Preliminary outcomes on phenotypic and genetic parameter estimates for body weight of indigenous Tswana goats in Botswana.

The aims of this study were to estimate the genetic and phenotypic parameters for growth traits and evaluate genetic trends on 585 indigenous Tswana goats. The population was maintained under low input production system at the Department of Agricultural Research in Lesego ranch, Botswana, from 2005 to 2008. Data included birth weight (BW), weaning weight (WW), weight at 8 months (PW), yearling weight (YW), pre-weaning average daily gain (ADG) and two post weaning average daily gains (ADG2 and ADGYW). Data was analysed using general linear model of SAS to determine non-genetic effects. Estimation of genetic and phenotypic parameters were estimated using ASREML fitting an animal model that accounted for fixed effect of parity, sex, type of birth and year of birth. Least squares means for BW, WW, PW and YW were 2.88 ± 0.03, 12.15 ± 0.17, 16.52 ± 0.28 and 21.04 ± 0.32Kg, respectively, while those for ADG, ADG2 and ADGYW were 74.52 ± 1.41, 28.78 ± 1.55 and 33.66 ± 2.28 g/day, respectively. Estimates of heritability for BW, WW, PW and YW were 0.79 ± 0.11, 0.63 ± 0.14, 0.32 ± 0.13 and 0.48 ± 0.16, respectively. The genetic correlations for all the traits studied were positive and moderate to high (0.48 to 0.82) whilst phenotypic correlations ranged from 0.21 to 0.72. Positive average genetic trends of 12.32% (WW), 13.39% (PW) and 7.38% (YW) were attained. The results have demonstrated the potential of this breed to be improved through selection.

Effect of birth type and sex on growth performance, wither height, humerus-radius bone dimensions, humerus-ulna growth plate width and selected hormone profile in growing Gurcu goat kids.

OBJECTIVES: In this study, the effects of sex and birth type on growth performance, withers height (WH), radiographic measurements and selected hormone profiles in Gurcu goat kids were investigated. METHODS: Twenty kids (single female = 5, single male = 5, twin female = 5, twin male = 5) were included in the study. Body weight (BW), WH, radiographic measurements (humerus length [HL], radius length [RL], proximal humerus epiphyseal plate width [HEP] and distal ulna epiphyseal plate width [UEP]) and biochemical analysis (for serum calcitonin, free triiodothyronine [FT3], free thyroxine [FT4], growth hormone [GH] and insulin-like growth factor-I [IGF-I]) were performed at 1, 3, 5, 7, 9 and 12 months of age. RESULTS: BW was significantly higher in males starting from the seventh month compared to females (p < 0.05). HL was higher in males at seventh (p = 0.009) and ninth (p = 0.033) months, whereas RL was lower in twins at the third month (p = 0.021). UEP was wider in males at seventh (p = 0.008) and ninth (p = 0.036) months. Closure of HEP was observed in 65% of kids by the 12th month. Calcitonin was lower in twins at third (p = 0.045) and fifth (p = 0.006) months, with changes observed due to group and time effects (p < 0.05), whereas other hormones only changed with time (p < 0.05). Positive correlations were observed between BW, WH, HL, RL and IGF-I. There was a negative correlation between BW, WH, HL, RL, IGF-I and HEP, UEP, calcitonin, FT3, FT4, GH. CONCLUSION: Sex and birth type in Gurcu goat kids may have an impact on growth performance, radiographic measurements and certain hormonal profiles.

Effects of drinking saline water on carcass traits and meat quality of growing and mature Blackhead Ogaden sheep and Somali goats.

Water salinity has a significant impact on water quality, posing challenges for livestock production and productivity, particularly in arid regions where climate change affects freshwater availability. This study aimed to determine the effect of drinking saline water on the carcass and meat quality traits of sheep and goats in Ethiopia. A total of 100 males with an average initial body weight of growing (18.17 ± 0.51) and mature (22.22 ± 0.52 kg) Blackhead Ogaden sheep and growing (17.99 ± 0.50) and mature (21.99 ± 0.54) kg) Somali goats were used. The design of the experiment was a three-way factorial RCBD with three-factor combinations (5 treatment levels, 2 species, and 2 age groups).Water treatments were natural water (Lake Basaka water (control), low saline water (L-SW), moderate saline water (M-SW), high saline water (H-SW), and very high saline water (VH-SW); that is, NaCl was added to natural water at concentrations of 7.95, 11.93, 15.90, and 19.88 g TDS/L, respectively. The finding showed that increasing salinity levels in drinking water reduced slaughter body weight (SBW), carcass weight (CW), dressing percentage (DP), rib eye area (RAE), total edible components (TEC), and increased total non-edible components (TNEC) (P < 0.05). Similarly, sheep and mature animals had higher (P < 0.001) SBW, CW, DP, RAE, and TEC than goats and growing animals. Sensory evaluation, shear force, and proximate analysis were affected by water salinity, species, and age groups (P < 0.05). Overall, the study revealed that consuming saline water above 11 g TDS/L affected carcass traits and meat quality in Somali goats and Blackhead Ogaden sheep.

