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PubMed2002

Effects of breeding date, weaning date, and grazing season length on profitability of cow-calf production systems in southeastern Montana.

Production data from 11 southeastern Montana ranches were used to parameterize a bio-economic computer model of cow/calf range production. Effects of changes in breeding date, weaning date, and range removal date on system performance for a ranch with a fixed forage resource base (3,060 animal unit months of range forage and 744 t of hay) were simulated. Input costs were locally established in 1994. Cattle prices were determined by week from 13-yr averages. For the base scenario, breeding season was 66 d with breeding starting on June 9. Weaning, range removal, and calf sales occurred on November 3. Cows were fed stored forages from November 3 until turnout to grazing (May 1). Five replications were simulated for combinations of breeding, weaning, and range removal dates in a factorial design. Each factor was deviated from the base scenario by +/- 14 and 28 d. Production efficiency was measured by break-even steer price. Gross margin (gross revenue - variable costs) was used as a measure of profitability. Increasing calf age (and weight) at sale time, by decreasing breeding date and(or) increasing weaning date, improved ranch efficiency and profitability. Increasing range removal date improved system performance even though extending the grazing season led to decreased herd size. Compared to the base system, the best system increased gross margin by approximately 17%. Responses for gross margin reflect the dynamics of herd size, purchased feed expense, and production efficiency. Results suggest that for range-based cow-calf enterprises in the northern Great Plains, production efficiency and profitability may be improved by increasing calf weaning age and extending the grazing season, even if herd size must be reduced.

Age Factors↗
PubMed2002

Maternal effects on traits measured during postweaning performance test of swine from four breeds.

The objective of this study was to investigate the importance of maternal genetic effects on postweaning performance traits of Yorkshire, Landrace, Duroc, and Hampshire breeds of swine. Data consisted of performance test records collected in a commercial swine operation from 1992 to 1999. Boars from 60% of the litters were culled at weaning based on a combination of maternal and performance indexes that differed by breed. Remaining boars and all females were grown to 100 d of age. At this time all pigs were weighed (WT100) and selected for testing using recalculated breed-specific indexes (n = 15,594, 55,497, 12,267, and 9,782 for Landrace, Yorkshire, Duroc, and Hampshire, respectively). All pigs were weighed at the end of the 77-d test, and backfat (BF) and loin eye area (LEA) were measured over the 12th rib by ultrasound. Average daily feed intake was calculated for boars, and ADG was calculated for all animals. Genetic parameters were estimated for each breed and trait using multiple-trait DFREML procedures. Fixed effects were contemporary groups and either initial or final test age as a covariate. Four models were examined. Model 1 included only the additive genetic effect of the animal. Model 2 added the common litter environmental effect; Model 3 added the maternal genetic value assumed to be uncorrelated with additive genetic effects. Model 4 was the same as Model 3 with additive and maternal genetic effects assumed to be correlated. All models were two-trait models with WT100 as the second trait. Ratios of likelihoods were used to compare models. Maternal effects were important (P < 0.05) for WT100, ADG, ADFI, LEA, and BF in Landrace; for WT100, ADG, LEA, and BF in Yorkshire; for WT100 and ADG in Duroc, and for WT100 in Hampshire. Estimates of heritabilities for direct additive effects using the appropriate model for ADG, ADFI, LEA, and BF were 0.28, 0.34, 0.48, and 0.63 for Landrace; 0.26, 0.31, 0.39, and 0.65 for Yorkshire; 0.14, 0.20, 0.26, and 0.35 for Duroc; and 0.17, 0.23, 0.25, and 0.31 for Hampshire, respectively. Heritability estimates for maternal genetic effects for ADG, ADFI, LEA, and BF were 0.02, 0.05, 0.06, and 0.07 for Landrace and 0.02, 0, 0.04, and 0.06 for Yorkshire, respectively. They were zero for all traits except ADG (0.03) in Duroc and for all traits in Hampshire. Maternal effects may need to be considered in genetic evaluation of performance traits in some breeds of swine.

Adipose Tissue↗
PubMed2005

The incidence of genotypes at codon 171 of the prion protein gene (PRNP) in five breeds of sheep and production traits of ewes associated with those genotypes.

