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Biomedical subjects

K L Butler

Publications and source records attributed to K L Butler.

24 records · Page 2Linked to original sources
PubMed1995

Reductions in milk production after induced parturition in dairy cows from commercial herds in south-western Victoria.

The milk production of cows after induced parturition was compared with that of non-induced cows with similar calving dates, in 37 winter-calving, pasture-fed, commercial dairy herds in south-western Victoria. Parturition was induced when most cows were between 27 and 35 weeks of pregnancy. Milk production was compared for the lactation that commenced immediately after induction. The percentage of cows whose lactations were terminated less than 120 days after calving was increased by induction. Mean percentages for untreated and induced groups were 3.0% and 5.4%, respectively. For cows with lactations of at least 120 days duration, lactation length was not affected by the prior induction of parturition. However, milk production during the subsequent lactation was 9.0% less in induced groups. Fat and protein concentrations were not substantially affected. The reduction in milk production was not affected by stage of pregnancy when cows were induced, but tended to be greater in herds that delayed milking of induced cows.

Animal Feed↗
PubMed1995

Direct effects of induced parturition on subsequent reproductive performance of dairy cows from commercial herds in south-western Victoria.

Reproductive performance was compared between cows whose previous parturition was induced and non-induced cows with similar calving dates, in 49 winter-calving, pasture-fed, commercial dairy herds in south-western Victoria. Parturition was induced in winter when most cows were between 27 and 35 weeks of pregnancy. Reproductive performance was assessed during the next mating period after induction which was mainly in spring of the same year. Percentages of cows in induced and untreated groups that were not pregnant after the mating period (9.0% and 7.2%, respectively) did not differ significantly. Induction tended to increase the percentage of cows of unknown pregnancy status. Mean percentages for induced and untreated groups were 11.5% and 7.9%, respectively. Induced and untreated groups calved at similar intervals after the planned start of calving in the following year, and the percentages of groups that required induction in that year did not differ significantly. The direct effects of induced parturition on reproduction were therefore concluded to be minimal. In seasonal calving herds, improvements in reproductive performance could be expected among cows whose calving dates were altered substantially by induction, due to increased intervals from calving to mating start date.

Animals↗
PubMedDate not supplied

Experimental inoculation of European starlings (Sturnus vulgaris) and American crows (Corvus brachyrhynchos) with Mycobacterium bovis.

The purpose of this series of pilot studies was to determine whether the passerine species studied are susceptible to infection with Mycobacterium bovis. Separate experiments were conducted on wild-caught starlings (Sturnus vulgaris) and American crows (Corvus brachyrhynchos). In each experiment, four birds were challenged intraperitoneally and four were challenged orally with microorganisms. Challenge dose was 1 x 10(5) colony-forming units of M. bovis cultured from a white-tailed deer (Odocoileus virginianus) case in Michigan. Birds were euthanatized at 1 and 2 mo postinoculation. Histologic lesions suggestive of mycobacteriosis, without the presence of acid-fast bacilli, were noted in all experimental groups. Mycobacterial cultures performed on pooled tissue samples were positive for M. bovis in only some of the intraperitoneal inoculates of each species.

Administration, Oral↗