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PubMed1998

Variation in the immune status of two Australian pig breeds.

OBJECTIVE: To investigate the variation in immune competence of two Australian pig breeds. DESIGN: A panel of immune tests were used to assess breed and sire differences in weaner piglets of Large White and Duroc breeds. PROCEDURE: All piglets were immunised against porcine leptospirosis. Blood samples were taken for studies on lymphocyte phenotypes, mitogenic responses of blood cells and serological analysis. RESULTS: Significantly larger blood leucocyte numbers were found in Large White piglets compared with Duroc piglets after vaccinations. No significant difference in concanavalin A induced blood cell proliferation was found between these two breeds before or after vaccinations. Some significant breed variation in blood lymphocyte phenotypes was found. While the age-related changes of lymphocyte phenotypes were similar for the two breeds, the Large White breed had significantly larger numbers of CD2+ and CD4+ cells than the Duroc breed after the two vaccinations. There were also significant sire effects on CD8+ cells within the Large White breed after the first vaccination. No significant breed difference was detectable in serum IgG concentrations but sire differences within each breed before the primary vaccination were found. The serum antibody response to vaccination against leptospirosis was generally small, and showed no variations due to either breed or sire. No gender effects were found during the entire study. CONCLUSION: The study demonstrated significant differences in some important immune components of the pig breeds studied. This may in turn indicate the variation in their immune competence or disease resistance. However, further investigation into the heritability and correlation with specific immune responses is required.

Agglutination Tests↗
PubMed2004

Genetic characterization of the Indian cattle breeds, Ongole and Deoni (Bos indicus), using microsatellite markers - a preliminary study.

BACKGROUND: Molecular characterization of cattle breeds is important for the prevention of germplasm erosion by cross breeding. The Indian zebu cattle have their significant role in evolution of present day cattle breeds and development of some of the exotic breeds. Microsatellites are the best available molecular tools for characterization of cattle breeds. The present study was carried out to characterize two Indian cattle breeds, Ongole and Deoni, using microsatellite markers. RESULTS: Using 5 di- and 5 tri-nucleotide repeat loci, 17 Ongole and 13 Deoni unrelated individuals were studied. Of the ten loci, eight revealed polymorphism in both the breeds. The di-nucleotide repeat loci were found to be more polymorphic (100%) than tri-nucleotide repeat loci (60%). A total of 39 polymorphic alleles were obtained at 4.5 alleles per locus in Ongole and 4.1 in Deoni. The average expected heterozygosity was 0.46 (+/-0.1) and 0.50 (+/-0.1) in Ongole and Deoni breeds, respectively. The PIC values of the polymorphic loci ranged from 0.15 to 0.79 in Ongole and 0.13 to 0.80 in Deoni breeds. Six Ongole specific and three Deoni specific alleles were identified. The two breeds showed a moderate genetic relationship between themselves with a FST value of 0.117 (P = 0.01). CONCLUSIONS: This preliminary study shows that microsatellite markers are useful in distinguishing the two zebu breeds namely, Ongole and Deoni. Further studies of other zebu breeds using many microsatellite loci with larger sample sizes can reveal the genetic relationships of Indian breeds.

Animals↗
PubMed1992

Variation in the timing of the reproductive season among breeds of sheep in relation to differences in photoperiodic synchronization of an endogenous rhythm.

