Gir Breed Research Articles

Genome-wide association study for milk yield, frame, and udder conformation traits of Gir dairy cattle

Genome-wide association studies (GWAS) are employed to identify genomic regions and candidate genes associated with several traits. The aim of this study was to perform a GWAS to identify causative variants and genes associated with milk yield, frame, and udder conformation traits in Gir dairy cattle. Body conformation traits were classified as "frame," and "udder" traits for this study. After genotyping imputation and quality control 42,105 polymorphisms were available for analyses and 24,489 cows with pedigree information had phenotypes. First, P-value was calculated based on the variance of the prediction error of the SNP-effects on the first iteration. After that, 2 more iterations were performed to carry out the weighted single-step genome-wide association methodology, performed using genomic moving windows defined based on linkage disequilibrium. The significant SNPs and top 10 windows explaining the highest percentage of additive genetic variance were selected and used for QTL and gene annotation. The variants identified in our work overlapped with QTLs from the animal QTL database on chromosomes 1 to 23, except for chromosome 4. The Gir breed is less studied than the Holstein breed and as such the animal QTL database is biased to Holstein results. Hence it is noteworthy that our GWAS had similarities with previously described QTLs. These previously known QTLs were related to milk yield, body height, rump angle, udder width, and udder depth. In total, 5 genes were annotated. Of these genes, FAM13A and CMSS1 had been previously related to bone and carcass weight in cattle.

Resultado de dois protocolos de tratamento para otite parasitária em gado Gir

ABSTRACT Parasitic otitis in cattle is normally caused by nematodes of the genus Rhabditis spp. and is a common problem in Gir breed. Parasitic otitis can cause premature culling and even death of animals. Despite its importance, there is no effective standardized treatment protocol for this condition. The objective of this study was to evaluate two treatments for parasitic otitis caused by Rhabditis spp. in Gir cattle. The external left ear of the animals was washed with 2% boricated alcohol, while the right ear received topical application of Triclorfon, allantoin and zinc oxide paste. The treatments were performed weekly in the first month and monthly over the next two months. Monthly, the ears of all animals were washed under pressure with a physiological solution before treatment. The recovered solution was analyzed, and the number of nematodes counted. Neither treatment was effective in reducing the number of nematodes recovered or the otitis score, but weekly treatment seemed more promising, independent of the drug used.

Conservation and Multiplication of Indigenous Animals (Bos indicus) Through in vitro Embryo Production

The objectives of the study were conservation and multiplication of superior germplasm in cattle by ovum pick up-In vitro fertilization technology, standardization of OPU process and standardization of IVF techniques/process. for this purpose, indigenous breeds viz. dangi, deoni, gaolao, gir, red kandhari and sahiwal reared in BAIF’s central cattle breeding farm were selected on the basis of minimum standard protocol set by Govt. of India. OPU was performed to aspirate the oocytes followed by IVM and the matured oocytes were processed for IVF which then kept for In vitro Culture (IVC). A total of 891 OPU Sessions were carried out. Totally 6416 oocytes were processed for In vitro culture and 2016 embryos were produced. The effect of breed, age of the animal and interval between two OPU sessions were evaluated for both number of oocyte and embryos produced per session. The average breed wise oocyte recovery was 6.58±0.45 and the average breed wise embryo production was 2.11±0.33 per session. Breed of cow and age at collection of oocyte were found to be significantly affecting the oocyte and embryo production. It was found that Gir breed has better oocyte recovery and embryo production efficiency in our study. Gir, Dangi and Sahiwal presented higher oocyte recovery and embryo production followed by Deoni, Gaolao and Red Kandhari. In conclusion, the process is standardized for Ovum Pick Up, In vitro Maturation, In vitro Fertilization, and In vitro Culture.

