Pre-weaning Daily Gain Research Articles

Effect of genotype and environment on the productive and survivability traits of lambs under a community-based management system

The aim of this study was to evaluate the growth and survival of local and Dorper crossbred lambs managed under a community-based management system, using data collected between 2012 and 2021. The fixed effects considered were breed, location, sex, type of birth, parity, season, and year of birth. The results revealed that Dorper crossbred lambs consistently weighed and gained more than local lambs (p<0.0001) at all ages and that environmental factors such as location, sex, type of birth, parity, season, and year of birth had considerable influence on most growth traits at all ages. The mean birth weight of local, low-grade, and high-grade Dorper crossbred lambs were 2.12 ± 0.04, 2.94 ± 0.03, and 3.08 ± 0.03 kg, respectively. The corresponding pre-weaning daily gain was 89.12 ± 1.85, 112.16 ± 1.38, and 117.98 ± 1.71 g/day, respectively. The post-weaning body weight gain at 90-180 days for the same groups was 32.6 ± 2.16, 46.85 ± 1.62, and 45.93 ± 1.98 g/day, respectively. Dorper crossbred lambs exhibited a bodyweight advantage of up to 45%, 31%, 34%, and 28% over local lambs at birth, 3, 6, and 12 months of age, respectively. Lambs born in the dry season had the lowest weaning (p<0.0001) and six-month (p = 0.0098) weight compared to those born in the rainy seasons. Lamb genotype didn’t have a significant influence on the survival of lambs at all ages, but most environmental factors influenced survivability. Lambs born to ewes in their 5th parity and above had a mortality risk of 0.51 times higher than those born to ewes in their 1st to 4th parity at the age of 6- months. Year of lambing affected lamb pre-weaning (χ2 = 0.0003) and post-weaning (χ2 = 0.0001) survival. Compared to the base year 2021, lambs born in 2017 and 2018 had a higher risk of mortality at 6-month (10.1 and 15.9 times, respectively) than those born in 2021. Season of birth also significantly (χ2 <0.001) affected lamb survivability, with lambs born in the dry season, having a higher mortality risk at weaning (0.46 times) and yearling (0.66 times). Lambs with a birth weight of 2 kg and below had a 2.3 times higher survival risk at 6-months compared to lambs born with 3 kg and above. In conclusion, Dorper crossbred lambs can be considered to improve lamb growth performance and produce fast-growing lambs. However, the study recommends further research to validate the crossbreeding program (considering the influential production environment, research on supplementation for lambs in the dry-season, adjusting the mating season, and the economic feasibility of crossbreeding are suggested).

Estimation of genetic parameters and inbreeding depression in Piau pig breed.

This study is aimed at estimating genetic parameters, effective population size, inbreeding, and inbreeding depression for birth weight, weaning weight, and average pre-weaning daily weight gain (ADG) in Piau pigs. We used information from 3841 Piau pigs, and four linear models were fitted in single-trait analyses, including or excluding maternal genetic effect, common litter effect, or a combination. The adjustments of the models were compared using the likelihood ratio test, in which the model that presented the best fit for each trait was used to estimate the (co)variance components. The inbreeding depression effect was evaluated using a linear model that included the fixed effects of sex, parity order, contemporary group, and inbreeding coefficient as a fixed covariate. The weights at birth and weaning showed low direct heritabilities (0.08 and 0.05, respectively), while the ADG showed moderate heritability (0.20). The weight at birth showed high genetic correlations with the weight at weaning (0.90) and the ADG (0.82). The weight at weaning and the ADG also showed a high genetic correlation (0.99). There was an inbreeding increase over the generations and a reduction in the effective population size. In the last generation evaluated, all the animals were inbred, the average inbreeding coefficient was 0.07, and the effective population size was 20.8. A significant inbreeding effect on ADG was observed, where an increase of 1% in the inbreeding coefficient resulted in a decrease of 0.005g in the ADG. Thus, increasing effective population size is mandatory for controlling inbreeding and reducing the loss of variability in this Piau pig population.

