Zebu Breeds Research Articles

Attention module incorporated transfer learning empowered deep learning-based models for classification of phenotypically similar tropical cattle breeds (Bos indicus).

Accurate breed identification in dairy cattle is essential for optimizing herd management and improving genetic standards. A smart method for correctly identifying phenotypically similar breeds can empower farmers to enhance herd productivity. A convolutional neural network (CNN) based model was developed for the identification of Sahiwal and Red Sindhi cows. To increase the classification accuracy, first, cows's pixels were segmented from the background using CNN model. Using this segmented image, a masked image was produced by retaining cows' pixels from the original image while eliminating the background. To improve the classification accuracy, models were trained on four different images of each cow: front view, side view, grayscale front view, and grayscale side view. The masked images of these views were fed to the multi-input CNN model which predicts the class of input images. The segmentation model achieved intersection-over-union (IoU) and F1-score values of 81.75% and 85.26%, respectively with an inference time of 296ms. For the classification task, multiple variants of MobileNet and EfficientNet models were used as the backbone along with pre-trained weights. The MobileNet model achieved 80.0% accuracy for both breeds, while MobileNetV2 and MobileNetV3 reached 82.0% accuracy. CNN models with EfficientNet as backbones outperformed MobileNet models, with accuracy ranging from 84.0% to 86.0%. The F1-scores for these models were found to be above 83.0%, indicating effective breed classification with fewer false positives and negatives. Thus, the present study demonstrates that deep learning models can be used effectively to identify phenotypically similar-looking cattle breeds. To accurately identify zebu breeds, this study will reduce the dependence of farmers on experts.

Current population size and risk status of the indigenous endangered Sheko cattle breed in south-west Ethiopia

This study assessed the current population size and risk status of the indigenous endangered Sheko cattle breed in four zones of South West Ethiopia. The Sheko cattle breed, known as the last remnants of Africa’s original Bos taurus cattle and the only trypanotolerant breed in Ethiopia, is facing a decline in their effective population size. The estimated population size of Sheko cattle is approximately 7252, with varying levels of genetic purity based on physical observations. The distribution of genetic purity levels of Sheko cattle indicates that there are approximately 4073, 2934, and 1145 individuals at the 1st (>80% pure), 2nd (>60% pure), and 3rd (>40% pure) levels, respectively. The breed is at risk due to factors such as aggressive behavior, interbreeding with zebu breeds, lack of pure Sheko bulls, and lack of awareness creation. To conserve the Sheko cattle breed, measures such as backcrossing to purebreds, genetic monitoring and evaluation, molecular characterization, assessment of genetic admixture and inbreeding, and collaboration among stakeholders are essential. Overall, this research emphasizes the urgent need for coordinated efforts to safeguard the genetic diversity and population size of the Sheko cattle breed.

Impact of diversified grazing systems on milk production, nutrient use and enteric methane emissions in dual-purpose cows.

This study evaluated three continuous grazing systems: Brachiaria Brizantha, Clitoria ternatea and naturalized pastures, complemented with commercial concentrate and C. ternatea silage on milk yield, nutrient use and enteric methane (CH4) emissions. Nine multiparous cows of local Zebu breeds, with an average weight of 448 ± 87kg, were used. The chemical composition of the food was determined. Live weight, milk production, and quality were assessed. Furthermore, serum urea, urea nitrogen, creatinine and glucose in blood were monitored, and nitrogen use efficiency were calculated. Enteric methane (CH4) emissions were estimated using Tier-2 methodology. A 3 × 3 latin square experimental design was applied. The grazing systems of B. brizantha and C. ternatea had the greater live weights of 465.8 and 453.3kg/cow, although the latter is similar to naturalized pasture. Milk production and quality were not affected by grazing system, with the exception of the non-fat solids, where the C. ternatea system was lower (102.2g/kg) than the other grazing systems. The crude protein and N intake, and N excretion in feces and urine were lower in naturalized pasture systems (1139.0g/day). N outputs in milk was high in the C. ternatea system (56.3g/cow/day). The naturalized pastures systems showed the better feed use efficiency (25.7%) compared to others. Serum urea and blood urea nitrogen were greater in B. brizantha followed by C. ternatea. Enteric CH4 emissions were indifferent among grazing systems when expressed as a percentage of greenhouse gases (7.1%). In conclusion, the grazing C. ternatea supplemented with commercial concentrate and C. ternatea silage maintains milk production and quality, reduced cow/day emissions (by 2.5%) and lowered energy losses as methane.