Scrapie is one of several transmissible spongiform encephalopathies of livestock. Disease susceptibility is linked to polymorphisms in the normal prion protein gene that encodes the mammalian prion precursor. Codon 171 of this gene is a major determinant of scrapie susceptibility. Selection for arginine (R) at codon 171 is encouraged by the USDA to decrease the incidence of scrapie. Objectives of this study were to determine the frequency of R allele variants at codon 171 in a sample of sheep from five breeds (Columbia, Hampshire, Rambouillet, Suffolk, and Targhee) and western white-faced commercial ewes and to determine whether the R allele is associated with ewe and lamb production traits. Genotyping was performed on 532 ewes and 901 lambs from the University of Wyoming flock, in addition to 820 rams from 52 sheep producers from Wyoming and surrounding areas, using a DNA mismatch assay that discriminated the R allele from others at codon 171. Genotyping was performed by DNA sequencing on 127 rams representing all breeds, except Hampshire from the USDA Sheep Experiment Station at Dubois, ID. The 171R allele was found in all five breeds and in the commercial western white-faced ewes. Genotype frequencies varied (P < 0.001) by breed in ewe and ram populations. Influence of R-allele frequency on ewe lambing records and individual lamb records was analyzed for Columbia (62, 161, 121), Hampshire (89, 193, 162), Rambouillet (87, 179, 133), Suffolk (67, 178, 161), and commercial sheep (227, 463, 324) for numbers of ewes, total number of ewe production records, and individual lamb records, respectively. Suffolk ewes without the R allele (non-R/non-R) gave birth to more (P or= 0.08) by ewe genotype. Lamb birth and weaning weights were not influenced (P >or= 0.12) by lamb genotype in any of the breeds or in the commercial flock. In this population, ultimate lamb production was only influenced by genotype at codon 171 in the Suffolk flock.

Animals↗
PubMed2006

Effects of breed and season on performance of lactating sows in a tropical humid climate.

A total of 179 lactations obtained on 71 multiparous sows [30 Creole (CR) and 41 Large White (LW)] between June 2001 and July 2004 were used to determine effects of breed (CR vs. LW) and season (hot vs. warm) in a tropical humid climate on performance during a 28-d lactation period. Mean daily ambient temperature was greater during the hot season than during the warm season (26.0 vs. 23.8 degrees C), and relative humidity was similar in both seasons (85% on average). For both breeds, ADFI was reduced (-700 g/d, P < 0.01), sow BW loss was greater (17 vs. 12 kg, P < 0.01), and piglet growth was reduced (197 vs. 210 g/d, P < 0.05) during the hot vs. the warm season. At farrowing, LW sows were heavier (255 vs. 186 kg, P < 0.01) and had less backfat (21 vs. 40 mm, P < 0.01) than CR sows. The growth rate of CR piglets was lower than that of LW piglets (192 vs. 215 g/d, P < 0.01). A breed x season interaction was observed (P < 0.05) for ADFI and sow BW loss. During the hot season, the reduction of ADFI was more pronounced in LW than in CR sows (-910 vs. -470 g/d). Regardless of the season, BW loss of CR sows remained constant (14.2 kg), whereas it increased during the hot season for LW sows (10 kg). The weaning-to-estrus and the weaning-to-conception intervals were not affected by breed or season and averaged 4.8 and 6.1 d, respectively. The rectal temperature was greater (0.3 degrees C) during the hot season than during the warm season and greater in LW than in CR sows (39.1 vs. 38.8 degrees C, P < 0.10). This study confirms the negative effect of hot season in a tropical humid climate on performance of lactating sows and that breed can have a significant effect on lactation performance. The results also suggest that CR sows are more heat tolerant than LW sows.

Animal Feed↗
PubMed1988

Simulation of genetic control of reproduction in beef cows. IV. Within-herd breeding value estimation with pasture mating.