Economic values for sustainable dairy cattle breeding in the tropics: A focus on climate change responsive traits

The goal of this study was to estimate economic values for feed efficiency (FE), resilience (RE), adaptability (AD), and disease resistance (DR). The indicator traits that were used to measure; FE, RE, AD and DR were residual feed intake (RFI), variance deviations in milk yield, heat stress using milk reduction due to an increase in temperature humidity index (THI) by 1 and brucellosis disease resistance, respectively. A bio-economic model was developed in python using both simple profit functions and risk-rated profit models and was used to compute economic values for FE, RE, AD, and revise economic values for traits in the existing breeding goal, which included milk yield (MY), fat yield (FY), protein yield (PY), age at first calving (AFC), calving interval (CI), pre-weaning daily gain (DG), post-weaning daily gain (PDG), mature live weight (LW), pre-weaning survival rate (PSR), post-weaning survival rate (PWR), and productive lifetime (PLT). The economic value for brucellosis disease resistance was derived using selection index methodology. The risk-rated economic values for the climate change responsive traits were; KES -15.54, KES 47.37, KES 175.48, and KES -58.71 for FE, RE, AD, and DR respectively. The revised risk-rated economic values for the other traits were; KES 47.6, KES 132.8, KES 136.1, KES -334.9, KES -171.9, 8.3 g/day, 3.4 g/day, KES -30.8, 7.49%, 7.66%, and KES 63.9 for MY, PY, FY, AFC, CI, DG, PDG, LW, SR, PSR, and PLT respectively. The profits realised per year were; KES 705.71, and 77,473.70 for the current breeding goal (CBG) and climate change responsive breeding goal (CCRBG) respectively. These economic values indicate that inclusion of climate change responsive traits in breeding goal would increase response to selection of dairy cattle in the tropics.

Variation in the ovine FOXP3 gene and its effect on growth traits in Egyptian Barki sheep

The aim of the present study was to detect the FOXP3 gene polymorphisms in Barki sheep at a variable region covering exon 13, intron 13 and the coding sequence in exon 14 and to test the association of these polymorphisms with growth traits. 122 Barki lambs were phenotyped for various growth traits, viz., birth weight (BW), weaning weight (WW), pre-weaning daily gain in weight (ADG1), post-weaning daily gain in weight (ADG2) and marketing bodyweight (MW). The polymerase chain reaction – single-strand conformational polymorphisms (PCR-SSCP) and DNA sequencing methods were used to identify the genetic variants in the FOXP3 gene. The associations between the variation in FOXP3 gene and growth traits were tested using a general linear model. Two variants (F1 and F2 with gene frequencies of 0.64 and 0.36, respectively), and three genotypes (F1F1, F1F2 and F2F2 with frequencies of 0.37, 0.53 and 0.10, respectively) were detected. The association of FOXP3 genotype was significant (p < 0.05) with ADG2 and MW. It is concluded that FOXP3 genotype might be helpful for sheep breeders to produce fast-growing lambs. However, further studies are needed in a large population to confirm the association we found.

Comparative Growth and Economic Performances between Indigenous Swamp and Murrah Crossbred Buffaloes in Malaysia.

