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PubMed2003

Approximate estimation of minimal sample size required for marker-assisted backcross breeding.

Backcross breeding is a useful method to transfer favorable alleles from a donor parent into a recipient parent. Marker-assisted selection (MAS) can speed up the process. To make an appropriate plan before using MAS in a breeding program, breeders need to know the minimal sample size of the progeny generation required. A method to estimate the minimal sample size required for marker-assisted backcross breeding when both foreground selection and background selection are conducted is proposed. On the basis of a simplified assumption that the target loci are introgressed and the genetic background are independent, the probability of selecting individuals with desired genotypes in each generation is approximately estimated combining analytical approach (for foreground selection) and simulation according to the graphic genotypes of backcrossing parents (for background selection). The minimal sample size required to obtain at least one desired individual with a given probability is estimated. Application of the method is demonstrated with hypothesized examples. The method can be conveniently applied to practical backcross breeding programs.

Alleles↗
PubMed2003

An assessment of mosquito breeding and control in four surface flow wetlands in tropical-subtropical Australia.

In Queensland, Australia, the tropical-subtropical climate is ideal to promote macrophyte growth in surface flow wetlands; however, there have been concerns that constructed wetlands are potential breeding sites for disease-bearing mosquitoes. The aim of this study was to assess whether mosquitoes were breeding in these constructed wetlands, and if so, where they breed, and what parameters might influence breeding: e.g. water quality, vegetation, or macroinvertebrate communities. A study of four surface flow constructed wetlands located in different climatic regions was undertaken. Mosquito larvae were sampled using 240 ml dippers and macroinvertebrates using dip nets. The wetland with the greatest biodiversity of macrophytes and macroinvertebrates had the least number of mosquito larvae (< 1% of all dips). Samples with most mosquito larvae occurred amongst dense mats of Paspalum grass or dead Typha. Despite the presence of larvae in some parts of these wetlands very few late instars or pupae were found i.e. completion of the mosquito life cycle to adult mosquitoes was unsuccessful. This study has shown that the presence of mosquito larvae can be minimised by increasing macroinvertebrate biodiversity, by planting a variety of macrophyte types and species, excluding aggressive plant species, and maintaining at least 30% open water. Macroinvertebrates are probably a crucial factor in the control of mosquito larvae ensuring that predation of the early instars prevents or limits the development of pupae and the emergence of adults.

Animals↗
PubMedDate not supplied

[Analysis of the prevalence of pastern dermatitis in German Coldblood horse breeds].

The prevalence of pastern dermatitis was investigated in 917 German Coldblood horses aged 2.5 to 26 years. Pastern dermatitis was prevalent in Black Forest Draught horses with 47.5% and in South German Draught horses with 58.5%. High prevalences were found in Mecklenburg (76.4%), Saxon-Thuringa (84.3%), Schleswig (86.0%), and Rhenisch German Coldblood (96.1%) horses. All four legs or both hind legs were affected most frequently. The most prevalent forms of pastern dermatitis were crusted and hyperkeratotic-hyperplastic. The occurrence of pastern dermatitis was dependent of age. The statistical analysis using a generalized linear model and a probit function showed the significant influence of the breed, age at examination, sex, position of the leg, interaction of breed by age at examination, and breed by position of the leg. So the analysis indicated that pastern dermatitis is a serious problem in all German Coldblood breeds investigated here.

Animals↗
PubMed2004

Fostering an infant rhesus monkey on to a non-lactating female in a group-housed breeding colony.

The reported case describes how an orphaned infant rhesus macaque (Macaca mulatta) was adopted by a non-lactating female animal from the same breeding group. Experience at our institution over the last 27 years has indicated that fostering infant rhesus macaques on to other females is unsuccessful. However, the described infant was held and carried by another female in his breeding group when his mother was sick. After the death of his natural mother, fostering on to a lactating female was attempted but failed, and he was returned to his breeding group and was adopted by the non-lactating female. The infant was hand-fed by animal care staff, and the feeding regimen is described. The fostering was successful, and the infant has had access to a mother figure and peers, although extensive contact with humans initially was necessary for feeding. This contact did not, however, appear to be detrimental to the mother-infant and peer-infant bond, as the infant did not preferentially seek human contact over monkey contact, and he was at no point rejected by mother or group. The disruption caused by removal and replacement of the infant did not cause agitation or increased fighting within the group. We anticipate that the contact with a matriarchal figure in a primate breeding group will minimize the psychological disturbances frequently found with hand-reared macaques.

Animal Husbandry↗
PubMed2002

[Rice breeding by space technology].

