Phenotypic Characterization and Reproductive Performance of Pallai Adu Goats of Tamil Nadu

The objectives were to describe the morphometric measurements and determine the best model for estimating the relationship between body weight and morphometric measurements of the two Sudanese antelopes, Dorcas Gazelle (Gazella dorcas) and Bohor Reedbuck (Redunca redunca). Twenty-four animals belonging to two Sudanese antelope species, six males and six females from each species were used. Data on body weight and body measurements were recorded from each species. Averages of body weight and morphometric traits of Bohor Reedbuck were larger than the corresponding values of Dorcas Gazelle, while the opposite was true in the case of horn thickness, which was larger in the later. Stepwise regression analysis indicated that, the best model for Dorcas Gazelle had the variables neck length, belly girth and chest height, while Bohor Reedbuck had body length, head length, neck length, tail length, chest girth and pelvic height. These variables explained 82% of the total variation in body weight of Dorcas Gazelle, and 92% of the variation of Bohor Reedbuck. These results are discussed in relation to morphometric measurements reported for antelopes elsewhere.

The study was conducted to characterize the husbandry practices, phenotypic characteristics and determination of live body weight using morphometrical measurements of indigenous sheep types under smallholder management condition in highlands of Gurage zone, Southern Ethiopia. Two districts, Gumer and Ejha were selected purposely based on sheep population distribution, flock size and their contribution to the farmers. Questionnaire survey was used to collect data from 156 households of smallholder farmers who own sheep. Qualitative trait, live body weight and body measurement were taken from a total of 402 indigenous sheep. Live body weights were also associated and predicted using linear body measurements. The mean flock size owned per household was 5.20 and 4.40 sheep at Gumer and Ejha district, respectively. In both districts generating income was the main purpose of sheep rearing followed by saving, meat consumption and manure. Natural pasture and crop residue were found to be the major sources of feed during wet and dry seasons. The main constraints of sheep production were feed scarcity, disease prevalence, market price fluctuation and water shortage. The overall mean age at first lambing and lambing interval were (13.8± 0.4) and (8.3± 0.15) months, respectively, while mean litter size was 1.5head. The majority of sheep were characterized by patchy color pattern and the combinations of brown and / or black and /or white color type which is locally called it “Gerebet”. The overall mean live body weight of male and female sheep was 28.3 and 23.4 kg, respectively. Gumer sheep population had significantly higher linear body measurements (P<0.05) than Ejha district. Sex, age, and sex by age interaction exerted significant differences (p<0.05) on live body weight and linear body measurements. Body weight was significantly (P<0.01) correlated with all linear measurement traits considered in this study. Chest girth and body length were found to be the best predictor of live body weight. Phenotypic characterization indicated variations within the studied population in qualitative and quantitative traits. Hence, there is a great possibility for genetic improvement through selection of rams within the studied population. Thus, implementation of planned genetic improvement strategy through community based breeding program that considers the major constraints hampering sheep production need to be addressed. Key words:  Characterization, husbandry practice, body weight, qualitative and quantitative traits.

Genetic parameters for body weight and morphometric traits in Santa Ines sheep using Bayesian inference

BackgroundAn exploratory field research was conducted in northwestern Ethiopia, to characterize the morphological features of Arab and Oromo goat populations as an input to design community-based breeding programs. Ten qualitative and nine quantitative traits were considered from 747 randomly selected goats. All data collected during the study period were analyzed using R statistical software.ResultsPlain white coat color was predominantly observed in Arab goats (33.72%) while plain brown (deep and light) coat color was the most frequent in Oromo goats (27.81%). The morphometric measurements indicated that Oromo goats have significantly higher body weight and linear body measurements than Arab goats. Positive, strong and highly significant correlations were obtained between body weight and most of the body measurements in both goat populations. The highest correlation coefficients of chest girth with body weight for Arab (r = 0.95) and Oromo (r = 0.92) goat populations demonstrated a strong association between these variables. Live body weight could be predicted with regression equations of y = − 33.65 + 0.89 × for Arab goats (R2 = 90) and y = − 37.55 + 0.94 × for Oromo goats (R2 = 85), where y and x are body weight and chest girth, respectively, in these goat types.ConclusionsThe morphological variations obtained in this study could be complemented by performance data and molecular characterization using DNA markers to guide the overall goat conservation and formulation of appropriate breeding and selection strategies.