Simple SummaryA buffalo breeding farm was selected to study the growth performance of Swamp and Murrah crossbred buffaloes. The farm was practicing extensive grazing system without supplementation since 2010 to 2011. In early 2012, the farm had implemented a new intervention to improve the growth performance via improving the feed and the feeding management. Farm records between 2010 to 2015 were analyzed for growth performance and partial budget analysis. So far, there is no comparative study done between Swamp and Murrah crossbred buffaloes in Malaysia. Therefore, in the present study, we aimed to study the differences in the biological and economical performances between Swamp and crossbred buffaloes in Malaysia. With a new intervention, a significant improvement was reported of the number of calves born, average birth weight, and reduced percentage of calf mortality rate, calving interval, and weaning age. Crossbred buffalo showed dominance in biological performance in terms of higher pre- and post-weaning daily weight gain and taking a shorter period to achieve market and breeding weight compared to Swamp buffaloes. Thus, reared Murrah crossbred buffaloes with new intervention management would give a farmer a higher profit return. However, with reared Swamp, the farmer potentially conserves the local indigenous breed of Swamp buffalo.This study was conducted to compare the growth and economic performances between Swamp and Murrah crossbred buffaloes. The records of 108 Swamp and 276 Murrah crossbred buffaloes born between January 2010 and December 2015 were used in this study. The farm was practicing an extensive grazing system without supplementation from January 2010 to December 2011 (pre-intervention) and a new implementation of supplement in the feeding regime from January 2012 to December 2015 (post-intervention). The birth, weaning, and body weight at three monthly intervals, number of calves born, and mortality rate of calves at different years and during pre- and post-intervention were analyzed using a general linear model procedure. The interventions in 2012 had a positive effect on increasing the number of calves born for both breeds, average birth weight, economic performance, and reduce mortality calf rate. As a result, the birth weight of Murrah crossbred buffaloes was higher (36.63 ± 0.50 kg) than Swamp buffaloes (34.69 ± 0.40 kg) (p < 0.05). The average pre-weaning daily weight gain for Swamp and Murrah crossbred buffaloes was 0.73 and 0.98 kg/day (p < 0.05), while the average post-weaning daily weight gain was 0.39 and 0.44 kg/day, respectively (p < 0.05). The Swamp and Murrah crossbred buffaloes achieved the targeted market weight of 250 kg at 18 and 15 months old, respectively, while the targeted breeding weight of 385 kg was achieved at 30 and 26 months old, respectively. In this farm, on average a total of 64 calves were born yearly, with the ratio number of born calves per number of mated dams recorded higher in Murrah crossbred buffaloes as compared to Swamp buffalo (0.64 vs. 0.37) (p < 0.05). Furthermore, the average number of calves born in the post-intervention period (January 2012–December 2015) was significantly higher than in the pre-intervention period (January 2010–December 2011), respectively (Swamp: 23 vs. 8 and Murrah crossbred: 53 vs. 31, respectively) (p < 0.05). Partial budget method was used to estimate the net gain or loss between the two breeds. The average annual revenue was 2304.14 MYR (566.13 USD) for Swamp buffaloes and 4531.50 MYR (1113.39 USD) for Murrah crossbred buffaloes. The average annual cost saving was 340.02 MYR (83.54 USD) for Swamp and 215.75 MYR (53.01 USD) for Murrah crossbred buffaloes. On the other hand, annual added cost was 84.95 MYR (20.87 USD) for Swamp and 96.76 MYR (23.77 USD) for Murrah crossbred buffaloes. Therefore, the annual net benefit was 2559.21 MYR (628.80 USD) for Swamp and 4650.49 MYR (1142.63 USD) for Murrah crossbred buffaloes. As a conclusion, this study had shown that the higher average daily weight gain contributes to better cost savings, as shown by the crossbred buffaloes.

GENETIC ASPECTS OF PREWEANING PERFORMANCE OF NDAMA CATTLE

Records on birth weight (BW), preweaning daily gain (PWG) and weaning weight (WW) of Ndama beef cattle were obtained from the Fashola Livestock Farm in Oyo State of Nigeria between 1954 and 1964 and were analyzed to estimate the phenotypic and genetic parameters of preweaning performances of this breed of cattle. For birth weight, preweaning daily gain and weaning weight respectively heritability was estimated as 0.13 ± 0.08, 0.30 ± 0.14 and 0.25 ± 0.12 from paternal half-sib relationship. The estimates of genetic and phenotypic correlations obtained from these data among the three pre-weaning traits were found to be similar to those already in the general literature on beef cattle.

Estimation of genetic parameters for pre-weaning growth traits in Central Anatolian Merino sheep