Machine learning-based early prediction of growth and morphological traits at yearling age in pure and hybrid goat offspring.

The purpose of this study was to evaluate the performance of various prediction models in estimating the growth and morphological traits of pure Hair, Alpine × Hair F1 (AHF1), and Saanen × Hair F1 (SHF1) hybrid offspring at yearling age by employing early body measurement records from birth till 9th month combined with meteorological data, in an extensive natural pasture-based system. The study also included other factors such as sex, farm, doe and buck IDs, birth type, gestation length, age of the doe at birth etc. For this purpose, seven different machine learning algorithms-linear regression, artificial neural network (ANN), support vector machines (SVM), decision tree, random forest, extra gradient boosting (XGB) and ExtraTree - were applied to the data coming from 1530 goat offspring in Türkiye. Early predictions of growth and morphological traits at yearling age; such as live weight (LW), body length (BL), wither height (WH), rump height (RH), rump width (RW), leg circumference (LC), shinbone girth (SG), chest width (CW), chest girth (CG) and chest depth (CD) were performed by using birth date measurements only, up to month-3, month-6 and month-9 records. Satisfactory predictive performances were achieved once the records after 6th month were used. In extensive natural pasture-based systems, this approach may serve as an effective indirect selection method for breeders. Using month-9 records, the predictions were improved, where LW and BL were found with the highest performance in terms of coefficient of determination (R2 score of 0.81 ± 0.00) by ExtraTree. As one of the rarely applied machine learning models in animal studies, we have shown the capacity of this algorithm. Overall, the current study offers utilization of the meteorological data combined with animal records by machine learning models as an alternative decision-making tool for goat farming.

Metabolomic and Transcriptomic Analyses Reveal the Potential Mechanisms of Dynamic Ovarian Development in Goats during Sexual Maturation.

The ovary is a crucial reproductive organ in mammals, and its development directly influences an individual's sexual maturity and reproductive capacity. To comprehensively describe ovarian sexual maturation in goats, we integrated phenotypic, hormonal, metabolomic, and transcriptomic data from four specific time points: after birth (D1), at 2 months old (M2), at 4 months old (M4), and at 6 month old (M6). The study showed that during the early stage (D1-M2), ovarian growth was the most rapid, with weight and morphology increasing by 284% and 65%, respectively, and hormone levels rose significantly, with estradiol increasing by 57%. Metabolomic analysis identified 1231 metabolites, primarily lipids, lipid molecules, and organic acids, which can support hormone balance and follicle development by providing energy and participating in signaling transduction. Transcriptomic analysis identified 543 stage-specific differentially expressed genes, mainly enriched in steroid biosynthesis, amino acid metabolism, and the PI3K/AKT pathway, which are key factors influencing ovarian cell proliferation, apoptosis, hormone secretion, and metabolism. The integrated analysis revealed the key processes in the ovarian steroid hormone biosynthesis pathway and gene/metabolite networks associated with ovarian phenotypes and hormone levels, ultimately highlighting scavenger receptor class B type 1 (SCARB1), Cytochrome P450 Family 1 Subfamily A Member 1 (CYP11A1), 3beta-hydroxysteroid dehydrogenase (3BHSD), progesterone, estradiol, and L-phenylalanine as key regulators of ovarian morphological and functional changes at different developmental stages. This study is the first to reveal the metabolic changes and molecular regulatory mechanisms during ovarian sexual maturation in goats, providing valuable insights for understanding reproductive system development and optimizing reproductive performance and breeding efficiency.

Effects of prenatal fish oil supplementation on the development and performance of female kids after weaning.