Background: This investigation aimed to portray the existing management practices, phenotypic variability, performance traits and distribution of the native goat (Surguji) population of Northern hills of Chhattisgarh. Methods: A comprehensive survey involving a sample size of 636 goats across 50 villages of Surajpur, Surguja and Balrampur districts was designed for exploring the morphological traits and performance potential of Surguji goats. All parameters were recorded following standard breed descriptor format prescribed by the National Bureau of Animal Genetic Resources (NBAGR), Karnal, Haryana. Result: Surguji goats were medium-sized, light brown and exhibit early puberty and sexual maturity, with favorable meat production characteristics. The average birth weights for male and female goats were 2.64±0.02 and 2.13±0.02 kg and adult body weights averaged 33.10±0.54 and 28.60±0.09 kg, respectively. The study reveals that the males were significantly heavier and taller than female goats. The average ages at first estrus, first mating, first kidding, service period and kidding interval were recorded as 208.15±1.21, 253.87±1.53, 441.99±1.88, 126.87±5.48 and 276.28±0.15 days, respectively. Milk production was reported to be very low, although multiple births were common. The findings indicate the presence of a unique goat population characterized by distinct morphometric, productive and reproductive traits.

The aim of the study was to identify and characterize the phenotype of goat genetic resources in the Bench Maji zone, south western Ethiopia. Focus group discussions, observation of physical attributes and morphology, and morphometrical measurements were employed for data collection. Descriptive statistics, chi-square tests, general linear model (GLM) and two-step cluster analysis were employed to analyse the data. The results of the analyses revealed that 90.7 percent of the female and 88.4 percent of the male goats have straight facial profile. Horns in the majority of females (85.7 percent) and males (73.4 percent) are straight with backward direction in 72.6 percent of females and 84.2 percent of males. In most cases the female goats lack ruffs (88.2 percent), wattles (73.8 percent) and beards (68.3 percent). Averaged quantitative traits of the female population were 56.97 ± 0.21 cm; 70.15 ± 0.27 cm, 60.08 ± 0.17 cm and 26.36 ± 0.21 kg for body length, chest girth, height at withers and body weight, respectively. The corresponding values of the male population were 60.81 ± 0.35 cm, 75.04 ± 0.50 cm, 64.47 ± 0.32 cm and 31.02 ± 0.50 kg, respectively. Goats from the different districts have shown significant (P < 0.01) differences in body length, height at withers and body weight of female and chest girth and body weight of males. 48 and 52 percent of the goat populations were distributed under two clusters indicating that the goat populations can be classified into two ecotypes (Meanit and Sheko).

Genetic parameters for lean meat yield, meat quality, reproduction and feed efficiency traits for Australian pigs: 3. Genetic parameters for reproduction traits and genetic correlations with production, carcase and meat quality traits