• Genetic parameters including maternal effects were estimated by this study. • Moderate heritability estimates were found for all pre-weaning growth traits. • Moderate negative genetic correlation was found between birth weight and weaning weight. • Moderate negative correlations were found between birth weight and average daily weight gain. • Remarkably low maternal heritability estimates were found for the traits. Quantitative traits such as pre-weaning growth is expressed as a result of combined genetic and environmental effects. The phenotypic expression of those traits in offspring is affected by direct genetic effect and sometimes also maternal genetic effect which is the ability of the dam to provide optimum nurturing conditions. The objective of the current study was to estimate genetic parameters for birth weight ( BW ), weaning weight ( WW ) and average pre-weaning daily weight gain ( ADWG ) in Central Anatolian Merino sheep. Observations of 9746 lambs descending from 171 rams and 2045 dams between 2014 and 2020 were included in the study. Generalized linear models were applied to determine the best fitting fixed effects model. Subsequently, the estimations of variance and covariance components were carried out by using the restricted maximum likelihood (REML) procedure applied on an animal linear mixed model including those significant effects on preceding analyses. In general, the direct heritability estimates of the traits were moderate for BW, WW and ADWG as found to be 0.22 ± 0.02, 0.32 ± 0.02 and 0.33 ± 0.02 respectively. On the other hand, maternal heritability estimates were considerably low for all traits with 0.04 ± 0.01 (BW), 0.03 ± 0.01 (WW) and 0.03 ± 0.01 (ADWG). The genetic correlations between BW and WW was moderate and negative as -0.30 ± 0.05 whereas, the phenotypic and residual correlations were close to zero. Similarly, the correlations between BW and ADWG were negative for all type of correlations. Especially, a moderate genetic correlation was found between the two traits as -0.37 ± 0.05. As expected, the correlations between WW and ADWG were quite high and positive for all type of correlations. The outcomes of the study will contribute to the world-wide sheep breeding literature with the crossbred performance of Merino and an indigenous sheep breed, as well as its parameters of interest in terms of designing breeding programmes with multi-trait selection indices.

AN ANALYSIS OF PREWEANING BODY WEIGHTS IN WEST AFRICAN DWARF GOATS AND THEIR CROSSES

preweaning performance record of seventy six West African dwarf (WAD) and WADX Red Sokoto (RS) half-bred kids were compared for production efficiency. Average weight at birth was 1.31±0.01kg for WAD kids and 1.44 ±0.01kg for haltbreds. At 90 days and 150 days of age, WAD kids weighed 4.87 :0.04 and 5.88±0.04kg respectively, while the Red Sokoto halfbred weighed 6.06±0.05kg at 90 days and 7.02±0.04kg at 150 days respectively. On the average, pre-weaning daily gain was 303Wday for the WAD kids and 37g/day for half bred kids between birth and 150 days of age. Genotype (P&lt;0.01) and sex (P &lt; 0.05) significantly affected weights at birth, 90 days and 150 days of age. Birth type (P&lt; 0.01) significantly affected weights only at birth. However, season of birth and all first order interactions did not affect weights at any age.

Estimates of (co)variance components and genetic parameters for pre-weaning body weight traits and Kleiber ratio in Sangsari sheep breed

The current study aimed to estimate (co)variance components and heritability for pre-weaning body weight traits and Kleiber ratio in Sangsari sheep. Data used in this research were collected over 30 years (1986–2016) at the breeding station of Sangsari sheep. Traits considered were birth weight (BW), weaning weight (WW), pre-weaning daily gain (PWDG), and Kleiber ratio (KR). Genetic parameters were estimated by the average information restricted maximum likelihood (AI-REML) procedure, using six animal models. The most suitable model was selected using the Akaike information criterion (AIC) for each trait. Direct heritability estimates for BW, WW, PWDG and KR were 0.30 0.04, 0.20 0.03, 0.15 0.02, and 0.13 0.05, respectively. Maternal heritability estimates varied from 0.06 0.02 for PWDG to 0.12 0.03 for BW. The maternal permanent environmental effects for the traits of KR, WW and PWDG account for about 7%, 9% and 12% of the phenotypic variance. The estimates of the direct genetic () and maternal genetic () correlations among pre-weaning growth traits were positive and ranged from 0.21 (BW-KR) to 0.98 (WW-PWDG) and 0.27 (WW-PWDG) to 0.48 (BW-WW), respectively. Therefore, to have an accurate genetic evaluation, maternal effects need to be considered in any program aimed at improving pre-weaning growth traits. In addition, due to the existence of genetic variation for early growth traits and generally positive and medium to high genetic correlations among them, it can be concluded that in the Sangsari breed of sheep, genetic progress for these traits is possible by selection. HIGHLIGHTS Genetic parameters (direct and maternal heritability) were estimated for the Sangsari breed of sheep. The low to moderate estimate of heritability for pre-weaning body weights and Kleiber ratio indicate that genetic improvement of these traits is possible by selection. Considerable genetic correlations among early body weights, pre-weaning daily weight gain, and Kleiber ratio in Sangsari sheep were estimated.