Photoperiod may regulate seasonal reproduction either by providing the primary driving force for the reproductive transitions or by synchronizing an endogenous reproductive rhythm. This study evaluated whether breed differences in timing of the reproductive seasons of Finnish Landrace (Finn) and Galway ewes are due to differences in photoperiodic drive of the reproductive transitions or to differences in photoperiodic synchronization of the endogenous rhythm of reproductive activity. The importance of decreasing photoperiod after the summer solstice in determining the onset and duration of the breeding season was tested by housing ewes from the summer solstice in either a simulated natural photoperiod or a fixed summer-solstice photoperiod (18 h light:6 h dark; summer-solstice hold). Onset of the breeding season within each breed did not differ between these photoperiodic treatments, but Galway ewes began and ended their breeding season earlier than Finn ewes. The duration of the breeding season was shorter in Galway ewes on summer-solstice hold than on simulated natural photoperiod; duration did not differ between photoperiodic treatments in Finn ewes. The requirement for increasing photoperiod after the winter solstice for initiation of anoestrus was tested by exposing ewes from the winter solstice to either a simulated natural photoperiod or a winter-solstice hold photoperiod (8.5 h light:15.5 h dark). Onset of anoestrus within each breed did not differ between these photoperiodic treatments, but the time of this transition differed between breeds. These observations suggest that genetic differences in timing of the breeding season in Galway and Finn ewes do not reflect differences in the extent to which photoperiod drives the reproductive transitions, because neither breed requires shortening days to enter the breeding season or lengthening days to end it at appropriate times. These findings are consistent with the hypothesis that photoperiod synchronizes an endogenous rhythm of reproductive activity in both breeds and that genetic differences in timing of the breeding season reflect differences in photoperiodic synchronization of this rhythm.

Anestrus↗
PubMed2000

Breed distribution of dogs with diabetes mellitus admitted to a tertiary care facility.

OBJECTIVE: To determine which dog breeds are at low and high risk for developing diabetes mellitus (DM). DESIGN: Cohort study. ANIMALS: Hospital population of 221 dogs with DM and 42,882 dogs without DM during 5.5 years. PROCEDURE: 165 breeds (including a mixed-breed category) were represented in the hospital population. Breed-specific expected numbers of dogs with DM were calculated by multiplying the proportion of all dogs admitted to the hospital that were determined to have DM during the study period by the breed-specific totals during the study period. Breeds or breed groups evaluated in the analysis (n = 20) were restricted to those that had a combined observed and expected count > 5 to document breeds at low and high risk for developing DM. Proportionate changes in the risk of developing DM by breed were calculated and presented using exact odds ratios, 95% confidence intervals, and P values. Mixed-breed dogs were chosen as the reference breed. RESULTS: Samoyeds, Miniature Schnauzers, Miniature Poodles, Pugs, and Toy Poodles were at high risk for developing DM. Dog breeds found to be at low risk for developing DM were German Shepherd Dog, Golden Retriever, and American Pit Bull Terrier. CONCLUSION AND CLINICAL RELEVANCE: The finding that certain dog breeds are at low or high risk for developing DM suggests that some genetic defects may predispose dogs to development of DM, whereas other genetic factors may protect dogs from development of DM.

Animals↗
PubMed2003

Association of breed with the diagnosis of congenital portosystemic shunts in dogs: 2,400 cases (1980-2002).

OBJECTIVE: To determine the annual and overall proportion of diagnoses of congenital portosystemic shunts (CPSS) in dogs and identify breeds at increased risk for CPSS. DESIGN: Retrospective study. ANIMALS: 2,400 dogs with CPSS from veterinary teaching hospitals that reported to the Veterinary Medical Database (VMDB) from January 1, 1980 to February 28, 2002. PROCEDURE: The proportion of diagnoses of CPSS was calculated for all dogs and each breed recorded in the VMDB annually and for the 22.2-year period. Odds ratios and adjusted confidence intervals were calculated for breeds with at least 100 accessions by comparing odds of each breed with a diagnosis of CPSS with that of mixed-breed dogs. RESULTS: Congenital portosystemic shunts were reported in 0.18% of all dogs and 0.05% of mixed-breed dogs. The proportion of diagnoses of CPSS increased from 5 in 10,000 dogs in 1980 to 5 in 1,000 dogs in 2001. Yorkshire Terriers had the greatest total number of diagnoses of CPSS. Thirty-three breeds were significantly more likely to have a diagnosis of CPSS, compared with mixed-breed dogs. The greatest proportions of diagnoses were found in Havanese (3.2%), Yorkshire Terriers (2.9%), Maltese (1.6%), Dandie Dinmont Terriers (1.6%), and Pugs (1.3%). CONCLUSIONS AND CLINICAL RELEVANCE: Certain breeds appear to be at increased risk for CPSS, compared with mixed-breed dogs. The increased odds ratios among specific breeds support the hypothesis of a genetic predisposition for CPSS. Clients and veterinarians should consider appropriate diagnostic tests for dogs with clinical signs and those used for breeding from breeds with increased risk of CPSS.