Pig farming is one of the most economically viable options for the rural backward and resource-poor farmers in Asian countries. Growth rate and litter size are the most important traits based on which the crossbreeding programs are typically planned in commercial pig farming. The modern system of farming with high yielding improved pig germplasm helps in economic growth in piggery enterprises. The present study was undertaken to evaluate the influence of various genetic and non-genetic factors on growth and reproductive performances of 75% crossbred progenies of Large White Yorkshire and indigenous Agonda Goan pigs. Body weights were recorded at birth, weaning, and at monthly intervals up to 10 months of age. Reproductive performances were also recorded for litter size and weights at birth and weaning stages, age at first farrowing, number of services per conception, farrowing interval, and pre-weaning mortality. The general linear model was used to estimate overall least square means of body weights at different ages considering the effects of different factors at certain levels viz., generation (i = first, second, third, fourth), sex (j = male, female), litter size at birth (k = 1-3, 4-6, 7-9, ≥10), parity (l = 1, 2, ≥3), season (m = summer, rainy, spring), and period of birth (n = 2012-2015, 2016-2019). The heritability and genetic correlations for different traits were estimated by restricted maximum likelihood (REML) method using WOMBAT software. The re(production) parameters were analyzed to assess the genetic improvement in successive generations. There was significant difference (p < 0.01) in body weights among different generations where animals belonging to latest generation showed maximum body weights indicating ideal selective breeding in the herd. Other fixed effects also had significant effects on growth performance which clearly signifies to the crucial influence of rearing environment and animal factors like parity of dams as well as litter size at birth. The overall birth weight, weaning weight, and weight at 10 months of age were 1.00 ± 0.01 kg, 7.57 ± 0.07 kg, and 81.58 ± 1.96 kg, respectively. Nevertheless, weaning weight and weight at marketing age (8 months) were 8.04 ± 0.27 kg and 75.48 ± 1.40 kg, respectively, in fourth generation, indicating higher post-weaning growth rate of 337.20 g/day. During this fourth generation, mean litter size at birth was 8.35 ± 0.43 and litter size at weaning was 7.79 ± 0.39 with lowest percentage of pre-weaning mortality (4.11 ± 1.51). The average age at first farrowing and farrowing interval was 293 ± 17.24 and 195 ± 4.78 days, respectively. There was apparently greater genetic gain in each generation except for the second generation which might be due to the environment and managemental issues that hindered reproductive performance traits and body growth. The heritability estimate for weaning weight was 0.45 and higher heritability values were observed for all the body weights except weight at third month. Genetic as well as phenotypic correlations were moderate to high among the growth traits. The heritability and genetic correlations at birth and weaning indicate the reliability of selection at an early age. The findings indicated that there is scope for improvement through genetic selection in later generations and the 75% crossbred pigs thrived well in the prevailing hot and humid tropical coastal climate. The improved germplasm could satisfy the farmers' need in a commercial venture with high economic return.

Background:Pleomorphic adenoma gene 1 (PLAG1) is a zinc finger transcription factor and is widely known to play an important role in regulating growth traits in bovine.Aim:This study aimed to evaluate the association of PLAG1 polymorphisms with body weight and measurement traits of Brahman cattle.Methods:A total of 57 blood samples of Brahman cattle and their body weight and measurement traits have been collected. Moreover, the polymerase chain reaction-restriction fragment length polymorphism method was used to determine the genotypes of the three polymorphisms in PLAG1, namely g.48308C>T, g.32212 (19 bp indel), and g.45233 T>C. A mix model effect was performed to evaluate the association of PLAG1 with body weight and measurement traits, while the Tukey HSD test was used to compare the means among genotypes.Results:Genotype variations were observed for the g.48308C>T single nucleotide polymorphism (SNP) and 19 bp indel. In detail, the CC and CT genotypes of g.48308C>T SNP were identified and all possible genotypes of 19 bp indel were also identified. On the other hand, g.45233T>C SNP showed no variation. The statistical analysis revealed that SNP g.48308C>T and 19 bp indel had a significant effect on body weight and chest girth (p < 0.05). Both CC genotypes of g.48308C>T SNP and DD genotype of 19 bp indel of the PLAG1 were favorable for those two traits.Conclusion:Based on these results, the SNP g.48308C>T and 19 bp indel in the PLAG1 could be a candidate marker for body weight and chest girth in the Brahman cattle population at the Center for Superior Animal Breeding and Forage (BPTU-HPT) Sembawa.