In order to inquire into the influences of space conditions on rice breeding,the dry seeds of 12 rice varieties were carried by recoverable satellite. After recovery,these seeds were showed in the yield, the inheritance and variation of the characters of their progenies were observed and analysed. The results showed that the characters of the progenies mutated under space conditions segregated and varied in many aspects and directions,and the segregated and varied characters were heritable. These progenies posoessed significant transgressive inheritance, a plenty of variation types and variation was characterized by short breeding period. The results in this study indicated that space technology breeding could be developed and used as a new method of mutation breeding.

English Abstract↗
PubMed2005

[The genetic diversity and genetic effects of Myf-6 gene in different pig breeds].

As a member of MRFs, Myf-6 gene plays an important role in the progress of myogenesis. The PCR-RFLP technique was applied in this study to analyze the distribution of Myf-6 gene in 12 different pig breeds and hybrid breeds. The genetic effects of Myf-6 gene on muscle fiber, carcass quality, carcass grading traits and meat quality traits were analyzed. The results indicated that: The polymorphisms of Myf-6/Ava I genotypes (intron1) were not abundant. Most of Chinese native pigs were AA homozygotes. B allele can be found only in foreign pig breeds and hybrid pigs originated from foreign pig breeds. Although no BB individuals were found in the experiment, the carcass lean percent of AB individuals (50.344 %) was significantly higher than that of AA individuals (45.875 %)(P<0.01), the loin eye area of AB individuals (27.097 cm2) was significantly larger than that of AA individuals (22.572 cm2)(P<0.01), and the carcass fat content of AB individuals (39.889 %) was significantly lower than that of AA individuals (44.503 %)(P<0.01). That means that the B allele can increase carcass lean percent and loin eye area, and decrease the carcass fat content, thus cause better carcass quality. No significant effects of the genotypes were found on the muscle fiber, FOM carcass grading traits and meat quality traits (P>0.05).

Alleles↗
PubMed2006

[Study on mtDNA D-loop of Chinese main indigenous sheep breeds using PCR-RFLP].

The polymorphism of mtDNA D-loop of 83 individuals from 9 Chinese indigenous sheep breeds and 2 imported sheep breeds were studied with 5 endonucleases, Hinf I, Msp I, Sau3A I, Xsp I and Taq I, using PCR-RFLP. The results indicated that there existed two basic haplotypes in the region of mtDNA D-loop. It could be inferred that Chinese indigenous sheep breeds originated from two maternal ancestors. The averaged polymorphic degree (Pi value=0.0421%) of mtDNA D-loop showed that the genetic diversity of mtDNA of Chinese indigenous sheep breeds was very poor.

Animals↗
PubMed1991

Role of Azolla in controlling mosquito breeding in Ghaziabad district villages (U.P.).

A survey was carried out during post-monsoon period (1988-89) in villages of Dhaulana Primary Health Centre, Distt. Ghaziabad (U.P.) to evaluate the utility of Azolla pinnata for the control of mosquito breeding in different habitats. Results of the survey revealed that pools, ponds, wells, rice fields and drains were infested with Azolla. Infestation rate and intensity of infestation varied from habitat to habitat. Maximum infestation (36.5%) was observed in pools and minimum (3.7%) in rice fields. Anopheline breeding was almost completely suppressed (0-1.6/dip) in pools, wells and ponds completely covered with Azolla. The breeding of Culex spp. was not completely inhibited in any habitat, though reduction in immature density was observed in comparison to control. The role of Azolla in controlling mosquito breeding and its association with the blue green algae which fixes nitrogen is discussed.

Animals↗
PubMed1991

[Changes in antiproteolytic activity in blood and ovarian follicular fluid in 3 breeds of sheep after stimulation of superovulation].

