The objective was to determine whether increased dietary protein would enhance mammary development in prepubertal heifers fed for rapid body growth (1.2 kg/d). Fifty-four Holstein heifers (weighing approximately 134 kg) were assigned to one of three treatments. Heifers were fed a total mixed ration with metabolizable energy at 2.85 Mcal/kg and metabolizable protein at low, standard, or high con...

The influence of nutrition during the last trimester of pregnancy and the early postpartum period on postpartum LH secretion was evaluated in two-year-old Hereford and Simmental heifers maintained on a high or low plane of nutrition (experiment 1) or in Hereford heifers fed a high or low energy (150% vs 100% NRC) ration (experiment 2). Amount of LH released with 10 mg estradiol benzoate (IM) at...

OBJECTIVE To evaluate the efficacy of an inactivated bovine herpesvirus-1 (BHV-1) vaccine to protect against BHV-1 challenge-induced abortion and stillbirth. DESIGN Prospective study. ANIMALS 35 beef heifers. PROCEDURES Before breeding, heifers were vaccinated with a commercially available BHV-1 inactivated vaccine SC or IM. The estrous cycle was then synchronized, and heifers were artifi...

The aim of the present study was to examine the LH response to exogenous estradiol in 4 heifers with ACTH-induced ovarian follicular cysts. During the control experiment, administration of estradiol 24 hr after PGF2alpha in luteal phase heifers resulted in a LH response in all 4 heifers. The LH response was obtained between 16-20 hr after estradiol administration. The peak LH concentration (Mea...

Due to the lower DMI, the IH200 heifers had lighter final weight and lower ADG on a live basis (P<.01) than the IHFH heifers, but these differences were reduced on a carcass-adjusted basis. The IH200 heifers had significantly improved feed conversion compared to FH and R200 (P = 0.01) and tended to have better feed conversion than IHFH (P = 0.14) on a carcass-adjusted basis. The IH200 heifers h...

Infertility and subfertility are important and pervasive reproductive problems in both domestic animals and humans. The majority of embryonic loss occurs during the first three weeks of pregnancy in cattle and women due, in part, to inadequate endometrial receptivity for support of embryo implantation. To identify heifers of contrasting fertility, serial rounds of artificial insemination (AI) w...

BACKGROUND Dichelobacter nodosus is the main causative agent of ovine footrot, and there are strong indications that the bacterium can be transferred to cattle grazing on the same pasture as sheep. The aim of this study was to investigate if benign and virulent D. nodosus strains isolated from sheep can be transferred to the interdigital skin of cattle under experimental conditions. Further, we...

The purpose of the heifer herd is to provide replacements for cows leaving the herd and to improve genetic progress. First-lactation cows significantly contribute to herd production and profit. A recommended goal for dairy replacement heifers is to calve at 24 months of age with a targeted postcalving body weight of 1250 pounds. A common misconception is that this goal is either unattainable or...

Yearling Bos indicus × Bos taurus heifers (n = 410) from three locations, were synchronized with either the Select Synch/CIDR+timed-AI (SSC+TAI) or 7-11+timed-AI (7-11+TAI) treatments. On Day 0 of the experiment, within each location, heifers were equally distributed to treatments by reproductive tract score (RTS; Scale 1-5: 1 = immature, 5 = estrous cycling) and body condition score. The 7-11+...

Seventy postpuberal dairy heifers were assigned to remain untreated (n = 26) or to receive the Syncro-Mate-B (SMB) treatment (n = 44). Untreated heifers were inseminated at 12 hr after detection of estrus, while SMB-treated heifers were inseminated either at 48 hr after implant removal (group 1) or at 12 hr after detection of estrus (group 2). Jugular blood was collected at regular intervals fr...