Characterization studies of the phenotypic and genetic diversity of Mongolian goats are limited, despite several goat breeds being registered in the country. This study aimed to evaluate the phenotypic and genetic diversity of 14 cashmere goat populations in Mongolia, consisting largely of identified goat breeds. Body weight, cashmere quality, and coat color were the phenotypic traits considered in this study. A linear model was used to fit body weight and cashmere traits, and least squares means (LSMs) were estimated for the region and location classes. Genetic diversity and structure were assessed using a goat 50K SNP array. The studied populations exhibited greater phenotypic diversity at the regional level. A very small overall differentiation index (Fst: 0.017) was revealed by Wright's Fst and a very small overall inbreeding index (F ROH1 :0.019) was revealed based on runs of homozygosity. Genetic clustering of populations by principal components showed large variances for the two goat populations of the Russian admixture (Gobi Gurvan Saikhan and Uuliin Bor), and smaller but differentiated clusters for the remaining populations. Similar results were observed in the admixture analysis, which identified populations with the highest (Govi Gurvan Saikhan and Uuliin Bor) and lowest (Tsagaan Ovoo Khar) exotic admixtures. A genomewide association study (GWAS) of body weight and cashmere traits identified a few significant variants on chromosomes 2, 4, 5, 9, and 15, with the strongest variant for cashmere yield on chromosome 4. The GWAS on coat color yielded nine significant variants, with the strongest variants located on chromosomes 6, 13, and 18 and potential associations with KIT, ASIP, and MC1R genes. These signals were also found in other studies on coat color and patterns in goats. Mongolian cashmere goats showed relatively low genetic differentiation and low inbreeding levels, possibly caused by the traditional pastoral livestock management system and the practice of trading breeding bucks across provinces, along with a recent increase in the goat population. Further investigation of cashmere traits using larger samples and alternative methods may help identify the genes or genomic regions underlying cashmere quality in goats.

