A 3-yr study was conducted with heifers (n = 170) whose dams were used in a 2 x 2 factorial arrangement of treatments to determine the effects of late gestation (LG) or early lactation (EL) dam nutrition on subsequent heifer growth and reproduction. In LG, cows received 0.45 kg/d of a 42% CP supplement (PS) or no supplement (NS) while grazing dormant Sandhills range. During EL, cows from each l...

A 3-yr study was conducted to evaluate the effects of calving system, weaning age, and postweaning management on growth and reproduction in beef heifers. Heifer calves (n = 676) born in late winter (average birth date = February 7 +/- 9 d) or early spring (average birth date April 3 +/- 10 d) were weaned at 190 or 240 d of age, and heifers born in late spring (average birth date May 29 +/- 10 d...

Two experiments were conducted to test the following hypotheses: 1) exposure of beef heifers to sterile bulls increases the proportion of heifers attaining puberty by 14 mo of age and 2) rate of growth interacts with bull exposure to influence age at puberty in beef heifers. In Exp. I, heifers were assigned to one of two treatments: 1) heifers were exposed to bulls (BE; approximately 70-d perio...

Seventy-four Angus and Angus × Hereford heifers were used in 2 successive years (yr 1, n = 43; yr 2, n = 31) to determine if luteal function of heifers during acute submaintenance feeding is related to variation in utilization of feed as determined by residual feed intake (RFI). Residual feed intake was determined for heifers beginning at 12.3 ± 0.1 mo of age in yr 1 and at 9.1 ± 0.1 mo of age ...

The objective of the current study was to evaluate the effects of supplement type on performance, reproductive, and physiological responses of grazing yearling beef heifers. Sixty Brahman x British crossbred heifers were stratified by initial body weight (BW) and age, and randomly allocated to 12 pens (five heifers/pen). Pens were randomly assigned to one of two treatments: 1) molasses-based su...

This study was conducted to determine the effect of Cu deficiency on acute-phase protein concentrations, superoxide dismutase activity, leukocyte numbers, and lymphocyte proliferation in heifers inoculated with live bovine herpesvirus-1 (BHV-1). Hereford × Angus heifers were allotted by weight and initial liver Cu concentrations into molybdenum (Mo)-supplemented (n = 6) or control (n = 6) group...

A total of ninety seven pre-pubertal Bunaji (BJ) and Friesian-Bunaji (FR x BJ) heifers were allotted randomly to two treatments groups for a period of 15 months. The treatment groups consisted of the followings: Mature Bull Exposure (MBE) and No Bull Exposure (NBE). Heifers were body condition scored and their live weights recorded on 28 days consecutive intervals. A heifer tactile stimulation ...

Two experiments were conducted in consecutive years to determine the effects of prepartum nutrient level and postpartum ruminally undegraded protein intake on nutrient status, milk production, subsequent calf production, and reproductive performance of 126 crossbred, primiparous beef heifers. Prepartum treatments were low nutrient intake (LN) (approximately 2.5 kg of TDN, .5 kg of CP animal-1.d...

The objective of this study was to investigate the effect of supplemental tribasic copper chloride (Cu(2)(OH(3))Cl; TBCC) vs. Cu sulfate (CuSO(4)) on Cu status and voluntary forage DMI in growing heifers. Two 90-d experiments were conducted using 48 non-pregnant, crossbred heifers (24 heifers/experiment; 355 +/- 10.7 and 309 +/- 9.9 kg for Exp. 1 and 2, respectively). In each experiment, 3 supp...

The aim of this study was to determine the effect of prepartum somatotropin injection in late-pregnant Holstein heifers on metabolism, milk production and resumption of postpartum ovulation. For this study, 31 late-pregnant Holstein heifers were used. The heifers were assigned randomly into two treatments: (1) 500 mg sc injections of somatotropin (somatotropin treatment, n = 15) at -35 and -21 ...