Effects of Feeding Perennial Peanut Hay on Growth, Development, Attainment of Puberty, and Fertility in Beef Replacement Heifers

The objective of this study was to determine the influence of supplemental feeding of perennial peanut hay (Arachis glabrata Benth.) on growth performance and age at puberty in growing beef cattle heifers. Over a two-year (2010 and 2011) period, 120 heifers were randomly allocated to pens and assigned to one of three supplement treatments: 80% corn and 20% soybean meal supplement (CSBM), perennial peanut hay supplement (PPH), and a control which received no supplement (CON). All heifers received ad libitum access to bermudagrass hay (Cynodon dactylon (L.) Pers.) during the 140-d developmental phase. Following the developmental phase, heifers were comingled for a 77-d breeding season during the breeding phase. Heifers gained weight at a greater (P = 0.002) rate during the breeding phase then the development phase. In addition, CON heifers tended (P = 0.06) to have lesser average daily gain (ADG) than CSBM and PPH heifers. There was a treatment × day interaction (P = 0.06) on mean body weight (BW) with heifers in the CON treatment being lighter at the end of the development phase (P = 0.02). Total dry matter intake (DMI) was affected by the treatments (P < 0.01) during the developmental phase with the PPH heifers consuming more of the diet than the CSBM and the CON heifers. Treatment did not impact the age, BW, or body condition score (BCS) at which puberty was reached. While there was no effect of treatment on days to calving, the CON heifers had reduced pregnancy rates. In conclusion, there were no differences among supplemented treatments in reproductive performance despite the occurrence of differences in DMI, BW, and ADG, making PPH a viable feed option in the southeastern United States of America for replacement heifer development.