Age Distribution↗
PubMed1991

Evaluation of between- and within-breed variation in measures of weight-age relationships.

Variation between- and within-breeds was evaluated for accretion of weight from birth to 7 yr of age and hip height at 7 yr for 1,577 cows sired by Angus, Brahman, Brown Swiss, Charolais, Chianina, Gelbvieh, Hereford, Jersey, Limousin, Maine Anjou, Pinzgauer, Sahiwal, Simmental, South Devon, and Tarentaise and from either Angus or Hereford dams. Parameters from Wt = A (1 - Be-kt) were estimated by nonlinear regressions and provided estimates of mature body weight (A) and rate of weight accretion relative to change in age (k) for each cow. Actual weight at birth, linear adjusted weights at 200, 365, and 500 d of age, ratios of these weights to mature weight, and height at the hip at 7 yr were analyzed. Beyond 20 mo, weights were adjusted to a constant condition score within breed of sire. Variance and covariance components were derived for breed (sigma 2 b), sires within breed (sigma 2 s), and progeny within sire (sigma 2 w). For all traits, the sigma 2 b estimate of genetic variance ranged from two to four times greater than the variance component for sigma 2 s. Between-breed heritabilities were .91 +/- .27 and .54 +/- .17 for A and k, respectively. Estimates of within-breed heritability for these two traits were .61 +/- .11 and .27 +/- .09. Estimates, both between- and within-breed, of the genetic correlation between A and k were moderate to large and negative; those between A and weights at 200, 365, and 500 d and height at maturity were large and positive. Selection for immediate change in measures of growth would be most effective among breeds. Sufficient direct genetic variation exists between breeds to enhance breed improvement of growth characters through breed substitution. Greater opportunity to alter the shape of the growth curve exists through selection for within-breed selection than through breed substitution.

Aging↗
PubMed1996

Influence of gilt age and body composition at first breeding on sow reproductive performance and longevity.

Regression analysis was used to evaluate the effects of gilt age and body composition at first breeding on sow performance over three parities. Eighty-seven Yorkshire x Landrace F1 gilts were used. Variation in age and body composition at first breeding was obtained by breeding gilts at puberty, second, or third estrus and by providing those gilts bred after puberty one of four nutritional regimens from puberty until breeding: 1) 2.7 kg/d of a 14.3% CP, 3.5 Mcal ME/kg diet (H), 2) maintenance ME and CP/d (M), 3) half-maintenance ME and CP/d (1/2M), and 4) M or 1/2M until anestrus, then 2.27 kg/d of a 14.0% CP corn-soybean meal diet until first breeding. Body composition at first breeding was determined using live weight, backfat thickness, and deuterium oxide space as variables in prediction equations. All females were treated similarly after first breeding. Age and body composition at first breeding were not related (P > .10) to litter size at birth or weaning in parities 1, 2, 3, or overall. Increasing age at first breeding was related to small increases in pig birth weights (P < .001) in parity 1 and average pig weaning weight (P < .001) in parities 1, 2, and overall. Body composition of gilts at first breeding was not related (P > .10) to pig birth weights and was inconsistently related to pig weaning weights in parities 2 and 3 (P < .001). Females heavier at first breeding remained heavier (P < .01) throughout the experiment. Age and body composition at first breeding were not different (P > .10) for gilts completing three parities (n = 53) compared with gilts failing to complete three parities (n = 34). Results show no large effects of gilt age or body composition at first breeding on sow productivity and longevity over three parities.

