In a national survey of US dairy producers, only 2.7 +/- 0.5% of Holstein dairy operations reported achieving recommended target ranges of age < or = 24 months and body weight (BW) > or = 550 kg at first calving. Allowing for wider target ranges, still only 14.6 +/- 1.3% of Holstein dairy operations reported achieving age < or = 25 months and BW > or = 544.3 kg at first calving. Ages of individ...

Holstein steers have a greater maintenance energy requirement (Zinn and Borquez, 1993) and visceral organ mass (Istasse et al., 1990), and consume approximately 8% more feed than traditional beef steers (NRC, 1987; Fox et al., 1988). Because of their heavy mature weights, Holstein steers calves grow faster than beef steers at comparable weights (Thonney, 1987), capable to increasing their live ...

A study was carried out to investigate the effect of restricting silage feeding on time of calving and calving performance in Holstein-Friesian cows. In the treatment group (n = 1,248 cows, 12 herds) silage feeding commenced in the evening (17:00 to 20:00 h), after a period of restricted access (2 to 10 h) while in the control group ad-libitum access to silage was provided over the 24 h period ...

It has been claimed that artificial insemination (AI) of cows with frozen-thawed semen treated with commercially produced kits, HeiferplusTM (HP, in favour of female gender) and BullplusTM (BP, in favour of male gender), increases the birth chance of calves with desired sex ratio by at least 20–25% and pregnancy rates by at least 5–20%. Hence, this study was conducted to investigate the efficac...

Recording of body weights dairy calves may assist producers in monitoring the health status and making feed-related management decisions. Traditional methods weighing can be time-consuming labor-intensive. The objective this study was to evaluate a forefront weight scale on stalls attached an automated calf milk feeder system determine accuracy for measuring Holstein crossbred calves. conducted...

Dystocia (DYS) is an important problem in Holstein cattle and imposes important economic losses on cattle producers. The etiologies and types of DYS are various and different factors can influence its incidence. In the present study, incidence of different types of dystocia was investigated in different seasons and parities in Holstein cows. One hundred and eighty two primiand multiparous cows ...

A rapid and simple technique for diagnosis of rotaviral diarrhea is polyacrylamide gel electrophoresis (PAGE) of dsRNA extracted from fecal samples. To determine the electrophoretype of Iranian calf rotavirus, 23 rotaviral positive fecal samples from diarrheic Holstein calves at the age of less than one month in Tehran region were examined. The viral dsRNA was extracted with phenol-chloroform, ...

Retrospective data from Sebele Dairy Farm were analysed for reproductive performance of Friesian/Holstein cows. Three hundred records from 1989 to 1995 were used. The herd was zero grazed and the data was analysed for age at first calving (AFC), calf birth weights (BW), calving interval (CI), days open (DO), calving rate (CR), reproductive wastage (RW) and calving difficulty (CD); dystocia, aft...

Twenty-four Angus x Holstein heifers were utilized in the single-calf heifer system. Calves were weaned from one-half of the dams between d 64 and 89 postpartum. Dam’s were gradually adapted to a high concentrate diet over a four wk period at the beginning of the trial. Heifers that had their calves early weaned (EW) gained 44.2% faster (P < .01) and consumed 10.8% less (P < .05) DM than lactat...