Breeding distribution and maternal genetic lineages in Lulu,a dwarf cattle population in Nepal

Lulu is a dwarf cattle population bred in the Mustang district of western and central Nepal. This area is located around the habitat boundary between Bos taurus and Bos indicus. The peculiarities of Lulu are their small size (weight range in the adult female: 68–153 kg) and rearing in high mountain areas at 2800 m to 4000 m in altitude. There were 5770 head of Lulu cattle in the Mustang district in 1998, 4333 females and 1437 males. The morphological appearance of Lulu is Bos taurus. However, one of the five Lulu studied in Kagbeni, Mustang had a Bos indicus mitochondrial DNA type based on the D‐loop sequence, while the other four were Bos taurus. It is suggested that there are hybrids of Lulu with Bos indicus maternal lineage in a mostly taurine‐breed genetic background. Steps must be taken to preserve the unique Lulu.     

Kazakhstani native cattle reveal highly divergent mtDNA from Bos taurus and Bos indicus lineages with an absence of Bos indicus Y chromosome

Kazakhstan is the largest landlocked country and contains two important propagation routes for livestock from the Fertile Crescent to Asia. Therefore, genetic information about Kazakhstani cattle can be important for understanding the propagation history and the genetic admixture in Central Asian cattle. In the present study, we analyzed the complete mtDNA D‐loop sequence and SRY gene polymorphism in 122 Kazakhstani native cattle. The D‐loop sequences revealed 79 mitochondrial haplotypes, with the major haplogroups T and I. The Bos taurus subhaplogroups consisted of T (3.3%), T1 (2.5%), T2 (2.5%), and T4 (0.8%) in addition to the predominant subhaplogroup T3 (86.9%), and the Bos indicus subhaplogroup of I1 (4.1%). Subsequently, we investigated the paternal lineages of Bos taurus and Bos indicus, however, all Kazakhstani cattle were shown to have Y chromosome of Bos taurus origin. While highly divergent mtDNA subhaplogroups in Kazakhstani cattle could be due to the geographical proximity of Kazakhstan with the domestication center of the Fertile Crescent, the absence of Bos indicus Y chromosomes could be explained by a decoupling of the introgression dynamics of maternal and paternal lineages. This genetic information would contribute to understanding the genetic diversity and propagation history of cattle in Central Asia.     

Genetic diversity and origin of Gayal and cattle in Yunnan revealed by mtDNA control region and SRY gene sequence variation

There are hump, humpless cattle and gayal distributed in Yunnan province, south‐west China, but their genetic background remains unclear. To determine the origin and genetic diversity of Yunnan gayal and cattle (Diqing, Nujiang and Wenshan cattle), we analysed mtDNA control region sequences of 71 samples and SRY gene sequences of 39 samples, together with the available sequences in GenBank. The neighbour‐joining phylogeny and the reduced median network analysis showed that Yunnan gayal originated from the hybridization between male Bos frontalis and female Bos taurus or Bos indicus, and that Yunnan cattle mostly originated from B. indicus, also containing some hybrids of male B. indicus and female B. taurus. The phylogenetic pattern of Yunnan cattle was consistent with the recently described cattle matrilineal pool from China and indicated more contribution to the Yunnan cattle from B. indicus than from B. taurus.     

Genetic structure and relationships of 16 Asian and European cattle populations using DigiTag2 assay

In this study, we genotyped 117 autosomal single nucleotide polymorphisms using a DigiTag2 assay to assess the genetic diversity, structure and relationships of 16 Eurasian cattle populations, including nine cattle breeds and seven native cattle. Phylogenetic and principal component analyses showed that Bos taurus and Bos indicus populations were clearly distinguished, whereas Japanese Shorthorn and Japanese Polled clustered with European populations. Furthermore, STRUCTURE analysis demonstrated the distinct separation between Bos taurus and Bos indicus (K=2), and between European and Asian populations (K=3). In addition, Japanese Holstein exhibited an admixture pattern with Asian and European cattle (K=3‐5). Mongolian (K=13‐16) and Japanese Black (K=14‐16) populations exhibited admixture patterns with different ancestries. Bos indicus populations exhibited a uniform genetic structure at K=2‐11, thereby suggesting that there are close genetic relationships among Bos indicus populations. However, the Bhutan and Bangladesh populations formed a cluster distinct from the other Bos indicus populations at K=12‐16. In conclusion, our study could sufficiently explain the genetic construction of Asian cattle populations, including: (i) the close genetic relationships among Bos indicus populations; (ii) the genetic influences of European breeds on Japanese breeds; (iii) the genetic admixture in Japanese Holstein, Mongolian and Japanese Black cattle; and (iv) the genetic subpopulations in Southeast Asia.     

