welfare implications in both clinical and subclinical states. The aim of this research was to sequence the hypervariable V4 region of the 16S rRNA gene to describe the microbial diversity and taxonomy of milk from clinically healthy ewes (Rambouillet, WF = 9; Hampshire, BF = 5). Experimental ewes represented a subset of a larger study assessing the impacts of divergent dietary zinc (Zn) concentrations [1 × National Academics of Sciences, Engineering, and Medicine (NASEM) recommendations = CON or 3 × NASEM recommendations = ZnTRT] throughout late gestation and lactation. Milk was collected at four periods during early lactation (18 to 24h, 7 d, 14 d, and 21 d postpartum) and at weaning (84 ± 14 d postpartum). Somatic cell counts (SCC) were quantified, averaged, and classed (low: < 500 × 103; medium: 500 × 103 - 100 × 104; high: > 100 × 104 cells/mL). Milk samples (n = 67) were sequenced to identify bacteria and archaea; the most abundant phyla were Actinobacteria, Bacteroidetes, Cyanobacteria, Euryarchaeota, Firmicutes, Fusobacteria, Lentisphaerae, Proteobacteria, Spirochaetes, Tenericutes, Saccharibacteria TM7, and Verrucomicrobia. Mastitis pathogens were among the most relatively abundant genera, including Staphylococcus, Mannheimia, Corynebacterium, and Pseudomonas. Effects of breed, dietary Zn concentration, SCC class, and their two-way interactions on milk microbiome diversity and taxonomy were assessed within early lactation (using a repeated measures model) and weaning samples. Alpha-diversity metrics included Pielou's evenness, Faith's phylogenetic diversity, and Shannon's entropy indices. The main and interactive effects between Zn treatment, breed, SCC class, and period were variable in early lactation and not evident in weaning samples. Milk from BF ewes had increased Faith's phylogenetic diversity and Shannon's entropy, and differed in unweighted UniFrac composition (P ≤ 0.10). Milk from CON ewes had a reduced rate of composition change through early lactation (P = 0.02) indicating greater microbiome stability than ZnTRT ewe milk. These results support that milk is not sterile, and breed, dietary Zn concentration, and SCC class variably affect the milk microbiome. Findings from the current study provide important foundational insights into the effects of increased dietary Zn supplementation on longitudinal changes in the milk microbiome and associations with mammary gland health and mastitis.

The genome of the black-footed cat: Revealing a rich natural history and urgent conservation priorities for small felids.

Habitat degradation and loss of genetic diversity are common threats faced by almost all of today's wild cats. Big cats, such as tigers and lions, are of great concern and have received considerable conservation attention through policies and international actions. However, knowledge of and conservation actions for small wild cats are lagging considerably behind. The black-footed cat, Felis nigripes, one of the smallest felid species, is experiencing increasing threats with a rapid reduction in population size. However, there is a lack of genetic information to assist in developing effective conservation actions. A de novo assembly of a high-quality chromosome-level reference genome of the black-footed cat was made, and comparative genomics and population genomics analyses were carried out. These analyses revealed that the most significant genetic changes in the evolution of the black-footed cat are the rapid evolution of sensory and metabolic-related genes, reflecting genetic adaptations to its characteristic nocturnal hunting and a high metabolic rate. Genomes of the black-footed cat exhibit a high level of inbreeding, especially for signals of recent inbreeding events, which suggest that they may have experienced severe genetic isolation caused by habitat fragmentation. More importantly, inbreeding associated with two deleterious mutated genes may exacerbate the risk of amyloidosis, the dominant disease that causes mortality of about 70% of captive individuals. Our research provides comprehensive documentation of the evolutionary history of the black-footed cat and suggests that there is an urgent need to investigate genomic variations of small felids worldwide to support effective conservation actions.

The influence of breed's difference on the hemogram and biochemistry profile of goats raised in Libya during winter.

