Effects of dietary tallow level on performance of Alpine does in early lactation

Sixty Alpine does (initial BW 47 +/- 1.3 kg) were sed to determine effects of dietary inclusion of different levels of partially hydrogenated tallow o n performance in early lactation (weeks 3-11). Treatments entailed a 30% co ncentrate, negative control (NC) diet and five diets higher in concentrate (42-46%) with 0, 1.5, 3.0, 4.5 or 6.0% DM of partially hydrogenated tallow (0T, 1.5T, 3.0T, 4.5T and 6.0T, respectively). DM intake was 1.54 kg per da y for the NC and 1.86, 1.80, 1.99, 2.17 and 1.96 kg per day for the five ta llow treatments, respectively, BW was similar among treatments and increase d as the trial progressed (47.4, 48.4, 49.8, 50.4, 50.8 and 51.3 kg at week s 3, 5, 7, 9, 11 and 13, respectively). Milk yield was lower (P < 0.05) for NC (2.61 kg per day) compared with the mean of the other diets and changed quadratically (P < 0.05) as tallow level increased (2.85, 3.08, 3.14, 3.21 and 2.69 kg per day for the five tallow treatments, respectively). Milk fa t concentration was lower (P < 0.05) for NC (2.94%) than fur the mean of ot her diets and increased linearly (P < 0.05) with increasing tallow level (3 .00, 3,17, 3.34, 3.48 and 3.58%) whereas, milk protein concentration was no t affected by level of tallow (2.72, 2.80, 2.93, 2.85, 2.90 and 2.90% for N C, and the five tallow treatments, respectively). The estimated NE1:4% fat- corrected milk yield ratio was 0.93 Mcal/kg for NC and 1.30, 1.11, 1.21, 1. 37 and 1.44 McaL/kg for he five tallow treatments, respectively. The result s indicated that in Alpine does, milk yield in early lactation increased as dietary tallow level was increased to 3 and 4.5% but decreased when the le vel was increased to 6%, although milk fat concentration increased linearly and the protein level was unchanged. These results suggest beneficial usag e by lactating Alpine does of low to moderate levels of partially hydrogena ted tallow in diets moderate in concentrate level, although ingredient avai lability and costs will influence ultimate dietary ingredient decisions. (C )2001 Elsevier Science B.V. All rights reserved.