Effect of nutritional management, trace mineral supplementation, and norgestomet implant on attainment of puberty in beef heifers.

Abstract

We conducted a study to evaluate the influences of nutritional management, trace mineral supplementation, and exogenous progesterone on attainment of puberty in beef heifers. Heifers (n = 180) were assigned at weaning to blocks and treatments. Treatments included two dietary regimens (corn silage vs pasture + oatlage), trace mineral supplementation, and puberty induction strategy (with or without progestin implant). Heifers that received pasture + oatlage were managed on grass-legume pastures from October 14 until December 14 and were then placed in pens and fed an oatlage-based diet through May 1994. Heifers fed the corn silage-based diet were housed in pens throughout the study. Norgestomet was implanted in half of the heifers on April 11 for 10 d. Progestin implant increased (P < .05) the number of heifers that had attained puberty by the end of the study, compared with nonimplanted heifers (89% vs 71%). Trace mineral supplementation did not affect percentage of heifers that reached puberty before the implant period. Plasma copper levels were below recommended levels in heifers fed oatlage-based diets without trace minerals. We conclude that heifers can be placed on regrowth in irrigated pastures during the fall and still make acceptable gains for attainment of puberty the following spring and that progestin treatment can aid in inducing heifers to reach puberty.

Effect of development system on growth and reproductive performance of beef heifers1,2

“…The present study further showed nutritional restrictions during the prebreeding period clearly affected heifer performance. When nutritionally restricted animals are placed on a higher plane of nutrition, they will subsequently gain BW faster and have a lower feed-to-gain ratio than animals not nutritionally restricted (Fox et al, 1972;Grings et al, 1998;Kelln et al, 2011). However, in the current study, BW differences following the winter development period were present until the first calving period (approximately 10 mo after the development period) and first-calf weaning period (approximately 17 mo after the development period), respectively.…”

Early weaning in Northern Great Plains beef cattle production systems: II. Development of replacement heifers weaned at 80 or 215d of age

“…Grings et al (2007) concluded that heifers, when weaned at 140, 190, or 240 d of age, and subsequently developed on either constant or delayed gain management strategies can all achieve similar reproductive success. Furthermore, spring-born heifers, of similar age, weaned on fall pasture then subjected to a period of dry lot confinement had similar attainment of puberty as heifers consuming a corn silage based diet throughout the same time period in the Northern Great Plains, USA (Grings et al, 1998). Clanton et al (1983) concluded that producers have many options to effectively develop replacement heifers as long as necessary body weight (BW; industry standard of 65% of mature BW) that supports reproductive competency is achieved by the start of breeding.…”

Effects of stair-step nutrition and trace mineral supplementation on attainment of puberty in beef heifers of three sire breeds.

“…However, the effects of trace element supplementation on reproduction in controlled experiments have been varied (DiCostanzo et al, 1986;Phillippo et al, 1987;Vaughan et al, 1994). We previously observed no effect of a combined Cu, Zn, and Mn supplement on the number of heifers reaching puberty before the first breeding season (Grings et al, 1998). Diet and animal breed can influence mineral utilization, and we, therefore, wanted to further evaluate mineral supplementation for heifers under different management than that previously studied.…”