Tuyển tập các báo cáo nghiên cứu về bệnh học thý y được đăng trên tạp chí Acta Veterinaria Scandinavica cung cấp cho các bạn kiến thức về bệnh thú y đề tài: Energy balance, leptin, NEFA and IGF-I plasma concentrations and resumption of post partum ovarian activity in swedish red and white breed cows...
This collection was selected from papers presented at a conference titled
“Veterinary Science, Disease and Livestock Economies,” which was organized
by the editors and held at St Antony’s College, Oxford, in June 2005.
The idea for the conference originated from our project, sponsored by the
Wellcome Trust, which explored the history of veterinary science at the
Onderstepoort Research Laboratories in South Africa during the first half
of the twentieth century.
Registration of animals. Farmers are selected based on their willingness for implementing the
ration balancing programme. Animals yielding 5 litres and higher milk per day identified for the ration
balancing programme are first ear tagged with a unique 12 digit number. Details of the animal, e.g.
species, breed, age, milking status (lactating/dry), number of calvings, last calving date and pregnancy
status are captured. Along with the animal’s details, the owner’s profile, e.g.
There has been only modest improvement in the productivity of indigenous cows, cross-
breds or buffaloes over the last two decades in India (Table 1). The average daily milk
production data at 6.52 kg for crossbreds, 2.10 kg for indigenous cattle and 4.44 kg for
buffaloes (NSSO, 2007) suggests that the productivity of these animals is far below their
There is a need to improve current practices in Asia with regard to selection of cattle
for breeding purposes, for both dairy and beef production. For many years, most of the
countries in the region have been importing cows, bulls, and semen, largely from the
temperate regions of the world, and using them to ‘upgrade’ the genetics of their existing
herds of indigenous cattle for producing ability. However, and based on current evaluation of
production levels and the productivity of cattle and buffalo, some doubts exist regarding the
need and wisdom to continue this practice.
When animals are selected from farmers’ herds, ideally farmers involved in the
selection programme will have several cows, so that animals can be compared both within and
across herds. When purchasing bull calves or females for future bulls, AI service providers
have to consider the production and reproduction records, general appearance, breed makeup
and pedigree performance of the cow. The most accurate way to select the best cows will be
to perform a statistical analysis to obtain a genetic evaluation. Many factors other than
genetics will affect an animal’s production.
Crossbreeding has been taken as a major tool for improving the animal productivity in
different Asian countries. Bos taurus cattle have been used as exotic breeds and mated with
local Bos indicus cows to introduce genes for higher productivity, resulting in much faster
advances in productivity than could be obtained through selective pure breeding of local
animals. The crossbreeding also brings in added advantages of heterosis. In dairy cattle,
Holstein-Friesian is most commonly used and seems to nick well with most of the Bos indicus
This low rate of improvement has
discouraged implementation of selection schemes for indigenous tropical breeds, since
the overall increase in production attainable by selection in cows yielding 500–1000 kg
is not of any great magnitude. It should, however, be recalled that even European breeds
were as unproductive as the tropical breeds before the application of selection programs
and it is the application of planned selection programs that has brought the advances that
we see today.