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PubMed1990

Propagation of improved breeds: the role of artificial insemination and embryo transfer.

Artificial insemination (AI) and embryo transfer (ET) are not just reproductive techniques, but indispensable tools for genetic improvement. In this sense, they play an effective part in propagating improved breeds. Analysis of the development of insemination of French cattle breeds since 1960 shows how breeders can alter their genetic choices to meet economic needs. AI and ET also have their place in selection programmes: evaluating bulls by progeny testing, exerting greater selection pressure on the dams of bulls, and shortening the generation interval of breeding animals. Finally, the income of breeders is closely linked to the genetic level of the livestock which they utilise.

Animals↗
PubMed1990

Variation in frequency in breeding of Anopheles gambiae s.l. and its relationship with in-door adult mosquito density in various localities in Accra, Ghana.

The work reported in this paper was undertaken to determine whether in a large urban area like Accra, emerging Anopheles gambiae s.l. adults are likely to invade the nearest houses to obtain a blood meal. Using data from previous studies, the frequency in breeding was compared with adult density graphically and by scatter diagrams. Graphically, frequency in breeding was associated with adult density in eight districts while on the geometric scatter plot, these parameters were associated in ten districts. The finding of association of low frequency in breeding with moderate adult density in only one district and a correlation coefficient significant at p less than 0.001 on 14 degrees of freedom for 8 districts indicates that in the majority of districts, most adult mosquitoes invaded the nearest human habitation.

Animals↗
PubMed1989

Importance of ewe/lamb relationship and breed in the epidemiology of maedi-visna virus infections.

Sheep from a closed experimental breeding flock containing Finnish Landrace, Ile de France, their F1 crossbreeds, and a new breed were tested for antibodies to maedi-visna virus in 1975 and 1985-86. Over the years, the percentage of seropositive sheep increased: the Ile de France, however, remained virtually negative. Since exposure to the virus was similar, the results indicated a breed-associated difference in susceptibility to maedi-visna virus infection. Analysis of the serological results of 1985-86 yielded a total of 173 dam/progeny pairs. A significant (P less than 0.05) association between the test results of the dams and their progeny was found: seropositive (infected) dams produced 36.6 per cent positive progeny, whereas the seronegative dams had 20.0 per cent positive progeny (odds ratio = 2.3). Further analysis showed that this association was most apparent between dams and their youngest progeny, which is explained by the fact that the chance of infection by horizontal transmission increases with age. These results provide evidence that the ewe/lamb relationship plays a role in the epidemiology of maedi-visna virus infections.

Animals↗
PubMed1989

The influence of breed and sex on the incidence of mortalities and skin tears in broiler carcasses.

The effects of nutrition, breed and sex on the incidence of mortalities and of skin tears on broiler carcasses were studied. Both sexes of 2 breeds, Hubbard and Ross, were given 4 dietary treatments consisting of a normal level of vitamin and mineral premix plus 300 ppm furazolidone, twice normal premix inclusion level plus 300 ppm furazolidone, a normal level of vitamin and mineral premix, and twice normal mineral premix inclusion level. A coccidiostat containing the active ingredient halofuginone was included at 6 ppm, twice the recommended dosage. Starter, grower and finisher diets were fed respectively up to Day 20, Day 30 and Day 48. Group growth performances, mortalities and the incidence of torn skin were monitored on both the live birds and carcasses. The effect of the different nutritional treatments on skin tears was not significant (P = 0.9533), as was the breed effect (P = 0.0547). However, the effect of sex was significant (P = 0.0044), the incidence in hens being higher. Mortalities among the Hubbard were significantly greater than among the Ross (P = 0.0001). Hens showed a slightly higher mortality rate than roosters, tending towards significance at the 5% level (P = 0.0554).

Animal Nutritional Physiological Phenomena↗
PubMed1988

The proposed use of melatonin in controlled sheep breeding.

The regulation by melatonin of hypothalamic-pituitary events in the ewe to advance seasonal oestrous activity, with no undesirable effects upon fertility, and its induction of those seasonal responses associated with short days indicates an essential role for melatonin in controlled-breeding programs in major sheep-producing countries. The development of suitable controlled-release systems to provide a choice of practical methods of melatonin delivery under field conditions is discussed as also are geographical and breed factors in controlled breeding with melatonin.

Animals↗
PubMed1988

Breeding soundness examination of yearling beef bulls.