Analysing the genetic diversity and population structure of five native Turkish cattle breeds using SNP data.

The conservation and sustainable utilization of cattle genetic resources necessitate a comprehensive understanding of their genetic diversity and population structure. This study provides an analysis of five native Turkish cattle breeds: Anatolian Black (ANB), Turkish Grey (TUR), Anatolian Southern Yellow (ASY), East Anatolian Red (EAR), and South Anatolian Red (SAN) using 50 K SNP data. These breeds were compared with three European breeds, Simmental (SIM), Holstein (HOL), and Jersey (JER), and three Asian Zebu breeds: Arabic Zebu (ZAR), Nelore (NEL), and Red Sindhi (RSI). Genetic diversity indices demonstrated moderate heterogeneity among the breeds, with TUR exhibiting the highest observed heterozygosity (Ho = 0.35). Wright's Fst values indicated significant genetic differentiation, particularly between Turkish breeds and both European (Fst = 0.035-0.071) and Asian breeds (Fst = 0.025-0.150). Principal component analysis distinguished the unique genetic profiles of each breed cluster. Admixture analysis revealed degrees of shared genetic ancestry, suggesting historical gene flow between Turkish, European, and Asian breeds. Analysis of molecular variance (AMOVA) attributed approximately 58% of the variation to population differences. Nei's genetic distances highlighted the closer genetic relatedness within Turkish breeds (distance ranges between 0.032 and 0.046) and suggested a more relative affinity of TUR with European breeds. The study's phylogenetic assessments elucidate the nuanced genetic relationships among these breeds, with runs of homozygosity (ROH) analysis indicating patterns of ancestral relatedness and moderate levels of inbreeding, particularly evident in Turkish breeds. Our findings provide valuable insights into the genetic landscape of Turkish cattle, offering a crucial foundation for informed conservation and breeding strategies aimed at preserving these breeds' genetic integrity and heritage.

Selection Signal Analysis Reveals Hainan Yellow Cattle Are Being Selectively Bred for Heat Tolerance.

Hainan yellow cattle are indigenous Zebu cattle from southern China known for their tolerance of heat and strong resistance to disease. Generations of adaptation to the tropical environment of southern China and decades of artificial breeding have left identifiable selection signals in their genomic makeup. However, information on the selection signatures of Hainan yellow cattle is scarce. Herein, we compared the genomes of Hainan yellow cattle with those of Zebu, Qinchuan, Nanyang, and Yanbian cattle breeds by the composite likelihood ratio method (CLR), Tajima's D method, and identifying runs of homozygosity (ROHs), each of which may provide evidence of the genes responsible for heat tolerance in Hainan yellow cattle. The results showed that 5210, 1972, and 1290 single nucleotide polymorphisms (SNPs) were screened by the CLR method, Tajima's D method, and ROH method, respectively. A total of 453, 450, and 325 genes, respectively, were identified near these SNPs. These genes were significantly enriched in 65 Gene Ontology (GO) functional terms and 11 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways (corrected p < 0.05). Five genes-Adenosylhomocysteinase-like 2, DnaJ heat shock protein family (Hsp40) member C3, heat shock protein family A (Hsp70) member 1A, CD53 molecule, and zinc finger and BTB domain containing 12-were recognized as candidate genes associated with heat tolerance. After further functional verification of these genes, the research results may benefit the understanding of the genetic mechanism of the heat tolerance in Hainan yellow cattle, which lay the foundation for subsequent studies on heat stress in this breed.

Animal growth models as a tool to estimate resilience indicators in Bos indicus and Bos taurus heifers: Selection effects and genetics parameters