This study was performed to determine the influence of fish oil, an omega-3 fatty acids source, supplemented to diets of goats throughout all stages of gestation on the growth and milk production of weaned female kids. Eighty German Fawn (75%) x Hair (25%) crossbred goats were randomly assigned to treatment (fish oil, FiO group) and control (Rumen protected fat, RPF group) groups during the first half of pregnancy. Subsequently, the FiO group was further allocated into FiO-FiO and FiO-RPF subgroups and RPF group was further divided into RPF-FiO and RPF-RPF subgroups containing 20 goats in each during the second half of pregnancy. The growth and feed intake of 41 female kids (aged 75.1 ± 6.73 days, with a mean live weight of 11.6 ± 3.00 kg) were recorded for a 98 day post-weaning, In the continuation of the study, live weight changes, milk yield and composition of young female goats from mating to the second month of lactation and the growth of female kids until weaning were studied for a total of 210 days. Maternal nutrition slightly influenced the live weight gain of female kids over a 98-day investigation period (p = 0.070). When growth performance was considered, a higher feed conversion efficiency of female offspring was determined in RPF-FiO (5.52) treatment group compare to female kids in other treatment groups (p = 0.086). However, the maternal feeding system significantly affected live weight in the RPF-FiO treatment group during the mating period (P = 0.054). Concerning the feed intake, maternal nutrition significantly affected the feed intake of female kids (p < 0.01) with the highest feed consumption in the FiO-RPF group. The findings of this study have shown that fish oil enriched diet given to goats during gestation improved daily live weight changes and total live weight gain of female kids despite the initial disadvantage after weaning. At mating time, the live weight of young female goats in the RPF-FiO treatment group, which exhibited the highest feed conversion ratio during the 98-day study, was higher than the remaining treatment groups. Maternal nutrition had no effect on milk yield or milk components in young goats during lactation. Young female goats born to dams in the FiO-RPF group showed better performance than the other groups regarding live weight performance of their offspring on 56th day postpartum.

The Transcriptome Characterization of the Hypothalamus and the Identification of Key Genes during Sexual Maturation in Goats.

Sexual maturation in goats is a dynamic process regulated precisely by the hypothalamic-pituitary-gonadal axis and is essential for reproduction. The hypothalamus plays a crucial role in this process and is the control center of the reproductive activity. It is significant to study the molecular mechanisms in the hypothalamus regulating sexual maturation in goats. We analyzed the serum hormone profiles and hypothalamic mRNA expression profiles of female goats during sexual development (1 day old (neonatal, D1, n = 5), 2 months old (prepuberty, M2, n = 5), 4 months old (sexual maturity, M4, n = 5), and 6 months old (breeding period, M6, n = 5)). The results indicated that from D1 to M6, serum hormone levels, including FSH, LH, progesterone, estradiol, IGF1, and leptin, exhibited an initial increase followed by a decline, peaking at M4. Furthermore, we identified a total of 508 differentially expressed genes in the hypothalamus, with a total of four distinct expression patterns. Nuclear receptor subfamily 1, group D, member 1 (NR1D1), glucagon-like peptide 1 receptor (GLP1R), and gonadotropin-releasing hormone 1 (GnRH-1) may contribute to hormone secretion, energy metabolism, and signal transduction during goat sexual maturation via circadian rhythm regulation, ECM receptor interactions, neuroactive ligand-receptor interactions, and Wnt signaling pathways. This investigation offers novel insights into the molecular mechanisms governing the hypothalamic regulation of goat sexual maturation.

Role of Csdc2 in Regulating Secondary Hair Follicle Growth in Cashmere Goats.

Cashmere goats possess two types of hair follicles, with the secondary hair follicles producing valuable cashmere fiber used for textiles. The growth of cashmere exhibits a seasonal pattern arising from photoperiod change. Transcription factors play crucial roles during this process. The transcription factor, cold-shock domain, containing C2 (Csdc2) plays a crucial role in modulating cell proliferation and differentiation. Our preceding research indicated that the expression of Csdc2 changes periodically during anagen to telogen. However, the mechanisms of Csdc2 in regulating SHF growth remain unclear. Here, we found that the knockdown of Csdc2 inhibits the proliferation of dermal papilla cells. ChIP-Seq analysis showed that Csdc2 had a unique DNA binding motif in SHFs. Through conjoint analysis of ChIP-Seq and RNA-Seq, we revealed a total of 25 candidate target genes of Csdc2. Notably, we discovered a putative Csdc2 binding site within roundabout guidance receptor 2 (Robo2) on chromosome 1 of the goat genome. Furthermore, qRT-PCR and dual-luciferase reporter assay confirmed Csdc2's positive regulatory influence on Robo2. These findings expand the research field of hair follicle transcriptional regulatory networks, offering insights into molecular breeding strategies to enhance cashmere production in goats.

