Effects of ruminally protected betaine and choline on performance of lactating Alpine goats

T. Shenkoru¹, F. N. Owens², R. Puchala¹, A. L. Goetsch¹, and T. Sahlu¹

¹E (Kika) de la Garza Institute for Goat Research, Langston University, Langston, OK
²Animal Science Department, Oklahoma State University, Stillwater, OK

Twenty-four Alpine does and 24 doelings were used to evaluate effects of dietary supplementing a 50% concentrate diet with protein or ruminally protected betaine or choline on milk yield and composition. Diets containing 15% CP (DM basis) were supplemented with 3% ruminally protected betaine (B), 3% ruminally protected choline (C), no added methyl donors (N), or feedstuffs high in ruminally undegradable protein to increase CP to 18% (H). Six animals, 3 doelings and 3 does, were allocated to each treatment and fed for ad libitum consumption. Doelings gained more weight (P < 0.05; 80 vs 15 g/d) but produced less milk (P < 0.05; 2.11 vs 3.24 kg/d) than does. Treatments had no effect on body weight gain by does or doelings (P > 0.10). Does fed H and B diets had higher DM intake than does fed N or C (P < 0.05; 2.13, 2.51, 2.24, and 2.49 kg/d); whereas, doelings consumed greater amounts of B and C (P < 0.05; 2.15, 2.68, 2.46, and 1.98 kg/d for N, B, C, and H, respectively). Treatments had no effect on milk production by doelings (2.08, 2.01, 2.18, and 2.15 kg/d) but B decreased milk production by does (P < 0.05; 3.45, 2.68, 3.27, and 3.54 kg/d for N, B, C, and H, respectively). Betaine decreased milk protein yield (P < 0.05; 82.7, 68.6, 80.1, and 83.8 g/d) and supplements decreased milk fat yield (P < 0.05; 83.5, 70.4, 71.8, and 72.1 g/d). Treatments had no effect on plasma NEFA or insulin in does, although B and C increased (P < 0.05) plasma NEFA and insulin in doelings. In summary, the lack of effect of additional protein in the diet indicates that protein status with 15% dietary CP was adequate. Betaine and choline altered plasma concentrations of some blood metabolites but did not improve milk production or body weight gain.