IntroductionAs a result of extensive changes in pig husbandry in the last 50 years, nutritional requirements of especially lactating sows nowadays differ strongly from those of sows in the past. Although diets are optimized to meet the requirements, sows still loose body reserves during lactation. Especially in primiparous sows, losses of body reserves during lactation are severe. These sows have not reached their mature body weight and therefore need nutrients for body development. However, due to a limited feed intake capacity, lactating primiparous sows mobilize body fat and protein to meet their requirements for maintenance and milk production.In general, these losses of body reserves result in impaired reproductive performance after weaning. The number of sows that remain anestrous after weaning is considerable and in sows that show estrus, weaning-to-estrus interval (WEI) is prolonged, ovulation rate seems decreased and embryonal mortality is increased.Therefore, nutrition is an important factor for optimal reproductive performance, especially in primiparous sows. An intermediate between nutrition and reproduction is the hormone insulin. Insulin is associated with the pulse frequency of luteinizing hormone (LH), WEI, ovulation rate, and farrowing rate. Feeding level, exogenous insulin injections, and diet composition can affect plasma insulin concentration. Effects of dietary energy source on plasma insulin concentration and its relationships with reproductive performance are hardly investigated.This study was conducted in primiparous sows to investigate: 1) effects of two specific dietary energy sources (fat: less insulin-stimulating vs starch: more insulin- stimulating) fed during different parts of the reproduction cycle, on reproductive traits, and 2) whether effects of these dietary energy sources on reproduction are dependent on the metabolic status during lactation (induced by feeding level).Dietary energy sources and plasma insulin concentration (Experiment 1)To investigate effects of dietary manipulated plasma insulin concentration on reproductive performance, firstly diets had to be composed that differ in insulin stimulation. Therefore, an experiment was conducted in cyclic gilts in which three diets, differing in major dietary energy sources, were investigated in their ability to stimulate plasma insulin secretion (Chapter 1). The studied major dietary energy sources were tallow, maize starch, and maize starch plus dextrose. The diet with tallow gave only a slight postprandial increase in plasma insulin level. The maize starch diet resulted in a higher postprandial insulin concentration, but two hours after feeding the plasma insulin concentrations were not different between the diet with tallow and with maize starch. The diet with maize starch plus dextrose resulted in the highest postprandial insulin levels and remained at a higher level during approximately 4.5 h after feeding. Preprandial insulin concentrations did not differ between diets.Design Experiment 2Because the diet with tallow (fat) and the diet with maize starch plus dextrose (starch) gave the largest contrast in plasma insulin concentration, these two diets were used in a large experiment with lactating primiparous sows. Sows received either the fat- or starch-rich diet from farrowing up to d 35 of the subsequent pregnancy. During lactation, sows were fed either a high (44 MJ NE/d; 1050 g CP/d) or a low (33 MJ NE/d; 790 g CP/d) feeding level. This was done to study, in addition to the main effects, the interactions between dietary energy source and feeding level on energy partitioning and reproduction. Within each feeding level, diets were fed to be isocaloric and isonitrogenous. After weaning, all sows remained at the same experimental diet, but all received the same amount of energy and protein (from weaning to estrus: 31 MJ NE/d; 740 g CP/d; from breeding to slaughter: 17.5 MJ NE/d; 420 g CP/d).During lactation, energy and nitrogen balance were determined and blood samples were collected to analyze insulin and LH profiles. After weaning (day 22 after farrowing), additional blood samples were taken to analyze periovulatory profiles of estradiol, LH, and progesterone. Sows were inseminated each day of standing estrus and slaughtered on d 35 of pregnancy. Results obtained from this experiment are described in Chapter 2 to 5.Dietary energy source and energy partitioning (Experiment 2)Effects of dietary energy source and feeding level on milk production, milk composition, piglet body composition, and energy partitioning of lactating primiparous sows are described in Chapter 2. At the low feeding level no differences between the two dietary energy sources were observed for milk composition, body composition of the piglets, or energy and nitrogen balance of the sow. At the high feeding level, however, the fat-rich diet resulted in milk with a higher fat concentration and in piglets with a higher body fat concentration compared with the starch-rich diet. This resulted in an interaction between dietary energy source and feeding level for energy balance of the sows. The energy balance of sows fed the low feeding level and of sows fed the fat-rich diet at the high feeding level were all similar, but the energy balance of sows fed the starch-rich diet at the high feeding level was less negative. These results suggest that extra fat in the diet enhances milk fat output, whereas extra starch is used for both milk production and prevention of severe body reserve losses of the sow.Dietary energy source, feeding level, and reproductive traits (Experiment 2)Whether the treatments affected plasma insulin profiles and reproductive traits during and after lactation is described