Procedures for breeding value estimation for reproductive traits under pasture mating conditions were developed and tested using a computer simulation model of genetic control of bovine reproduction. The model generated annual calving rates (BCR) (0 or 1) and calving dates (CD) for each cow as a function of underlying genetic variation in two independent traits: single-service conception rate, which was indicative of the ability to conceive when estrus occurs, and postpartum interval (PPI) from calving to first estrus. Observed values for BCR and CD were shown to be complex, nonlinear functions of breeding values for ability to conceive (CRG) and for postpartum interval (PPIG) and of the previous CD. Effects of CRG on BCR and CD were small at high values of CRG, but these effects increased as CRG declined. Effects of PPIG on BCR and CD were small for cows that previously calved within the first 21 d of the calving season, but these effects increased for cows that calved after d 21. Previous CD had substantial nongenetic carryover effects on both BCR and CD. Unbiased estimates of CRG and PPIG could not be derived in the absence of breeding information. However, CD were reasonably highly correlated with breeding values for ability to conceive, provided information on open cows was included in the evaluation. Calving dates were only weakly associated with breeding values for PPI, in part because of the relatively short mean PPI (70 d) that was simulated.

Animals↗
PubMed1989

Composition of the whole body and component fractions in mature ewes from seven breeds.

In a sheep production system, effects of body composition on nutrient requirements for maintenance, tissue deposition and lean meat production may be important. Composition of body fractions differing in expected metabolic activity was measured for 12 nonpregnant, nonlactating, 3- to 4-yr-old ewes from each of seven breeds representing diverse body size and performance characteristics. Half the ewes in each breed had ad libitum access to feed and half were fed at maintenance levels for an average of 41 d. Ewes were slaughtered after a 72-h fast. Empty bodies were divided into visceral organs and blood (ORB); gastrointestinal tract and internal fat (GIF); head, hooves and pelt (HHP); and carcass (CAR). Water, fat, ash and the remaining fat-free dry organic matter (FFDOM) contents were determined for each fraction. Mean empty body weight (EBW) was 60.8 kg and mean composition was 47.6% water, 34.1% fat, 14.8% FFDOM and 3.5% ash. Among breeds, larger mature size generally was associated with a higher percentage of fat and a lower percentage of water (P less than .01), in agreement with carcass composition. Ewes with ad libitum access to feed had more fat and less water in their EBW than did those fed at maintenance levels, especially in the GIF fraction. Distribution of EBW averaged 58.1%, CAR, 19.0%, GIF, 15.4% HHP and 7.5% ORB. The larger, faster growing breeds had the highest proportion of the EBW and of each chemical component located in the carcass. The smaller, more prolific breeds had the highest percentages of EBW in the ORB and GIF fractions. Effects of these large genetic differences in body composition and tissue distribution on production efficiency need to be evaluated.

Adipose Tissue↗
PubMed1989

Genetic parameters for ewe productivity traits in the Columbia, Suffolk and Targhee breeds.

Estimates of repeatability and heritability were obtained for the following productivity traits of ewes: litter weight at birth (LWB) and weaning (LWW), litter size at birth (LSB), litter size alive at birth (NBA), litter size at weaning (LSW), neonatal survival rate (SRB) and preweaning survival rate (SRW). Phenotypic and genetic correlations were estimated for litter traits. The data set contained 6,394 ewe breeding records from three state stations over 10 yr on 1,731 ewes that were the progeny of 488 sires among three breeds (Columbia, Suffolk and Targhee). Pooled intra-station estimates of repeatability ranged from .11 to .22 for LWB and LWW among the three breeds. For litter size at birth, number born alive and litter size at weaning these estimates varied from .09 to .17 and for the survival traits (SRB and SRW) the variation was from .11 to .20. Intra-station estimates of heritability for the three breeds varied from .12 to .28 for LWB and LWW, and for LSB, NBA and LSW estimates varied from .05 to .35. Heritability estimates for survival traits (SRB and SRW) were low, ranging from .00 to .14. Phenotypic correlations among LWB, LWW, NBA and LSW ranged from .35 to .92 among the breed-station subclasses, with higher correlations occurring where a part-whole relationship existed. The study suggests that selection of ewes with high litter size at birth or at weaning and(or) litter weight at birth or at weaning will genetically improve total litter weight at weaning per ewe lambing.