Evaluation of Rumen Methane Emission in Sahiwal and Gir Calves Supplemented with Combination of Methanogenic Inhibitors

Methane is one of the main greenhouse gases emitted by ruminants around the world. It is essential to investigate novel approaches to increasing animal production while reducing greenhouse gas emissions from ruminants. This study was conducted to examine the effect of methane inhibitors, such as nitrate, linseed oil, and anthraquinone, on nutritional digestibility, rumen fermentation processes, and methane emission in Sahiwal and Gir cattle calves. Twelve calves (6–12 months old), six of each Sahiwal and Gir breed, were selected and divided into four groups; Sahiwal control (C) and treated (T) calves; Gir control (C) and treated calves (T) of three calves each based on average body weight. Switch over a design was used as for periods 1 and 2. Animals in all groups were fed chopped oat fodder, wheat straw, and a concentrate mixture. Additionally, treated groups were fed a ration with potassium nitrate (1%), linseed oil (0.5%), and anthraquinone (4 ppm). The results revealed that the addition of methane inhibitors had no impact on nutrient intake and apparent digestibility. The levels of propionate, ammonia nitrogen, and total nitrogen were increased significantly (p < 0.05), while butyrate decreased in the treated groups of both breeds. However, there was no change in acetate and pH between the groups. Methane emission (g/d) was lower (p < 0.05) in the treated groups as compared to the control group. This study concludes that supplementation of methane inhibitors in calves feed can be utilized to lower methane emissions without affecting the intake and digestibility of nutrients. Combining diverse dietary mitigation strategies could be an effective way to mitigate methane emissions to reduce global warming while minimizing any negative impacts on ruminants to accomplish sustainable animal production.

Imputation accuracy for genomic selection using embryo biopsy samples in Gir

The aim of this study was to establish a platform for genomic selection of in vitro-fertilized (IVF) Gir embryos. Multiple displacement amplification (MDA)-based embryo biopsy samples were genotyped, and genomic estimated breeding values (GEBV) for milk yield (305MY) were calculated. The concordance of GEBV and accuracy between embryo biopsies and the respective liveborn were assessed. Imputation was performed using two panels (Z-Chip and Bovine HD, Illumina) based on a database of 73,110 lactating cow’s database and pedigree files from 147,131 animals. Biopsied embryos had similar pregnancy rates (39% vs 40%), pregnancy loss rates (18% vs 20%), and pregnancy length compared to Control embryos. After genotyping, low call rate means were detected for biopsy samples compared to the respective calf samples (0.80 vs 0.98). Imputation presented 0.83 (Z-Chip) and 0.96 (HD) accuracy (CORRanim). Embryo GEBV accuracy levels were higher in BovineHD imputation (0.82) than Z-Chip imputation (0.55) or no imputation (0.62), and the correlation between embryo/calf pairs’ accuracy was 0.85 for BovineHD imputation, 0.11 for Z-Chip imputation, and 0.02 for no imputation. GEVB estimates correlation between embryo/calf pairs was 0.87 for BovineHD imputation, 0.80 for Z-Chip imputation, and 0.41 before imputation. The call rate of embryo samples did not affect the correlation between embryo/calf pairs for accuracy and GEBV before and after BovineHD imputation. Embryos obtained on the same farm presented GEBV 305MY differences of up to 800 kg, emphasizing the expected impact of embryo genomic selection for the Gir breed.

Potential status of A1 and A2 variants of bovine beta-casein gene in milk samples of Indian cattle breeds

This study aimed to determine the polymorphism in 7th exon of beta-casein gene (CSN2) gene in seven domestic (Kosali, Tharparkar, Gangatiri, Sahiwal, Gir, Khariar, Motu) and two exotic cattle breeds (Jersey and Holstein-Friesian). Genomic DNA was extracted from 1000 milk samples, and the C > A polymorphism in CSN2 was determined using the tetra-primer amplification refractory mutation system-polymerase chain reaction method. In all Indigenous cattle breeds, the mean frequency of A1A2 and A2A2 genotypes was 0.19 and 0.80, respectively. The A1A1 genotype was absent in all seven domestic cattle breeds. The frequency of the A2A2 genotype was highest in the Gir breed (0.93). However, the Sahiwal, Tharparkar, and Motu breeds also had a higher frequency of A2A2 genotype compared to other breeds. In contrast, Gangatiri breed of India showed lowest frequency of A2A2 genotype. The mean A1 and A2 allele frequency was 0.09 and 0.91, respectively. In exotic breeds, the mean frequencies of the A1A1, A1A2, and A2A2 genotypes were 0.42, 0.55, and 0.03, respectively. Similarly, the mean A1 and A2 allele frequency was 0.69 and 0.31, respectively. This study suggests the high potential of Gir, Sahiwal, Tharparkar, and Motu cattle for A2 milk production since they carry a favorable A2 genotype.

Identification of copy number variations in the genome of Dairy Gir cattle.