Genetic diversity and structure in Bos taurus and Bos indicus populations analyzed by SNP markers

The purpose of this study was to assess genetic diversity, phylogenetic relationship and population structure among nine Eurasian cattle populations using 58 single nucleotide polymorphism (SNP) markers. The calculated distribution of minor allele frequencies and heterozygosities suggested that the genetic diversity of Bos indicus populations was lower than that of Bos taurus populations. Phylogenetic analyses revealed the main divergence between the Bos taurus and Bos indicus populations, and subsequently between Asian and European populations. By principal components analysis, the Bos taurus and Bos indicus populations were clearly distinguished with PC1 (61.1%); however, six Bos taurus populations clustered loosely and the partial separation between European and Asian groups was observed by PC2 (12.5%). The structure analysis was performed using the STRUCTURE program. Distinct separation between Bos taurus and Bos indicus was shown at K = 2, and that between European and Asian populations at K = 3. At K = 4, 5 and 6, Mongolian population showed an admixture pattern with different ancestry of Asian and European cattle. At K = 7, all Bos taurus populations showed each cluster with little proportion of admixture. In conclusion, 58 SNP markers in this study could sufficiently estimate the genetic diversity, relationship and structure for nine Eurasian cattle populations, especially by analyses of principal components and STRUCTURE.     

Plasma Antimullerian Hormone as a Predictor of Ovarian Antral Follicular Population in Bos indicus (Nelore) and Bos taurus (Holstein) Heifers

In Bos taurus cattle, antimullerian hormone (AMH) has been demonstrated to have a high degree of correlation with ovarian antral follicle count and the number of healthy follicles and oocytes. To document the correlation between the plasma concentration of AMH and follicular number in Bos indicus and Bos taurus heifers, Nelore (Bos indicus, n = 16) and Holstein heifers (Bos taurus, n = 16) had their ovarian follicular waves synchronized. After synchronization, ovarian antral follicular population (AFP) was evaluated three times at 60‐day (d) intervals (T‐120 d, 120 days before plasma AMH determination; T‐60 d, 60 days before; and T0, at the time of plasma AMH determination). The plasma AMH concentration was positively correlated with the number of ovarian follicles on the day of the follicular wave emergence in Bos indicus (Nelore) and Bos taurus (Holstein) heifers at each evaluation time (p < 0.05). The AFP was higher in Bos indicus (Nelore) than in Bos taurus (Holstein) heifers (p < 0.05). Similarly, the AMH concentration was higher in Bos indicus (Nelore) than in Bos taurus (Holstein) heifers (p < 0.0001). When heifers were classified as to present high or low AFP according to the mean of the AFP within each genetic group, high‐AFP heifers presented a greater (p < 0.0001) AMH concentration than low‐AFP heifers, regardless of the genetic group. In conclusion, the AFP is positively correlated with plasma AMH concentration in both Bos indicus (Nelore) and Bos taurus (Holstein) heifers. Furthermore, Bos indicus (Nelore) heifers presented both greater plasma AMH concentrations and AFP than Bos taurus (Holstein) heifers.     

