University of Arkansas, Fayetteville Division of Agriculture


Cows offered low quality hay require supplementation to meet their nutritional requirements. Our objective was to determine the impact of supplementation with soybean hulls (SH), distiller’s dried grains with solubles (DDGS), or a 50:50 mixture of each (MIX) at 0.5% of body weight on ruminal fermentation characteristics and in situ forage disappearance in lactating (n = 3) and non-lactating (n = 3) ruminally cannulated cows (679 ± 18.7 kg body weight). Tall fescue was offered free-choice from large round bales for 6, 21-d periods. Dacron bags containing ground fescue hay were placed into the rumen of each cow at specified intervals over a 7-d period and removed on d 21. Rumen fluid samples were collected on d 21 of each period at 2 h intervals from 1600-2400 h for analyses of ruminal ammonia and volatile fatty acids (VFA). Ruminal forage disappearance was not affected (P ≥ 0.44) by diets. Total VFA were greater (P < 0.05) from SH but the propionate percentage was greater (P < 0.05) from DDGS. Therefore, supplementation with DDGS should improve the energy status of cows fed poor-quality hay compared with SH or MIX.