Studying structural variants that can control complex traits is relevant for dairy cattle production, especially for animals that are tolerant to breeding conditions in the tropics, such as the Dairy Gir cattle. This study identified and characterized high confidence copy number variation regions (CNVR) in the Gir breed genome. A total of 38 animals were whole-genome sequenced, and 566 individuals were genotyped with a high-density SNP panel, among which 36 animals had both sequencing and SNP genotyping data available. Two sets of high confidence CNVR were established: one based on common CNV identified in the studied population (CNVR_POP), and another with CNV identified in sires with both sequence and SNP genotyping data available (CNVR_ANI). We found 10 CNVR_POP and 45 CNVR_ANI, which covered 1.05 Mb and 4.4 Mb of the bovine genome, respectively. Merging these CNV sets for functional analysis resulted in 48 unique high confidence CNVR. The overlapping genes were previously related to embryonic mortality, environmental adaptation, evolutionary process, immune response, longevity, mammary gland, resistance to gastrointestinal parasites, and stimuli recognition, among others. Our results contribute to a better understanding of the Gir breed genome. Moreover, the CNV identified in this study can potentially affect genes related to complex traits, such as production, health, and reproduction.

Geographical distribution of zebu breeds and their relationship with environmental variables and the human development index

The environment is vital to the agricultural sector since it can cause adversities throughout the entire productive chain. This study evaluated the geographical distribution of zebu breeds in Brazil and correlated their occurrence with environmental variables and the human development index. Herds of purebred zebu cattle (Bos indicus) in Brazil were classified as beef, dairy, and dual-purpose breeds, and all breeds were spatialized in the ArcGIS program. Environmental (precipitation, temperature, relative humidity index) and the human development index (HDI) were examined. We conducted regression and logistic analyses. Zebu cattle showed a lower distribution in the Northeastern states compared to other locations, possibly due to harsh weather conditions, namely long periods of high temperatures and lower precipitation, directly affecting local livestock. Beef breeds were evenly spread throughout the country in regions influenced by environmental variables of higher precipitation, normalized difference vegetation index (NDVI), temperature, relative humidity (RH), and temperature humidity index (THI), as well as properties without smallholder farmers and rivers and streams with riparian vegetation. The regions for dual-purpose and dairy breeds were predominantly cultivated with cutting forages (e.g., sugarcane - Saccharum officinarum), with the integration of crops, livestock and/or forestry (i.e., combining different activities in the same area) and areas with a rotational grazing system (i.e., grazing management), indicating a higher occupation in fertile lands. The Gir breed, the only dairy breed evaluated in this study, was seen in establishments with smallholder farmers, characterized by small to medium farms, and in regions at higher altitudes.

Genomic breed composition of pure registered Brazilian Gir.

Gir is a Bos indicus breed originally from India, first imported to Brazil in 1850. High-performance Dairy Gir has been systematically selected in Brazil from its arrival. Since the major phenotypic difference between Gir in India and Brazil is a higher milk production in the former, it is speculated that Brazilian Gir was strategically crossed with Holstein or another Bos taurus to improve milk yield. This study evaluated the purity of Brazilian Gir breed stocks from BASA Farms in Brazil, trying to identify possible admixture events with other cattle breeds based on DNA analysis. The population included 1061 pure registered individuals genotyped using two commercial platforms with 37 k and 25 k SNPs. Admixture analysis was performed individually to estimate levels of genomic composition derived from six different reference populations, three indicine and three taurine breeds. A Gir ancestry of 99% or higher was found for 94.2% of the population, while the remaining showed levels of non-Gir ancestry up to 6.8%. Only five individuals were identified with possible taurine ancestry, all of them exhibiting levels lower than 2%. The remaining non-Gir ancestry identified was derived from indicine breeds. The levels of admixture observed in the population were from low to non-detectable. No consistent patterns of admixture were observed indicating sustained introgression of taurine lines as means of genetic improvement. According to these results, genetic improvement achieved by Brazilian Gir breeders is the result of within-breed selection methods applied intensively over the past five decades, rather than the result from sustained introgression.

Analysis of the epidemiological variables associated with a high prevalence of bovine surra in the Chhattisgarh state of India.