Aging↗
PubMed2001

Breed and heterotic effects on postweaning traits in Altex and New Zealand White straightbred and crossbred rabbits.

Postweaning data from 1,111 straightbred and reciprocally crossbred rabbits were analyzed to evaluate Altex and New Zealand White (NZW) breeds for individual growth and litter traits. The Altex is a recently developed sire breed, whereas the NZW is a popular commercial dam breed. Individual fryer growth traits were weaning (28 d; WW) and market (70 d; MW) weights and ADG. Litter traits included litter size (LSW) and total weight of litter at weaning (LWW), 28 to 70 d total feed intake (LFI), feed efficiency (LFE = total litter gain/LFI), survival rate, and within-litter MW uniformity. Least squares models consisted of fixed effects of sire breed, dam breed, season of weaning, doe parity, two- and three-way interactions, and random effects of sire within sire breed, litter within sire x dam breed, and(or) residual error (depending on whether an individual or a litter trait was analyzed). Crossbreeding parameters (direct breed additive, maternal breed, and individual heterosis) were estimated. Altex sires increased WW, ADG, and MW by 40 g (P < 0.10), 2.5 g/d, and 152 g (P < 0.001), respectively. Individual growth traits were not significantly influenced by the maternal breed effect. Litter size at weaning and LWW means were numerically similar for Altex and NZW dams. Direct heterosis increased ADG (1.7 g/d; P < 0.01) and MW (66 g; P < 0.10). In straightbred Altex compared to NZW fryers, ADG and MW were increased by 3.6 g/d and 216 g, respectively (P < 0.001). In Altex (sire) x NZW (dam) crossbred compared to NZW straightbred fryers, WW and MW were heavier (55 and 218 g; P < 0.10 and < 0.001) and ADG was more rapid (4.2 g/d; P < 0.001). For litter traits, Altex compared to NZW sires increased LFI by 1.28 kg (P < 0.10). Individual crossbreeding parameters did not affect (P > 0.05) other litter traits. No relationship existed between breed type of fryer and survival status (chi2 = 2.81; P > 0.25). For litter traits, straightbred Altex had significantly greater LFI by 2.45 kg and increased LFE by 0.015 units relative to NZW. Combined direct breed additive and heterosis effects increased LFI by 1.84 kg (P < 0.05) in Altex (sire) x NZW (dam) crossbreds compared to NZW straightbreds. Also, 25% more Altex (sire) x NZW (dam) crossbred fryers were marketable (body weight > or = 1.8 kg) by 63 d of age than NZW straightbred fryers. These data suggest that crossing Altex bucks to NZW enhanced breeding efficiency of fryer growth performance.

Animals↗
PubMed2005

Breeding for societally important traits in pigs.

Pig breeding programs traditionally focus on the genetic improvement of production and reproduction traits that have a clear economic value. Because citizens and consumers increasingly attach value to traits that have little or no direct relationship to production costs or to the price of a product, pig breeding organizations want to pay more attention to societally important traits, such as the welfare and health of pigs, the ecological effects of pork production, and the healthiness and sensory quality of pork. Most societally important traits have an economic and a noneconomic value and are sufficiently heritable for effective genetic selection, although many genetic and phenotypic (co)-variances still have to be estimated. However, it often is not clear to a pig breeding organization how it may deal with the noneconomic value of breeding-goal traits. In this study, a retrospective selection-index method is proposed to obtain the proper weights for societally important traits in the breeding goal. First, the genetic-progress space for each breeding-goal trait is explored by increasing the weights, in a stepwise manner, to each societally important trait in the breeding goal, starting from zero. Subsequently, a pig breeding organization can adopt the resulting genetic-progress scenario that it considers most sustainable or most acceptable. The weights underlying the adopted scenario are considered to be the proper breeding-goal weights. The noneconomic value of each societally important breeding-goal trait is found by deducting its economic value from its obtained weight and is thereby expressed in monetary units. In addition to obtaining weights for societally important breeding-goal traits, the proposed method offers the possibility to estimate the societal costs of selecting for economic traits only, as well as the societal benefits and the economic costs of selecting for traits with a noneconomic value. The method is therefore a useful tool for the development of sustainable breeding goals. An example has been worked out for a sow-line breeding program.

