Abstract #M168

# M168
Partial replacement of starch and protein sources in dairy cows rations with sustainable feeds: Effects on milk production, rumen health, and digestibility of fiber.
L. M. E. Mammi1, D. Cavallini*1, A. Palmonari1, E. Giaretta1, G. Canestrari1, V. Massa2, A. Formigoni1, 1Department of Veterinary Medical Sciences, University of Bologna, Italy,, 2Dalma Mangimi, S.p.a, Marene (CN), Italy,.

To increase sustainability of cow nutrition and reduce food wastage, we partially replaced protein and energy sources of dairy cows rations with 2 sustainable feeds coming from grain industry. Four isoproteic diets were formulated including condensed wheat distillers soluble (D), former foodstuff (F) or both (DF), as protein (D) or starch source (F). These diets were compared with a standard dairy cows ration (CTR). The effect of these diets on milk yield, rumen health and degradability of fiber was evaluated in a replicated 4 × 4 Latin square trial with 8 mid-lactating Holstein cows. Cows were blocked by parity and average milk production, and received dietary treatments for 4 21-d periods, composed of 14 d of adaptation and 7 of data recording. Individual TMR delivered and residual was analyzed 3 times/period, while individual feed and water intake, milk yield, rumination time and rumen pH were recorded daily. In each period, milk was sampled 4 times for composition, SCC and urea content. Fecal composition was analyzed 4 times/period to evaluate Total-tract Fiber Degradability (TTDpdNDF) of diets. Data were analyzed with a mixed model with diet and period as fixed effects and cow within block as random effect. Data recorded daily were analyzed with repeated measures including in the model the time within cow effect. The treatments did not influence DMI (23 kg/d on average) or TTDpdNDF of the diets. The F diet tended to increase milk yield compared with the CTR and the D, while the DF significantly increased production of 1 kg/d (P < 0.05) without affecting milk quality. Rumination time was not influenced by the treatments, as well as average daily rumen pH and time with pH < 5.5. Conversely, the DF diet significantly increased the time with rumen pH < 5.8 (min. 172 vs 56, 105 and 109, P < 0.05 for DV, CTR, D, and V diet, respectively). The inclusion of former foodstuff in the diets can increase sustainability of cow nutrition without impairing cow performance and health nor DMI or digestibility of the diets. However, further studies are needed to explain possible interactions of these feeds on rumen fermentations.