Effects of treatment of periparturient dairy cows with recombinant bovine somatotropin on health and productive and reproductive parameters.

The objectives of the current experiment were to evaluate the effects of treating periparturient dairy cows with recombinant bovine somatotropin (rbST) on incidence of postpartum diseases and performance. Holstein (HO) and Jersey (JS) cows from 2 herds were enrolled in the experiment at 253 ± 3 d of gestation and assigned to the control (n = 432) and rbST125 (n = 437) treatments. Cows in the rbST125 treatment received 125 mg of rbST, weekly, from -21 to 21 d relative to calving.

Time of insemination relative to reaching activity threshold is associated with pregnancy risk when using sex-sorted semen for lactating Jersey cows.

The objective of this observational experiment was to determine the association between the interval from reaching activity threshold (AT) to artificial insemination (AI) with sex-sorted semen and the probability of pregnancy. Jersey cows (n = 678) from a commercial dairy herd were fitted with heat-rumination long-distance collars (SCR Ltd., Netanya, Israel) at approximately 42 ± 7 days postpartum.