Keywords: Age at first
calving,
Calving interval, Crossbreeding, Dairy cattle, Pregnancy rate, Subtropics.
Although a positive trend in production traits has been achieved, there is a growing concern for the reproductive performance of the dams, in particular to
calving events leading to economic losses in the farm.
Calving at 24 months could yield another two calves per cow per lifetime for an average 25-strong Welsh herd.
The delay in a heifer's first
calving is usually due to the fear of
calving immature, undersized heifers, but with the right management heifers can and should be run with a bull at 14 months.
The Beverly herd has three immediate neighbouring herds with traditional
calving grounds recorded through Aboriginal knowledge and aerial surveys: the Qamanirjuaq traditional
calving grounds about 400 km to the southeast (Heard, 1983; BQCMB, 1999a, b), the Bathurst
calving grounds about 450 km to the northwest (Heard, 1983; Gunn et al.
Factors that predispose a calf to developing navel infection include an umbilical cord the breaks off or is cut at a level too close to the body wall poor navel hygiene practices (like not dipping the navel with a disinfectant for a few days after birth) and unfavorable environmental conditions such as birth in a dirty
calving area inadequate colostrum or having the umbilical stump sucked on by other calves (Smith 2003).
The indications of the
calving season were found for the first time thanks to a detailed survey in Abu Dhabi waters, which recorded 138 dolphins of two species.
Tweeddale Invincible had a Terminal Index and
Calving Ease EBV in the top 10% of the breed.
Table 1 shows the effect of sex of calf, parity of cow and season of
calving on birth weight, weaning weight at 7 months and pre-weaning average daily gains (from birth up to 7 months) of the Friesian x Sanga calves.
About 12-13% protein in the far-off dry cow diet and 14-15% protein in the prefresh diet fed the last 3 weeks before
calving is recommended.
At this time of the year we tend to be very busy with
calvings.
This table shows that there is a significant increase at 48 and 72h after birth in contrast with 24h after and at birth time in males; and in females we have a significant increase in zinc levels in all times in contrast with birth time; Also except the
calving time significant increase are seen in female calves in contrast with males (p<0.