The aim of the study is to analyze different growth models for the estimation of resilience indicators and to assess the impacts of selection for yearling weight and breed on the resilience capacity of Nelore, Guzerá and Caracu heifers. Weight records of females (n = 38,937) from birth to the measurement of weight adjusted to 550 days of age (W550) were used to fit growth curves. Next, three resilience indicators were calculated based on weight deviations (residuals): natural logarithm of residual variance (LnVar), lag-one autocorrelation (rauto), and skewness of deviations. The means of the resilience indicators were compared between Nelore selection lines (NeC: selected based on the mean of the contemporary groups for W550; NeS: selected based on the highest selection differential for W550; and NeT: selected based on an index considering highest selection differential for W550 and lower residual feed intake) and breeds (Nelore, Guzerá, and Caracu). Additionally, the heritabilities of the resilience indicators were estimated, as well as the genetic correlations between these indicators and productive traits using blupf90+ program. The results indicated that selection for yearling weight had an impact on the resilience capacity of the animals, with NeS and NeT heifers exhibiting greater weight variability (mean LnVar: 6.09 ± 0.02 and 6.12 ± 0.02, respectively) but also the highest recovery rate (rauto: 0.04 ± 0.01 and 0.04 ± 0.01, respectively). Nelore heifers were the most resilient, with a fast recovery rate (rauto: 0.01 ± 0.05) and there was little influence of the environment on performance (skewness: 0.00 ± 0.01). Caracu was the breed most affected by environmental disturbances (LnVar: 6.46 ± 0.02), with inverse subsequent weight deviations (rauto: -0.12 ± 0.05). The heritabilities of the resilience indicators were low and moderate, with the highest estimates being observed for LnVar in the three breeds (0.05 ± 0.05 to 0.38 ± 0.07). LnVar and skewness showed moderate positive genetic correlations with W550 (0.29 ± 0.18 to 0.55 ± 0.12), while the genetic correlations of rauto with W550 were weak and negative (-0.19 ± 0.17 to -0.28 ± 0.20). Selection for yearling weight influenced the resilience capability to environmental challenges in heifers during the growth phase. The results reinforce the greater adaptation capacity of zebuine breeds (Bos indicus) to tropical environments when compared to taurine breeds (Bos taurus). LnVar showed enough genetic variability to be included in breeding programs for zebu breeds aiming selection for more resilient animals.

Exploring the genetic factors behind the discrepancy in resistance to bovine tuberculosis between African zebu cattle and European taurine cattle

Caused by the pathogenic agent Mycobacterium bovis, bovine tuberculosis (bTB) is a major concern in cattle breeding due to both its zoonotic potential and economic impact. Greater resistance to this disease has been reported in certain African zebu breeds compared to European taurine breeds. However the genetic basis for the lower susceptibility to bTB infection observed in zebu cattle remains poorly explored. This study was conducted on whole genome sequencing data of three bTB infection-resistant African zebu breeds and two bTB infection-susceptible taurine breeds to decipher the genetic background. A set of four selection signature statistics based on linkage disequilibrium, site frequency spectrum, and population differentiation were used on SNPs whereas between population variance based VST and t-test were used on CNVs. As a complement, genes from previous literature reported as candidate genes for bTB resistance were also inspected to identify genetic variations. Interestingly, the resulting nine candidate genes had deleterious missense variants (SHC3, IFNGR1, TLR2, TLR6, IL1A, LRRK2, EP300 and IRAK4) or a CNV difference (CD48) segregating between the groups. The genes found in the study play a role in immune pathways activated during Mycobacterium infection, contributing to the proliferation of immune cells and the granuloma formation, ultimately modulating the outcome of the infectious event. In particular, a deleterious variant in the LRRK2 gene, whose deficiency has been linked to improved prognosis upon tuberculosis infection, was found in the bTB infection-resistant zebu breeds. Therefore, these genes constitute credible candidates in explaining the discrepancy in Mycobacterium bovis infection susceptibility among different breed.

In vitro evaluation of crosslinked bovine pericardium as potential scaffold for the oral cavity.

Bovine pericardium (BP) is a scaffold widely used in soft tissues regeneration; however, its calcification in contact with glutaraldehyde, represent an opportunity for its application in hard tissues, such as bone in the oral cavity. To develop and to characterize decellularized and glutaraldehyde-crosslinked bovine pericardium (GC-BP) as a potential scaffold for guided bone regeneration GBR. BP samples from healthy animals of the bovine zebu breed were decellularized and crosslinked by digestion with detergents and glutaraldehyde respectively. The resulting cell-free scaffold was physical, chemical, mechanical, and biologically characterized thought hematoxylin and eosin staining, DNA quantification, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), uniaxial tensile test, cell viability and live and dead assay in cultures of dental pulp stem cells (DPSCs). The decellularization and crosslinking of BP appeared to induce conformational changes of the CLG molecules, which led to lower mechanical properties at the GC-BP scaffold, at the same time that promoted cell adhesion and viability of DPSCs. This study suggests that the decellularized and GC-BP is a scaffold with the potential to be used promoting DPSCs recruitment, which has a great impact on the dental area.

