Sheep Population Research Articles

Disease Ecology of a Low-Virulence Mycoplasma ovipneumoniae Strain in a Free-Ranging Desert Bighorn Sheep Population.

Simple SummaryLike many wildlife diseases, bighorn sheep pneumonia can vary in burden. Here, we report on a bighorn sheep pneumonia event that showed much lower symptom and mortality burdens than have been documented previously. We provide detailed descriptions of symptoms, diagnostic testing results, and mixing patterns throughout the population, and end by discussing mechanisms that could have generated the distinct disease ecology associated with this event.Infectious pneumonia associated with the bacterial pathogen Mycoplasma ovipneumoniae is an impediment to bighorn sheep (Ovis canadensis) population recovery throughout western North America, yet the full range of M. ovipneumoniae virulence in bighorn sheep is not well-understood. Here, we present data from an M. ovipneumoniae introduction event in the Zion desert bighorn sheep (Ovis canadensis nelsoni) population in southern Utah. The ensuing disease event exhibited epidemiology distinct from what has been reported elsewhere, with virtually no mortality (0 adult mortalities among 70 animals tracked over 118 animal-years; 1 lamb mortality among 40 lambs tracked through weaning in the two summers following introduction; and lamb:ewe ratios of 34.9:100 in the year immediately after introduction and 49.4:100 in the second year after introduction). Individual-level immune responses were lower than expected, and M. ovipneumoniae appeared to fade out approximately 1.5 to 2 years after introduction. Several mechanisms could explain the limited burden of this M. ovipneumoniae event. First, most work on M. ovipneumoniae has centered on Rocky Mountain bighorn sheep (O. c. candensis), but the Zion bighorns are members of the desert subspecies (O. c. nelsoni). Second, the particular M. ovipneumoniae strain involved comes from a clade of strains associated with weaker demographic responses in other settings. Third, the substructuring of the Zion population may have made this population more resilient to disease invasion and persistence. The limited burden of the disease event on the Zion bighorn population underscores a broader point in wildlife disease ecology: that one size may not fit all events.

The Bighorn Habitat Assessment Tool: A Method to Quantify Conservation Value on Landscapes Impacted by Mining

We present a methodology to assess the conservation value of mitigation lands for desert bighorn sheep (Ovis canadensis nelsoni) within landscapes impacted by historic and ongoing industrial uses. The Bighorn Habitat Assessment Tool (BHAT) was developed to support the adaptive management of the Cushenbury population of bighorn sheep located on the north slope of the San Bernardino Mountains in southern California, USA. We use a novel formulation of conservation value integrating the results of resource selection function analysis and reclamation credits, reflecting the degree to which degraded habitat is enhanced to benefit wild sheep. Our method seeks to balance conservation objectives simultaneously with the economic development of a working mine landscape. Specifically, the BHAT can be used to (a) establish a habitat reserve providing maximum benefit to the unique requirements of bighorn sheep; (b) incentivize voluntary action by industry to ensure mining activities are compatible with conservation; (c) allow for the evaluation of multiple mine planning and resource management alternatives; and (d) ensure that future compensatory mitigation actions for mining activity are grounded in the best available science. Our methodology is transferrable to the management of other wild sheep populations occupying mine-influenced landscapes for which sufficient data are available to complete resource selection analyses.

Insights into Human Cystic Echinococcosis in the Kurdistan Region, Iraq: Characteristics and Molecular Identification of Cysts.