Animal Husbandry↗
PubMed2007

A longitudinal study on growth and growth variables in dogs of four large breeds raised in domestic environments.

The main objective of this study was to describe the growth patterns of 4 large dog breeds [Newfoundland (NF), Labrador retriever (LR), Leonberger (LEO), and Irish wolfhound (IW)] raised in domestic environments and concomitant changes in 2 growth-related clinical variables: total serum alkaline phosphatase (ALP) and the circumference of the distal radius and ulna (CDRU). The second objective was to investigate whether these measurements were affected by a range of independent variables like age, sex, litter number, and birth weight. Seven hundred dogs were included in the study, and BW data, separated by breed and sex, were fitted to the Gompertz function. Birth weight, adjusted for litter number, differed significantly between sexes for 3 breeds (LEO, P = 0.004; NF, P = 0.02; LR, P = 0.009) and approached significance for IW (P = 0.07). Estimated mean BW increased rapidly during the first 100 d after birth in all 4 breeds, then plateaued, with maturity being reached between 351 (female LR) and 413 d (male NF). Estimated mature BW ranged from 30.8 kg for the female LR up to 65.7 kg for the male IW. Weight gain, as expressed by the derivative of the Gompertz function, reached its peak in the smallest breed (LR) at the youngest age, 89 d for the females and 95 d for males. Log-transformed BW was significantly related to age, breed, and sex, and the age x sex and age x breed interactions. Within breeds, age, birth weight, and litter number had a significant effect on log-transformed BW. The estimated average CDRU increased from 90 d of age toward a peak at 180 d. Thereafter, CDRU declined and stabilized at about 1 yr of age. The estimated total ALP concentrations decreased from 90 to 360 d of age, after which they stabilized, at mean concentrations varying among breeds from 98 to 131 IU/L. Maximum least squares mean total ALP concentrations were found at 3 mo of age in all breeds, with the greatest least squares mean concentration in the IW breed (713 IU/L). In a mixed model analysis of the complete data set, total ALP was affected (P < 0.001) by age, breed, and the interaction of age x breed. This study described the main factors influencing growth and provided reference data for other studies, including those related to nutrition and disorders of growth.

Aging↗
PubMed1989

Breeding performance of beef bulls assigned to two-sire cow groups on pasture.

Angus, Polled Hereford and Santa Gertrudis bulls from ages 1 through 5 and 7 yr were assigned to 26 two-sire breeding groups. Each year, straightbred and crossbred cows of these breeds were allotted at random within breed composition, age of dam and calving date to breeding groups on pasture. Sires within each breeding group or pair were the same age at breeding and were two of the three breeds of sires. Neither calving rate nor the proportion of calves born by one vs the other sire in the two-sire breeding groups was affected by sire age among breeding groups. For a given breed, there was no uniformity among the sires in the proportion of calves they sired in their two-sire breeding groups. The proportion of calves born for the 26 sire pairs averaged .64 vs .36 (SE = 0.4 for either high or low value) for one vs the other sire in a sire pair with no indication that calving rate was affected by unequal proportions of calves by sires within sire pairs. Cows calved significantly earlier in the calving period (b = -.775 +/- .127) as calving rate increased among sire pairs. The number of days from the start of the breeding period to calf birth was affected by differences between sires in sire pairs for 8 of the 26 pairs, but there were no significant differences due to sire pair or breed of sire because of interaction between these two variables.