Allele frequencies of gene polymorphisms related to economic traits in Bos taurus and Bos indicus cattle breeds

Allele frequencies of 10 representative polymorphisms for beef and milk traits were investigated for a total of 240 animals from Bos taurus and Bos indicus breeds, including two Japanese groups (Japanese Black and Japanese Brown), two East Asian groups (Korean and Mongolian), three European groups (Holstein, Angus and Hereford) and a Bos indicus group in South Asia (Myanmar, Laos and Cambodia). The Japanese Black revealed unique genetic construction in GH, FASN and SREBP‐1 and the other Asian populations show intermediate frequencies between European and Japanese populations. The Bos indicus group showed low favorable allele frequencies in most of the genes. The study showed the variability and distribution of 10 genes affecting economic traits among world representative cattle breeds. The genetic information would contribute to elucidating the genetic background for worldwide cattle breeds and the possibility of improvement using the markers.     

Comparison of Antral and Preantral Ovarian Follicle Populations Between Bos indicus and Bos indicus‐taurus Cows with High or Low Antral Follicles Counts

The objective was to compare populations of antral and pre‐antral ovarian follicles in Bos indicus and Bos indicus‐taurus cows with high and low antral follicle counts. Nelore (Bos indicus, n = 20) and Nelore X Angus (1/2 Bos indicus‐taurus, n = 20) cows were subjected to follicular aspiration without regard to the stage of their oestrous cycle (day of aspiration = D0) to remove all follicles ≥3 mm and induce growth of a new follicular wave. Ovaries were examined by ultrasonography on D4, D19, D34, D49 and D64, and antral follicles ≥3 mm were counted. Thereafter, cows were assigned to one of two groups: high or low antral follicular count (AFC, ≥30 and ≤15 antral follicles, respectively). After D64, ovaries were collected after slaughter and processed for histological evaluation. There was high repeatability in the numbers of antral follicles for all groups (range 0.77–0.96). The mean (±SD) numbers of antral follicles were 35 ± 9 (Bos indicus) and 38 ± 6 (Bos indicus‐taurus) for the high AFC group and 10 ± 3 (Bos indicus) and 12 ± 2 (Bos indicus‐taurus) follicles for the low AFC. The mean number of preantral follicles in the ovaries of Bos indicus‐taurus cows with high AFC (116 226 ± 83 156 follicles) was greater (p < 0.05) than that of Bos indicus cows (63 032 ± 58 705 follicles) with high AFC. However, there was no significant correlation between numbers of antral and preantral follicles.     

Prospects for increasing the utilization of cattle embryo transfer by small-scale milk and meat producers in tropical regions

Small community cattle farmers in the tropics are facing challenges to deliver quality products whilst under pressure to increase milk and beef yields per cow. These challenges could be partially met by crossbreeding Bos taurus with Bos indicus (F1) cattle utilizing embryo transfer (ET) technology. The Bos taurus infusion would increase milk production, whilst the Bos indicus influence can improve resistance to the harsh environment of the tropics. Here, individuals from existing herds can be used to produce F1 embryos which benefit from hybrid vigour. Resultant female offspring would in turn receive an F1 embryo on reaching breeding maturity. This approach would help to provide a cost-effective, systematic approach to improve productivity in dairy and beef cattle in the tropics. However, full usage of ET, including in vitro applications, in the tropics will require improvements in procedures, resources and education.     

Molecular phylogeny and diversity of Myanmar and Bhutan mithun based on mtDNA sequences

The mithun (Bos frontalis), synonymous with mithan and gayal, is considered to be a domesticated form of gaur (B. gaurus). However, there has been a controversy concerning its origin. In an effort to address this issue, the mitochondrial cytochrome b (cytb) genes of 20 mithun from Myanmar and 13 from Bhutan were sequenced to trace its maternal origin. Seven cytb haplotypes were found in the 33 mithun, and the phylogenetic tree for these haplotypes clearly showed three embranchments involving five gaur types, a B. indicus type, and a B. taurus type. Sixteen Myanmar and 12 Bhutan mithun had gaur haplotypes, while a B. indicus haplotype was found in three Myanmar and one Bhutan mithun. The B. taurus haplotype was detected in a single Myanmar animal. These results demonstrated that the principal maternal origin of mithun was gaur and suggested that it was directly domesticated from gaur. However, some introgression of domestic cattle existed in current mithun populations. The presence of cattle mtDNA raised the question of how many cattle nuclear genes might have been integrated into the gene pool of mithun.     