Cystic echinococcosis (CE) is a neglected worldwide distributed parasitic disease caused by the Echinococcus granulosus sensu lato (s.l.) species complex. For a better understanding of the pathways of transmission of this parasite, clinical and molecular epidemiological studies are particularly needed from endemic areas where data are scant, such as in the Middle East. The study aimed to identify the characteristics, location, cyst stage and species/genotypes of E. granulosus s.l. complex in humans from the Kurdistan region, Iraq. To this aim, from June 2019 to February 2021, 64 echinococcal cysts were surgically removed from 62 patients in Azadi and Vajeen reference Hospitals at Duhok city, Duhok governorate (Kurdistan region, Iraq). The results confirmed the liver as the most common anatomical site of CE with 72.58% of the cases, followed by the lungs in 19.35%, while 66.13% of CE cases were females. The highest rate of infections occurred in the age class 21–30 (27.42%). High rates of CE were reported among patients living in rural areas and housewives, which were 54.84% and 43.55% of the CE patients, respectively. The fertility of echinococcal cysts was 82.81%, and the viability of fertile protoscoleces was 70.53%. Cysts were staged with ultrasound according to the WHO-IWGE classification as 32.8% CE1, 32.8% CE2, 7.8% CE3a, 9.4% CE3b, 15.6% CE4 and 1.6% CE5. Molecular analyses using mitochondrial NAD5 gene showed that all analyzed samples (n = 59) belonged to the genotypes G1 or G3 of E. granulosus sensu stricto (s.s.), thus, confirming sheep–dog–human transmission in the Kurdistan region, Iraq. No statistically significant correlation was found between the genotypes G1–G3 of E. granulosus s.s. and variables, such as the fertility, location and cyst stage classification. Based on the present findings, it is necessary to implement monitoring and control programs in sheep and dog populations to decrease the odds of human infections. Public health education campaigns are required to be implemented at the community level to reduce the risk of acquiring CE in humans in the Kurdistan region, Iraq.

Development and Application of a High-Resolution Melting Analysis with Unlabeled Probes for the Screening of Short-Tailed Sheep TBXT Heterozygotes.

Simple SummaryTBXT (c.333G > C; c.334G > T) has been identified as a molecular genetic marker in short-tailed sheep. This paper describes a high-resolution melting (HRM) analysis using unlabeled probes and asymmetric PCR for the detection of genetic variants of TBXT in short-tailed sheep populations. The detection results of this method are consistent with those of Sanger sequencing and can help farmers with marker-assisted breeding.The short-tailed phenotype has long been considered one of the best traits for population genetic improvement in sheep breeding. In short-tailed sheep, not only is tail fat eliminated but also the pubic area is exposed due to the lack of a tail covering, giving them an advantage in reproduction. Recent studies have shown that two linked mutations in sheep TBXT at nucleotides 333 and 334 are associated with the short-tailed phenotype. In the population of short-tailed sheep, several heterozygous mutants of this gene are found. In our research, we used high-resolution melting (HRM) to identify homozygous and heterozygous genotypes in a flock of short-tailed sheep and compared the results with those of Sanger sequencing, which were identical. This demonstrates that our established HRM method, a rapid and inexpensive genotyping method, can be used to identify homozygous and heterozygous individuals in short-tailed sheep flocks.

Maternal Relationships among Ancient and Modern Southern African Sheep: Newly Discovered Mitochondrial Haplogroups.

Simple SummaryThe genetic diversity of southern African sheep remains under-studied. We present here the complete mitochondrial genomes of archaeological southern African sheep, as well as the genomes from three indigenous southern African breeds—Damara, Namaqua Afrikaner, and Ronderib Afrikaner. We show that southern African sheep exhibit limited genetic diversity which is consistent with our understanding of their migration south from northernmost Africa. Intriguingly, many of the modern sheep show close relationships with the archaeological sheep, implying an ancestor-descendant relationship. Similarly, the sheep that do not exhibit a close relationship with the archaeological sheep nonetheless cluster closely with each other and do not show a close relationship with European and Asian sheep. This suggests that they too are descendants of indigenous sheep and not the product of historic introductions of exotic breeds.We investigated the genetic diversity and historic relationships among southern African sheep as well as the relationships between them and sheep outside the continent by sourcing both archaeological and modern sheep samples. Archaeological sheep samples derived from the site Die Kelders 1, near Cape Town, date to approximately 1500 years ago. The modern samples were taken as ear snips from Damara, Namaqua Afrikaner, and Ronderib Afrikaner sheep on a farm in Prieska in the Northern Cape. Illumina sequencing libraries were constructed for both ancient and modern specimens. Ancient specimens were enriched for the mitochondrial genome using an in-solution hybridization protocol and modern specimens were subjected to shotgun sequencing. Sequences were mapped to the Ovis aries reference genome, assigned to haplogroups and subhaplogroups, and used to calculate a phylogenetic tree using previously published, geographically dispersed mitochondrial genome sheep sequences. Genetic diversity statistics show that southern African sheep have lower diversity than sheep in other regions. Phylogenetic analysis reveals that many modern southern African sheep are likely descended from prehistoric indigenous sheep populations and not from sheep imported from Europe during the historic period.

