Two experiments evaluated prebreeding target BW or progestin exposure for heifers developed lighter than traditional recommendations. Experiment 1 evaluated the effects of the system on heifer performance through subsequent calving and rebreeding over 3 yr. Heifers (229 kg) were assigned randomly to be developed to 55% of mature BW (299 kg) before a 45-d breeding season (intensive, INT; n = 119...

Programs for developing replacement heifers are designed for heifers to calve at 2 yr of age and to extend their stayability in the herd and minimize feed cost. The experimental objective was to determine whether developing prepubertal heifers on less dietary energy and to a BW of 55% rather than 65% of mature BW at 14 mo of age would compromise ovarian development and reduce fertility. In a 3-...

Reproductive traits were evaluated in Bos taurus and Bos indicus crossbred heifers that were fed different diets during the postweaning period. The study was designed in a 2 x 2 x 2 factorial arrangement of treatments. Angus x Hereford (AH; n = 148) and Brahman x Hereford (BH; n = 148) heifers were sorted after weaning by body weight into light (LW) and heavy (HW) weight blocks. Heifers in each...

An experiment was conducted to determine if exogenous luteinizing hormone-releasing hormone (LHRH) administered iv intermittently as pulses (P) or by continuous sc infusion (I) using osmotic minipumps could sustain pulsatile LH release and induce estrous cyclicity in prepubertal heifers. Prepubertal heifers were assigned randomly to: 1) receive pulses of LHRH (n = 6; 2.5 micrograms LHRH/2 h for...

The objective of this experiment was to compare two progestins and three treatments for synchronizing follicular wave emergence and ovulation in protocols for fixed-time AI in beef heifers. On d 0 (beginning of the experiment), Angus and Angus-Simmental cross beef heifers at random stages of the estrous cycle either received a CIDR-B device (n = 257) or were started on 0.5 mg x anima(-1) x d(-1...

Four experiments were conducted to evaluate the effects of dried distillers grains + condensed distillers solubles (DDG+CDS) supplements on measures of performance of beef heifers, and apparent dry matter (DM), neutral detergent fiber (NDF), and crude protein (CP) digestibility of beef steers. In Exp. 1, heifers supplemented with DDG+CDS blocks (SweetPro; SP) for 42 d had lesser free-choice sup...

The objective of this study was to determine the effects of feed delivery method on growth, feeding competition, feeding, and sorting behavior of dairy heifers. Thirty-two Holstein heifers (146.2+/-21.9 d of age) were divided into 8 groups of 4 and exposed to 1 of 2 feed delivery treatments for 13 wk. The treatment rations contained 65% grass/alfalfa haylage and 35% textured concentrate (on a d...

Heifers produced from sires of seven breeds (Hereford, Angus, Belgian Blue, Piedmontese, Brahman, Boran, and Tuli) and Angus, Hereford, and MARC III (four-breed composite) cows were evaluated. Weaned heifers were placed in three treatment groups of moderate nutrition (15.8 Mcal ME/d), 80% of moderate nutrition (12.6 Mcal ME/d), or fed as a mixed-breed group (16.3 Mcal ME/d). Average daily gain ...

Lactating dairy cows have unique reproductive responses compared to when they were heifers that result in distinctly different reproductive measurements and pregnancy outcomes that can be partially overcome with pharmacological strategies. These parameters include circulating progesterone and estradiol concentrations, ovulatory follicle and corpus luteum diameter, incidence of anovulation and d...

Docking the tails of dairy cattle causes mild to moderate behavior changes and physiological indicators of acute pain, but no studies have investigated the possibility that tail docking may lead to chronic pain. In human amputees, an incidence of increased limb surface temperature is associated with phantom limb pain, a central nervous system representation that survives peripheral loss. The ob...