Genome-wide association study of growth and reproductive traits based on low-coverage whole-genome sequencing in a Chubao black-head goat population.

The Chubao black-head goat is a novel hybrid breed that combines the advantages of Macheng black goats, such as good reproductive performance, strong adaptability, and resistance to rough feeding, with the superior growth and meat characteristics of Boer goats. Given the substantial economic importance of growth (such as birth weight, body height, body length, and chest circumference across different growth stages) and reproductive traits (particularly average litter size after first parity), the aim of this study was to identify significant SNPs and candidate genes associated with these traits in Chubao black-head goats. Through whole-genome sequencing (with 34 goats at approximately 15× coverage and 466 goats at approximately 1× coverage), genotype imputation, and quality control, 22,665,331 SNPs were identified and subsequently used for genetic analyses. Heritability estimates indicated that growth traits exhibit moderate to high heritability (ranging from 0.297 ± 0.071 to 0.535 ± 0.118), while reproductive traits demonstrated low to moderate heritability (with a value of 0.220 ± 0.108). By performing FarmCPU-based genome-wide association studies, we identified 48 potentially significant SNPs associated with growth traits and 7 with reproductive traits. Additionally, 85 candidate genes (such as COL14A1, ZNF148, and TTC39C) linked to growth traits were identified and enriched in pathways associated with fundamental molecular biological activities such as protein deubiquitination, regulation of mRNA stability, and the MAPK signaling pathway. Furthermore, 10 candidate genes (such as SOHLH2, CCNA2, and SOX7) associated with reproductive traits were identified and enriched in pathways related to specific reproductive processes such as oocyte differentiation, endoderm formation, and progesterone-mediated oocyte maturation. Overall, these findings provide valuable preliminary insights into the molecular mechanisms underlying growth and reproductive traits in Chubao black-head goats. However, further functional validation is needed to effectively use these potential SNPs and candidate genes in improving the breeding of these traits in this breed.

Genome-wide association study for cashmere traits in Inner Mongolia cashmere goat population reveals new candidate genes and haplotypes.

BACKGROUND: The cashmere goat industry is one of the main pillars of animal husbandry in Inner Mongolia Autonomous Region, and plays an irreplaceable role in local economic development. With the change in feeding methods and environment, the cashmere produced by Inner Mongolia cashmere goats shows a tendency of coarser, and the cashmere yield can not meet the consumption demand of people. However, the genetic basis behind these changes is not fully understood. We measured cashmere traits, including cashmere yield (CY), cashmere diameter (CD), cashmere thickness (CT), and fleece length (FL) traits for four consecutive years, and utilized Genome-wide association study of four cashmere traits in Inner Mongolia cashmere goats was carried out using new genomics tools to infer genomic regions and functional loci associated with cashmere traits and to construct haplotypes that significantly affect cashmere traits. RESULTS: We estimated the genetic parameters of cashmere traits in Inner Mongolia cashmere goats. The heritability of cashmere yield, cashmere diameter, and fleece length traits of Inner Mongolia cashmere goats were 0.229, 0.359, and 0.250, which belonged to the medium heritability traits (0.2 ~ 0.4). The cashmere thickness trait has a low heritability of 0.053. We detected 151 genome-wide significantly associated SNPs with four cashmere traits on different chromosomes, which were very close to the chromosomes of 392 genes (located within the gene or within ± 500 kb). Notch3, BMPR1B, and CCNA2 have direct functional associations with fibroblasts and follicle stem cells, which play important roles in hair follicle growth and development. Based on GO functional annotation and KEGG enrichment analysis, potential candidate genes were associated with pathways of hair follicle genesis and development (Notch, P13K-Akt, TGF-beta, Cell cycle, Wnt, MAPK). We calculated the effective allele number of the Inner Mongolia cashmere goat population to be 1.109-1.998, the dominant genotypes of most SNPs were wild-type, the polymorphic information content of 57 SNPs were low polymorphism (0 < PIC < 0.25), and the polymorphic information content of 79 SNPs were moderate polymorphism (0.25 < PIC < 0.50). We analyzed the association of SNPs with phenotypes and found that the homozygous mutant type of SNP1 and SNP3 was associated with the highest cashmere yield, the heterozygous mutant type of SNP30 was associated with the lowest cashmere thickness, the wild type of SNP76, SNP77, SNP78, SNP80, and SNP81 was associated with the highest cashmere thickness, and the wild type type of SNP137 was associated with the highest fleece length. 21 haplotype blocks and 68 haplotype combinations were constructed. Haplotypes A2A2, B2B2, C2C2, and D4D4 were associated with increased cashmere yield, haplotypes E2E2, F1F1, G5G5, and G1G5 were associated with decreased cashmere fineness, haplotypes H2H2 was associated with increased cashmere thickness, haplotypes I1I1, I1I2, J1J4, L5L3, N3N2, N3N3, O2O1, P2P2, and Q3Q3 were associated with increased cashmere length. We verified the polymorphism of 8 SNPs by KASP, and found that chr7_g.102631194A > G, chr10_g.82715068 T > C, chr1_g.124483769C > T, chr24_g.12811352C > T, chr6_g.114111249A > G, and chr6_g.115606026 T > C were significantly genotyped in verified populations (P < 0.05). CONCLUSIONS: In conclusion, the genetic effect of single SNP on phenotypes is small, and SNPs are more inclined to be inherited as a whole. By constructing haplotypes from SNPs that are significantly associated with cashmere traits, it will help to reveal the complex and potential causal variations in cashmere traits of Inner Mongolia cashmere goats. This will be a valuable resource for genomics and breeding of the cashmere goat.