Microsatellite Genotyping of Two Bulgarian Sheep Breeds

The aim of this study was to compare the genetic structure and genetic diversity of two Bulgarian sheep breeds. A total of 41 individuals from a modern Bulgarian sheep population (Rhodopean Tsigai, RT) and 46 representatives of a local Bulgarian sheep population (Middle Rhodopean Sheep, MRS) were investigated based on 12 STR (short tandem repeat, also known as microsatellite) markers. In total, 121 alleles were found in the two populations using 12 microsatellite loci. The mean number of alleles, the effective number of alleles, and the polymorphism information content (PIC) values per loci were 10.08, 4.96, and 0.73, respectively. When comparing the allelic diversity across the populations, the highest Na was observed in the MRS breed (10.58 ± 0.87), while the value of this parameter in the RT breed was 9.58 ± 0.71. The largest genetic diversity was found at locus INRA005 with 14.5 alleles and the smallest polymorphism was noted for locus ETH152 with 5.5 alleles. The level of observed heterozygosity was in the range of 0.60 to 0.860. The expected heterozygosity level range was 0.62 to 0.87. When 12 microsatellite loci were compared, the INRA005 locus showed the highest level of genetic variability. Using Nei’s standard genetic distance, the observed genetic distance between the RT and MRS breeds was 0.103. Both sheep breeds demonstrated mixed genetic profiles based on the studied microsatellite markers. The clustering obtained by STRUCTURE analysis showed that the MRS breed is a more homogenous population, whereas the RT breed is more heterogenous.

Excessive replacement changes drive evolution of global sheep prion protein (PRNP) sequences.

Sheep prion protein (PRNP) is the major host genetic factor responsible for susceptibility to scrapie. We aimed to understand the evolutionary history of sheep PRNP, and primarily focused on breeds from Turkey and Ethiopia, representing genome-wise ancient sheep populations. Population molecular genetic analyses are extended to European, South Asian, and East Asian populations, and for the first time to scrapie associated haplotypes. 1178 PRNP coding region nucleotide sequences were analyzed. High levels of nucleotide diversity driven by extensive low-frequency replacement changes are observed in all populations. Interspecific analyses were conducted using mouflon and domestic goat as outgroup species. Despite an abundance of silent and replacement changes, lack of silent or replacement fixations was observed. All scrapie-associated haplotype analyses from all populations also showed extensive low-frequency replacement changes. Neutrality tests did not indicate positive (directional), balancing or strong negative selection or population contraction for any of the haplotypes in any population. A simple negative selection history driven by prion disease susceptibility is not supported by the population and haplotype based analyses. Molecular function, biological process enrichment, and protein-protein interaction analyses suggested functioning of PRNP protein in multiple pathways, and possible other functional constraint selections. In conclusion, a complex selection history favoring excessive replacement changes together with weak purifying selection possibly driven by frequency-dependent selection is driving PRNP sequence evolution. Our results is not unique only to the Turkish and Ethiopian samples, but can be generalized to global sheep populations.

Effect of climate variability on livestock population in the Sokoto Rima River Basin, Nigeria

The study examines the effect of climate variability on livestock population in the Sokoto Rima River Basin, Nigeria. The cluster sampling technique was used to administer the questionnaire to 450 farmers who were sampled from 15 agricultural settlements in fifteen local governments in the basin. Data were analysed using frequency, percentages, and multiple regression. The population of cattle and sheep decreased while that of goats increased during the period of study. However, the slaughtered cattle, sheep, and goats increased tremendously. The annual rainfall and temperature had no significant influence on cattle, sheep, and goat population in Sokoto-Rima River Basin, except at Sokoto where temperature significantly influenced goats positively at p<0.05. The coefficient of determination revealed that annual temperature explained 72% of the variation in the goats' population at Sokoto while 28 % of goats' population variation was explained by non-climatic elements including forage quality, management practices, ill-health, epidemic disease, and so on.

Genetic variation in skin traits in New Zealand lambs.