Age Factors↗
PubMed2006

Optimization of dairy cattle breeding programs for different environments with genotype by environment interaction.

Dairy cattle breeding organizations tend to sell semen to breeders operating in different environments and genotype x environment interaction may play a role. The objective of this study was to investigate optimization of dairy cattle breeding programs for 2 environments with genotype x environment interaction. Breeding strategies differed in 1) including 1 or 2 environments in the breeding goal, 2) running either 1 or 2 breeding programs, and 3) progeny testing bulls in 1 or 2 environments. Breeding strategies were evaluated on average genetic gain of both environments, which was predicted by using a pseudo-BLUP selection index model. When both environments were equally important and the genetic correlation was higher than 0.61, the highest average genetic gain was achieved with a single breeding program with progeny-testing all bulls in both environments. When the genetic correlation was lower than 0.61, it was optimal to have 2 environment-specific breeding programs progeny-testing an equal number of bulls in their own environment only. Breeding strategies differed by 2 to 12% in average genetic gain, when the genetic correlation ranged between 0.50 and 1.00. Ranking of breeding strategies, based on the highest average genetic gain, was relatively insensitive to heritability, number of progeny per bull, and the relative importance of both environments, but was very sensitive to selection intensity. With more intense selection, running 2 environment-specific breeding programs was optimal for genetic correlations up to 0.70-0.80, but this strategy was less appropriate for situations where 1 of the 2 environments had a relative importance less than 10 to 20%. Results of this study can be used as guidelines to optimize breeding programs when breeding dairy cattle for different parts of the world.

Animals↗
PubMed2002

[Studies of population genetic relationships among 24 Chinese and exotic pig breeds using AFLP analysis].

A total of 12 AFLP primer combinations were used to detect genetic variation of pooled DNA in a sample of 19 Chinese native pig breeds, 1 cultivated pig breed and 4 European and American pig breeds. The genetic similarity coefficient of 24 pig beeds was calculated from AFLP data, UPGMA cluster analysis was also performed. The 12 primer combinations generated more than 1000 bands, of which 208 bands were polymorphic, 17.3 polymorphic markers were detected by one primer combination on the average. Thirteen putative breed specific bands were produced in the pooled DNA of 8 pig breeds. The cultivated pig breed and 4 exotic pig breeds were clustere into one group, while 19 Chinese native pig breeds were gathered into the other group in the UPGMA tree. The result indicated that AFLP analysis had high assay efficiency index (Ai) and provided a valuable tool for assaying genetic diversity and breed characterization in pigs. Chinese native pig breeds and exotic pig breeds show remarkable genetic differentiation, which had farther genetic relationships. Nanchang White pig and Large White pig, Yushan Black pig and Yanshan Black pig had intimate genetic relationships with each other respectively, which were consistent with its breeding history, geographical distribution and RAPD analysis results. In addition, the reasons for cluster results of some pig breeds from AFLP data were not consistent with morphology, geographical distribution and existing classification were discussed.

Animals↗
PubMed1998

Endocrine and testicular changes in a short-day seasonally breeding bird, the emu (Dromaius novaehollandiae), in southwestern Australia.

