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At least 19 recordsLinked to original sources
PubMed1977

Behavioural and hormonal responses of male rhesus monkeys introduced to females in the breeding and non-breeding seasons.

Six adult male rhesus monkeys were introduced individually to an all-female group for 10 days during the mating season. The initial aggressive responses of the females were rapidly replaced by positive social behaviour, and each male achieved alpha status and had access to social and sexual partners. A repetition of this paradigm in the non-breeding season produced significantly more female aggression, and no male attained high rank or engaged in sexual or other social behaviour. Male testosterone levels rose following introduction to the females in both seasons, but were significantly higher during the breeding season. Hormonal levels following removal from the females suggest a complex interplay between social, sexual and seasonal variables and recent social experiences. The differences in female social behaviour with newly introduced males, as a function of season, suggest an explanation for the seasonal limitation of male troop transfers.

Aggression↗
PubMed1976

Progress report on the Charles River Breeding Laboratories' free-ranging rhesus monkey breeding colony on Key Lois, Florida.

The nucleus of a breeding colony of free-ranging rhesus monkeys (Macaca mulatta) free from tuberculosis, herpes-B virus, shigellosis, and salmonellosis has been established on Key Lois, Florida, USA. Standardized procedures for trapping, quarantine, and shipping from the wild in India to the island have been established. The monkeys seem to have adapted well to the Florida Keys' climate. Reproduction has proceeded according to expectations, and social groups have been formed with continual restructuring as each new group is placed on the island. The isolation of Key Lois from other inhabited keys by the open sea affords good isolation and has discouraged intrusion by unwanted visitors. The operational costs of this island breeding program are encouraging. It is projected that by 1976 or 1977, monkeys should be available from this colony at a lower price than for animals bred in indoor facilities; and their availability will be in excess of animals trapped in the forest and subjected to a conventional conditioning and quarantine period.

Animal Feed↗
PubMedDate not supplied

Testicular capillary blood flow in the impubertal lamb and the ram during the breeding and non-breeding seasons.

The testicular capillary blood flow was measured by the 133Xenon clearance technique in the Ile-de-France lambs and rams in Spring and Autumn. Anaesthetized animals were maintained in the supine position and 133Xe was injected into the testicle through the scrotal skin. In the adult, the blood-flow (ml/min./100 g) depended upon the season: 8.3 +/- 1.0 vs 12.7 +/- 0.7 in May and October (P less than 0.001). In the impubertal lamb (50 days old) regardless of the period of the year, the blood flow was the same as in the adult in the breeding season (11.4 +/- 1.2 vs 12.7 +/- 0.7). In prepubertal lambs (120 days old) the rapid increase in testicular weight was not correlated with an increase in the blood flow (9.4 +/- 0.7).

Animals↗
PubMed1976

[Changes in the blood picture during puerperium of Czech white-breed sows under large-scale breeding conditions].

A dynamics of the changes of the red and while blood cell count during puerperium (1st-27th day post partum) was studied in 293 sows of the Czech White breed kept in typical large-scale production conditions. An average count of erythrocytes amounted to 5 513 000 +/- 385 514. In the course of puerperium their count slightly decreased in comparison with the value obtained on the first day p. p. (on the 10th day p. p. the decrease was even highly statistically significant - P less than 0.01). An average amount of hemoglobin was 12.48 +/- 1.22 g per 100 ml of blood; in the course of the nearly whole of puerperium it was slightly higher than on the first day p. p. (in the third week on the threshold of the statistical significance up to the statistical significance - P less than 0.10-0.05-0.01). The value of hematocrit did not fluctuate (average = 38.65 +/- 3.89%), sedimentation slowed down, especially from the end of the second week p. p. The protein of the blood plasma amounted, on an average, to 7.71 +/- 0.84 g per 100 ml; the protein content raised during puerperium in comparison to the 1st day .p. An average count of leukocytes during puerperium was in comparison to the 1st day p.p. An average count of leukocytes during puerperium 12 755 +/- 1529, and it slightly increased in relation to the 1st day p. p. The percentage of neutrophile granulocytes and lymphocytes did not change very much; it reached 46%: 45%. The character of the sow blood during puerperium fluctuated all the time between neutrophile and lymphocytic type with a slight tendency to the prevalence of neutrophile granulocytes. Nevertheless, the proportion of neutrophile granulocytes with rodlike nuclei decreased, and on the other hand, the proportion of neutrophile granulocytes with segmented nuclei increased (a nucleus shift to the right). Original values and ratio of the first day p. p. (T = 6.91%: Seg = 41.13%) changed in the average value of T = 1.93%: Seg = 43.96% during the whole puerperium.

Animal Husbandry↗
PubMed1977

[Microbiological pollution of the environment due to breeding. I. Enterobacteriaceae due to cattle breeding].

