Effects of Supplemental Undegradable Protein During Early Lactation on the Performance of Beef Cows Grazing Native Range |
| |
| Institution: | 1. Department of Animal Science, University of Nebraska–Lincoln, Lincoln 68583;2. Panhandle Research and Extension Center, University of Nebraska, Scottsbluff 69361;2. Panhandle Research and Extension Center, University of Nebraska, Scottsbluff 69361;1. Oklahoma State University, Department of Animal Science, Stillwater, OK 74078, USA;2. Mississippi State University, Department of Animal and Dairy Sciences, Mississippi State, MS 39762, USA;3. Oklahoma State University, Department of Statistics, Stillwater, OK 74078, USA;4. New Mexico State University, Department of Animal and Range Sciences, Las Cruces, NM 88003, USA |
| |
| Abstract: | Two experiments were conducted (Exp. 1, n = 63; Exp. 2, n = 72) using Angus x Hereford cows grazing Oklahoma dormant tallgrass prairie to determine the effects of increasing supplemental undegradable intake protein (UIP) on performance. In each experiment following parturition (February and March), cows were blocked by body weight, body condition score (BCS), and calving date and randomly assigned to one of four dietary treatments. For Exp. 1, supplements provided 396 g/d of degradable intake protein (DIP) with increasing amounts of UIP (211, 274, 337, and 400 g/d, respectively). For Exp. 2, supplements provided 281 g/d of DIP with 142, 196, 248, and 301 g/d UIP, respectively. Cows were individually fed 1.59 kg supplement 6 d/wk. Body weight and BCS were determined biweekly until the end of supplementation (Exp. 1, 37 + 1.5 d; Exp. 2, 45 + 1.2 d). Milk production was estimated 30 and 45 d postpartum. Plasma progesterone concentrations were quantified weekly to determine interval to first normal luteal function (PPI). Weight loss, BCS, and PPI were not influenced by treatment. In Exp. 2, there was a linear (P<0.08) decrease in weight gain of calves post-treatment to weaning as supplemental UIP increased, and a quadratic effect (P<0.06) of additional UIP on milk production at 30 d postpartum. In these experiments, metabolizable protein requirements were met by microbial protein, forage UIP, and a minimum of 142 g of supplemental UIP. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
