Effects of Creep Feeding and Monensin on Reproductive Performance and Lactation of Beef Heifers

Abstract

A 23 factorial arrangement of treatments was utilized to determine the effect of breed, creep feeding and monensin on subsequent reproductive performance and lactation of 32 primiparous heifers. One-half of each breed (Angus and Hereford) group had access to creep feed (2.67 Mcal metabolizable energy/kg) while nursing their dams. Approximately 40 d before breeding through 120 d of lactation, all heifers were fed a suboptimal energy diet and 50% of each breed and creep group received 200 mg monensin/head daily. Estrus was synchronized with a progestogen. Volatile fatty acids (VFA) were determined periodically throughout the monensin-feeding portion of the experiment. Twenty-four hour milk production, percentage butterfat and percentage solids-not-fat were determined at 60 and 120 d postpartum. Weaning weights (adjusted to 205 d and for age of dam) of the original heifers were heavier (P less than .05) for those that were creep fed compared with those not creep fed (219 vs 202 kg). Monensin-supplemented females gained significantly more weight from the initiation of treatment to immediately postcalving and gave birth to heavier calves (P less than .05) even though they received comparable amounts of dietary energy as those that did not receive monensin. The energy stressed, monensin-supplemented first-calf heifers exhibited a shorter postpartum interval (P less than .05) to first estrus than did those that did not receive monensin (55.7 vs 69.1 d, respectively). First-calf heifers that had been creep fed while nursing their dams had a lower (P less than .05) daily milk yield at 120 d post-partum than those that did not have access to creep feed. No detrimental effects were observed due to long-term monensin supplementation.

Growth, reproductive performance, mammary development, and milk production of beef heifers as influenced by prepubertal dietary energy and administration of bovine somatotropin.

“…In Trial 2, creep feeding did increase rates of gain, and these heifers had decreased subsequent milk production and calf performance. It has been shown previously that creep feeding high-energy feedstuffs to prepubertal beef heifers may decrease subsequent milk production (Hixon et al, 1982;Cremin, 1989;Buskirk et al, 1996) and reduce calf weight gains (Martin et al, 1981). Although not statistically significant, the comparison of milk production between dietary energy treatments in Trial 3 was numerically similar to that in Trial 2.…”

“…Reproductive benefits are real-ized with rapid weight gains of prepubertal heifers (Patterson et al, 1992); however, high-energy diets may reduce subsequent milk production in dairy heifers (Waldo and Capuco, 1992). Likewise, if replacement beef heifers are given access to creep feed, milk production is reduced (Hixon et al, 1982;Buskirk et al, 1996), thereby lowering lifetime calf weaning weights (Martin et al, 1981). The deleterious effects of high-energy diets on mammogenesis and milk production have been proposed to be mediated by bovine somatotropin ( bST) .…”

Effects of reduced in utero and post-weaning nutrition on milk yield and composition in primiparous beef cows

“…However, there is great latitude in how this can be achieved (Clanton et al, 1983). Development of heifers at an increased rate of gain post weaning can lead to low pregnancy rates (Ferrell, 1982) and impaired milk production (Hixon et al, 1982;Sejrsen and Foldager, 1992;Sejrsen et al, 2000). However, Endecott et al (2013) suggests changes in mature BW have occurred over the decades and the recommendation for heifer target BW before breeding of 60% to 65% of mature weight may be different today than when first reported.…”

Effect of administration of a controlled-release monensin capsule on incidence of calving-related disorders, fertility, and milk yield in dairy cows

“…The lack of treatment effect was expected because retention of fetal membranes is a multifactorial condition and other variables are more important predisposing factors for retained fetal membranes. 28,29 However, another study 30 found no effect of monensin on calf birth weight. Although dystocia is also a multifactorial condition, those persons providing calving assistance were unaware of group assignments.…”