Enterobacteriaceae from faeces of cattle belonging to four cattle farms situated in the Ferrara district were investigated. At the same time, investigation was made of effluent sewage and recipient wells (upstream and downstream). The cattle (of the Italian Frisona breed) resulted uncontaminated by Salmonellae, but proved to be very susceptible to Arizona, Citrobacter, Shigella and S. gallinarum-pullorum infections, coming from the environment. Predominant species in faeces were as follows: Proteus, Klebsiella, Enterbacter and coliforms. One farm proved to be heavily polluted by Edwardsiella tarda. Yersinia enterocolitica strains were also isolated from faeces and sewage.

Air Microbiology↗
PubMed1992

To breed or not to breed: an analysis of the social and density-dependent constraints on the fecundity of female badgers (Meles meles).

Data from post-mortem examinations, population density estimates and long term capture-mark-recapture studies have been combined to look at the pattern of reproductive behaviour and the social factors leading to reproductive failure in badgers in Britain. The results are used to evaluate whether the hypothesis that the defence of oestrous females (as opposed to defence of food resources) best explains territorial behaviour and the social organization of badgers. Badgers in Britain have two peaks of reproductive activity, one immediately post partum and one in the summer/autumn. These coincide with two peaks of ovulation, and in the late winter/spring there is a steep rise in the number of sows carrying blastocysts, to reach an asymptote in June for yearling sows and April in older sows. Measured by their contribution to overall productivity, winter/spring matings were much more important than summer/autumn matings, contributing 65% of total autumn blastocysts in yearling sows and 71% of autumn blastocysts in older sows. The relative importance of the two mating periods is reflected in the seasonal pattern of bite wounding in adult male badgers; minor bite wounding in January-March was 2.3 times as frequent as in August-October, and moderate-extensive bite wounding was 3.1 times more frequent. In the populations studied, pre- and post-natal losses were high, with reproductive failure occurring at all stages of the breeding cycle, so that less than 30% of potential productivity was achieved. Indeed 22% of sows failed to develop blastocysts; these had a lower body mass, less body fat, larger adrenal glands, poorer health and higher bite wound scores than sows with blastocysts. Only 44% of adult sows implanted their blastocysts and proceeded to the end of pregnancy. However, it was less easy to identify features characteristic of sows that did or did not go on to implant their blastocysts. Finally, 35% of sows that produced cubs ceased lactation early, and this loss of entire litters was thought to be due to infanticide by dominant sows. The presence of annexe setts correlates with increased productivity in younger sows, and this is thought to be because annexe setts enable younger sows and their cubs to avoid the aggression of older, more dominant sows. Living in large social groups has no net reproductive gain for adult males or females, and there was a decline in productivity (per adult) with increasing group size.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1975

A study of the morphology of stallion semen during the breeding and non-breeding seasons.

Season was shown to markedly influence semen characteristics of stallions in Holland, including ejaculate volume, sperm motility, total number of spermatozoa/ejaculate and the percentage of spermatozoa showing morphological abnormalities. Maintenance of normal stallions in continuous light during the winter months and administration of a vitamin and mineral supplement to sub-fertile stallions before the start of the breeding season appeared to improve spermatogenesis significantly.

Animals↗
PubMed2026

A genome-wide assessment of the population structure of thirteen admixed and pure Australian beef cattle breeds.

Knowledge of population structure is a key factor for successful multi-breed genomic prediction, especially in single-step analysis when metafounders are considered. In Australia, current assessments mostly focus on single breeds using a single-step genomic prediction method. However, the effective integration of pedigree, phenotypic, and genomic data in a multi-breed framework still requires further research, especially for combined analyses including admixed and multi-breed populations. This study began with 602,952 genotyped individuals with 8K SNPs in common from 13 beef cattle breeds (Alexandria, Angus, Brahman, Brangus, Charolais, Droughtmaster, Hereford, Kynuna, Limousin, Santa Gertrudis, Shorthorn, Speckle Park, and Wagyu). Due to different numbers of animals being genotyped in each breed, a representative subset of animals was chosen by employing a validated sampling strategy using Gaussian Mixture Models (GMM) complemented by Principal Component Analysis (PCA) within each breed. Subsequently, a specific number of animals in each cluster were randomly selected to capture the entire genetic diversity per breed, with a total of 260 animals from each breed. The first three principal components explained 59.89% of the total variation, with PC1 (33.54%) clearly separating Bos indicus from Bos taurus lineages. Admixture analysis identified stable ancestral components and defined the genetic makeup of both pure and composite populations. The results showed extensive genetic diversity in some breeds and highlighted distinct genetic differences between Bos indicus and Bos taurus breeds. In addition, six composite breeds' admixture levels confirmed their origin and breed history, revealing a directional shift in ancestry proportions by a longitudinal increase in Brahman ancestry within tropical composites over time. Thus, the findings pave the way for more effective utilization of genetic diversity both within and across populations and provide a framework for designing multi-breed genetic evaluations and breeding programs to improve productivity and profitability in Australian beef production.

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↗