Prediction of carcass weight using the morphometry of ankle bones in hair goats.

BACGROUND: Morphologic measurements such as body lenght, wither height, heart girth, chest width, body leght, cannon-bone circumference is used to predict carcass weight. For this purpose, estimating carcass weight with measurements of key bones such as ankle bones, which play a significant role in the balance distribution of body weight, seems possible. OBJECTIVES: The aim of this study is to create new regression models for effective carcass weight estimation by using the morphometric data of the talus and calcaneus bones of hair goats. METHODS: Study materials consisted of talus and calcaneus bones obtained from abattoir products of hair goat kids (12-18 months old, 20 female and 20 male) and adult hair goats (36-48 months old, 20 female and 20 male). Morphometric measurements of the talus and calcaneus of each animal were taken by a digital caliper. Using the morphometric measurements, an index and a factor were calculated for each bone. Regression analysis and correlations were examined in IBM SPSS 21 programme. RESULTS: As a result, statistical analysis of GLc, GLt, Bd, Calfactor and Talfactor were statistically significant on predicting carcass weight. CONCLUSION: Specific anatomical structures, such as certain bone measurements, such as talus and calnaneus could serve as indicators of growth performance and also carcass weight performance. In addition new anatomical factors and indices may be produced and new regression methods may be applied with these new parameters to predict carcass weight.

Genetic analysis of efficiency-related traits in Boer x Central Highland goats.

This study aimed to identify important non-genetic factors and estimate genetic parameters for efficiency-related traits in Boer x Central Highland goats. The genetic parameters were estimated using the Average Information Restricted Maximum Likelihood algorithm using the WOMBAT program fitting animal model. The least-squares means for growth efficiency from birth to 3 months (GE1), 3-6 months (GE2), 6-12 months (GE3), relative growth rate from birth to 3 months (RGR1), 3-6 months (RGR2) and 6-12 month (RGR3) were 294.0 ± 5.06, 36.6 ± 1.20, 44.9 ± 1.81, 1.46 ± 0.01, 0.32 ± 0.01 and 0.19 ± 0.01, respectively. Birth type, blood level, sex of the kid, and year of kidding had a sizable effect on efficiency-related traits. About 18, 3.0, 23, 20, and 12% of the phenotypic variation in GE2, GE3, RGR1, RGR2, and RGR3 was explained by the direct additive genetic effect. Except for RGR3, all investigated traits were under the influence of maternal genetic effect, and maternal heritability ranged from 0.09 to 0.17. The total heritability estimate depicts that slow genetic progress would be expected from selection. Nevertheless, even with this level of heritability, selection for efficiency-related traits would improve the efficiency of chevon production as these traits are economically important traits. Nearly six-months of age was when farmers sold Boer crossbred goats. Therefore, improving the growth efficiency till the marketing age (GE2) in such a scenario could increase the production efficiency.

Review: Update of nutritional requirements of goats for growth and pregnancy in hot environments.