Animals↗
PubMed2005

Surveillance of above- and below-ground mosquito breeding habitats in a rural midwestern community: baseline data for larvicidal control measures against West Nile Virus vectors.

BACKGROUND: Mosquitoes in the genus Culex are thought to play a major role as vectors in the transmission cycle of West Nile virus (WNV) and other arboviruses in the United States. Effective control of mosquitoes through larviciding and adulticiding is expensive for communities and should be guided by reliable surveillance data on the distribution of mosquito breeding habitats. However, few small to medium sized cities in rural areas of the midwestern United States have this type of baseline information available. OBJECTIVE: During the summer of 2004, we investigated the characteristics of Culex and other mosquito-breeding habitats in a rural central Wisconsin community with a population of approximately 19,000. Such baseline information will aid in the development of rational strategies to control mosquito populations and prevent human exposure to WNV and other mosquito-transmitted viruses. METHODS: Mosquito larvae were collected and identified weekly from 14 below-ground storm water catch basins and 10 above-ground standing water sites distributed throughout the community. Collection began June 4, 2004 and continued through September 24, 2004. For each collection site the primary and adjacent land use patterns were determined. RESULTS: Over the study period, 1,244 larvae were collected from catch basins; 94% were Culex species. Breeding activity was first detected in early July. Peak breeding was observed during a period of several weeks when average daily temperatures were at the maximum observed and rainfall had declined. Organically enriched catch basins in low intensity urban sites adjacent to forests and wetlands were found to be more productive breeding habitats compared to catch basins having little organic debris located in isolated high intensity urban sites. Above-ground standing water sites produced 1,504 larvae; 66% of which were Culex species. Flood control ditches and permanent wetlands with stagnant water were most productive, while ditches with moving water were least productive habitats. Larvae were produced earlier in the season by above-ground sites than were produced by catch basins. However, larvae production was more variable in above-ground sites since half the sites became dry at some point during the study period. CONCLUSION: The observed differences in Culex larvae production based on the variables of habitat-type, temperature, and precipitation support the need for ongoing surveillance in communities to guide public health officials in planning for and prioritizing mosquito control efforts.

Animals↗
PubMed2006

Effects of breed and region on longevity traits through five years of age in Brown Swiss, Holstein, and Jersey cows in the United States.

The objective of this study was to assess breed, and breed x region interactions for several longevity-related traits, measured up to 5 yr of age in Brown Swiss, Holstein, and Jersey cows in 7 regions of the United States. Data were analyzed using logistic, poisson, and linear models, and survival analyses. The traits were stayability (yes/no survived to 5 yr of age), number of completed lactations, days lived, herd-life, and days in milk (DIM) to 5 yr of age. Probable lifetime DIM were also estimated using data from the first 5 yr of age of the cows. Herd-life was defined as the days lived up to 5 yr of age minus the age at first calving. Days in milk consisted of herd-life up to 5 yr of age minus the dry periods. Three data files were analyzed: herds with one breed of cows, herds with Holstein and Brown Swiss, and herds with Holstein and Jersey cows. Breed x region interaction was usually significant, with larger effects for the southern regions. Jerseys obtained largest values for the ratio of DIM to days lived, and for the number of completed lactations to 5 yr of age. Brown Swiss had the largest probabilities of surviving to 5 yr of age (stayabilities) in all regions. For the other traits, the results for Brown Swiss were inconsistent, but usually the cows of this breed had shorter herd-life and DIM to 5 yr of age than Holsteins. Brown Swiss cows were expected to have more total DIM in their lifetime in the Southeast than Holsteins. Survival analysis gave the most readily interpretable information, although the linear, poisson, and logistic analyses answered slightly different questions. Adjustment for herd size did not modify the results.

Animals↗
PubMed2006

Short communication: a polymorphism in ABCG2 in Bos indicus and Bos taurus cattle breeds.