BACKGROUNDThis study explored the genetic variability in the New Zealand sheep population for economically important skin traits. Skins were collected at slaughter from two progeny test flocks, resulting in 725 skins evaluated for grain strain, flatness, crust leather strength and overall suitability for shoe leather. DNA profiles collected from skins post‐slaughter were matched to individual animals using previously collected high‐density genotypes.RESULTSConsiderable phenotypic variation for skin traits was observed, with around 40% of the skins being identified as suitable for high‐value shoe leather production. Several key traits associated with leather production, including flatness, tear strength, grain strength and grain strain were found to be moderate to highly heritable (h 2 = 0.28–0.82).There were no major significant genome‐wide association study (GWAS) peaks associated with many of the traits examined, however, one single‐nucleotide polymorphism (SNP) reached significance for the flatness of the skin over the hindquarters.CONCLUSIONThis research confirms that suitable lamb skins can be bred for use as high‐value shoe leather. While moderately to highly heritable, skin traits in New Zealand lambs appear to be polygenic with no genes of major effect underlaying the traits of interest. Given the complex nature of these traits, the identification and selection of animals with higher‐value skins may be enabled by geomic selection. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

First evidence of Crimean-Congo haemorrhagic fever virus circulation in Bosnia and Herzegovina.

BackgroundCrimean–Congo haemorrhagic fever (CCHF) is a widespread tick‐borne zoonosis with reported detection of virus and/or virus‐specific antibodies from over 57 countries across Africa, Asia, Europe and the Middle East and is endemic in the Balkans. Detection of Crimean–Congo Haemorrhagic Fever Virus (CCHFV) antibodies in domestic ruminants has been important in providing initial evidence of virus circulation and in localising CCHFV high‐risk spots for human infection.ObjectivesThe present study investigated the possible exposure of sheep to CCHFV in Bosnia and Herzegovina (B&H).MethodsTo investigate the presence of anti‐CCHFV antibodies in sheep, all sera (n = 176) were tested using multi‐species double antigen enzyme‐linked immunosorbent assay (ELISA). Reactive sera were further complementary tested by adapted commercial indirect immunofluorescence assay (IFA) using FITC‐conjugated protein G instead of anti‐human immunoglobulins.ResultsCCHFV specific antibodies were detected in 17 (9.66%) animals using ELISA test. All negative sera were determined as negative by both tests, while 13 out of 17 ELISA‐positive reactors were also determined as unambiguously positive by IFA test. The age group with the highest proportion of seropositive rectors were the oldest animals.ConclusionsThis is the first report of anti‐CCHFV antibodies in sheep from B&H providing the evidence of CCHFV circulation in the country's sheep population. So far, these findings indicate the circulation of the virus in the westernmost region of the Balkans and point to the potential CCHFV spread further out of this endemic area.

Sequencing Reveals Population Structure and Selection Signatures for Reproductive Traits in Yunnan Semi-Fine Wool Sheep (Ovis aries).

Yunnan semi-fine wool sheep are among the most important cultivated sheep breeds in China. However, their population structure, genetic characteristics and traits of interest are poorly studied. In this study, we systematically studied the population characteristics and selection signatures of 40 Yunnan semi-fine wool sheep using SNPs obtained from whole-genome resequencing data. A total of 1393 Gb of clean data were acquired. The mapping rate against the reference genome was 91.23% on average (86.01%–92.26%), and the average sequence depth was 9.51X. After filtering, 28,593,198 SNPs and 4,725,259 indels with high quality were obtained. The heterozygosity rate, inbreeding coefficient and effective population size of the sheep were calculated to preliminarily explore their genetic characteristics. The average heterozygosity rate was 0.264, the average inbreeding coefficient was 0.0099, and the effective population size estimated from the heterozygote excess (HE) was 242.9. Based on the Tajima’s D and integrated haplotype score (iHS) approaches, 562 windows and 11,356 core SNPs showed selection signatures in the Yunnan semi-fine wool sheep population. After genome annotation and gene enrichment analysis, we found traces of early domestication in sensory organs, behavioural activity and the nervous system as well as adaptive changes in reproductive and wool traits under selection in this population. Some selected genes related to litter size, including FSHR, BMPR1B and OXT, were identified as being under selection. Specific missense mutations of the FSHR gene that differed from the reference genome were also identified in the population, and we found some SNP variations that may affect litter size. Our findings provide a theoretical basis for the conservation and utilization of Yunnan semi-fine wool sheep. Furthermore, our results reveal some changes common to sheep after domestication and provide a new opportunity to investigate the genetic variation influencing fecundity within a population evolving under artificial selection.