Seasonal changes in testicular morphology and blood plasma concentrations of LH, testosterone, and prolactin are described for captive male emus in southwestern Australia. Testicular mass and testicular testosterone did not differ between the non-breeding (spring-summer) and the breeding (autumn-winter) seasons. Nevertheless, the testes obtained in the breeding season (May and August) were nearly two fold greater in mass than those collected in the non-breeding season (October and February). The highest testicular concentrations of testosterone were observed in February and lowest in October, while the values during the breeding season were intermediate. The patterns of histological changes in the testes also indicate that emus breed over the autumn-winter months. Tubule diameter was larger in the breeding season than in the non-breeding season, whereas the relative volume of the interstitium was larger in the non-breeding and smaller in the breeding season. Moreover, during the autumn and winter months, plasma LH and testosterone concentrations were high. Outside this period, in spring and summer, the concentrations of these hormones were low. Prolactin concentrations rose around the winter solstice, after the initial increases in plasma LH and testosterone. The end of the breeding season, in early spring, was marked by a gradual decrease in plasma LH concentrations but a rapid fall in testosterone concentrations. Prolactin concentrations continued to increase and peaked near the spring equinox, several weeks after the breeding season ended, and then decreased to reach baseline values by mid-summer. These testicular and endocrine changes are consistent with observations that the emu is a short-day breeder in southwestern Australia. Reproductive activity in the male begins soon after the summer solstice, well in advance of the development of suitable breeding conditions, and is then terminated in spring before food resources become limited by the onset of the dry season.

Animals↗
PubMed1998

Genetic relationships among European cattle breeds.

Genetic relationships among 37 European cattle breeds were investigated using blood group and serum protein polymorphisms. The 18,859 animals included in the study represented a random sample from pedigree populations in the UK. Within-breed variation was estimated by average heterozygosity and number of alleles observed, and breed relationships were evaluated by genetic distance. Standard errors of the heterozygosity, number of alleles and genetic distance were obtained by bootstrapping. The significance of breed differences was tested using an exact test of differentiation. French, Italian and Channel Island breeds were found to have generally higher heterozygosities and a greater number of alleles than breeds from mainland Britain and North Europe. Genetic distances ranged between 0.011 (+/- 0.005) and 0.309 (+/- 0.071). Two major breed groups were identified; a group of French, Italian and Channel Island breeds together with the Simmental and Gelbvieh, and a second group consisting of the mainland British and North European breeds. The exact test of breed differentiation showed all breeds to be significantly different from one another (P < 0.0001). Overall relationships among breeds reflected their geographical origin and common ancestry rather than the agricultural use for which the breeds have been selected.

Alleles↗
PubMed2005

Evaluation of genetic differentiation in Bos indicus cattle breeds from Marathwada region of India using microsatellite polymorphism.

Elucidation of genetic variability and genetic relationship among breeds has direct relevance with the issues of sustainable use of domestic animal genetic resources. In the present study, genetic polymorphism was evaluated using 22 microsatellite loci in unrelated samples of Red Kandhari and Deoni cattle breeds inhabiting the same geographical area of Marathwada region in Maharashtra state (western India). This work was mainly aimed at assessing the current genetic diversity to understand whether the two zebu populations in question are genetically differentiated. A total of 164 alleles were detected with an average of 5.82 and 5.86 alleles per locus (MNA) in Red Kandhari and Deoni breeds, respectively. The estimated mean observed (Ho) and expected (He) heterozygosity were 0.47 and 0.64 in Red Kandhari vs. 0.57 and 0.69 in Deoni cattle, respectively, demonstrating considerable level of genetic variation in both the populations. Mean estimates of F statistics were: F (FIT) = 0.315 +/- 0.035, f(FIS) = 0.231 +/- 0.031, theta(FST) = 0.110 +/- 0.022, with both the breeds exhibiting significant deficit of heterozygotes (FIS = 0.179 in Deoni; 0.278 in Red Kandhari). The multilocus FST values implied that 11.0% of the total genetic variation corresponds to breed and were statistically greater than zero for the two populations, suggesting population division. The evaluation of exact test also indicated that allele frequencies across all the loci differed significantly (P < 0.001) between two zebu breeds, further supporting population differentiation. Different genetic distance measures showed considerable levels of distances between the two cattle breeds (0.318 = Nei's standard DS; 0.250 = Nei's DA; 0.416 = Cavalli-Sforza and Edwards's Dc; 0.164 = Reynold's, and 2.64 = Delta mu square (dmicro)2. Bayesian statistical approach to assign each individual to the population also supported considerable differentiation between the two cattle breeds, possibly reflecting the limited gene flow between the two Marthwada cattle populations. The existence of cohesive breeding structure of both the breeds was further substantiated by allele-sharing distance measures (DAS) among individual animals. The results of this study thus revealed that the two Bos indicus breeds sharing the common breeding tracts are genetically differentiated enough as separate breeds.