Genetic associations between stayability to consecutive calvings and traits of economic interest in taurine and zebu breeds.

Stayability (STAY) is a way to evaluate the productive longevity of females. Measuring the STAY at each cow calving allows earlier indicators of longevity to be obtained. Our objective with this study was to verify the association between STAY and consecutive calvings and traits potentially used as selection criteria in beef cattle, such as age at first calving (AFC), days to calving (DC), weaning weight (WW), and yearling weight (YW). Data from the Nelore, Angus/Brangus, and Hereford/Braford breeds were used. The estimation of variance components and subsequent prediction of breeding values were performed for all traits. The estimated breeding values (EBV) were used to analyse the association between STAY and the other traits. The Pearson's correlation estimated between the EBV for the intercept coefficient for STAY to consecutive calvings and those of AFC, DC, WW (direct and maternal effects), and YW was favourable and of low magnitude (<0.25) depending on the breed studied. The influence of the genetic merit of AFC on the chance of selection for STAY was favourable and relevant regardless of the intensity of selection and breed. DC and WW (maternal effect) traits were favourably influenced by the chance of selection for STAY, irrespective of breed. The WW (direct effect) did not affect the chance of selection for STAY for the Nelore and Hereford/Braford breeds and negatively influenced, but to a small extent, the Angus/Brangus breed. For YW, an increase in genetic merit affected the chances of selection for STAY, depending on the breed and selection intensity evaluated. The influence of the genetic merit for AFC, DC, and WW (maternal effect) on the chance of selection for STAY to consecutive calvings was favourable and relevant regardless of the selection intensity scenario evaluated. The WW (direct effect) did not influence the chance of selection for STAY. For the scenario with high selection intensity, the selection for YW favourably influenced the chance of selection for STAY in Angus/Brangus and Hereford/Braford breeds but not in Nelore.

AGRONOMY OF MULATO GRASS CULTIVAR (BRACHIARIA SP.) IN GRAZING CONDITIONS IN QUINTANA ROO, MEXICO

The objective of this study was to determine the behavior of Mulato grass under grazing conditions in Quintana Roo. This work was carried out in the Chetumal Experimental Field of INIFAP in Quintana Roo, which is located 25 km from Chetumal, in the vicinity of the Juan Sarabia ejido, on km 25 of the Chetumal federal highway. For the development of the study, two hectares were used, 1 ha of Brachiaria humidícola (Chetumal) and another of Brachiaria sp. (mulato). For each type of pasture, three recently weaned steers of the Holstein for Zebu and Swiss for Zebu breeds with an approximate initial weight of 242 ± 3 kg were used the variables measured were seasonal dry matter production, plant cover and height, forage supply, and the botanical composition of the meadow. Subsequently, the steers were changed by load adjustment and the weight gain was determined. The design used was totally randomized with three repetitions per treatment and the analysis of the information was carried out through the ANOVA. No differences (P≥0.05) were found in the number of plants 12 weeks after establishment. For the coverage parameter, differences (P≤0.05) were observed with values ​​of 89% and 77 for Chetumal and mulatto grass, respectively. The values ​​of weight gain among the grasses under study (650 vs 675 for Chetumal and mulatto, respectively) did not indicate differences (P≥0.05) between them. Therefore, mulatto grass should be considered as an option for livestock in the state.

Indigenous cattle of Sri Lanka: Genetic and phylogeographic relationship with Zebu of Indus Valley and South Indian origin.

