AIM This study was designed to evaluate the effect of gonadotropin-releasing hormone (GnRH), human chorionic gonadotropin (hCG), and progesterone impregnated intra-vaginal device on progesterone profile and conception rate in repeat-breeding crossbred cows. MATERIALS AND METHODS Repeat-breeding crossbred cows aged 3-8 years (n=32), lactating and negative to white side test were randomly divid...

First-parity Holstein (H), Normande-Holstein (NxH) crossbred, Montbeliarde-Holstein (MxH) crossbred and Scandinavian-Holstein (SxH) crossbred cows calving from June 2001 to December 2003 were compared for dystocia and stillbirths from seven California herds. Dystocia scores ranging from 1 (no assistance) to 5 (hard pull) and stillbirths (1 for alive and 0 for dead) were recorded for 1695 Holste...

The fourth through sixth parity of 5- to 10-yr-old cows were used to evaluate trade-offs involved with sires of large mature size vs medium mature size in a terminal sire crossbreeding program and to characterize five breeds and their crosses for their potential as dam lines. Charolais and Red Poll bulls, representing large (L) and medium (M) mature size, respectively, were mated to cows repres...

A study was conducted to assess the effect of estrus synchronization technique on fertility and estrus induction response in crossbred cows under field conditions. Totally 30 infertile cows (anoestrous 13 and repeat breeder 17) were selected and divided randomly into two groups having 15 cows each. Estrus synchronization protocol (Triu-B) was adopted in Group I and Group II cows were kept as co...

Hereford cows were randomly bred to Hereford, Angus, Simmental X Hereford and Simmental sires. Each sire breed group was represented by nine or 10 sires. These matings produced approximately 100 calves in each sire breed group over 4 yr. The objective of this study was to determine the effect of calf breed on characteristics of the cow such as milk production, reproduction, measures of conditio...

Lifetime productivity of young (2 to 6-yr-old) crossbred cows containing various proportions (0, 1/4, or 1/2) of Braham breeding was evaluated using 188 spring-calving and 154 fall-calving cows. Cows were mated to Limousin sires to produce 1983 through 1986 calf crops. The 1987 calf crops were produced using Limousin and Salers sires. Significant (P less than .10) genotype (crossbred cow group)...

AIM The present study was aimed to investigate the relationship of udder shape, teat-end shape, teat length, and teat diameter with intra-mammary infection in Jersey crossbred cows under hot-humid climate. MATERIALS AND METHODS A total of 24 lactating Jersey crossbred cows were evaluated for udder shape (pendulous/regular) and teat-end shape (flat/inverted/pointed) by visual examination, whil...

The role of rumen-protected L-tyrosine as a nutritional signal altering LH release and other reproductive traits in cattle was studied. In Exp. 1, 28 suckled crossbred cows were assigned randomly to five treatments (0 or 40 g of tyrosine daily in feed for 3 d followed by a single i.v. injection of 200 micrograms of GnRH or 1 mg/kg of naloxone on d 26 +/- 1 postpartum; no tyrosine plus an inject...

Oestrus and ovarian activity were studied in a group of crossbred SahiwalShorthorn beef cows over four lactation periods of varying length throughout different seasons of the year. In the first lactation, cows were in poor condition (body weight 303 kg) and the mean interval from calving to first oestrus was 2202 16 days. Five COWS were still anoestrus 18 months after calving and were culled. T...

Omasal impaction is a serious disease problem in cattle in India, but it is difficult to diagnose clinically. Ultrasonography has been proposed for the noninvasive evaluation of omasal disease. The objectives of this study were to compare the in vitro and in vivo ultrasonographic appearance of the omasum and to compare omasal appearance, limits, and size in clinically healthy cows with those in...