Alleles↗
PubMed2006

Genetic variation and relationships among eight Indian riverine buffalo breeds.

Twenty-seven microsatellite loci were used to define genetic variation and relationships among eight Indian riverine buffalo breeds. The total number of alleles ranged from 166 in the Toda breed to 194 each in the Mehsana and the Murrah. Significant departures from the Hardy-Weinberg equilibrium were observed for 26 locus-breed combinations due to heterozygote deficiency. Breed differentiation was analysed by estimation of F(ST) index (values ranging from 0.75% to 6.00%) for various breed combinations. The neighbour-joining tree constructed from chord distances, multidimensional scaling (MDS) display of F(ST) values and Bayesian clustering approach consistently identified the Toda, Jaffarabadi, and Pandharpuri breeds as one lineage each, and the Bhadawari, Nagpuri, Surati, Mehsana and Murrah breeds as admixture. Analysis of molecular variance refuted the earlier classification of these breeds proposed on the basis of morphological and geographical parameters. The Toda buffaloes, reared by a tribe of the same name, represent an endangered breed from the Nilgiri hills in South India. Divergence time of the Toda buffaloes from the other main breeds, calculated from Nei's standard genetic distances based on genotyping data on seven breeds and 20 microsatellite loci, suggested separation of this breed approximately 1800-2700 years ago. The results of the present study will be useful for development of rational breeding and conservation strategies for Indian buffaloes.

Animals↗
PubMed2005

Frequency and distribution of alleles of canine MHC-II DLA-DQB1, DLA-DQA1 and DLA-DRB1 in 25 representative American Kennel Club breeds.

The frequency and distribution of dog leucocyte antigens (DLA) class II -DQA1, -DQB1 and -DRB1 alleles were determined for 25 American Kennel Club (AKC) registered dog breeds, representing 360 dogs from each of the seven major performance categories. Six to twenty-eight (average n=11) dogs were studied per group, with the exception of the Akita dog (n=94). All dogs were unrelated with no common grandparents based on AKC pedigree records (F-value <0.125). DLA class II allelic diversity was broad across breeds; 31/61 published DLA-DRB1 alleles, 11/18 published DLA-DQA1 alleles and 31/47 published DLA-DQB1 alleles were found among the 25 breeds. However, allelic diversity was severely limited within a breed. Seventeen of the DLA-DRB1 alleles were each found in only a single breed, and only seven alleles were shared by seven or more breeds. DLA-DRB1*00101 and DLA-DRB1*01501 were shared by 16 and 19 breeds, respectively. DLA-DQA1*00101 and DLA-DQA1*00601 alleles were shared by many breeds. The Rough Collie (DLA-DQA1*00901), English Setter (DLA-DQA1*00101) and Scottish Terrier (DLA-DQA1*00101) were monoallelic for DLA-DQA1. Eleven DLA-DQB1 alleles were each found only in a single breed and only seven alleles were shared by six or more breeds. DLA-DQB1*00201 and DLA-DQB1*02301 were shared by 17 and 18 breeds, respectively. Forty per cent of dogs typed were homozygous at DLA-DRB1, 52% at DLA-DQA1 and 44% at DLA-DQB1. Nine new DLA class II alleles were identified; three for DRB1 and six for DQB1. Comparison of our study of North American purebred dogs to previous European DLA surveys showed a similar use of common alleles consistent with known founder effects. However, more alleles were detected in European breeds, compared to their North American descendents, indicating that additional DLA class II diversity was lost when European breeds were established in North America.

Alleles↗