Performance of heifers supplemented with different levels of corn on pasture

Abstract

In southern Brazil, production systems are typically extensive and rely on grazing that often results in limited forage quantity and quality, decreasing efficiency and compromising reproductive tract development. The aim of this study was to evaluate the productive performance and reproductive tract development of heifers supplemented with different levels of corn on pasture. The following supplemental treatments were evaluated: T0 [40 g trace-mineralized salt per heifer per day (80 g phosphorus/kg product)]; T1 [0.5% of body weight (BW) cracked corn + 40 g trace-mineralized salt per heifer per day]; T2 [1% of BW cracked corn + 40 g trace-mineralized salt per heifer per day], and T3 [1.5% of BW cracked corn + 40 g trace-mineralized salt per heifer per day]. Thirty-nine phenotypically homogeneous Brangus heifers (average BW = 184±17 kg, average age = 269±27 days) raised on winter pasture (Lolium multiflorum Lam.) were randomized to 13 paddocks (one hectare each), with three heifers/paddock, to evaluate the effect of feeding different energy levels. Body condition score, average daily gain, frame score, dry matter availability, reproductive tract score, and stocking density were evaluated. The body condition score, average daily gain, reproductive tract score and stocking density increased (P<0.05) with increasing level of corn supplementation. Daily supplementation levels lower than 1.0% on Lolium multiflorum Lam. pasture can compromise the target breeding weight at 13 months of age. Therefore, daily supplementation at 1.0% of BW after weaning is a strategy to improve the economic and biological efficiency of livestock production systems, allowing to increase stocking density and to anticipate the age of heifers at first breeding.Keywords: benefit-cost analysis, grazing, supplementation. Palavras-chave: análise de custo-benefício, pastoreio, suplementação. DESEMPENHO DE NOVILHAS EM PASTOREIO SUPLEMENTADAS COM DIFERENTES NÍVEIS DE MILHO

Energy supplements for beef heifers on cool season pastures - a database analysis

“…Furthermore, this result can be linked with diet equilibrium provided by supplement use, which is a degradable carbohydrate source for rumen that optimizes volatile fatty acids and propionic acid production, hence increasing glycose availability for muscular, uterine, and fatty tissues storage (NOVIANDI et al, 2014). Supplementation of heifers on ryegrass pastures increases ADG and anticipates reproductive system development of 13-month-old heifers (GONZALEZ et al, 2016). BCS of higher supplemented animals was determined by weight gain composition by the end of the grazing period.…”

Average daily gain rates determine eye muscle area and rump fat depth of beef heifers

“…Although there are studies associating BW with age (Bond et al 2015;Titterington et al 2015;Gonzalez et al 2016) and longissimus muscle in heifers (Guggeri et al 2014;Reis et al 2015), few studies have evaluated the impact of ADG on body composition in beef heifers under grazing conditions.…”

“…However, to achieve these forecasts, the heifer systems need to be fully understood and optimised, as heifers improve the genetics of cow herds because they are the backbone of beef production systems (Hersom et al 2013). Therefore, in the beef cattle industry, the growth and development of replacement heifers deserve special attention because they affect the age at puberty and the onset of reproductive activity (Randel and Welsh 2013;Gonzalez et al 2016), as well as heifer retention rate and cow longevity (Endecott et al 2013;Roberts et al 2015).…”