A STUDY OF THE EPIDEMIOLOGY OF ANAPLASMA MARGINALE INFECTIONS OF CATTLE IN SOUTHERN QUEENSLAND: CLINICAL DISEASE AND THE PREVALENCE OF COMPLEMENT FIXING ANTIBODIES

SUMMARY A total of 386 clinical outbreaks of anaplasmosis were confirmed in Queensland south of the 22nd parallel over the period 1967 to 1976. Seventy-eight per cent of these outbreaks occurred during autumn and winter and only 6.8% involved cattle less than 1 year of age compared with 54.8% for cattle more than 3 years old. Dairy breeds were involved in 48.1% of 258 outbreaks compared with 51.9% for beef breeds. Bos taurus beef breeds were involved in 90.7% of 118 outbreaks compared with 9.3% for Bos indicus crossbreds. Approximately 3 times as much clinical disease per head of population was confirmed in tick (Boophilus microplus) infested southern Queensland south of the 25th parallel (south zone) than in areas between the 25th and 22nd parallel (north zone). A survey was conducted during 1975 in which 3,810 cattle from 241 herds were sampled on the basis of the distribution of the cattle population. The prevalence of CF reactors in tick-infested areas was 42.1% of 3,026 samples compared with 0.4% of 784 samples from tick-free areas. The prevalence in the north zone was 52.3% compared to 30.2% for the south zone and it also varied with the type of animal sampled. The prevalence in Bos taurus cattle was significantly greater than in Bos indicus types and it increased with age of the animal. No significant difference in susceptibility to infection attributable to sex could be demonstrated. Animals exposed to heavy to medium tick infestations had significantly more CF reactors than those exposed to light infestation. Higher stocking densities were associated with higher prevalence levels. Thus anaplasmosis is predominantly a disease of autumn and winter and of cattle greater than 1 year of age. Both clinical and subclinical infection occur only in tick-infested areas and B. microplus is considered to be the main, if not the only vector. Both clinical and inapparent infection are more frequent in Bos taurus than in Bos indicus types.     

Aspects of reproduction in female Bos indicus cattle: a review

SUMMARY Differences occur between female Bos indicus and Bos taurus cattle in various aspects of reproductive physiology and behaviour. These may be associated with different natural and human selection pressures, compounded by strong genotype-environment interactions. B indicus cattle are better adapted for tropical environments (despite overall poor cattle reproductive rates in these regions) which tend to be more stressful for B taurus genotypes. Conversely, B taurus cattle generally show superior reproductive and productive traits under more favoured, temperate conditions. Despite genotype-environment effects, B indicus females are generally considered to take longer to achieve puberty and to have longer gestation lengths, exhibit prolonged postpartum anoestrus, show greater seasonality of reproductive traits (tending to be long-day breeders), display a shorter, less overt oestrus as well as less tendency to allow riding behaviour by subordinate females. Some groups appear to have increased losses both during pregnancy and in the neonatal period. On the positive side, B indicus females respond well to managerial and nutritional interventions, tend to have greater reproductive longevity and they generally exhibit strong maternal traits. Culling of infertile females and selection for greater male scrotal circumference and sex-drive, in conjunction with the use of target weights, body condition scoring and weaning stratagems can improve reproductive rates in B indicus females.     

Effect of breed of cattle on innate resistance to infection with <i>Babesia bovis, B bigemina and Anaplasma marginale