Trypanosoma evansi, a unicellular haemoflagellate, causes surra in bovines and other economically important livestock species. We report here the epidemiological variables associated with the high prevalence of T. evansi infection in cattle in the plain agro-climatic zone of Chhattisgarh state, India. A total of 920 blood and sera samples were tested by a combination of parasitological, molecular and serodiagnostic tests. An overall prevalence of T. evansi was recorded as 4.57% (95% CI: 3.22-5.92%), 6.09% (95% CI: 4.54-7.63%), 63.91% (95% CI: 60.81-67.01%) and 55.33% (95% CI: 52.12-58.54%) by direct microscopy, PCR, ELISA and IFAT, respectively. The Chi-Square test established a significant correlation between the prevalence of T. evansi and the season, breed and place of the study, while the association with the gender and age of the animals was insignificant. The analysis of the prevalence ratio revealed a significant association of the breed, season and place of study with the prevalence of T. evansi. As per PR observed, the prevalence was 1.63 times higher in summer and 1.68 times higher in the rainy season than in the winter (reference season). The prevalence was higher in all the districts as compared to Rajnandgaon (reference district). The prevalence ratio in Sahiwal and HF cross-breed cattle was significantly higher than the Gir breed of cattle (reference). Durg district recorded the highest prevalence of surra, and the difference was significant. The medium IFAT titre, determined in a large number of sera collected from Durg, predicted a higher incidence of trypanosomosis in that district. Since T. evansi has a broad host range, the study predicted that a large population of livestock in Chhattisgarh state were at high risk of T. evansi infection. Treatment of the subclinically and clinically infected animals with selective curative drugs, such as diminazene aceturate, isometamidium chloride or the combination of quinapyramine sulphate and quinapyramine chloride, could help restore productivity and help in containing the infection.

Characterization of runs of homozygosity, heterozygosity-enriched regions, and population structure in cattle populations selected for different breeding goals

BackgroundA decline in the level of genetic diversity in livestock can result in reduced response to selection, greater incidence of genetic defects, and inbreeding depression. In this context, various metrics have been proposed to assess the level of genetic diversity in selected populations. Therefore, the main goals of this study were to: 1) investigate the population structure of 16 cattle populations from 15 different pure breeds or composite populations, which have been selected for different breeds goals; and, 2) identify and compare runs of homozygosity (ROH) and heterozygosity-enriched regions (HER) based on different single nucleotide polymorphism (SNP) panels and whole-genome sequence data (WGS), followed by functional genomic analyses.ResultsA total of 24,187 ROH were found across all cattle populations, with 55% classified in the 2-4 Mb size group. Fourteen homozygosity islands were found in five populations, where four ROH islands located on BTA1, BTA5, BTA16, and BTA19 overlapped between the Brahman (BRM) and Gyr (GIR) breeds. A functional analysis of the genes found in these islands revealed candidate genes known to play a role in the melanogenesis, prolactin signaling, and calcium signaling pathways. The correlations between inbreeding metrics ranged from 0.02 to 0.95, where the methods based on homozygous genotypes (FHOM), uniting of gametes (FUNI), and genotype additive variance (FGRM) showed strong correlations among them. All methods yielded low to moderate correlations with the inbreeding coefficients based on runs of homozygosity (FROH). For the HER, 3576 runs and 26 islands, distributed across all autosomal chromosomes, were found in regions containing genes mainly related to the immune system, indicating potential balancing selection. Although the analyses with WGS did not enable detection of the same island patterns, it unraveled novel regions not captured when using SNP panel data.ConclusionsThe cattle populations that showed the largest amount of ROH and HER were Senepol (SEN) and Montana (MON), respectively. Overlapping ROH islands were identified between GIR and BRM breeds, indicating a possible historical connection between the populations. The distribution and pattern of ROH and HER are population specific, indicating that different breeds have experienced divergent selection processes or different genetic processes.

Test day yield, lactation curve and production potential of Gir cattle under hot and humid conditions of Tamil Nadu

Test day milk yield records (5130), milk production and milk composition traits from 19 lactations of Gir cows collected for two years (2019 and 2020) were used to understand the performance of Gir breed in hot and humid conditions of Tamil Nadu. Different lactation curve models were used for modelling test day records and model diagnostics like adjusted R-square, BIC and RMSE were used to obtain the model of best fit. The mean test day yield, fat per cent, SNF (%), total milk yield, peak yield, days to attain peak yield and calving interval observed were 5.78 kg, 5.05%, 7.65%, 1507 kg, 9.23 kg, 46.5 days and 447 days respectively. Ali and Shaeffer model offered the best fit for lactation curve in Gir cows. Mahadevan method and Gamma function were used to calculate the persistency of milk yield which was obtained as 1.33 and 6.348 respectively. Results of the study indicated that Gir cattle were able to adapt themselves through maintenance of reproductive traits comparable with that of the native tract but the new humid environment has caused a slight decrease in the performance of milk production traits.