In Libya, goats are considered as one of the most important livestock in which there are many breeds of goats such as Kurdi, Hegazi, Cyprus, Shami, and Mahali. A little hematological and biochemical information is known on these goat breeds raised in Libya. The main purpose was to verify the effect of breed variations on the hematological and biochemical parameters of goat breeds raised in Libya. The blood samples were collected in the winter season from 70 clinically healthy animals of different breeds for hematology and biochemical analysis. Regarding the effect of breeds on blood hematology, significantly higher number (p < 0.01) of Mid cells were found in Hegazi (3.12 ± 1.30 × 103/µl) and Cyprus (2.41 ± 1.69 × 103/µl) when compared to other goat's breeds including Kurdi (2.28 ± 0.95 × 103/µl), Shami (1.90 ± 0.84 × 103/µl), and Mahali (1.37 ± 0.88 × 103/µl). Moreover, the percentage of Mid cells was highest in Hegazi (22.34% ± 9.40%), 11.40% ± 4.34%), followed by Kurdi (17.71% ± 8.16%), Cyprus (15.84% ± 8.33%), Shami (13.38% ± 5.76%), and lowest in Mahali (11.40% ± 4.34%). There are significant differences (p < 0. 01) in hemoglobin (Hb), red blood cells (RBCs), hematocrit (HCT), mean corpuscular hemoglobin (MCH), red cell width distribution-coefficient of variation (RDW-CV, %), and red cell distribution width-standard deviation (RDW-SD, fl) values among all different breeds of Libyan goats. The results of biochemistry displayed significant changes among the studied goats' breeds, where the highest serum alanine aminotransferase (ALT, U/L) activity was observed in Cyprus (17.81 ± 7.95) and Shami (17.27 ± 1.15) compared with Hegazi (15.31 ± 6.13) and Mahali (14.60 ± 0.46), while Kurdi breed (11.68 ± 7.95) showed the lowest ALT activity. Moreover, significant differences (p < 0.01) in serum lactate dehydrogenase (LDH, U/l), total and direct bilirubin, glucose (GLU), creatinine, lipid profile, and electrolyte levels were recorded among different breeds used in this study. On the other hand, non-significant variations (p >0. 05) are reported in aspartate aminotransferase (U/l), alkaline phosphatase (U/l), total protein (g/dl), albumin (g/dl), urea and magnesium (Mg, mg/dl) levels. These results showed a significant difference between some blood parameters of goat breeds raised in Libya. This could aid veterinarians in interpreting laboratory data properly in order to improve the management and conservation of those breeds.

The Effects of Breed and Body Mass Index on the Incidence of Arrested Laying Associated with Polycystic Ovarian Syndrome in Geese

The Effects of Breed and Body Mass Index on the Incidence of Arrested Laying Associated with Polycystic Ovarian Syndrome in Geese

Season and Breed Effect in Fresh Semen Parameters at a Bull Semen Production Center in Peru

Season and Breed Effect in Fresh Semen Parameters at a Bull Semen Production Center in Peru

The effect of body size and inbreeding on cancer mortality in breeds of the domestic dog: a test of the multi-stage model of carcinogenesis.

Cancer is a leading cause of death in domestic dogs. Deaths due to cancer vary widely among breeds, providing an opportunity for testing the multi-stage model of carcinogenesis. This model underpins evolutionary and basic studies of cancer suppression and predicts a linear increase in cancer with breed size, an expectation complicated by bigger breeds having a shorter lifespan (decreasing risk). Using three independent datasets, the weight and lifespan of breeds provided a good fit of lifetime cancer mortality to the multi-stage model, the fit suggesting many canine cancers are initiated by four driver mutations. Of 85 breeds in more than one dataset, only flat-coated retriever showed significantly elevated cancer mortality, with Scottish terrier, Bernese mountain dog and bullmastiff also showing notable risk (greater than 50% over expected). Analysis of breed clades suggested terriers experience elevated cancer mortality. There was no evidence that the lower mass-specific metabolic rate of larger breeds reduced cancer risk. Residuals indicated increased breed inbreeding shortened expected lifespan, but had no overall effect on cancer mortality. The results provide a baseline for identifying increased breed risk for specific cancers and demonstrate that, unless selection promotes increased cancer suppression, the evolution of larger longer-lived animals leads to a predictable increased cancer risk.

The reproductive system of breast organs in cows and evaluation the function using a mineral adaptogen

Infertility problems still remain an urgent task of practical veterinary medicine. There are many drugs known to have an effect on the organs of the reproductive system, but the search for universal remedies is a priority. The effectiveness of drugs that prevent infertility can be assessed by reducing infertility days and reducing the cost of purchasing sperm products. Restoration, enhancement and prolongation of lactation also ensures the effectiveness of dairy cattle breeding. Therefore, the search for effective means of prevention and treatment is the purpose of this study. The article describes the results of research on the effect of mineral adaptogen on the function of the reproductive system and breast organs in cows. The article presents the results of changes in hematological and biochemical blood tests in cows receiving adaptogen during the dry period and the state of the reproductive system, breast and milk productivity, against the background of taking adaptogen. As a result of the conducted research, a decrease in the incidence of reproductive organs and udders was noted. Reduction of complications in childbirth and the postpartum period. A decrease in the incidence of neonatal pathology in newborn calves was noted. In addition, an increase in dairy productivity.