Yearling beef bulls were subjected to a breeding soundness examination (BSE) at completion of performance testing programs at 4 locations over 5 years. Of 862 bulls, 80.1% were classified as satisfactory potential breeders, 7.3% as questionable potential breeders, and 12.7% as unsatisfactory potential breeders. Year (P less than 0.01), location (P less than 0.01), and breed (P less than 0.01) affected the percentage of bulls classified as satisfactory; age of the bulls did not affect this percentage. Adjusted mean scrotal circumference (SC) measurements were 31, 33.2, and 34.8 cm for bulls classified as unsatisfactory, questionable, and satisfactory (P less than 0.01), respectively. Of 109 bulls classified as unsatisfactory, 2.8% were so classified because of poor semen quality alone; 41.3% had no ejaculate in 4 separate electroejaculation attempts. Other abnormalities in these 109 bulls included reproductive tract infections (22%), persistent penile frenulum (16.5%), testicular abnormalities (8.3%), fibropapilloma (1.8%), hernia (1.8%), aplastic epididymis (1.8%), penile abnormalities (1.8%), pendulous sheath (0.9%), and eye abnormalities (0.9%). Age had a significant effect on SC in bulls at 3 locations and on percentage of normal cells, primary abnormalities, and secondary abnormalities as well as BSE score at 1 location. Percentage of primary and secondary abnormalities as well as SC were different across years at 2 locations, and percentage of normal and motile cells as well as BSE score were different across years at 1 location. Breed effects were significant for SC, percentage of primary abnormalities, and BSE score at 3 locations and for percentage of normal and motile cells at 1 location.

Animals↗
PubMed1988

Dental configuration among different breeds of sheep.

Three breeds of sheep, Southdown, Suffolk and Romney, and two mixed breeds, Border Leicester over Romney and Coopworth over Romney, managed identically on a research station, where they were free from culling and allowed to live their natural life, had their dental configuration examined. The sheep were divided into age groups with 10 sheep in each. The least variation was found in the relation of the upper dental pad to the lower jaw. The most statistically significant differences were found in the first age group: one year six months. The Suffolk breed was noticeably different from the others. Deepened gingival sulci, as well as the inconsistency of bleeding after probing associated with labial gingivitis highlighted the problems of using these latter criteria as indicators of health or disease among sheep on the basis of a single examination.

Age Factors↗
PubMed1988

[The cattle breeding program of the Republic of Cuba].

The Cuban cattle breeding programme has remained unchanged over more than 20 years and aims at the genetic transformation of the indigenous population by means of crossbreeding within a high-performance cattle stock. Focus is on the breeds Holstein X Zebu in order to produce the crosses "Holstein Tropical" (7/8H 1/8Z), "Mambi" (3/4H 1/4Z), and "Siboney" (5/8H 3/8Z). Besides these, other new breeds are envisaged for milk and meat production. Representative parameters of the production and reproduction of the new genotypes are being reported and discussed.

Animals↗
PubMed1987

[Breeding policy and pedigree dog populations].

Data on the effects of selection in breeds of dogs were collected. Particularly, effects on behavioural traits, characteristics of type and movement and state of health. The data were collected by studies of the literature and discussions with dog breeders and their organisations. The data collected was used to design a model of a dog population. In this model, various genetically determined traits were introduced and the breeding policy for these traits was then discussed with experts in breeding of animals of other species.

Animals↗
PubMed1972

Breeding of Aedes aegypti and A. simpsoni under the escarpment of the Tanzanian plateau.

Villages under the escarpment of the Tanzanian plateau were surveyed for breeding of Aedes aegypti. In some places more than 27% of the water containers outside houses harboured A. aegypti larvae, while there was practically no breeding in containers inside houses. From 2% to 10% of tree holes contained A. aegypti larvae. In places, as many as 47 A. simpsoni larvae were collected from one pineapple plant, and the total mean number of larvae per pineapple was 6.6, while the percentage of plants with larvae was as high as 93.6. The total mean number of larvae per colocasia plant was 2.9, but the number per banana plant was only 0.3. The plant Crinum was discovered to be a breeding site of A. simpsoni. Eggs of A. simpsoni were found in 55-80% of ovitraps placed in four villages. Of 20 traps found to contain eggs of this species 30% were in the village, 60% in gardens, and 10% at the edge of forest. It was observed that A. simpsoni females lay their eggs at all levels up to 5 m, but prefer ground level.

Aedes↗
PubMed1982

[Breed, line and sex differences of phagocytic activity in relation to broiler poultry resistance to Marek's disease virus].

The phagocytic activity was studied of 421 poulets and cocks of lines 66 and 77 of the Cornish breed, and lines 88 and 99 of the White Plymouth rock breed. Breed and linear differences were noticed in the changes of the phagocytic activity (phagocytic number and phagocytic index) with birds infected with the virus of Marek's disease. The rise of the phagocytic activity with lines 66 and 77 was slighter as compared with that of the White Plymouth Rock lines 88 and 99. Strongest were the changes in the phagocytic activity with birds that were strongly susceptible to Marek's disease, and slight est--with birds that were resistant to the disease. A trend of a better expressed phagocytic activity was noticed with the cocks of all investigated lines.

Animals↗
PubMed1984

Breeding and offspring rearing ability of C57BL/6J dystrophic mice.