Estimates of phenotypic and genetic trends of growth traits in N'dama herd in Nigeria

Data on birth weight (BTHWT), 205-day adjusted weaning weighi (ADWNWT), and pre-weaning daily gain (ADG) of N'Dama reared at Fasola Stock Farm between 1947 and 1984 were obtained and used to estimate phenotype and genetic trends of these traits. Estimated phenotypic trend was 0.07+0.02 kg/vr, 0.18-0.06kg/yr and -0.005 +0.003kg/yr for BTHWT, ADWNWT and ADG respectively. In contrast, all estimated genetic trends were relatively small and not significantly different from zero. They were 0.02+0.05kg/yr, 0.02+0.05kg/yr and 0.1g/yr for BTHWT, ADWNWT and ADG respectively. The sequential polynomial fitting of the data set indicated that quadratic function adequately described the data with the following regression equation: Y = 9.91 + 0.016 + 0.026 Y = 46.44 - 0.156 + 0.0162 Y = 0.21 - 0.00025 + 1.1862 for BTHWT, ADWNWT and ADG respectively for phenotypic trend curve while for genetic trend curve Y = 0.10 -0.016-0.346' was obtained for BTHWT and ADWNWT and Y = 0.002 - 0.00026' - 70.85b for ADG.

Expected Genetic Gain for Selection of Preweaning Growth Traits in Egyptian Buffaloes

Data on 1946 buffalo calves born between 2000 and 2016 at Mahallet Mousa farms belonging to Animal Production Research Institute, were utilized in this study. Genetic parameters of birth weight (BW), preweaning daily gain (PWDG) and weaning weight (WW) were estimated using MTDFREML. The different selection indices for previous traits were constructed by Matlab program. Means of BW, PDWG and WW were 37.40 kg, 493.53 g and 90.37 kg, respectively. The heritability estimates for above-mentioned traits were 0.24, 0.26 and 0.29, respectively. The genetic correlations among the mentioned growth traits were ranged from 0.18 to 0.79. Corresponding phenotypic correlations among same traits were ranged from 0.13 to 0.48. The expected genetic gains for direct selection of BW, PWDG and WW were varied between 0.23 -1.18 kg, 10.80 – 23.74 g and 0.50 - 3.06 kg, respectively. Comparison among selection indices indicated that the highest expected genetic gains for PWDG (8.73 g) and WW (3.50 kg) were obtained from the index I4 included (PDWG and WW). Moreover, the accuracy of this index was closest to the highest index of accuracy. Thus, selection based on index I4 could be improve the response of aggregate genotype for preweaning growth traits of Egyptian buffalo calves.

Effect of Inbreeding on Preweaning Growth Traits in Egyptian Buffaloes

The aims of the current study were to estimate the effect of inbreeding and genetic parameters of birth weight (BW), preweaning daily gain (PDG) and weaning weight (WW) in buffalo calves. Data were collected from weight records of buffalo calves raised at Mahallet Mousa Farms belonging to the Animal Production Research Institute. It included 2015 progeny of 125 sires, through 17 consecutive years. Effect of inbreeding was highly significant for all studied traits. The overall average of inbreeding coefficient was 0.53% in whole population and 15% in the inbred animals. The means of BW, PDG and WW in non-inbred group were 37.318, 0.490 and 88.86 Kg, respectively. While, the means of the same traits in inbred group were 31.96, 0.446 and 78.82 Kg, respectively. Corresponding the inbreeding depression as overall means of levels for above traits were -0.350, -0.003 and -0.716, respectively. Direct heritability (h2a) in inbred animals for BW, PDG and WW were 0.28, 0.25 and 0.19, respectively. On the other hand, the h2a of studied traits in non-inbred animals were 0.32, 0.30 and 0.23, respectively. The maternal heritability (h2m) for mentioned traits were 0.25, 0.26 and 0.21 within inbred animals and 0.29, 0.28 and 0.22 within non-inbred animals, respectively. Likewise, the genetic correlations (rg) among studied traits were ranged from (0.12 to 0.56) in inbred animals and were ranged from (0.16 to 0.63) in non-bred animals. As well the phenotypic correlation (rp ) among studied traits were ranged from (0.04 to 0.50) for inbreds and were varied between (0.04 and 0.54) for non-inbreds. The inbreeding was pronounced detrimental effects of studied traits in buffalo calves. Therefore, breeding strategies should be develop for reduce the inbreeding effects and inclusion the effects of inbreeding in genetic evaluation programs in Egyptian buffalo calves.