Haematological reference intervals for pregnant Icelandic mares on pasture

BackgroundFew studies have been conducted on haematological reference intervals (RIs) in Icelandic horses. Reference intervals have been published for Icelandic horses in Austria and a preliminary study in Iceland compared haematological values in riding horses to published RIs for other breeds as well as Icelandic horses abroad. Haematological parameters can vary greatly due to factors such as breed, gender, age, reproductive status, and training, as well as feeding, prior exercise and management method. Icelandic broodmares are kept on pasture under supervision throughout the year, with haylage provided during the winter, and it is therefore of interest to establish haematological reference intervals for pregnant broodmares in Iceland. The purpose of this study was to establish haematological RIs specific to Icelandic broodmares in the first months of pregnancy, kept on pasture. Blood samples from 183 mares, stabilised in EDTA were analysed using IDEXX ProCyte Dx and total protein was analysed in serum samples from 157 of the 183 mares, using IDEXX Catalyst One analyser. The RIs were established using the guidelines of the American Society for Veterinary Clinical Pathology.ResultsThe RIs for red blood cell count, haematocrit and haemoglobin were higher in pasture-kept Icelandic mares in early pregnancy, most of which were lactating, than in pregnant mares of other breeds. This was also true for white blood cell count, as well as numbers of monocytes, eosinophils, and basophils, which in some instances might illustrate problems in the automated categorisation of some leukocytes.ConclusionsAs no RIs have been published for other pasture-kept Icelandic horses, future investigations should include other groups of pasture-kept Icelandic horses. Such an analysis might elucidate the effect of breed, management, and pregnancy on haematological values in pasture-kept Icelandic horses.

The effect of breed and body weight at slaughter on histochemical muscle fiber characteristics and meat quality of longissimus lumborum and semitendinosus lamb muscles

Abstract. The skeletal muscles of mammals are composed of fibers of different morphological, metabolic and functional characteristics. The properties of muscle fibers may be determined genetically as well as by environmental factors such as the age of the animals, their physical activity, the level of nutrition, or the selection intensity. The present study was conducted to determine the influence of genotype (Polish Lowland vs. Polish Heath) and body weight at slaughter (23–25 kg vs. 35–40 kg) of lambs on histological characteristics of muscle fibers in musculus longissimus lumborum (LL) and musculus semitendinosus (ST) skeletal muscles and their impact on chosen meat quality features. Three types of muscle fibers were identified: slow-twitch oxidative (STO), fast-twitch oxidative (FTO) and fast-twitch glycolytic (FTG). Differences in the diameters of individual fiber types between the LL and ST muscles have been found in both investigated genotypes. The diameters of the analyzed types of fibers were usually larger in the ST muscle compared to the LL muscle. The lambs of the more primitive Polish Heath breed were characterized by a smaller diameter of all fiber types, especially in the LL muscle. The higher proportion of STO fibers and the lower proportion of FTO fibers have been found in the LL muscle of Polish Heath lambs in the group with lower body weight. The breed of lambs, muscle type and slaughter body weight had an impact on some meat quality characteristics, especially color, intramuscular fat content and expressed juice.

Environment rather than breed or body site shapes the skin bacterial community of healthy sheep as revealed by metabarcoding.

The skin is inhabited by a variety of micro-organisms, with bacteria representing the predominant taxon of the skin microbiome. In sheep, the skin bacterial community of healthy animals has been addressed in few studies, only with culture-based methods or sequencing of cloned amplicons. The objectives of this study were to determine the sheep skin bacterial community composition by using metabarcoding for a detailed characterisation and to determine the effect of body part, breed and environment. Overall, 267 samples were taken from 89 adult female sheep, belonging to three different breeds and kept on nine different farms in Switzerland. From every individual, one sample each was taken from belly, left ear and left leg and metabarcoding of the 16S rRNA V3-V4 hypervariable region was performed. The main phyla identified were Actinobacteriota, Firmicutes, Proteobacteria and Bacteriodota. The alpha diversity as determined by Shannon's diversity index was significantly different between sheep from different farms. Beta diversity analysis by principal coordinate analysis (PCoA) showed clustering of the samples by farm and body site, while breed had only a marginal influence. A sparse partial least squares discriminant analysis (sPLS-DA) revealed seven main groups of operational taxonomic units (OTUs) of which groups of OTUs were specific for some farms. These findings indicate that environment has a larger influence on skin microbial variability than breed, although the sampled breeds, the most abundant ones in Switzerland, are phenotypically similar. Future studies on the sheep skin microbiome may lead to novel insights in skin diseases and prevention.