Objective To assess the innate resistance of naive Bos taurus, Bos taurus cross Bos indicus and Bos indicus cattle to virulent Babesia bovis, B bigemina and Anaplasma marginale parasites. Design Groups of 10, pure B indicus, fi B indicus cross,/B indicus cross and pure B taurus steers were infected with virulent B bovis, B bigemina and A marginale parasites. Procedure Sequential infections were carried out by intravenous inoculation of infected blood containing 1 times 10⁸ parasites of B bovis, followed by B bigemina and then A marginale. To assess resistance, measurements were made of parasitaemia, rectal temperature, packed cell volume and the number within a group requiring chemotherapy to control infection. There was a recovery period between each infection. Results Infection with B bovis showed that pure B indicus steers were significantly more resistant to B bovis infection than the other groups, with none of this group requiring treatment. There was no significant difference between fi B indicus cross and/B indicus cross with 30% and 20%, respectively, of steers in these groups requiring treatment. The pure B taurus steers were significantly more affected then those in the other three groups with 80% requiring treatment. Infections of B bigemina produced a mild response in comparison to that of B bovis and none of the steers required treatment. However, the pure B taurus group was significantly more affected than the other three groups for all other measurements. After the A marginale infection, B indicus steers were moderately affected with 50% requiring treatment, whereas 70% of the fi B indicus group, 80% of the /B indicus cross group and 100% of the pure B taurus group required treatment. Conclusions All breeds of cattle, ranging from pure B indicus to pure B taurus may be at risk of severe disease if exposed to virulent A marginale. The results confirm that pure B indicus cattle are relatively resistant to B bovis, but there could be a significant risk of severe mortalities if cross-bred herds are exposed to virulent infection.     

Milk protein loci polymorphism in taurine (Bos taurus) and zebu (Bos indicus) populations bred in hot climate

The genetic variation at four milk protein loci α_s1‐casein (CSN1S1), β‐casein (CSN2), κ‐casein (CSN3) and β‐lactoglobulin (LGB) was investigated in 358 animals belonging to seven populations well adapted to hot climatic conditions, reared in Africa and Italy. Bos taurus (Somba, Lagune and Modicana), Bos indicus (Sudanese Zebu Peul, Azaouak and Adamawa), and B. taurus × B. indicus (Borgou) were studied by adapting different molecular methodologies to evaluate their genetic variability. All loci were polymorphic and a new CSN2 synonymous variant, named A²′, was detected and characterized. Noteworthy differences in the distribution of alleles and haplotypes were observed between zebuine and taurine cattle showing that milk protein polymorphism is suited for discriminating B. taurus from B. indicus efficiently, and also taurine breeds. Milk protein loci, being positively selected loci, can also provide information about the occurrence of germplasm particularly useful for breeding strategies and production improvement.     

The effect of breed,sex, and drug concentration on the pharmacokinetic profile of ivermectin in cattle

Ivermectin (IVM) is one of the most widely used antiparasitic drugs worldwide and has become the drug of choice for anthelmintic and tick treatment in beef cattle production. It is known that pharmacokinetic parameters are fundamental to the rational use of a drug and food safety and these parameters are influenced by different factors. The aim of this study was to evaluate the pharmacokinetic profile of IVM in Bos indicus, Bos taurus, and crossbreed cattle (B. indicus × B. taurus) kept under same field conditions and the possible impacts of sex and IVM formulation (1% and 3.15%). It was observed that IVM concentration was significantly affected by breed. The plasma concentrations of IVM, AUC, C_max, and t_1/2β were significantly higher in B. indicus compared to B. taurus. Crossbreed animals showed an intermediate profile between European and Indian cattle. No alteration in pharmacokinetics parameters was detected when comparing different gender. Concerning the pharmacokinetic data of IVM formulation, it was verified that T_max, AUC, and t_1/2β were higher in 3.15% IVM animals than those from 1% IVM formulation. The results clearly indicated that the IVM plasma concentrations in B. indicus were higher than that in B. taurus.     

THE RELATIONSHIP BETWEEN A SERVING CAPACITY TEST AND FERTILITY OF BEEF BULLS

SUMMARY In a trial using Bos indicus and Bos taurus bulls in a tropical environment the serving capacity, defined as the number of complete services achieved during a 40-minute yard test, failed to predict the fertility of the bulls after 3 or after 7 weeks of mating. The numbers of services achieved during the yard test were much lower than those reported from a temperate region using Bos taurus bulls.     