in Chapter 3 and 4. Plasma insulin concentration was higher in sows fed the starch-rich diet than in sows fed the fat-rich diet during lactation. LH pulse frequency during lactation tended to be lower in sows fed the fat-rich diet compared to those fed the starch-rich diet. At the high feeding level, no effect of dietary energy source on WEI was found. However, at the low feeding level, the fat-diet resulted in a 22 h longer WEI compared with the starch-rich diet. Dietary energy source did not affect other reproductive traits.Feeding level did not affect plasma insulin profiles during lactation. Sows fed the high feeding level during lactation had a higher LH pulse frequency during and after lactation, a lower risk to remain anestrous after weaning, and a higher ovulation rate compared with sows fed the low feeding level. Periovulatory profiles of estradiol, LH, and progesterone hardly differed between treatments. No differences between treatments were observed for the number of embryos, uterine-, and placental development.Plasma insulin concentrations during lactation were never related with the determined reproductive traits. Furthermore, no relationships were found between energy- or nitrogen balance and reproductive characteristics.Based on the results obtained from experiment 2, it can be concluded that dietary energy source during lactation affects plasma insulin concentration but has minor effects on reproductive performance of primiparous sows. A reduction of 25% in lactational feed intake seems to have more impact on reproductive traits.Overall analyses, regardless of treatments, showed that the relationship between the number of LH pulses on the day of weaning and the WEI was best explained by a linear-plateau model. An increase from two to seven LH pulses per 12 h resulted in a linear decrease in WEI, whereas more than 7 pulses did not shorten the WEI further. Furthermore, it was demonstrated that the mean plasma progesterone concentration in early pregnancy was positively related with the percentage of embryo survival, especially in progressing pregnancy (from 170 h after the LH surge onwards).Dietary energy source and reproductive performance (Experiment 3).In the experiment described above (Chapter 2 to 4), sows were fed either the fat- or starch-rich diet from parturition until d 35 of subsequent pregnancy It is therefore, impossible to distinguish effects of dietary energy source fed during the lactation period, the WEI, or the early pregnancy, on reproduction. Effects found during pregnancy may be a result of changes during WEI or even lactation. Therefore, another experiment was conducted in which primiparous sows were fed either the fat- or starch-rich diet during the weaning-to-ovulation interval or during early pregnancy (until d 35). The results obtained from this experiment are described in Chapter 6. Sows fed the fat-rich diet before ovulation had a higher risk to maintain anestrous after weaning than sows fed the starch-rich diet. No effect of dietary energy source fed either before ovulation or during early pregnancy was found on uterine, placental, and embryonic traits.IGF-1 and reproductive performance (Experiment 2 and 3)Because plasma insulin concentration did not show relationships with reproductive traits (Chapter 3 and 4), additional analyses were performed to determine plasma IGF-1 (insulin-like growth factor-I) concentration during and after lactation, and its relationships with reproductive characteristics. In literature, IGF-1, together with insulin, is often posited as an intermediate between nutrition and reproduction in the pig. Results of these analyses are described in Chapter 5. Plasma IGF-1 concentration was higher in sows fed the high feeding level during lactation and also in sows fed the starch-rich diet. Furthermore, IGF-1 concentrations on d 21 of lactation and on d 22 (weaning) were positively related with the LH pulse frequency on d 22 and the height of the preovulatory LH surge. Finally, IGF-1 concentration in sows with a low body weight at farrowing and severe lactational body weight loss was decreased compared to heavier sows at farrowing or sows with less lactational body weight loss.Conclusions and implicationsThe major question to be answered in the present study was whether dietary energy source affects plasma insulin concentrations and reproductive performance of primiparous sows. Based on the results obtained from the three experiments, it can be concluded that fat-rich diets fed during lactation depress the secretion of insulin compared to starch-rich diets. The LH secretion by the pituitary during lactation tended to be decreased in sows fed the fat-rich diet, possibly explaining the finding that the return to estrus was delayed in these sows. However, this lower LH pulsatility and delayed return to estrus were not related to plasma insulin concentration. Dietary energy source does not seem to affect reproductive traits on the uterus level.The second question to be answered was whether effects of dietary energy source on reproductive performance are dependent on the metabolic status of sows during lactation. In the present study, no interaction between dietary energy source and metabolic status on reproductive traits was found, even though the energy balance of the lactating sows was affected by dietary energy source.Based on these results, the use of fat-rich diets for primiparous sows, and probably also for multiparous sows, needs to be critically evaluated. Based on the metabolic and reproductive point of view, starch-rich diets seem to be more beneficial for sows than fat-rich diets. Effects of fat-rich diets on litter performance after weaning need to be investigated further.