Goats play an important role in the agricultural business, providing valuable income sources through producing high-quality animal protein. They are widespread livestock for rural households due to their inherent resiliency, adaptability to many environments, and suitability in sustainable production systems. While goats are reared in highly diverse environments, a great portion of their population is reared in hot environments. Heat stress is known to affect goats' productive and reproductive performance negatively. However, goats can remarkably thrive in harsh conditions due to physiological, metabolic, and molecular adaptive mechanisms. In the face of it, in the last decades, the nutrition of goats, particularly their nutritional requirements, has received special attention. Research groups worldwide have dedicated their efforts to updating feeding systems for goats. Our objective was to present the recent findings on the energy and nutrient requirements of growing and pregnant goats in hot environments. Energy and protein requirements for the maintenance and growth of goats are influenced by sex and genotype only when mature weight is not considered in the models. Sex and genotype affect the efficiency of energy use for growth but do not affect the efficiency of protein use. Major mineral requirements for maintenance and growth are not affected by sex, except for magnesium. However, the phosphorus, sodium, and potassium requirements of goats raised in hot environments differ from those in the feeding systems. This difference may be related to the adaptation mechanisms goats employ to cope with the hot environmental conditions. Regarding requirements for pregnancy, there was no effect of days of pregnancy on the energy or protein requirements. The efficiency of metabolizable energy utilization for pregnancy increased with the progress of pregnancy. Mineral accretion for pregnancy differs between single and twin pregnancies and, irrespective of pregnancy type, the mineral requirements increase as pregnancy progresses. The differences between the estimated dietary requirements of goats raised in hot environments and the most widely adopted feeding systems suggest that these goats may be using energy and nutrients to cope with heat stress and other stressors associated with hot environments. The recent findings on energy, protein, and mineral requirements of growing and pregnant goats can be an important resource of information for enhancing feeding systems worldwide.

Impacts of thyme and/or garlic oils on growth, immunity, antioxidant and net farm income in Damascus goats.

This study aimed to evaluate the impact of thyme and/or garlic oil administration on growth performance, immunity, antioxidant, biochemical parameters, and net farm income of Damascus goats. Forty weaned Damascus goats were allocated into four groups. The first group was the control without oral administration, while the 2nd (Th), 3rd (Gr), and 4th (ThGr) groups were orally administrated by (2 ml/goat/day) of thyme oil, garlic oil and their mixture (1:1), respectively during the whole experiment period. The final body weight of goats orally administered oil mixture was the heaviest group, it was 10, 4.5 and 3.5% than the control, Th. and Gr. groups, respectively with better feed conversion ratio and high net farm income. Goats of ThGr. group revealed the best immunity, antioxidant and general health condition than the control group with 50% reduction of MDA. Liver (AST, 33% and ALT, 38%) and kidney (creatinine, 88%) functions improved by oils mixtures orally administration compared with the control group. LDL, triglyceride and cholesterol were reduced by 47, 33 and 21% compared with the control group, respectively. Thus, mixture oil administration (thyme and garlic at the ratio of 1:1, 2 ml/goat/day) improved growth (10%), antioxidant status (MDA 50%), liver (AST, 33% and ALT, 38%), kidney function (creatinine, 88%), the FCR (17.4%) and net farm income (21%), of Damascus goats.

Identification of FASN Gene Polymorphisms, Expression and Their Relationship with Body Size Traits in Guizhou White Goat (Capra hircus) with Different Genders.

To investigate the nucleotide variation sites (SNPs) and expression differences of the fatty acid synthase gene (FASN) in Guizhou white goats, the relationship between the variation and body size traits was investigated. In this study, DNA was extracted from the blood of 100 samples of white goats from different regions in Guizhou province, China, and the variation sites were screened using pooled sequencing by mixing DNA samples, and 242 blood samples with body size traits were used for association analysis. The allele frequency, genotype frequency, homozygosity, heterozygosity and effective gene number were calculated by using PopGene 32.0 software, the population polymorphism information content was calculated by using PIC software (Version 0.6), and the state of genetic balance of the genes was analyzed by using the chi-square test. The mRNA of FASN gene expression levels in male and female goats were investigated by using real-time fluorescence quantitative PCR (RT-qPCR). The general linear mixed model of MINTAB software (Version 16.0) was used to analyze the association between FASN gene nucleotide mutation sites and body size traits. The results showed that there was one nucleotide mutation site g.141 C/T in the target fragment of FASN gene amplification, and revealed two alleles, C and T, and three genotypes CC, CT and TT. The genotype frequencies for CC, CT and TT were 0.4308, 0.4205 and 0.1487, respectively. The allele frequencies for C and T were 0.6410 and 0.3590, respectively. The genetic homozygosity (Ho) was higher than the heterozygosity (He). The χ2 test showed that the mutation site was in the Hardy-Weinberg equilibrium state (p > 0.05). The RT-qPCR results showed that the FASN gene had different expression levels in the longissimus dorsi muscle of male and female goats, and its expression was significantly higher in male goats than in female goats. The association analysis results showed that the mutation of the FASN gene had different effects on body size traits of male and female goats, and the presence of the populations of the T allele and the TT genotype recorded higher body size traits (body weight, heart girth and wither height) in female populations. Therefore, the site of the FASN gene can be used as a candidate marker for the early selection of growth traits in Guizhou white goats.