The present study reports the population structure, genetic admixture and phylogeography of cattle breeds of Sri Lanka viz. Batu Harak, Thawalam and White cattle. Moderately high level of genetic diversity was observed in all the three Sri Lankan zebu cattle breeds. Estimates of inbreeding for Thawalam and White cattle breeds were relatively high with 6.1% and 7.2% respectively. Genetic differentiation of Sri Lankan Zebu (Batu Harak and White cattle) was lowest with Red Sindhi among Indus Valley Zebu while it was lowest with Hallikar among the South Indian cattle. Global F statistics showed 6.5% differences among all the investigated Zebu cattle breeds and 1.9% differences among Sri Lankan Zebu breeds. The Sri Lankan Zebu cattle breeds showed strong genetic relationships with Hallikar cattle, an ancient breed considered to be ancestor for most of the Mysore type draught cattle breeds of South India. Genetic admixture analysis revealed high levels of breed purity in Lanka White cattle with >97% Zebu ancestry. However, significant taurine admixture was observed in Batu Harak and Thawalam cattle. Two major Zebu haplogroups, I1 and I2 were observed in Sri Lankan Zebu with the former predominating the later in all the three breeds. A total of 112 haplotypes were observed in the studied breeds, of which 50 haplotypes were found in Sri Lankan Zebu cattle. Mismatch analysis revealed unimodal distribution in all the three breeds indicating population expansion. The sum of squared deviations (SSD) and raggedness index were non-significant in both the lineages of all the three breeds except for I1 lineage of Thawalam cattle (P<0.01) and I2 lineage of Batu Harak cattle (P<0.05). The results of neutrality tests revealed negative Tajima's D values for both the lineages of Batu Harak (P>0.05) and White cattle (P>0.05) indicating an excess of low frequency polymorphisms and demographic expansion. Genetic dilution of native Zebu cattle germplasm observed in the study is a cause for concern. Hence, it is imperative that national breeding organizations consider establishing conservation units for the three native cattle breeds to maintain breed purity and initiate genetic improvement programs.

Hematological Normality, Serum Biochemistry, and Acute Phase Proteins in Healthy Beef Calves in the Brazilian Savannah.

The Brazilian savannah region, characterized by high average temperatures, well-defined rainy and dry seasons, soil with low productive potential, and high pressure for parasitic diseases, is home to the highest percentage of the beef herd, which is the world's largest commercial beef producer. Therefore, breeds that present rusticity combined with productivity are the focus of research in cattle breeding in the region. Considering their geographic particularities and their effects on the animals' blood parameters, the objective was to study the behavior of hematological variables, serum biochemistry, and acute phase proteins in beef calves at weaning age. Jugular blood samples were collected in a single day from 30 weaning calves (about eight months old and 200 kg of body weight) from the following breeds: Nellore, Senepol, Nellore × Aberdeen Angus cross, Nellore × Senepol cross, and Nellore × Aberdeen Angus × Senepol cross. Hematological data were obtained using an automatic cell counter, serum biochemical measurements were obtained using commercial kits, and the electrophoretogram was obtained using the SDS-page technique. In general, the results were consistent with data already published in similar situations regarding health status, age, and level of metabolic activity. However, differences observed between groups can be explained by differences observed in other concurrent variables like temperament. The pure zebu breed was more reactive than pure taurine. While crossbreds showed intermediate values, and parasitic infestation, the pure taurine breed with higher parasite infestation, while the zebu breed had lower values, which produced effects in some laboratory tests, and generated differences between breeds. In conclusion, the reference intervals available for healthy animals can be routinely used without interference from the geographic region for animals produced without nutritional failures as long as changes are recorded in pathological, infectious, metabolic, or nutritional deficiency situations. However, it is suggested that a study covering a larger number of herds may demonstrate a greater geographic effect on the studied variables.

The First Serological Detection and Risk Factors Analysis of Akabane Virus in Egyptian Cattle.

Akabane virus (AKAV) is an insect-borne virus belonging to the genus Orthobunyavirus of the family Peribunyaviridae. It is the etiologic agent of Akabane disease (AD), which emerged in Asia, Australia, and the Middle East causing severe economic losses among domestic and wild animals. AKAV has not received enough attention in Egypt, and its evidence among Egyptian animals has never been reported. Therefore, this study used ELISA assay to investigate the seroprevalence of AKAV among Egyptian dairy and beef cattle in eight localities of Beheira province, north Egypt. Out of 368 investigated plasma samples, the overall AKAV seroprevalence was 54.3% (95% CI: 50.8-61.4). AKAV antibodies were detected in all examined cattle farms (7/7) and the majority of abattoirs (8/9). Age, sex, breed, and location of the tested cattle were analyzed as risk factors for AKAV infection. A higher significant increase in seropositivity was obtained in cattle who were aged >5 years (p < 0.0001; OR = 9.4), females (p < 0.0001, OR = 8.3), or Holstein breed (p < 0.0001, OR = 22.6) than in younger ages, males, and Mixed and Colombian zebu breeds, respectively. Moreover, a significant variation in AKAV seroprevalence between the tested locations was noticed. Ultimately, a multivariable analysis concluded that age (p = 0.002, OR = 3.32, 95% CI = 1.57-7.04) and breed (p = 0.03, OR = 1.69, 95% CI = 1.05-2.72) were significant risks for AKAV infection. In conclusion, this study is the first to detect AKAV infection in Egyptian animals.