Repeatability and random regression models to estimate genetic parameters for oocyte and embryo production in the Gir breed

Context Greater production of oocytes and embryos from Gir donors contributes to greater fertility and genetic progress. Aims This study aimed to obtain genetic parameters for oocyte and embryo production in the Gir breed. Methods Repeatability and random regression models were applied to data consisting of 17 526 Ovum Pick Up observations from 1641 Gir donors from five different herds. Single and multi-trait analyses were carried out with the application of both models for the traits: number of viable oocytes, number of total oocytes and number of embryos, using the BLUPF90 family programs. Legendre polynomials of second order were used in the random regression model. Key results Considering the repeatability model, additive genetic variance ranged from 0.06 to 0.13 and permanent environment variance ranged from 0.05 to 0.08 for all evaluated traits. Residual variance ranged from 0.30 to 0.45. Heritability estimates were 0.10 for number of embryos, 0.24 for total oocytes, and 0.25 for viable oocytes. Repeatability estimates were moderate, ranging from 0.20 to 0.40, and genetic correlation estimates were always above 0.80. Phenotypic correlation was high only between viable and total oocytes (0.95), and moderate in the other cases. Random regression model results were consistent with those from the repeatability model. The heritability values remained similar throughout the donors’ ages, with moderate values for viable and total oocytes, and low values for number of embryos. Genetic correlations among ages for each trait were moderate to high. Also, the genetic correlations between traits within each age were high, with values always above 0.7. Conclusions Selection of Gir donors for total oocyte production at any time, between 1 and 16 years of age, might lead to an increase in the number of viable oocytes and embryos obtained, but it’s preferable at younger ages to hasten genetic progress. Repeatability models could be the best method, as they require less computational effort when compared to the random regression models and the parameter estimates do not vary substantially throughout different ages of the donor. Implications The use of repeatability models to estimate genetic parameters of oocytes and embryos resulted in similar results compared to random regression models.

Cattle and Buffalo Genetic Resources of India

There are 50 registered breed of cattle and 19 breeds of buffalo in the country, these breeds are well adapted to diverse climate of the country and contributing significantly to the livelihood. India possesses 193.4 million cattle and 109.85 million buffalo in the year 2019. The crossbred and buffalo population has increased all the time since the livestock census initiated. Among the cattle and buffalo, 52% cattle and 45.4% buffalo population are non-descript and need to be defined on priority so their development programs can be initiated. India is home of best breeds of buffalo in the world i.e. Murrah and Sahiwal, Gir, Ongole and Tharparkar breeds of cattle. Mehsana and Niliravi are the breeds of buffalo those are equally good in performance in the country. Gir breed of cattle and Murrah breed of buffalo had maximum heads in the country. Breed wise trends during the years 2013-2022, showed that among the 37 cattle breeds included in breed survey/census, 15 are showing increasing trends and 22 showed declining trends. In buffalo, 13 breeds were included in breed survey/census, 4 are showing declining trends and 9 showed increasing trends. For improving the bovines in the country, we need to define non-described bovines on priority and registered unique population as distinct breed, if eligible, accurate breed census/survey, performance recording system at farmers door, ensure availability of superior germplasm, more population to be covered through Artificial Insemination and establishment of breed societies and breed nucleus farms adopting open nucleus breeding system.

Diagnostic performance of the BHBCheck β-hydroxybutyrate meter for hyperketonaemia in Indian cows and buffaloes.