Comparison of genomic prediction methods for early growth traits of Inner Mongolia cashmere goats based on multi trait models.

Inner Mongolia cashmere goat is an excellent livestock breed formed through long-term natural selection and artificial breeding, and is currently a world-class dual-purpose breed producing cashmere and meat. Multi trait animal model is considered to significantly improve the accuracy of genetic evaluation in livestock and poultry, enabling indirect selection between traits. In this study, the pedigree, genotype, environment, and phenotypic records of early growth traits of Inner Mongolia cashmere goats were used to build multi trait animal model., Then three methods including ABLUP, GBLUP, and ssGBLUP wereused to estimate the genetic parameters and genomic breeding values of early growth traits (birth weight, weaning weight, average daily weight gain before weaning, and yearling weight). The accuracy and reliability of genomic estimated breeding value are further evaluated using the five fold cross validation method. The results showed that the heritability of birth weight estimated by three methods was 0.13-0.15, the heritability of weaning weight was 0.13-0.20, heritability of daily weight gain before weaning was 0.11-0.14, and the heritability of yearling weight was 0.09-0.14, all of which belonged to moderate to low heritability. There is a strong positive genetic correlation between weaning weight and daily weight gain before weaning, daily weight gain before weaning and yearling weight, with correlation coefficients of 0.77-0.79 and 0.56-0.67, respectively. The same pattern was found in phenotype correlation among traits. The accuracy of the estimated breeding values by ABLUP, GBLUP, and ssGBLUP methods for birth weight is 0.5047, 0.6694, and 0.7156, respectively; the weaning weight is 0.6207, 0.6456, and 0.7254, respectively; the daily weight gain before weaning was 0.6110, 0.6855, and 0.7357 respectively; and the yearling weight was 0.6209, 0.7155, and 0.7756, respectively. In summary, the early growth traits of Inner Mongolia cashmere goats belong to moderate to low heritability, and the speed of genetic improvement is relatively slow. The genetic improvement of other growth traits can be achieved through the selection of weaning weight. The ssGBLUP method has the highest accuracy and reliability in estimating genomic breeding value of early growth traits in Inner Mongolia cashmere goats, and is significantly higher than that from ABLUP method, indicating that it is the best method for genomic breeding of early growth weight in Inner Mongolia cashmere goats.

Application of growth models to South African Boer goat castrates and does under feedlot conditions.

Mathematical models may aid researchers in describing biological processes, like growth, in animals. This study aimed to collect the body weight data of 18 Boer goat castrates and 20 Boer goat does, from birth until maturity, to model growth and determine growth trends. This is a novel investigation as sufficient information on an age-weight database for these two Boer goat sexes from birth to maturity, is lacking. Using age-weight data, four nonlinear models, namely the Brody, Gompertz, Logistic and Von Bertalanffy growth models, were plotted and evaluated. The model parameters of each growth model were compared for differences between the two sexes. The statistical effectiveness of fit was determined for each model using AIC and RMSE, with R2 also being considered. All models except the Brody model, predicted significantly heavier mature weights for castrates. The Brody model was deemed unfit to describe Boer goat growth as the function severely over-predict weights from birth until maturity for both sexes. The Von Bertalanffy (R2 = 91.3) and Gompertz functions (R2 = 91.3) showed the best fit for Boer goat castrates, while the Gompertz model (R2 = 95.1) showed the best fit for Boer goat does. The Gompertz function is the preferred model to depict Boer goat growth overall, as it accurately characterized growth of both sexes. According to the Gompertz model the age at which the inflection point of the growth curve was reached, did not differ significantly between castrates and does (141.80 days versus 136.31 days). There was also no significant difference in maturation rate between the two sexes.

Transcriptome analysis of mRNA and miRNA in the development of LeiZhou goat muscles.