A single nucleotide change (A/C) in exon 14 is capable of encoding a substitution of tyrosine-581 to serine (Y581S) in the ABCG2 (ATP binding cassette, subfamily G, member 2) gene and affects milk production traits. The ABCG2(A) allele decreases milk yield and increases protein and fat concentration. The allele frequencies were determined in 32 Bos taurus and 3 Bos indicus breeds; ABCG2(A) was predominant in all populations. This allele approached fixation in 23 out of 35 breeds, including all 3 Bos indicus breeds. The ABCG2(C) allele was found in the Belgian Blue (beef), Belgian Blue Mix, British Friesian, Bohemian Red, East Anatolian Red, German Angus, German Black Pied, German Brown, German Simmental, Israeli Holstein, Menorquina, and US Holstein breeds. Thus, the genetic gain expected from selection for ABCG2(A) may be limited. The detection of ABCG2(C) only in Bos taurus breeds may indicate that ABCG2(A) is the ancestral allele, and that the Y581S substitution occurred after the separation of the Bos indicus and Bos taurus lineages.

ATP-Binding Cassette Transporters↗
PubMed1983

Structure of dairy cattle breeding in Western Europe and comparisons with North America.

The cattle population of Western Europe is slightly smaller than that of the United States but contains 32 million dairy cows versus 11 million. The dairy herd provides 80% of the beef produced against 20% in the United States. The dairy cow population in the European Economic Community consists of 15 million Friesian type cows and 10 million non-Friesian, making up 29 separate breeding populations. The structure and organization of the breeding program in these 29 populations are described. A strong inflow of North American genetic material (Holstein into the Friesian populations. Brown Swiss and Red Holstein into the others), which has been going on for some years, is quantified. Many European populations will be more than 50% North American in genetic constitution within a decade. The reasons for this shift in breeding policy are discussed. A method is introduced for describing the effectiveness of an artificial insemination bull selection program by numbers of bulls tested per million inseminations and lifetime usage of selected bulls. This method is used to compare the breeding programs of 10 North American breeding organizations with those of 20 European and 2 New Zealand populations. In general, the European populations are making much higher investments in bull testing, whereas the North American organizations tend to have higher rates of bull usage.

Animals↗
PubMed1986

Interrelationships between recent developments in molecular genetics and cytogenetics and animal breeding.

Animal breeding traditionally has entailed devising means to apply quantitative and population genetic theory to increase productive capacity of livestock. A highly developed and successful industry has been built on foundations established by academic animal breeders. Recent developments in related sciences such as reproductive biology, molecular biology, cellular biology, and cytogenetics offer prospects for the emergence of a number of methodologies that might usefully be applied to animal breeding. Scientists engaged in development of the newer technologies are not wholly familiar with the livestock industry, its breeding structure, its objectives, its institutions or its peculiarities. Animal breeders, however, are not fully cognizant of the scientific advances being made in related fields, their potential for development and application or their limitations, and therefore, animal breeders have not seriously thought about how they might be integrated most usefully and efficaciously into the animal breeding enterprise. A collaboration is needed in which the laboratory scientists produce new ideas, products, and methods and the animal breeders--using system analysis, simulation procedures, and laboratory animal and livestock breeding tests--help make rational choices, partially direct work of the laboratory scientists, help the industry integrate new methods, and monitor the extent of success of adapted innovations.

Animal Husbandry↗
PubMed1993

Associations of breeding values for disease traits and genetic markers in dairy cattle estimated with a mixed model.

Since 1985, all veterinary treatments on dairy cows in Sweden have been recorded and utilized for estimation of sire breeding values for resistance to clinical mastitis and to diseases other than clinical mastitis. The purpose of the present investigation was to study the relationship of blood groups and blood protein polymorphisms with these traits and to extend a method previously applied to international comparisons of dairy sires for milk production to estimation of marker gene effects. The data comprised 1171 AI sires of the Swedish Red and White dairy breed that had a blood typing record and breeding values for disease resistance. Information was available on the breeding values of sires, the number of daughters of each sire, and the relationships among sires. This information was used to deregress the sire breeding values to average daughter performances, which then were analyzed by a mixed linear model. The reduction in error variance that was due to inclusion of the markers in the model was small. Several substitution effects of the markers were statistically significant. The largest effects corresponded to a deviation of .7 percentage units for the frequency of veterinary treatments among the average daughters of the sires.