Genome-Wide Association Study of Weaning Traits in Lori-Bakhtiari Sheep

Abstract Weaning traits, including preweaning daily gain (PWDG) and weaning weight (WW) are important economic traits, especially for meat type mammals, with high impacts on growth performance and survival rate in higher ages. This study was conducted to perform a genome-wide association study (GWAS) on weaning traits in a meat type breed of sheep. Body weight records of 7557 Lori-Bakhtiari sheep with PWDG and WW records were used to estimate breeding values (EBVs) using an animal mixed model. A total of 132 animals were selected by two-tailed selection strategy, based on EBVs for body weight and then were genotyped using Illumina 50k Ovine SNP chip. After quality control, a total of 130 animals and 41323 SNPs were remained for further analyses. De-regressed estimates of breeding values were used as a pseudo-phenotype in GWAS analysis. Based on Bonferroni-adjusted p-values, five SNPs, located on chromosomes 2, 3, 4, 12 and 22 were significantly (p &lt; 0.05) associated with weaning traits and accounted for 5.06% and 0.37% of total genetic variations of PWDG and WW, respectively. Two SNPs on chromosomes 2 and 3 were located near to previously reported QTLs for weaning traits. Three genes, including ANGPTL7, mTOR and WDR11, were found within 50 kbp distances from the significant SNPs and thus could be considered as candidate genes for weaning traits. The detected QTLs and candidate genes could be studied for construction of breeding programs for genetic improvement of growth performance in meat type sheep.

Genetic Evaluation Of Red Chittagong Cattle In Bangladesh

The current study was carried out using data of the Nucleus Herd and Community Herd of Red Chittagong Cattle (RCC) established through USDA funded Red Chittagong Cattle project under the Department of Animal Breeding and Genetics, BAU, Mymensingh. Data on 151 calves and 75 lactating cows were analyzed. The estimated heritability values were 0.45 ± 0.05 for birth weight, 0.48 ± 0.05 for weaning weight, 0.41 ± 0.08 for pre-weaning daily gain, 0.47 ± 0.06 for lactation length, 0.43 ± 0.07 for lactation milk yield and 0.35 ± 0.09 for average daily milk yield. The highest Breeding Value (BV) were for birth weight (3.2 kg), weaning weight (24.46 kg), pre-weaning daily gain (82.39g), lactation length (52.25 days), lactation milk yield (186.04 kg) and average daily milk yield (0.66 kg). The minimum and maximum phenotypic index values by using phenotypic parameters were for growth traits (1196.24 and 4713.24) and milk production traits (8573.93 and 40670.81). The minimum and maximum genetic index values by using breeding values were for growth traits (1812.49 and 2870.21) and milk production traits (-1812.49 and 2870.21). All the estimated index values can be used in animal selection and breeding programs for RCC improvement and similar index selection can be applied for other indigenous cattle development programs in Bangladesh or elsewhere.&#x0D; SAARC J. Agri., 17(2): 141-154(2019)

Genome-wide association scan for heterotic quantitative trait loci in multi-breed and crossbred beef cattle