The antiepileptic drug phenytoin, administered in drinking water for 104 days, was used to reduce the neural overactivity (pseudomyotonia) of C57BL/6J dystrophic (dy2J/dy2J) male mice in an attempt to improve their breeding success over a 90-day period. Male dy2J/dy2J mice have difficulty in successfully mounting females due to the pseudomyotonia affecting their hindlimb musculature. Breeding success, as judged by litter frequency, of dy2J/dy2J males receiving phenytoin (5 micrograms/ml serum) was compared with untreated dy2J/dy2J and phenotypically normal (+/?) male and female mice. Phenytoin did not enhance male dy2J/dy2J breeding success. Based on dy2J/dy2J crosses with +/? animals, the dy2J/dy2J female was a more successful breeder than the dy2J/dy2J male. In terms of litter frequency, litter size, and offspring birth weight, dy2J/dy2J females (age 8-21 wks.) bred as efficiently as +/? females of the same age. Dystrophic females were deficient in offspring rearing capabilities as evidenced by lower offspring survival rates and weaning weights.

Animals↗
PubMed1984

Possibilities and limits of breeding for immune responsiveness.

Studies on defence mechanisms in mice and farm animals are demonstrated. The results indicate that selective breeding might become a more important tool in disease control. But intensive research work is required before a "General Disease Resistance Index" can be used in animal breeding. More common efforts of research workers in veterinary medicine and animal breeding are necessary.

Animals↗
PubMed1983

[Testosterone levels of the plasma of bulls in relation to growth, breed, semen quality and sexual activity].

Using Anderson's method for estimation of testosterone level by competitive protein binding, the authors determined plasma testosterone level in young bulls of three breeds: black and white, and red and white lowland. It was found that in bulls of black and white and red and white lowland breed the testosterone level showed great fluctuations without growing tendency. In charolais bulls, in pubescence, testosterone level was low and did not exceed 1 ng/1 ml, but it systematically increased beginning from the 14th month of life. No correlation of testosterone level with protein and energy intake or with sexual activity was observed in adult bulls (breeders) of black and white lowland breed during 12 months of examination.

Animals↗
PubMed1983

[Need for development and implementation of a program of standardizing cattle breeding].

The problems associated with the intensification of cattle breeding in this country are successively dealt with. It is stated that the successful solution of all problems of the intensification of production and the intelectualization of public labour in cattle breeding requires the working out of a package of normative and technical documents on the standardization of terms, which are to implemented into practice along with the definitions, technologies, pedigree and selection work, diagnostics of diseases, output of meat and milk and products thereof, protection of natural environment, and reproduction of natural resources. The tasks could be successfully fulfilled only with the aid of an overall, perspective, and anticipating standardization as well as after favourable conditions are developed for the complex scientific service in cattle breeding, and the building up of a scientific and methodical approach to resolve the problems in animal husbandry.

Animal Husbandry↗
PubMed1977

Haematological studies in relation to environmental temperature and different periods of breeding cycle in an air breathing fish, Heteropneustes fossilis.

Investigations were made on different haematological parameters in H. fossilis at two environmental temperature (18 degrees C and 32.5 degrees C) and different periods of breeding cycles. The RBC counts 302.0-10(4)/mm3), WBC counts (10.6-10(4)/mm3), Hb concentration (19.0g%), haematocrit (36.0%), M.C.H.C. (57.7%), total blood volumes (0.966 ml) and per cent blood volumes (1.542%) gave significantly high values but M.C.V. (119.2 micrometer3) and erythrocyte surfaces (52.96 micrometer2) gave low values at higher temperature (32.5 +/- 1 degrees C) and during breeding period (G.S.I. = 10.4 +/- 0.52 g). The higher values obtained for different haematological parameters during breeding period at high temperature may be probably related to greater physical activity and higher metabolic activity at the time of reproduction.

Animals↗
PubMed1981

[Ruminants as breeding animals (author's transl)].

Ruminants can be considered as up graders of the quality of food when they are kept on feeds low in nitrogen and rich in structural carbohydrates such as cellulose. Many feeds and agricultural wastes of no value or unattractive to monogastric animals can be converted into tractive power, milk, wool, meat and offspring by ruminants. To attain levels of production, concentrates which are readily degraded and high in protein are being increasingly fed, which results in improper use of the ruminant, production losses and metabolic disorders due to unstable rumen fermentation. This is also associated with the fact that our domesticated cattle belong to a group of ruminants particularly equipped to deal with roughage. Most other ruminants in the group of the large roughage feeders are even superior to European cattle breeds in digesting poor roughage. When it would become necessary to increase the use of roughages and agricultural lignocellulose wastes in the near future, a large ruminal volume and a high salivation rate should be adopted as criteria of selection in breeding new cattle breeds.

Animal Feed↗
PubMed1980

A monogamous system of breeding chimpanzees in a controlled environment.

The management and reproductive performance of a chimpanzee colony is discussed. Short-term monogamous breedings, arranged at the estimated time of ovulation, as determined by the cyclical changes in sex skin tumescence and by a new immunological test for the preovulatory peak in urinary LH excretion, are planned according to blood group and social compatibility. Progress of gestation is monitored weekly by the "NICHD subhuman primate pregnancy test" and by prenatal clinical examinations in the last trimester. Fertility of individual animals, and of the colony as a whole, is reflected in the number of cycles of breeding required for conception. The indoor system of single caging of adults and the special system of animal waste collection offers the ability to completely control and manipulate the animals for efficient breeding, for clinical health care, and for implementation of scientific protocols.

Animals↗