Genome-wide assessment of genetic diversity in Mexican Sardo Negro breed

Sardo Negro is a Mexican zebu cattle breed utilized in tropical regions in America due to its ability to cope with hot and humid weather and its resistance to parasites such as ticks. This study aimed to characterize the genetic identity through within- and across-breed genetic diversity studies. The study included 555 Sardo Negro genotypes from the 65k SNP array. In addition, genomic data of 134 other worldwide cattle breeds were retrieved from an open-access repository. Within-breed genetic diversity was evaluated by observed and expected heterozygosity, effective population size, and inbreeding coefficients. The latter was computed by PLINK (FIS), by subtracting one from the diagonal elements of the genomic relationship matrix (FGRM), and by runs of homozygosity (FROH) of different length classes. Genetic diversity across breeds was assessed by pairwise Wright FST, principal components, and cluster analysis. Observed and expected heterozygosity, FIS, FGRM, FROH and effective population size were 0.268, 0.275, -0.02, 0.11, 0.08 and 220, respectively. Correlations between FIS and all FROH were significant. Sardo Negro cattle show little differentiation with indigenous Indian and Pakistan zebu breeds. With a cluster plot, Sardo Negro cattle showed weak differentiation in the reference populations due to their near historical development and the low differentiation among zebu breeds. This research study suggests no immediate risks associated with loss of genetic variation in this breed, and Sardo Negro retains enough genetic variability from their founder's populations.

Phenotypic variation in milk fatty acid composition and its association with stearoyl-CoA desaturase 1 (SCD1) gene polymorphisms in Gir cows.

Individual variation in milk fatty acid (FA) composition has been partially attributed to stearoyl-CoA desaturase 1 (SCD1) gene polymorphisms in taurine breeds, but much less is known for Zebu breeds. This study investigated the phenotypic variation in milk FA composition, and the influence of SCD1 variants on this trait and on milk fat desaturase indices (DI) in Gir cows. The functional impact of SCD1 variants was predicted using bioinformatics tools. Milk and blood samples were collected from 312 cows distributed in 10 herds from five states of Brazil. SCD1 variants were identified through target sequencing, and milk FA composition was determined by gas chromatography. Phenotypic variation in milk FA composition fell within the range reported for taurine breeds, with SCD18 index showing the lowest variation among the DI. Fourteen SCD1 variants were identified, six of which not previously described. Regarding the A293V polymorphism, all cows were homozygous for the C allele (coding for alanine), whereas all genotypes were detected for the second SNP affecting the 293 codon (G > A), with compelling evidence for functional effects. Significant associations (based on raw p-values) were found between this SNP and C12:0, cis-9, trans-11 CLA and short-chain FA, and between another SNP (rs523411937) and C15:0 and odd-chain linear FA. A new SNP on Chr26:21277069 was associated with trans-11 C18:1, cis-9, trans-11 CLA, C18:3 n-3 and n-3 FA. These findings indicate that SCD1 polymorphisms also contributes to the phenotypic variation in milk FA composition of Gir cows, with potential use in their breeding programmes.

Genetic Structure Analysis of 155 Transboundary and Local Populations of Cattle (Bos taurus, Bos indicus and Bos grunniens) Based on STR Markers.

Every week, 1-2 breeds of farm animals, including local cattle, disappear in the world. As the keepers of rare allelic variants, native breeds potentially expand the range of genetic solutions to possible problems of the future, which means that the study of the genetic structure of these breeds is an urgent task. Providing nomadic herders with valuable resources necessary for life, domestic yaks have also become an important object of study. In order to determine the population genetic characteristics, and clarify the phylogenetic relationships of modern representatives of 155 cattle populations from different regions of the world, we collected a large set of STR data (10,250 individuals), including unique native cattle, 12 yak populations from Russia, Mongolia and Kyrgyzstan, as well as zebu breeds. Estimation of main population genetic parameters, phylogenetic analysis, principal component analysis and Bayesian cluster analysis allowed us to refine genetic structure and provided insights in relationships of native populations, transboundary breeds and populations of domestic yak. Our results can find practical application in conservation programs of endangered breeds, as well as become the basis for future fundamental research.