Detection and immune cell response of natural maedi visna virus (MVV) infection in Indian sheep and goats

Maedi is a lentiviral disease characterized by progressive interstitial pneumonia with humoural as well as cell mediated immune response. The present investigation was designed to detect the presence of MVV in different biological samples and to evaluate the immune response in naturally MVV infected sheep and goats. Total of 701 biological samples (289 lung tissues, 233 blood, 54 brain tissues, 74 mammary gland tissues and 51 joint tissues were screened for the MVV by nested PCR. MVV nucleic acid was detected in 10.41% of samples and it was observed that sheep samples showed positivity of 8.7% and goat samples 12.6%. Blood samples showed highest positivity (14.59%) followed by joint tissue (13.72), lungs (8.6%), mammary gland (8.1%) and brain (1.85%). MVV p28 antigen was detected in the cytoplasm of mononuclear cells, particularly in the macrophages of lungs and lymph nodes. Antibodies against SRLVs were detected by cELISA and seroprevalence of 19.58% was observed in both sheep and goats serum samples. The seropositivity was higher in sheep (22.9%) as compared to the goats (15.59%). IHC was done to identify the nature of the immune cells infiltrated in the MVV infected tissues and it was observed that B cells, CD8+ and macrophages were the predominant immune cells infiltrated in the lungs showing MVV infection. Expression of the cytokines was assessed by real time PCR and it was observed that expression of IL-10, IFN-γ, TNFα, IL-4, IL-2 and IL6 was down regulated in most of the cases but few samples showed upregulation. In conclusion, MVV is circulating in the sheep and goat population of the India and the disease causes altered immune response in the animal which may make the infected animals more prone to other infectious diseases.

Sero-epidemiological survey of Coxiella burnetii in livestock and humans in Tana River and Garissa counties in Kenya.

Coxiella burnetii is a widely distributed pathogen, but data on its epidemiology in livestock, and human populations remain scanty, especially in developing countries such as Kenya. We used the One Health approach to estimate the seroprevalance of C. burnetii in cattle, sheep, goats and human populations in Tana River county, and in humans in Garissa county, Kenya. We also identified potential determinants of exposure among these hosts. Data were collected through a cross-sectional study. Serum samples were taken from 2,727 animals (466 cattle, 1,333 goats, and 928 sheep) and 974 humans and screened for Phase I/II IgG antibodies against C. burnetii using enzyme-linked immunosorbent assay (ELISA). Data on potential factors associated with animal and human exposure were collected using a structured questionnaire. Multivariable analyses were performed with households as a random effect to adjust for the within-household correlation of C. burnetii exposure among animals and humans, respectively. The overall apparent seroprevalence estimates of C. burnetii in livestock and humans were 12.80% (95% confidence interval [CI]: 11.57-14.11) and 24.44% (95% CI: 21.77-27.26), respectively. In livestock, the seroprevalence differed significantly by species (p < 0.01). The highest seroprevalence estimates were observed in goats (15.22%, 95% CI: 13.34-17.27) and sheep (14.22%, 95% CI: 12.04-16.64) while cattle (3.00%, 95% CI: 1.65-4.99) had the lowest seroprevalence. Herd-level seropositivity of C. burnetii in livestock was not positively associated with human exposure. Multivariable results showed that female animals had higher odds of seropositivity for C. burnetii than males, while for animal age groups, adult animals had higher odds of seropositivity than calves, kids or lambs. For livestock species, both sheep and goats had significantly higher odds of seropositivity than cattle. In human populations, men had a significantly higher odds of testing positive for C. burnetii than women. This study provides evidence of livestock and human exposure to C. burnetii which could have serious economic implications on livestock production and impact on human health. These results also highlight the need to establish active surveillance in the study area to reduce the disease burden associated with this pathogen.

Penyuluhan Pemberian Probiotik Bioplus Terhadap Performa Domba di Kelompok Wanita Tani Sauyunan

The population of sheep in Kaso Village, Tambaksari District is still very low compared to the average number of needs each year. One of the feed manipulation techniques that can be done is by giving Bioplus probiotics. This study aims to analyze the increase in knowledge and skills of farmers on the provision of Bioplus probiotics. This study aims to analyze the improvement of farmers' knowledge and skills on the provision of Bioplus probiotics The extension technique used uses a combination of media and extension methods such as lectures, discussions, demonstrations of methods, and applied studies and is combined with powerpoint media and posters. The instrument used is a questionnaire that has been tested for validity and reliability using SPSS version 21. The counseling respondents consisted of 30 members of KWT Sauyunan. The evaluation of the extension was analyzed using the Padmowiharjo formula (1999). The results of the extension evaluation show the criteria of Success for the knowledge aspect and Fairly Successful in the skill aspect. Thus the extension of the provision of Bioplus probiotics to sheep is able to increase the knowledge and skills of members of the women's farmer group.

