Sex-sorted semen can increase the profitability of dairy cattle by producing offspring of the desired sex. The objective of the present study was to compare conception rate, stillbirth, calving difficulty and sex ratios from sexed and conventional semen in a commercial dairy herd in Isfahan province, Iran. Data were collected from April 2009 until December 2015 on 13,343 inseminations in 8,011 ...

OBJECTIVE To determine whether prepartum intramammary treatment of dairy heifers with pirlimycin hydrochloride would reduce the prevalence of intramammary infection (IMI) and lower the somatic cell count (SCC) during early lactation or improve 305-day mature equivalent milk production. DESIGN Prospective clinical trial. ANIMALS 183 Holstein-Friesian heifers (663 quarters) from 2 dairy farms...

Herd-level risk factors for dairy calf and heifer mortality in France were identified by calculating herd-level variables (including mortality risk or rate) using the National Bovine Identification Database (2005 and 2006). Eleven dairy production areas representing different livestock systems were also included. Statistical analyses were based on a probit model (mortality risk or rate=0 or >0)...

One approach to improving efficiency of protein and nitrogen use for optimal productivity in dairy heifers is to provide adequate levels of protein with differing rumen degradabilities. The objective of this experiment was to determine effects of manipulating RDP in diets of dairy heifers precision fed low- and high-quality forage. Eight rumen-cannulated Holstein heifers (448 ± 19 kg BW) were r...

The National Dairy Heifer Evaluation Project was a cooperative, USDA-sponsored project involving state agricultural departments, the Cooperative Extension Service, the National Agricultural Statistics Service, and the Animal and Plant Health Inspection Service. A series of retrospective and prospective descriptive surveys using a multiple list and area frame sampling technique were conducted. I...

Data included pubertal, reproductive and lactation records of primiparous females produced in a diallel of Angus, Brahman, Hereford, Holstein and Jersey. Brahman heifers were oldest, tallest and heaviest at puberty, while Jersey heifers were youngest, shortest and lightest. Crossbred heifers were 22 d younger (P less than .01) at puberty than straightbred heifers; no significant differences wer...

Data were collected on the heart girth (n = 8,565; a measure of body weight) and height at withers (n = 8,568) of Holstein dairy heifers from 659 dairy farms as part of the National Dairy Heifer Evaluation Project during 1991 and 1992. Means and standard deviations for weight and height were determined for ages .5 to 23.5 mo. Third-order polynomial regression equations were derived to study the...

Selenium (Se), copper (Cu), and zinc (Zn) play important antioxidant role during the transition period of dairy cattle. However, there is limited information about their blood fluctuations during the entire transition period, especially in heifers. Furthermore, it is questionable whether the use of clinoptilolite, a natural zeolite, affects the availability of these trace elements during this p...

A novel adjuvant (Immunoboost®) to enhance antibody titer response to a commercial vaccine (Lysigin®) against Staphylococcus aureus mastitis in dairy heifers was evaluated. In Phase 1, hyper-immunization with Lysigin® to enhance serum titers did not result in titers that exceeded conventional immunization. In Phase 2, anti-S. aureus titers in heifers immunized with Lysigin® + Immunoboost® tende...

Much research has been carried out and published on dairy replacement management, in order to rear heifers as efficiently as possible, from both a technical and economical point of view. In most cases, the aim is to rear the heifers at the lowest cost possible without any deleterious effects on future performances. However, the importance of dairy heifer husbandry is not sufficiently well recog...