Effects of Training for First Milking Involving Positive Tactile Stimulation on Post-Calving Maternal Behaviors in Primiparous Gyr Dairy Cows

In dairy systems with Zebu breeds, calves are not immediately separated from their dams after calving; consequently, maternal care and protective behavior are important, influencing both productive performance and stockpeople's safety. Our objectives were to: (1) investigate the effects of a training protocol involving pre-calving positive stimulation, delivered prior to calving, on the maternal care of primiparous Gyr cows; and (2) evaluate the effects of this training protocol on maternal protective behavior towards handlers during the first calf handling. Primiparous dairy Gyr cows (n = 37) were allocated into two groups: training (n = 16) and control (n = 21). Animal behaviors were recorded in three periods: post-calving, first calf handling, and post-handling. Maternal protective behavior during calf handling was assessed from measures of aggressiveness, attention, displacement, and agitation. Calf latency to stand up (p < 0.01) and sex (p < 0.01) differed between the training and control groups. The training group had less touching (p = 0.03), more time not interacting with the calf (p = 0.03), tended to be less protective (p = 0.056), and moved less (p < 0.01) during the first handling of their calves. In conclusion, the primiparous dairy Gyr cows subjected to pre-calving training protocol displayed less maternal care and displacement during the first handling of their calves and tended to be less protective.

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.

Evaluation of the breeding practices and population trend of the Fogera cattle breed in Ethiopia

The study was conducted to estimate the population size, herd structure, and breeding objectives of Fogera cattle in Ethiopia. It was carried out in 23 purposively selected kebeles in five districts of three zones bordering Lake Tana. Interviewed farmers were selected based on their livestock ownership. Primary information on the general production system and trends of Fogera cattle was collected from 527 farmers, and a population count included 479 respondents. To differentiate the pure Fogera cattle from the mixed and highland zebu breeds, color photographs of the three breeds were used by each enumerator. Kebele administrators and elders as well as district and zone officials assisted in the operation to identify the true type of Fogera cattle. MS-Excel (2010) and SPSS (version 20) were used to analyze population size and production systems, respectively. The average cattle holding per household was 7.03 ± 0.2 heads. Analysis of multiple responses revealed that the dominant reasons for keeping cattle in the herd were traction power (96.67%), milk (92.76%), and manure (83.95%). More than half of the respondents (64.65%) practiced culling both male and female animals from their herds. Interviewed farmers selected bulls for mating by coat color (56.84%), body conformation (55.08%), and body size (47.46%). They also indicated that they selected the Fogera breed (48.63%), highland zebu (18.16%), and mixed (17.38%) as bulls for mating with their cattle. Based on the respondents’ information, the population trend of the Fogera breed decreases (40%), increases (13%), is stable (6%), and is not known (41%). From the total population estimated, households own the relatively pure Fogera (41%), Fogera–zebu mix (35%), and highland zebu (24%). In this study, the total estimated number of breeding Fogera cattle was 55,646 ± 16,579 heads. It was concluded that the breed has declined and is dealing with genetic deterioration as the population size decreases due to the shift of grazing lands to crop production. As population estimation was performed by morphological features, further research supported by molecular study should be conducted.

Kappa and beta-casein alleles in dairy zebu cattle

The kappa (CSN3) and beta-casein (CSN2) genes are intensively genotyped in dairy cattle for selection purposes. This information is also generated and disseminated for Zebu breeds adapted to tropical climates. The objective of this work was to gather information on the genotypes for the CSN3 and CSN2 genes in three breeds (Gyr, Guzerat and Sindhi), and to verify the genotypic frequencies in the populations. The genotype AA and allele A frequencies are high for the CSN3 gene, without changes in values over the years, possibly indicating a small gene participation in traits under selection. In addition, the A2A2 frequencies are high for the CSN2 gene (<∼0.80). It is recommended to verify the association and contribution of CSN3 genotypes in productive traits for these breeds. The potential of A2 milk production by these genetic groups is also confirmed.