Insemination Technology Research Articles

Reproductive behaviour in poultry: implications for artificial insemination technology.

1. Reproductive ability requires both endocrine and behavioural components. 2. Most reproductive behaviour is dependent upon the presence of sufficient circulating concentrations of the gonadal steroids, which in turn are synthesised and secreted in individuals who are in good reproductive condition. Mating behaviour patterns are thus not only essential for reproduction, but can provide excellent indices of the reproductive ability of an individual. 3. A number of factors can suppress or enhance reproductive behaviour in poultry, including management practices, flock social interactions, environmental variables, stressors, and disease. 4. Aspects of the regulation of reproductive behaviour and the endocrine control of reproductive processes in the male and in the female are reviewed in this paper. 5. An understanding of the impact of social and environmental stressors on reproductive physiology and behaviour is extremely important, both in order to improve breeding efficiency in natural mating systems and to facilitate the most effective application of artificial insemination technology.

Oviducal storage of spermatozoa in the turkey: its relevance to artificial insemination technology.

1. This paper addresses questions concerning the role of oviducal sperm selection and storage in the relative inefficiency of turkey reproduction. 2. Before the onset of egg production, the turkey has the biological potential to store spermatozoa in its oviduct for periods up to 5 weeks; after the onset of production fewer spermatozoa are retained by the oviduct. 3. A better understanding of the biological mechanisms which regulate sperm selection and storage in the turkey oviduct is necessary to make significant advances in artificial insemination technology.

Is basic research the answer to improved artificial insemination technology (AI) in poultry?

Is basic research the answer to improved artificial insemination technology (AI) in poultry?

Mating Behavior and the Social Hierarchy in Small Flocks of White Leghorns

Mating Behavior and the Social Hierarchy in Small Flocks of White Leghorns

Increase in mid-continent oil : Kansas and Oklahoma petroleum production greater by 3,000,000 barrels in 1911 than in 1910, according to United States geological survey

Holsteins are the most numerous dairy cattle breed in North America and the breed has undergone intensive selection for improving milk production and conformation. Theoretically, this intensive selection could lead to a reduction of the effective population size and reduced genetic diversity. The objective of this study was to investigate the effective population size of the Holstein Y chromosome and the effects of limited Y chromosome lineages on male reproduction and the future of the breed. Paternal pedigree information of 62,897 Holstein bulls born between 1950 and 2013 in North America and 220,872 bulls evaluated by multiple-trait across-country genetic evaluations of Interbull (Uppsala, Sweden) were collected and analyzed. The results indicated that the number of Y chromosome lineages in Holsteins has undergone a dramatic decrease during the past 50 years because of artificial selection and the application of artificial insemination (AI) technology. All current Holstein AI bulls in North America are the descendants of only 2 ancestors (Hulleman and Neptune H) born in 1880. These 2 ancestral Y-lineages are continued through 3 dominant pedigrees from the 1960s; namely, Pawnee Farm Arlinda Chief, Round Oak Rag Apple Elevation, and Penstate Ivanhoe Star, with a contribution of 48.78, 51.06, and 0.16% to the Holstein bull population in the 2010s, respectively. The Y-lineage of Penstate Ivanhoe Star is almost eliminated from the breed. The genetic variations in the 2 ancestral Y-lineages were evaluated among 257 bulls by determining the copy number variations (CNV) of 3 Y-linked gene families: PRAMEY, HSFY, and ZNF280BY, which are spread along the majority (95%) of the bovine Y chromosome male-specific region (MSY). No significant difference was found between the 2 ancestral Y-lineages, although large CNV were observed within each lineage. This study suggests minimal genetic diversity on the Y chromosome in Holsteins and provides a starting point for investigating the effect of the extremely limited number of Y-lineages on male reproduction and other traits important for the future of the Holstein breed.