Polymorphisms in growth hormone gene and their associations with calf weight in Japanese Black cattle

The objectives of this study were to detect effective genetic polymorphisms of bovine growth hormone (bGH) gene associated with calf weight in Japanese Black cattle. Fifty‐eight sires and 47 breeding cows were used to detect the polymorphisms in exons by single‐strand conformation polymorphism (SSCP). Four homozygous and six heterozygous SSCP genotypes were identified in exon 5. Although each single nucleotide polymorphism (SNP) had been reported, these genotypes were caused by three SNPs at the nucleotide positions 2141, 2277 and 2291. Four haplotypes C‐C‐A, G‐C‐A, C‐C‐C and G‐T‐A were newly identified. It was suggested that other haplotypes not detected in this study may not exist, considering the allele frequencies reported in Bos taurus and Bos indicus, and the migrating process of native Japanese cattle. Thereafter, we examined associations between the detected polymorphic sites in exon 5 by PCR – restriction fragment length polymorphism and calf weight using 53 breeding dams and 135 calves. The birth weights of calves with haplotype G‐C‐A are significantly lighter and calves' weights produced by cows with such haplotype are also lighter at 30 days old, using regression analysis. Although further research is necessary, these results may serve as a useful criterion to select breeding stocks, especially in maternal abilities.     

Lack of evidence for bovine Y-chromosomal variation in beef traits. A Bayesian analysis of Simmental data

Y-chromosomal loci are genetically responsible for some male-specific biological processes. The sex determining region Y (SRY), a protein with DNA-binding activity, is known as the trigger for sex differentiation in mammals. In humans the SRY is encoded by a single exon located on the short arm of the Y chromosome, close to the pseudoautosomal boundary (S inclair et al. 1990). Moreover, the Y chromosome harbours the male-specific histocompatibility antigen (reviewed by S impson et al. 1997) and there are at least two regions of the Y chromosome, which have been shown to be essential for normal spermatogenesis in mice (E lliott and C ooke 1997). The sexual dimorphism of aggression in mice has led to a search for its foundation on the Y chromosome. The existence of Y-chromosomal genetic variation for aggressiveness with genetic factors borne both on the pseudoautosomal (YPAR) and on the nonpseudoautosomal (YNPAR) region of the Y chromosome (S luyter et al. 1996) has been shown. Another example for Y-induced genetic variation in mice is the testis autosomal trait (occurrence of ovaries or ovotestes in XY animals), which is observed when specific Y chromosomes interact with the autosomal background of certain laboratory mouse lines (E isner et al. 1996). A comparison of the resemblance of different types of relatives indicated a nonzero Y-chromosomal variance for body weight in mice (B& uuml ; nger et al. 1995). In cattle the Y chromosomes of the Bos taurus and Bos indicus subspecies can be morphologically distinguished: its shape is submetacentric in B. taurus and acrocentric in B.indicus. This difference is caused by a pericentric inversion (G oldammer et al. 1997) and has frequently been used to investigate the introgression of zebu genes into B. taurus breeds. The polymorphism of the bovine Y chromosome itself and the results of mouse research both direct the scientific curiosity on the possible contribution of the bovine Y chromosome to quantitative genetic variation in cattle, a question which, to the authors’ knowledge, has not been investigated before. In this paper we first discuss the contribution of autosomal, imprinted, and sex-linked genes to the resemblance of full and half sibs and then present a Bayesian estimation of a Y-chromosomal variance component for each of four beef traits in young Simmental bulls using mixed linear and threshold models.     

Polymorphism of 5'-region of the bovine growth hormone receptor gene

Genes coding for growth hormone (GH) and GH receptor (GHR) are candidates for quantitative trait markers in farm animals. This work describes a search for nucleotide sequence polymorphisms within the 5′‐region of the bovine GHR gene. Two new single nucleotide polymorphisms were found: restriction fragment length polymorphisms (RFLPs) at a Fnu4HI/TseI site (C/T transition at position ?1104), and at a Sau96I site (C/T transition at position ?262). The Fnu4HI/TseI polymorphic site is located within the 1.2‐kbp LINE‐1 retrotransposon upstream of the P1 promoter, while the Sau96I RFLP locates in the P1 promoter for exon 1A. The appearance of the Sau96I RFLP was studied in representatives of two bovine species, Bos taurus and Bos indicus. An absolute correlation was observed between Sau96I genotype and the insertion/deletion of LINE‐1.