Average kinship within bighorn sheep populations is associated with connectivity, augmentation, and bottlenecks

AbstractUnderstanding the influence of population attributes on genetic diversity is important to advancement of biological conservation. Because bighorn sheep (Ovis canadensis) populations vary in size and management history, the species provides a unique opportunity to observe the response of average pairwise kinship, inversely related to genetic diversity, to a spectrum of natural and management influences. We estimated average pairwise kinship of bighorn sheep herds and compared estimates with population origin (native/indigenous/extant or reintroduced), historical minimum count, connectivity, and augmentation history, to determine which predictors were the most important. We evaluated 488 bighorn sheep from 19 wild populations with past minimum counts of 16–562 animals, including native and reintroduced populations that received 0–165 animals in augmentations. Using the Illumina High Density Ovine array, we generated a dataset of 7728 single nucleotide polymorphisms and calculated average pairwise kinship for each population. Multiple linear regression analysis determined that connectivity between populations via dispersal, greater number of animals received in augmentations, and greater minimum count were correlated with lower average pairwise kinship at the population level, and whether the population was extant or reintroduced was less important. Thus, our results indicated that genetic isolation of populations can result in increased levels of inbreeding. By determining that natural and human‐assisted gene flow were likely the most important influences of average pairwise kinship at the population level, this study can serve as a benchmark for future management of bighorn sheep populations and aid in identifying populations of genetic concern to define priorities for conservation of wild populations.

Functionally distinct T-helper cell phenotypes predict resistance to different types of parasites in a wild mammal

The adaptive immune system is critical to an effective response to infection in vertebrates, with T-helper (Th) cells pivotal in orchestrating these responses. In natural populations where co-infections are the norm, different Th responses are likely to play an important role in maintaining host health and fitness, a relationship which remains poorly understood in wild animals. In this study, we characterised variation in functionally distinct Th responses in a wild population of Soay sheep by enumerating cells expressing Th-subset specific transcription factors and quantifying Th-associated cytokines. We tested the prediction that raised Th1 and Th2 responses should predict reduced apicomplexan and helminth parasite burdens, respectively. All measures of Th-associated cytokine production increased with age, while Th17- and regulatory Th-associated cytokine production increased more rapidly with age in males than females. Independent of age, sex, and each other, IL-4 and Gata3 negatively predicted gastro-intestinal nematode faecal egg count, while IFN-γ negatively predicted coccidian faecal oocyst count. Our results provide important support from outside the laboratory that Th1 and Th2 responses predict resistance to different kinds of parasites, and illustrate how harnessing specific reagents and tools from laboratory immunology will illuminate our understanding of host-parasite interactions in the wild.

Comparative evaluation of different animal models for genetic analysis of body weight traits in an organized Corriedale sheep population

The present study aimed to evaluate different animal models for their appropriateness to best fit the body weight data of Corriedale lambs at different ages and reared under temperate conditions. Data used in this study consisted of 24,907 body weight records on a total of 6162 lambs of Corriedale sheep population. The data pertained to body weight traits at different ages i.e., at birth (BW), weaning (WW), six months (SW), nine months (NW) and yearling age (YW). The (co)variance components of five traits were estimated using univariate analysis based on restricted maximum likelihood (REML) algorithm in WOMBAT program. Six different univariate animal models, with or without maternal genetic effect, maternal permanent environment effect and covariance between additive genetic and maternal genetic effects, were fitted on the body weight data of the Corriedale sheep population. All univariate animal models incorporated season (winter, spring) and period of lambing (8 periods, each of 5-year duration), and sex of lamb (male, female) as fixed effects. AIC, Log-likelihood and likelihood ratio test results were used to evaluate the best fit models for body weights at different ages. Model I, incorporating additive genetic effect of the individual as random effect, showed the minimum AIC estimate for BW. Model III showed the minimum AIC values for all other traits under consideration i.e., WW, SW, NW and YW. The direct additive genetic heritability for birth weight was 0.025 under the best fit model i.e., model I. The direct heritability estimates for WW, SW, NW and YW were 0.151, 0.216, 0.103 and 0.132, respectively under the best-fit models. Maternal genetic heritability ranged from 0.043 to 0.087 for different body weights, except BW for which model I was the best-fit. Most of the covariance and correlation estimates between direct additive genetic and maternal genetic effects were negative. Low estimates of heritability found in best-fit models in this research are suggestive of the less appropriateness of applying individual selection for this population as it may only result in slow progress for body weight traits in Corriedale sheep. Environmental factors played a significant role in generating the variation in body weight traits in Corriedale sheep.