The objective of the study was to evaluate the diagnostic performance of the electronic handheld BHBCheck meter (BHM) (PortaCheck, Inc., USA) to determine whole blood, plasma and serum β-hydroxybutyrate (BHB) against serum BHB determined using reference laboratory method of Randox D-3 Hydroxybutyrate Ranbut assay (RSM) in Indian dairy cows and buffaloes. Blood samples were collected by puncturing coccygeal vessels for determining whole blood, serum and plasma BHB using BHM and serum BHB using RSM from 217 cows (Gir breed; median 42 DIM and 3rd lactation) and 223 buffaloes (non-descript; median 39 DIM and 3rd lactation) from nearby herds. The Pearson's correlation between whole blood (0.988; 0.987), plasma (0.985; 0.983) and serum (0.985; 0.983) BHB determined using the BHM and serum BHB determined with the RSM in Indian cows and buffaloes, respectively, were significant. Bland-Altman plot demonstrated an excellent agreement between whole blood, plasma and serum BHB determined with BHM, against the serum BHB determined with RSM in Indian cows and buffaloes, respectively. For hyperketonaemia with reference serum BHB cut-off values ≥ 1.2 and 1.4mmol/L determined with RSM, it recorded optimized BHB thresholds, sensitivity and specificity for whole blood (≥ 0.9 to 1.0mmol/L; 91 to 95% and 88 to 98%), plasma (≥ 0.9 to 1.0mmol/L; 91 and 100%) and serum (≥ 0.9 to 1.0mmol/L; 92 to 100% and 85 to 94%) with BHM in cows and buffaloes, respectively. In conclusion, BHB determined with BHM demonstrated an excellent correlation, agreement and test characteristics with BHB determined with RSM and hence can accurately determine whole blood, plasma and serum BHB in cows and buffaloes.

Estimation of genomic breeding values in Gir cattle using Bayesian methods

The paper evaluates different Bayesian methods in estimating genomic breeding values using a female reference population of Gir breed and assesses their predicting ability and compares the results achieved with those using Genomic Best Linear Unbiased Prediction (GBLUP). In the current study, BayesA, BayesB, BayesCπ, Bayes Lasso, and Bayes-GBLUP methods were used on the same dataset that employed GBLUP and compared the predicting ability of methods using the same five cross-validation data sets. Phenotypic standard 305-day lactation records of 2571 Gir cows extracted from the INAPH database were used in the current study. The milk yield records were pre-corrected for environmental effects. All 2571 cows were genotyped using INDUSCHIP developed by National Dairy Development Board (NDDB). The correlation of SNP effects between BayesCᴨ and Bayesian Lasso was 0.99 and their correlations to BayesA and BayesB were 0.814 and 0.685 respectively. The correlation of SNP effects of BayesA and BayesB was 0.977. The correlations between the predicted genomic breeding values and the corrected phenotypic values in all methods were about 0.89 and those between estimated genomic breeding values of different Bayesian methods were equal to one. On comparison of the correlations between estimated genomic breeding values and corrected phenotypic values of five cross-validation data sets for each of five Bayesian methods, it was observed that the Bayes-GBLUP performed better than GBLUP and also better than all other four Bayesian methods. The other four Bayesian methods BayesA, BayesB, BayesCᴨ, and BayesBL performed slightly better than GBLUP. The correlations among them were more or less the same. From the current study, it could be concluded that Bayesians methods are very useful in estimating both genetic marker effects associated with QTLs and genomic breeding values and that they could be applied in practice for selecting young calves without phenotypic records, based on their genomic breeding values with reasonably high confidence.

Genomic selection in Gir cattle using female reference population

When a sizeable reference population of proven bulls is not available for implementing Genomic selection for a particular trait, and when a recording of certain traits on large scale is difficult, the use of a female reference population is recommended. Gir, one of the important milk purpose cattle breeds of India falls under this category. There is no large scale Progeny Testing (PT) programme in Gir, so proven bulls based on daughter performance in large numbers are not available. Considering the constraints, a genomic BLUP (GBLUP) model was implemented based on recorded cow reference population in Gir breed. Cows (3491) and 23 bulls were genotyped using INDUSCHIP for this purpose. Due to non-availability of pedigreed data, conventional breeding values (BV) of bulls and their reliabilities were not known. For comparison, assumed theoretical reliability of BV of a bull selected based on its dam's yield was compared with reliability obtained for genomic breeding value (GBV) using a GBLUP model. The reliability estimates for GBVs were 4 times higher than that for BVs. The predictive ability of the model was demonstrated by measuring the correlation between corrected phenotypes and GBVs for animals whose records were masked in a five-fold cross-validation study. The correlation was around 0.45 showing reasonable predictability of the GBLUP model. The GBVs were not biased. The regression coefficient between the corrected phenotype and GBV was 1.045. The present study demonstrates that it is feasible to implement genomic selection in Gir cattle in Indian conditions using a female reference population. It is expected that the bulls can be selected with around 4 fold more accuracy than the current method of selecting based on their dams' yield accelerating expected genetic growth in Gir cattle.