Serine proteases help to regulate the ovarian cycle at different levels and they are subjected to the control of gonadotropic hormones and protease inhibitors. Superovulation stimulations influence the activities of trypsin inhibitors (model serine protease) in blood plasma (BP) and in follicular fluid (FF), and also in dependence on the breed. Trypsin inhibiting activities were determined from the reduced rate of trypsin hydrolysis of a chromogenic substrate (TAPA) and they were determined in percent. A change in absorbancy at 405 nm = 1.0 after 10-minute incubation at 25 degrees C and pH = 8.05 was taken as 100%. The incubation mixture as a sample contained 100 microliters blood plasma or 10 microliters follicular fluid, diluted with gammaglobulin at 1:10. The differences in the trypsin inhibiting activities (TIA) of BP in ewes of the Merino, Tsigai and Wallachian breeds were insignificant, but Agelin synchronization (20 mg chlorsuperlutin per vaginal swab) induced statistically significant differences. The lowest TIA BP was recorded in the Tsigai breed (T), P less than 0.001 in comparison with the Wallachian (W) and Merino (M) breeds. Following the administration of 1,500 IU PMSG, the TIA BP within 120 hours decreased in W (P less than 0.001), it increased in T (P less than 0.1) and in M the changes in the TIA BP were insignificant. The average numbers of ovulations increased from 2.25 +/- 2.5 to 3.0 +/- 1.2 in W; from 0.25 +/- 0.43 to 2.5 +/- 1.6 in T and from 0.00 +/- 0.0 to 2.5 +/- 2.3 in M. Following the single administration of 2,000 IU PMSG after Agelin synchronization, the changes in M ewes were also insignificant, and there were no different responses in pregnant (1st to 2nd month) and nonpregnant ewes. In pregnant T ewes the TIA BP increased after Agelin synchronization and stimulation (P less than 0.01), in nonpregnant ewes these changes were not significant. In W lambing ewes the TIA BP increased (P less than 0.001), the effects of Agelin were greater than those of PMSG. The TIA of follicular fluid (FF) of antral follicles were on average tenfold if compared with BP. After hormonal treatment of ovaries, the TIA FF mostly increased at different levels of statistical significance. The TIA FF of follicles less than 10 mm were lower than in follicles greater than 10 mm (P less than 0.001 for M and W, P less than 0.1 for T).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Observations on the breeding of anophelines in rice fields of Shahjahanpur district, Uttar Pradesh.

Studies on ecological succession and association of anophelines in selected paddy fields of Dadraul PHC were carried out in 1988 during the paddy cultivation period from June to October. Breeding of five anophelines was observed in paddy fields. Out of the adults that emerged from larval collections the percentage of An. subpictus was the highest followed by An. nigerrimus, An. culicifacies, An. annularis and An. barbirostris. Further, An. culicifacies and An. subpictus breeding occurred in the early stage of rice cultivation and stopped before the breeding of An. nigerrimus started i.e., nearly 30 days after rice transplantation. An. nigerrimus breeding continued till harvesting. An inverse correlation between larval density of both An. culicifacies and An. subpictus and the height of the rice plants was observed.

Animals↗
PubMed1979

The influence of breed on the susceptibility of sheep of Haemonchus contortus infection in Kenya.

The relative resistance of six breeds of sheep to Haemonchus contortus infection was investigated under field conditions on two stations situated in a semi-arid zone in Kenya. As judged by faecal egg counts, monitored throughout a two-year period, it was found that there were consistent differences between the breeds. The breeds studied in order of increasing susceptibility were Red Masai, Blackhead Persian, Merino, Dorper, Corriedale and Hampshire. Post mortem findings confirmed that the differences in faecal egg count were related to the establishment of worms rather than larval inhibition or the suppression of worm egg production. There was also evidence that the Red Masai showed self-cure more frequently than the other breeds.

Animals↗
PubMed1989

Thymus transplantation and disease prevention in the diabetes-prone Bio-Breeding rat.

Bio-Breeding rat T lymphocytes proliferate poorly in response to alloantigen. Transplantation of Bio-Breeding rats with fetal thymus tissue from diabetes resistant rats leads to an improvement in the T cell proliferative response, but only if the thymus contains bone marrow-derived, radiation-resistant thymic antigen presenting cells of the diabetes-resistant phenotype. The current study provides evidence that thymus transplantation leading to the restoration of Bio-Breeding T cell proliferative function can also significantly reduce the incidence of insulitis and prevent the development of diabetes. It appears that a defect in the bone marrow-derived thymic APC population contributes to an abnormal maturation of Bio-Breeding T lymphocytes which in turn predisposes animals to insulitis and diabetic disease.

Animals↗
PubMedDate not supplied

[First detection of Anopheles species mosquitoes breeding in water-filled cellars].

Studies of the breeding of blood-sucking mosquitos in water-filled cellars of Astrakhan were carried out in 1980-1986 using routine entomological techniques of assessment, collection and determination of blood-sucking mosquitos. In July, 1986, Anopheles sp. breeding in the cellars of 2 multistory buildings was registered along with commonly observed breeding of C. pipiens. The rate of preimago development stages of Anopheles sp. was 2 to 10 sp. per 1 cubic meter of water surface. Water-filled cellars are full of ground water mixed with sewage. It increases epidemiological value of the fact of mosquitos' breeding in populated areas, which should be taken into account during mosquito control.