Maternal processes in the cold-adaptation of mice.

Purpose The purpose of this paper is to investigate the chest girth and height related to men’s upper body dimensions to develop men’s grading system for semi-customized clothing. Design/methodology/approach A data set of the 3,012 men between the age group of 18 and 59 years from 6th Size Korea was used in this study. The men’s upper body dimensions were tested in terms of five horizontal lengths, seven circumferences and seven vertical lengths. Experiment and data analysis were carried out with two methods: one is multiple linear regression with chest girth and height as each independent variable and the other is calculating variation among chest girth size groups and height size groups, respectively. Findings Regression analysis showed that some horizontal lengths are affected not only by chest girth, but also by height, and some vertical lengths are affected not only by height, but also by chest girth. In variation analysis it was found that the variation value for each part of the body is different and it was observed that with an increase in chest girth vertical length also increases. In variation analysis of height, it is found that some horizontal body dimensions and hip girth increase with an increase in height. In the comparison of upper body dimension variation among height groups with the size based on the chest girth, we found that a tall person who already has long vertical length is less affected by the increase in dimensions by increases in their horizontal girth than a short person. Originality/value The findings showed detailed numerical body shape changes according to chest girth and height, and it may be used as the basis for determining pattern grading values by chest girth or height.

Seed production can be improved if genetic selection is applied to key reproductive traits when a substantial amount additive genetic variation is present that can be exploited in a selective breeding program. Despite the commercial importance of reproductive traits to the seed production sector currently, few quantitative genetic studies have been conducted to address these traits in farmed penaeid shrimp culture lines. Here, we investigated genetic parameters for a number of key reproductive traits that directly impact nauplii production in Pacific white shrimp (P. vannamei) hatcheries in China. Our objectives were to determine the additive genetic variance associated with reproductive traits, and to anticipate any potential impacts on reproductive performance when selecting for increased body weight by assessing genetic correlations between post-spawning body weight and specific female reproductive traits. Data were collected on 595 females from 78 full-sib families over 30 days, with a total of 1,113 spawning events recorded. Traits studied included: body weight after spawning (WAS), number of eggs per spawn (NE), number of nauplii per spawn (NN), egg hatching rate per spawn (HR), number of eggs produced relative to female weight (g) (FE), and spawn frequency over 30 days (SF). Estimated heritability was high for WAS (h2 = 0.64 ± 0.10) and moderate for NE (0.26 ± 0.07), NN (0.18 ± 0.06), and SF (0.15 ± 0.06), respectively. In contrast, h2 for HR (0.04 ± 0.03) and FE (0.05 ± 0.04) were low. The genetic correlations between growth trait (WAS) with NE, NN and SF were 0.93 ± 0.10, 0.84 ± 0.10, and 0.57 ± 0.18, respectively. While the genetic correlation between WAS and HR was low (0.02 ± 0.33), a negative genetic correlation was found between WAS and FE (−0.50 ± 0.27). Overall, we concluded that it is possible to improve the key female reproductive traits (i.e. NE, NN, and SF) in cultured white shrimp lines via genetic selection, but not for HR or FE. The genetic relationship between the growth trait and reproductive traits predicts that selection on fast growth would increase the production in the seed sector, with little or no compromise on the eggs quality.

Simple SummaryReproductive and growth traits are important economic characteristics in sheep, regulated by complex molecular mechanisms. Identifying SNPs or candidate genes associated with these traits can provide a theoretical basis for molecular breeding and offer new insights into the genetic foundations of sheep reproduction and growth. Therefore, this study used 483 Tianmu prolific sheep as the research subjects. Through genome-wide association analysis and subsequent bioinformatics analysis, we identified 13, 4, and 7 reliable SNPs associated with litter size, body weight traits, and body size traits, respectively, as well as 18, 8, and 12 candidate genes linked to these traits.Reproductive and growth traits are key economic traits in sheep. This study aims to identify key single nucleotide polymorphisms (SNPs) and candidate genes associated with reproductive and growth traits in Tianmu polytocous sheep through a genome-wide association study (GWAS). The findings are expected to provide both a theoretical foundation for molecular breeding in this breed and novel insights into the genetic basis of ovine reproductive and growth performance. This study took 483 adult Tianmu polytocous ewes as the research subjects, collected their lambing records, measured their phenotypic values of growth traits (3 weight and 11 body size traits), and collected their blood samples for whole-genome resequencing to identify SNPs in the Tianmu polytocous sheep genome. The results identified a total of 9,499,019 (3× coverage) and 27,413,216 (30× coverage) high-quality SNPs in the Tianmu polytocous sheep genome. Subsequently, the association analysis between SNPs and reproductive and growth traits was conducted using a mixed linear model. A total of 92, 66, 18, 28, 6, 42, 3, 3, 6, 1, 12, 3, 22, 8, 6, and 3 SNPs were found associated with litter size at first parity, litter size at second parity, litter size at third parity, litter size at fourth parity, birth weight, weaning weight, body height, withers height, body length, head length, head width, cannon bone circumference, forelimb height, chest girth, chest depth, and withers width, respectively. Further, based on SNP annotation, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, candidate genes associated with the reproductive and growth traits were identified. Among these genes, 11 LOC, DEPTOR, GNG12, GRM7, PTH, PTH2R, WWOX, INHA, and NRG3 are candidate genes associated with litter size at first parity or litter size at third parity. These genes are involved in the G protein-coupled receptor signaling pathway, G protein-coupled receptor activity, ovarian tissue development, and hormone secretion. Additionally, TFRC and NTN1 are candidate genes associated with birth weight, while five UGT1A and CASR are candidate genes associated with weaning weight. These candidate genes are primarily involved in lipid metabolism. Finally, the following genes were identified as candidates associated with specific traits: DLG2, TMEM126A, and TMEM126B with body height; DSCAM and SCN8A with body length; BARX1 with cannon bone circumference; four LOC genes with forelimb height; EPHA4 with chest depth; and MRS2 with withers width.