BackgroundHeterosis has been suggested to be caused by dominance effects. We performed a joint genome-wide association analysis (GWAS) using data from multi-breed and crossbred beef cattle to identify single nucleotide polymorphisms (SNPs) with significant dominance effects associated with variation in growth and carcass traits and to understand the mode of action of these associations.MethodsIllumina BovineSNP50 genotypes and phenotypes for 11 growth and carcass traits were available for 6796 multi-breed and crossbred beef cattle. After performing quality control, 42,610 SNPs and 6794 animals were used for further analyses. A single-SNP GWAS for the joint association of additive and dominance effects was conducted in purebred, crossbred, and combined datasets using the ASReml software. Genomic breed composition predicted from admixture analyses was included in the mixed effect model to account for possible population stratification and breed effects. A threshold of 10% genome-wide false discovery rate was applied to declare associations as significant. The significant SNPs with dominance association were mapped to their corresponding genes at 100 kb.ResultsSeven SNPs with significant dominance associations were detected for birth weight, weaning weight, pre-weaning daily gain, yearling weight and marbling score across the three datasets at a false discovery rate of 10%. These SNPs were located on bovine chromosomes 1, 3, 4, 6 and 21 and mapped to six putative candidate genes: U6atac, AGBL4, bta-mir-2888-1, REPIN1, ICA1 and NXPH1. These genes have interesting biological functions related to the regulation of gene expression, glucose and lipid metabolism and body fat mass. For most of the identified loci, we observed over-dominance association with the studied traits, such that the heterozygous individuals at any of these loci had greater genotypic values for the trait than either of the homozygous individuals.ConclusionsOur results revealed very few regions with significant dominance genetic effects across all the traits studied in the three datasets used. Regarding the SNPs that were detected with dominance associations, further investigation is needed to determine their relevance in crossbreeding programs assuming that dominance effects are the main cause of (or contribute usefully to) heterosis.

Growth of Bovine Females and Meat Production Systems of the Subregion Mojana Sucre Colombia

Objectives: To evaluate some growth characteristics Birth Weight (BW), Adjust Weaning Weight (AWW) and Daily Weight Gains (DWG) between birth and weaning of bovine females managed under grazing conditions in the Mojana subregion of the department of Sucre Colombia. Methods / Statistical Analysis: Made an analysis of the information of the productive records of the offspring born from the year 2017 – 2018 in 3 livestock farms. The genetic analysis belonged to the race Zebu, F1 Romo x Zebu and F1 Simmental x Zebu was done. The statistical model used included the effects of year of birth, weaning, farm, racial group, paternal and maternal race. For the analysis, the minimum squares method was used by the PROC GLM procedure, contained in the Statistical Analysis System (SAS). Tukey’s multiple comparison test was performed to determine differences between means, when these differed statistically in the analysis of variance. Findings: The mean for BW, AWW and DWG were 27.5 ± 3.1; 155.5 ± 3.2 kg and 485, ±06 gr/day respectively. The effects of racial group, paternal type and farm were significant (p≤0.05; p≤0.01). On the contrary, the year of birth, as well as the year of adjusted weaning, did not significantly affect (p>0.05) the characteristics analyzed. Application: There are differences between the genetic groups for the analyzed characteristic, which can be used in animal genetic improvement programs in the farms analyzed, in order to achieve increases in the productive variable of growth. Keywords: Birth Weight, Crossing, Genetic Groups, Pre-Weaning Daily Gain, Weaning Weight

Relationships of Weaning Weight with Gestation Length, Birth Weight, and Pre-weaning Daily Gain in Hanwoo

Relationships of Weaning Weight with Gestation Length, Birth Weight, and Pre-weaning Daily Gain in Hanwoo