Spatial ecology of female bighorn sheep in a prairie landscape in Nebraska

AbstractUnderstanding the spatial ecology of small populations at the periphery of their range is important for identifying factors limiting population growth and developing sound management strategies. Bighorn sheep were reintroduced to Nebraska in 1981 and persist in a small population at the easternmost extent of the distribution of the species, where 1 of the 2 subpopulations is declining. Bighorn sheep space use and movement has been studied extensively in mountain and desert populations, but information is sparse from prairie populations in the Northern Great Plains. We investigated the spatial ecology of female bighorn sheep in Nebraska, USA, with global positioning system (GPS) telemetry. We tested the hypothesis that space use and movements would vary across seasons, years, and individuals but predicted that migration would involve relatively short distances in this translocated population (relative to native populations) occupying a fragmented landscape. Overall, females used smaller seasonal home ranges (3.3–7.8 km2) than most of those reported previously for the species and exhibited a high degree of variability in space use and movements across seasons, subpopulations, and individuals. Most females (92–100%) exhibited fidelity to their home ranges across seasons and years. Six females migrated between spatially distinct core lambing and winter ranges, although the distances (range = 7.9–8.7 km) and mean elevations (range = 31–41 m) between these core seasonal ranges were less than those reported for most native, migratory bighorn sheep populations. After accounting for variation in season, subpopulation, and years, home range size was positively associated with road density in both subpopulations (P &lt; 0.001), suggesting that females incur greater energetic costs associated with greater space use in areas of higher fragmentation. Our results establish the basic spatial ecology of female bighorn sheep in Nebraska where their behavior appears to reflect the isolated nature of suitable habitat in this fragmented prairie landscape.

Dynamics of livestock population in Himachal Pradesh

An attempt has been made to analyse the trends in livestock population in Himachal Pradesh in last two decades. Minor livestock species like Yak, Pig, Horse, Mule, Donkey and Camel population was excluded from the study as their all combined population accounted for only 1% of the total livestock population in the state in the 20th livestock census. The percent growth rates were calculated for all inter census period from 1997 to 2019. The study concluded that total livestock population in Himachal Pradesh has shown negative trend over the years 1997-2019. Except for the 190.2 % growth of crossbred/ exotic cattle population in the state, all other including Indigenous cattle, Buffalo, sheep and goat population has shown negative growth in the mentioned period i.e. 1997-2019. The recent census has recorded negative growth rate for all livestock species excluding crossbred cattle.

Association of SNPs within PTPN3 gene with wool production and growth traits in a dual-purpose sheep population

Protein tyrosine phosphatase non-receptor type 3 (PTPN3), a member of the membrane-associated non-receptor protein tyrosine phosphatase (PTP) family, plays significant roles in the cytoplasm and affects the development and growth of skin and hair. A recent study identified the PTPN3 as the potential gene related to sheep wool quality. To detect single-nucleotide polymorphisms (SNPs) of PTPN3 and elucidate its association with wool production and growth traits in fine wool sheep a total of 644 healthy SG (South African mutton merino♂ × Gansu alpine fine-wool sheep♀, SG) and SSG (South African mutton merino♂ × SG♀, SSG) hybrid sheep were selected. Pooled-DNA sequencing and SNPscan methods were used to scan and genotype SNPs within PTPN3. Association analyses between SNPs and wool production and growth traits were implemented. Consequently, the results revealed that PTPN3 has six SNPs (two missense mutations, one synonymous mutation, and three intron mutations), of which four loci (SNP2, SNP3, SNP4, and SNP5) were significantly positively correlated with growth and wool traits (p < 0.05). SNP4 was significantly (p < 0.05) linked with thigh wool length, and SNP6 was significantly (p < 0.05) associated with abdomen wool length. Moreover, one strongly linked SNP block was identified to be correlated with wool production and growth traits (body weight and body size). The significant SNPs founded by this study could serve as useful genetic markers for breeding fine-wool sheep.®