摘要:

Extract

ISSN:0048-0169    

DOI:10.1080/00480169.1980.34675

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Advances in biochemical genetics have resulted in the ability to detect carriers of some recessively inherited diseases. Instigation of control programmes based on this ability will depend, at least partly, on the costs and benefits to industry, individual breeders or members of a breed society with a vested interest. Such programmes may involve all animals in a particular population or be more selective. These factors are analysed and discussed using the bovine mannosidosis programme in New Zealand as a model. At a heterozygote prevalence of 10%, there were benefit:cost ratios of 2.89:1 and 4.14:1 over a 20-year and infinite-time horizons, respectively. When lower prevalence figures were examined, present value costs equalled present value benefits when 5 or 6% (depending on time horizon) of the population were heterozygous. The model developed and principles discussed should prove useful in developing similar, or alternative, schemes for this or other diseases of livestock.

ISSN:0048-0169    

DOI:10.1080/00480169.1980.34676

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Between 1977 and 1979, twenty thoroughbred mares each received an uterine infusion of 120 mls of mare colostrum in 380 mls of normal saline during mating heats. In 2 of the 20 mares the infusion was repeated after they had foaled normally in 1978. The mares ranged from 7 to 24 years old. In 1977, four of the six mares treated at two studs (A and B) produced live foals. During the current season (1978–79), 16 were irrigated, 6 at Stud A and 10 at Stud B. Ten were manually tested in-foal 45 days after last covering.

ISSN:0048-0169    

DOI:10.1080/00480169.1980.34677

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A 110-sow intensive piggery experienced a sudden drop in production. This first became apparent as an agalactia with subsequent piglet deaths. Investigations showed that this was a primary agalactia resulting from a lack of mammary development which, together with a reduction in birth weights, led to the loss of several litters. Toxin intake via one or more batches of feed was suspected. The feed source was changed, whereupon the syndrome disappeared. Chromatographic analysis revealed no known toxins but the clinical signs indicated the influence of a toxin.

ISSN:0048-0169    

DOI:10.1080/00480169.1980.34678

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Lactation was successfully induced in 14 of 15 non-pregnant cows treated for 7 days with twice daily subcutaneous injections of 15 mg oestradiol-17βand 37.5 mg progesterone. The successfully induced cows were first machine-milked about 8 days after the end of treatment and, although they milked for as long as their naturally calving identical twins, produced significantly less milk, fat and lactose. Augmenting the basic regimen with Opticortenol or thyrotrophin-releasing hormone produced no advantage. Plasma and milk hormone analyses were conducted and used to study the onset of lactogenesis and possible meat and milk residues. Ten of the 15 treated cows showed frequent oestrous activity and 4 became lame. Pregnancy rates after an 8-week insemination period were 69% and 93% for treated and control cows, respectively. It is concluded that the technique is unlikely to gain wide acceptance in the form used here.

ISSN:0048-0169    

DOI:10.1080/00480169.1980.34679

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0048-0169    

DOI:10.1080/00480169.1980.34680

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Equivalent doses of sodium selenate and sodium selenite were equally effective in preventing selenium deficiency in ewes on a diet containing a very low level of selenium.

ISSN:0048-0169    

DOI:10.1080/00480169.1980.34681

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0048-0169    

DOI:10.1080/00480169.1980.34683

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor