Characteristics of oestrous cycles in Holstein cross-bred dairy heifers: an evidence of delayed post-ovulatory progesterone rise.

The aims of the current study were to illustrate figures for the characteristics of oestrous cycles especially on follicular dynamics, corpus luteum and changes in progesterone and prostaglandin F2alpha, in the Holstein cross-bred dairy heifers. Twenty six healthy and sexual-mature virgin heifers were monitored for signs of oestrus. Their ovaries were sonically examined and the numbers and the sizes of the follicles as well as of the corpus luteum were documented.

Different types of postpartum luteal activity affected by the exposure of heat stress and subsequent reproductive performance in Holstein lactating cows.

The aim of the present study was to determine the effect of heat stress on postpartum (PP) luteal activity and subsequent reproductive performance in lactating cows. Thirty Holstein-Friesian (HF, >or=75%) cows (hot season, n = 15 and cool season, n = 15) were studied over 60 days after calving. The changes of temperature-humidity index (THI) were monitored within both seasons.

Early embryonic development in Thai swamp buffalo (Bubalus bubalis ).

A total of 33 nonsurgical embryo collections was carried out to investigate early embryo development in Thai swamp buffalo. Collections were performed on Days 5.5, 6.

Investigation into the use of prostaglandin F2 alpha (PGF2 alpha) and oxytocin for the induction of farrowing.

This experiment was conducted in order to compare the effects of injecting PGF2 alpha alone, PGF2 alpha with oxytocin and placebo on the induction of farrowing in swine and to compare the relative effects of 3 different dosages of oxytocin (10, 20 and 30 iu per animal) when combined with PGF2 alpha (10 mg). The findings revealed that animals treated with 30 iu oxytocin farrowed within 10.6 h which was similar to those receiving PGF2 alpha only (9.