Animals↗
PubMed1987

[Routes of salmonellosis spread beyond the confines of a swine-breeding farm complex].

Salmonella contamination of swine and morbidity rates among the workers of swine-breeding complexes and the members of their families, as well as among the population inhabiting the zone of possible influence rendered by such complexes on the environment, have been studied as exemplified by 4 complexes for large-scale swine breeding, differing in their technology of swine raising and fattening, their systems of the purification and utilization of manure-containing sewage. Besides, the influence of the raw meat (pork) and meat products, contaminated with salmonellae, sold in town, on salmonellosis morbidity among the urban population has been analyzed. The study has revealed that salmonellae are spread from swine-breeding complexes with the fluid and solid fractions of manure-containing sewage, as well as with the animals supplied to the meat-packing plant; the contamination of the workers of swine-breeding complexes with salmonellae becomes possible due to the low culture of the production and to the breach of sanitary and epidemic-control regulations and the contamination of the population occurs through meat and meat products.

Adolescent↗
PubMed1988

Controlled breeding in the Asiatic buffalo (Bubalus bubalis).

Recent developments in exogenous hormone therapy to control and facilitate breeding in domestic buffalo cows (B. bubalis) are reviewed. Oestrus in domestic animals was synchronized satisfactorily during the normal breeding season by both of the standard treatments with prostaglandins or progestagens initially developed for use in Bos taurus cattle. Anoestrous cyclic cows treated with prostaglandin showed synchronized oestrus and conception rates similar to those recorded in normal cyclic animals, though the responses may have depended to some extent on increased intensity of observation of oestrus. Seasonally acyclic animals treated with progestagens and pregnant mare serum gonadotrophin also showed synchronized oestrus and conception rates equivalent to those recorded in cyclic animals, but these observations did not include prepubertal heifers or cows in the early stages of post-partum anoestrus. Controlled breeding did not overcome a general problem of low conception rates at spontaneous oestrus. Further investigations of controlled breeding should incorporate other management strategies, such as better feeding and reduced heat stress, which are known also to improve buffalo reproduction.

Animals↗
PubMed1986

Canine storage disease characterized by hereditary progressive neurogenic muscular atrophy: breeding experiments and clinical manifestation.

Progressive neurogenic muscular atrophy due to storage of a compound lipid in the lower motor neurons was diagnosed in 3 English Pointers that were littermates. Using 2 clinically normal littermates of these 3 affected dogs and 2 clinically normal dogs of the 2nd litter from the parents of the original 3 affected dogs as the initial breeding stock, a breeding experiment was performed, resulting in a breeding line of 26 dogs, 4 of which had the disease and 6 of which died before 3 months of age. Results indicated that the disease may have an autosomal recessive mode of inheritance. The clinical manifestation and electrophysiologic findings indicated lower motor neuron involvement in the affected dogs produced by breeding consistent with findings in the original 3 affected dogs. Upper motor neurons or the sensory system was not involved. The disease appeared to be distinct from other canine storage diseases previously reported.

Animals↗
PubMed1985

Selecting pet dogs on the basis of cluster analysis of breed behavior profiles and gender.

Using a computer-generated data base of rankings of 56 breeds of dogs on 13 behavioral traits, a factor analysis was performed to determine the extent to which a few general underlying behavioral tendencies are manifested in specific characteristics. Three factors, referred to as reactivity, aggression, and trainability, accounted for 81% of the variance in the 13 behavioral traits. Subsequently, a cluster analysis was performed to generate 7 clusters of dog breeds on the basis of similarity in scores for each of the 3 main factors. The clusters reflected to some degree the conventional groupings of dogs into working, sporting, hound, and terrier breeds. A quantitative analysis of the ranking of male dogs vs female dogs for the 13 characteristics revealed that males differed from females on 10 traits. It was concluded that these gender and cluster profiles will allow people to select a breed or gender of dog that is most likely to match the emotional and physical needs of the person who will provide a home for the pet.

Animals↗
PubMed1985

Progesterone as a predictor of cyclicity in Bolivian squirrel monkeys during the breeding season.

In a squirrel monkey breeding colony, two distinct groups of females were observed during the breeding season, December through March. One had low and the other had high estradiol (E2) and progesterone (P) concentrations. The conception rate in females with high E2 and P values was 74%. However, only 25% of monkeys with low steroid concentrations became pregnant during the breeding season. This study showed that all mature females in a colony may not be cycling concurrently and that two serum P measurements obtained at four-day intervals may be utilized to detect noncycling monkeys during the breeding season.

Animals↗