The progression of muscle development is a pivotal aspect of animal ontogenesis, where miRNA and mRNA exert substantial influence as prominent players. It is important to understand the molecular mechanisms involved in skeletal muscle development to enhance the quality and yield of meat produced by Leizhou goats. We employed RNA sequencing (RNA-SEQ) technology to generate miRNA-mRNA profiles in Leizhou goats, capturing their developmental progression at 0, 3, and 6 months of age. A total of 977 mRNAs and 174 miRNAs were found to be differentially expressed based on our analysis. Metabolic pathways, calcium signaling pathways, and amino acid synthesis and metabolism were found to be significantly enriched among the differentially expressed mRNA in the enrichment analysis. Meanwhile, we found that among these differentially expressed mRNA, some may be related to muscle development, such as MYL10, RYR3, and CSRP3. Additionally,, we identified five muscle-specific miRNAs (miR-127-3p, miR-133a-3p, miR-193b-3p, miR-365-3p, and miR-381) that consistently exhibited high expression levels across all three stages. These miRNAs work with their target genes (FHL3, SESN1, PACSIN3, LMCD1) to regulate muscle development. Taken together, our findings suggest that several miRNAs and mRNAs are involved in regulating muscle development and cell growth in goats. By uncovering the molecular mechanisms involved in muscle growth and development, these findings contribute valuable knowledge that can inform breeding strategies aimed at enhancing meat yield and quality in Leizhou goats.

The Identification of Goat KCNJ15 Gene Copy Number Variation and Its Association with Growth Traits.

(1) Background: Copy number variation (CNV) is a critical component of genome structural variation and has garnered significant attention. High-throughput screening of the KCNJ15 gene has revealed a correlation between the CNV region and the growth traits of goats. We aimed to identify the CNV of the KCNJ15 gene in five goat breeds and analyze its association with growth characteristics. (2) Methods: We utilized 706 goats from five breeds: Guizhou black goat (GZB), Guizhou white goat (GZW), Bohuai goat (BH), Huai goat (HH), and Taihang goat (TH). To evaluate the number of copies of the KCNJ15 gene using qPCR, we analyzed the correlation between the CNV and growth characteristics and then used a universal linear model. The findings revealed variations in the distribution of different copy number types among the different goat breeds. (3) Results: Association analysis revealed a positive influence of the CNV in the KCNJ15 gene on goat growth. In GZB, individuals with duplication types exhibited superior performance in terms of cannon bone circumference (p < 0.05). In HH, individuals with duplication types exhibited superior performance in terms of body slanting length (p < 0.05). Conversely, normal TH demonstrated better body height and body weight (p < 0.05), while in GZW, when CN = 3, it performed better than other types in terms of body weight and chest circumference (p < 0.05). However, in BH, it had no significant effect on growth traits. (4) Conclusions: We confirmed that the CNV in the KCNJ15 gene significantly influences the growth characteristics of four distinct goat breeds. The correlation between KCNJ15 gene CNVs and goat growth traits offers valuable insights to breeders, enabling them to employ precise and efficient breeding methods that enhance livestock welfare, productivity, and overall economic benefits in the industry.

Genome-wide detection of selective signals for fecundity traits in goats (Capra hircus).

Fecundity in livestock is an economically important complex quantitative trait that is influenced by both genetics and the environment. However, the underlying genetic mechanism of reproductive performance in goats has not been well investigated. To investigate the genomic basis of fecundity in goats, genomic sequencing data of the Jining grey goat (a high prolificacy breed in China) were collected, as well as data for other commonly available goat breeds, and a mass of genomic variants were generated after variation calling. We screened the Jining grey goat (20 individuals) using a selective sweep with the Asian wild goat population (5 individuals), and potential candidate genes were proposed, such as STIM1, ESR1, LRRC14B and SLC9A3. Among, STIM1 is a most promising one associated with high reproductive capacity. When compared to Chinese domestic goats with low fecundity (17 individuals), the genes including MLLT10, SPIRE2, TCF25, ZNF276 and FANCA were screened, and the SPIRE2 gene was thought to be associated with fecundity traits. Meanwhile, the functional enrichment of these candidate genes revealed that they were involved in biological processes of mammary gland morphogenesis, uterus development, gastrulation, mesoderm morphogenesis and formation, and blood vessel development, which might undergo natural or artificial selection during reproductive trait formation in goats. Thus, our findings could enrich the genetic basis of reproductive trait selection during goat domestication, which may serve to improve goat breeding practices.