Alleles↗
PubMed1996

Tonic immobility reaction and heterophil to lymphocyte ratio in hens from three Spanish breeds laying pink eggshells.

Tonic immobility reaction and heterophil:lymphocyte ratio were studied in hens laying pink eggs from three brown egg Spanish breeds (Barred Red Vasca, Red Vasca, Red Villafranquina). There was no significant difference among breeds in terms of tonic immobility duration or heterophil:lymphocyte ratio. Tonic immobility duration was significantly shorter in the pink (220 + or - 23 s) than in the normal brown shell group of hens (416 + or - 23 s; P < 0.001). Differences were consistent across the breeds, tonic immobility of hens laying pink eggs being shorter than that of control hens in all three breeds. Birds of the group with pink shells appeared to be less fearful when defined by either the duration of tonic immobility or the number of inductions to achieve it. There was a significant difference in the heterophil:lymphocyte ratio between the two groups of hens (P < 0.001), mean value being significantly higher in the pink shell (0.73 + or - 0.03) than in the control group (0.35 + or - 0.03). The heterophil:lymphocyte ratio from the pink shell hens increased significantly in the three breeds. Hens that laid pink eggs had significant heterophilia and lymphopenia (P < 0.001). Thus, hens laying pink eggs were less fearful and more stressed than control hens, as indicated by the tonic immobility reaction and the heterophil:lymphocyte ratio, respectively. A significant negative correlation was found between both measurements (r = A).28; P < 0.01). A similar significant negative association (P < 0.001) was found between pink shell color and shell strength.

Analysis of Variance↗
PubMed1976

[Suitability of various food mixtures for breeding and rearing of beagle dogs. 3. Methods and results for the Ingelheim team].

Two different modes of nutrition during breeding and rearing of dogs are investigated to determine which of them has the better effect. The use of a complete feed for breeding and maintenance (Altromin H) was compared with the use of a special breeding feed (Zahn Z), respectively, together with a special maintenance feed (Zahn H). A palatability test was made, a 2-year test for the effect on breeding, observation of weight gain and food consumption in the rearing phase on all the dogs of the strain Chbi:BEAGLE. The palatability test showed no preference for either diet. Initially, on changing diets, the dogs ate more of whichever new food was given. From 22 parameters which characterize the breeding effect the only statistically significant difference determined was an 11% higher consumption in the Altromin H group. Although in the rearing phase the food consumption in the Altromin H group was higher, male dogs in the younger age group made more weight gain on the special food (Zahn Z) and older bitches fed Altromin H were heavier for a time.

Age Factors↗
PubMed2002

[Genetic analysis and estimation of genetic diversity in east-European breeds of swift hounds (Canis familiaris L.) based on the data of genomic studies using RAPD markers].

The method of polymerase chain reaction with a set of arbitrary primers (RAPD-PCR) was used to describe genetic variation and to estimate genetic diversity in East-European swift hounds, Russian Psovyi and Hortyi Borzois. For comparison, swift hounds of two West-European breeds (Whippet and Greyhound) and single dogs of other breed groups (shepherd, terriers, mastiffs, and bird dogs) were examined. For all dog groups, their closest related species, the wolf Canis lupus, was used as an outgroup. Variation of RAPD markers was studied at several hierarchic levels: intra- and interfamily (for individual families of Russian Psovyi and Hortyi Borzois), intra- and interbreed (for ten dog breeds), and interspecific (C. familiaris-C. lupus). In total, 57 dogs and 4 wolfs were studied. Using RAPD-PCR with three primers, 93 DNA fragments with a length of 150-1500 bp were detected in several Borzoi families with known filiation. These fragments were found to be inherited as dominant markers and to be applicable for estimation of genetic differences between parents and their offspring and for comparison of individuals and families with different level of inbreeding. A high level of intra- and interbreed variation was found in Russian Psovyi and Hortyi Borzois. In these dog groups, genetic similarity indices varied in a range of 72.2 to 93.4% (parents-offspring) and 68.0 to 94.5 (sibs). Based on the patterns of RAPD markers obtained using six primers, a dendrogram of genetic similarity between the wolf and different dog breeds was constructed, and indices of intragroup diversity were calculated. All studied breeds were found to fall into two clusters, swift hounds (Borzoi-like dogs) and other dogs. Russian Borzois represent a very heterogeneous group, in which the Russian Psovyi Borzoi is closer to Greyhound than the Russian Hortyi Borzoi. All studied wolfs constituted a separate cluster. Significant differences were found between the wolf and dogs by the number of RAPD markers (92.8 and 86.1, respectively) and by the indices of genetic diversity (54.3 and 64.8%, respectively). The reasons for the high intraspecific variation of dogs (including Russian Borzois) and the prospects of using the studied group of markers for genetic analysis and differentiation in C. familiaris are discussed.