Performance Evaluation of Barbari Goats in Semi-Arid Region of India: A Review

Barbari goat, a medium sized dual purpose goat breed in India, is known for its good lactation performance, high prolificacy, early maturity, low kidding interval, high kidding rate and better growth rate. The average weights of kids at birth, 3, 6, 9 and 12 month of age were 1.66±0.47, 5.88±0.41, 9.36±0.17, 12.85±0.25 and 16.08±0.35 kg, respectively. The average pre-weaning (0–3 months) daily weight gain was 59.9 g while post weaning (3–12 months) gain was 43.4 g. The feed conversion efficiency of this breed was 8.27±0.40% and is reported to vary from 6 to 10%. The average lactation milk yield at 90 and 140 days of lactation was 49.59±3.71 and 67.56±7.60 l, respectively with an average lactation length of 143.19 days. Regarding reproductive performance, the age of first mating and first kidding for this breed is reported as 12–14 and 17–19 months, respectively. The single, twin and triplet kidding varied from 50.6 to 59.0%, 32.3 to 39.8% and 5.59 to 10.67%, respectively. The average slaughter weight (kg), carcass weight (kg) and dressing (%) of adult animal of this breed was 25.57±1.73, 11.54±0.85 and 45.11±1.61 respectively. As the population of the breed in its home tract is declining over the years, so, there is a need for conservation of this breed. The central institute for research on goats (CIRG), Makhdoom, Uttar Pradesh, India has initiated to conserve this breed in its home tract. Keywords : Barbari goat, growth performance, milk yield, carcass evaluation, India Cite this Article Ajoy Mandal, Behera R, Rai S et al. Performance Evaluation of Barbari Goats in Semi-Arid Region of India: A Review. Research & Reviews: Journal of Dairy Science and Technology . 2016; 5(2): 25–29p.

Genetic parameter estimation for pre-weaning growth traits in Jordan Awassi sheep.

Aim:The aim of this study was to estimate the heritability, genetic and phenotypic correlations, and the genetic trends for pre-weaning growth traits including the birth weight (BWT), weaning weight (WWT), pre-weaning daily gain (PWDG), and weaning age (WA) in Awassi lambs.Materials and Methods:A total of 5131 Awassi lambs from two Jordanian sheep breeding stations were used. A multitrait animal model and restricted maximum likelihood methods were used to estimate the covariances between the studied traits.Results:The mean±standard deviation of BWT, WWT, PWDG, and WA was 4.48±0.8 kg, 17.13±0.7 kg, 0.2±0.07 g, and 65.5±0.7 days, respectively. Heritability estimates were 0.30±0.04 for BWT, 0.19±0.04 for WWT and PWDG, and 0.2±0.04 for WA. Positive genetic correlations were obtained between BWT and other traits, while negative correlations were obtained between WWT, PWDG, and WA (−0.50±0.12) and between WWT and WA (−0.67±0.14). The positive phenotypic correlation was obtained between WA and PWDG (0.63±0.01). The highest additive genetic variance was obtained for WA (34.58), while the lowest was estimated for PWDG (6.22E-04). The highest phenotypic variance was obtained for WA (175.5), while the lowest value obtained was for BWT (0.54). Maternal additive variance ranged between 0.13 and 0.03. The genetic trends were around zero for all studied traits.Conclusion:Selection should be conducted using animals with high estimated breeding values through controlled breeding.

Analysis of genetic parameters and genetic trends for early growth traits in Iranian Afshari sheep

The purpose of the present study was estimation of genetic parameters and genetic trends of early growth traits using Bayesian approach by Gibbs3f90 software in Iranian Afshari sheep. The data set [birth weight (BW), weaning weight (WW) and pre-weaning daily weight gain (PWDG)] were collected during the period 1999 to 2010 from Agriculture Jahad of Zanjan province, Iran. The fitted fixed effects were herd-year-season as interactions, sex (male, female), birth type (single, multiple) and age of dam. Based on Derivative Information Criteria (DIC), for studied traits the most appropriate model was determined. Therefore, based on the most appropriate fitted model, the direct additive heritabilities estimate for BW, WW and PWDG were 0.32?0.02, 0.05?0.01 and 0.24?0.02, respectively. The estimates of maternal heritabilities were 0.17?0.04, 0.07?0.02 and 0.12?0.05 and total heritabilities 0.11?0.05, 0.08?0.02 and 0.08?0.03 for BW, WW and PWDG, respectively. Direct genetic trends were positive for all traits but only significant for BW 0.75?0.31 g/year (P &lt;0.05). Also, maternal genetic trends were for all traits negative and was significant for BW -0.63?0.27 g/year (P &lt;0.05). The moderate estimates of heritabilities for early growth traits indicate that in Afshari sheep faster genetic improvement through selection is possible for these traits. Furthermore, the results genetic trends in this current study indicated that genetic improvement through selection is suitable only for BW in Afshari sheep.