Productive diagnosis of Girolando cows on a farm in Alto Sertão Sergipano

Girolando breed has several blood grades, from 1/4 Dutch (Hol) x 3/4 Gir (G), to 7/8 Hol x 1/8 G. These animals have good milk production characteristics inherited from the Dutch breed and a good acquired rusticity of the Gir breed. In view of this, this work aimed to evaluate the productive performance of three different blood grades of the Girolando breed on a farm in the Alto Sertão Sergipano. For the research, the data used referred to the highest production in 305 days of distinct lactations, between the first and the fourth lactation. The blood grades evaluated were: 1/2 HG (G1); 3/4 HG (G2) and 7/8 HG (G3). For the diagnosis, the Individual Control Chart was used, which is one of the tools of the Statistical Process Control (SPC), with the purpose of evaluating and controlling, in a global way, all the production. The results obtained do not demonstrate superiority of production among the three genetic groups. However, the G1 group showed the highest regularity in milk production, with the highest average production and the lowest average range. However, in order to obtain a better diagnosis of milk production, more studies are needed addressing milk production in 305 days with different blood grades of the Girolando breed, in the Alto Sertão Sergipano region.

Single-step genome-wide association studies (GWAS) and post-GWAS analyses to identify genomic regions and candidate genes for milk yield in Brazilian Girolando cattle

Milk production is economically important to the Brazilian agribusiness, and the majority of the country's milk production derives from Girolando (Gir × Holstein) cows. This study aimed to identify quantitative trait loci (QTL) and candidate genes associated with 305-d milk yield (305MY) in Girolando cattle. In addition, we investigated the SNP-specific variances for Holstein and Gir breeds of origin within the sequence of candidate genes. A single-step genomic BLUP procedure was used to identify QTL associated with 305MY, and the most likely candidate genes were identified through follow-up analyses. Genomic breeding values specific for Holstein and Gir were estimated in the Girolando animals using a model that uses breed-specific partial relationship matrices, which were converted to breed of origin SNP effects. Differences between breed of origin were evaluated by comparing estimated SNP variances between breeds. From 10 genome regions explaining most additive genetic variance for 305MY in Girolando cattle, 7 candidate genes were identified on chromosomes 1, 4, 6, and 26. Within the sequence of these 7 candidate genes, Gir breed of origin SNP alleles showed the highest genetic variance. These results indicated QTL regions that could be further explored in genomic selection panels and which may also help in understanding the gene mechanisms involved in milk production in the Girolando breed.

Effect of seasons on physiological responses, milk production and composition in Indigenous cows

The present investigation was carried out to find the effect of seasons on milk production and composition in indigenous Sahiwal, Tharparkar and Gir cows maintained under the intensive management practices at the institute livestock farm. Fifteen lactating cows of Tharparkar (TP), Sahiwal (SW) and Gir breed were selected in early lactation. The experiment was conducted for a period of 10 months and the seasons were categorized as hot-humid, hot-dry, autumn and winter season. Blood and milk samples collected at fortnightly intervals were analysed for minerals and plasma hormones. Physiological responses-respiration rate (RR), pulse rate (PR) and rectal temperatures (RT) were recorded. The results showed that the milk fat, solid not fat SNF and urea levels were higher in TP cows in comparison to SW and Gir cows (p<0.01), however, protein % was lower (p<0.01) in TP cows. Milk Mg, Ca and Na levels were lower in hot-humid season than in winter season (p<0.05) in TP cows in comparison to SW and Gir. Plasma cortisol level was higher and aldosterone level was lower in hot-humid and hot-dry season in all the breeds of cows (p<0.05) than the values observed in winter season. TP cows were found to have higher aldosterone level as compared to SW and Gir cows in all the seasons. The cows response to ambient temperature in terms of RR, RT and PR was higher in hot-humid season and lowest in winter season (p< 0.01) in all the breeds, however changes in RT were of less magnitude in TP cows than SW and Gir cows in hot-hot humid season. It was concluded that TP cows have higher plasma aldosterone, milk urea and sodium levels and less diurnal variation in RT, PR and RR in comparison to SW and Gir cows in hot-dry and hot humid season which makes TP cows more heat tolerant than SW and Gir.