Animals↗
PubMed2003

[Analysis of genetic diversity of Shandong indigenous chicken breeds using microsatellite marker].

Microsatellite marker is one of the frequently used molecular markers. It has been used in the genotype identification, pedigree analysis and estimation of genetic distance. In this paper, five microsatellite markers with high polymorphisms were selected to detect the genetic diversity of seven chicken breeds. The alleles frequencies, polymorphism information content (PIC) and average heterozygosity within each population, and DA genetic distance among breeds were analyzed. The application of microsatellite polymorphisms to the detection of genetic variability and relationship among populations was discussed. Altogether, forty alleles were found in this experiment, and among them the most alleles (10) were detected by ADL0136 and the least (5) were detected by ADL0146. The distribution of alleles was not balanced, each locus having one or more dominant alleles. The average heterozygosity in the Shouguang chicken was the lowest (0.3327), and that in other breeds was also less than 0.4. It can be seen then that microsatellite polymorphisms can be used to reveal the variability within population through calculation of average heterozygosity. The PIC values ranged from 0.6169 (Shouguang chicken) to 0.7027 (Laiwu Black chicken). UPGMA tree was completed through analysis of DA genetic distance. In the tree, the Rizhao Pockmarked and the Jining Hundred chicken were first grouped together with a bootstrap value of 92%, before they were grouped with the Laiwu Black and the Shouguang chickens. The Anoka Yellow and the Guangxi Yellow chicken were grouped together with a bootstrap value of 80%, but the Luxi Fighting chicken had its own branch. In summary, the UPGMA tree well reflected the evolutionary and breeding history of the seven breeds.

Alleles↗
PubMed2004

[Study on mitochondrial DNA genetic diversity of some cattle breeds in China].

The complete mitochondrial D-loop sequences, 910 bp in length, in 22 individuals from 8 cattle breeds in China were analyzed. The results showed that A% + T% was about 61.65%. Comparisons of these 22 sequences revealed 66 polymorphic sites, and 5 types of mutation, transition, transversion, insertion, deletion and coexistence site of transition and transversion were observed,with the percentage of 81.82%, 6.06%, 7.57%, 3.03%, 1.52%, respectively. In reference to complete mtDNA D-loop of the European cattle as a control, eight Chinese cattle breeds were classified into 3 groups according to the average percentage of D-loop nucleotide variations. The lowest average percentage of mtDNA D-loop nucleotide variation was in Xizhen cattle, Mongolian cattle, Holstein, Qinchuan cattle with 0.37%, 0.44%, 0.52%, 0.66%, the mediate in Nanyang cattle and Jiaxian cattle with 1.91%, 2.02% and the highest in Jinnan cattle and Yueyang cattle with 4.47%, 4.73%, respectively. The average sequence divergence estimated from D-loop region within breeds and among breeds in China varied from 0.55% - 5.39% and 1.21% - 6.59%, respectively. Comparisons of these 22 sequences revealed 19 mitochondrial haplotypes, the percentage of haplotype was 86.36%, showing that abundant mitochondrial genetic diversity exists in Chinese cattle. The molecular phylogenetic tree of mtDNA D-loop of 8 Chinese cattle breeds was constructed by Neighbor-Joining method. The NJ tree indicated that these mtDNA sequences fell into 3 distinct haplotype groups, it also suggested in molecular level that there were probably 3 maternal origins, of which the main origins of Chinese cattle were from Bos taurus and Bos indicus.

Animals↗