Effects of organic acids in total mixed ration and feeding frequency on productive performance of dairy cows

This study aimed to evaluate the effects of organic acid (OA; Mold-Zap, Alltech, Nicholasville, KY) inclusion in total mixed ration (TMR) and feeding frequency TMR for lactating dairy cows on intake, total-tract apparent digestibility, sorting index, behavior, ruminal fermentation, milk yield composition, nitrogen balance, serum metabolites. Twenty-four Holstein cows, 4 with rumen cannulas, (mean ± standard error) 247 22.2 d milk, 672 14.6 kg body weight, 31.1 1.09 at beginning experiment were used. The distributed a balanced contemporary × Latin square experimental design randomly assigned 2 factorial arrangement OA [0 (OA−) or 0.5 (OA+) L Mold-Zap/tonne natural matter basis] offered once day (1×) twice (2×). Each period lasted 21 d, 14 acclimation 7 data collection. treatments tested TMR, which its temperature was recorded every h through 24-h each period. Organic acid-treated showed lower during compared nontreated TMR. had no effect intake digestibility dry nutrients, aside from tendency increase neutral detergent fiber fed 2×. Also, 1× tended select more particles between 19 8 mm refused smaller than mm, whereas mm. Cows greater protein lactose yields, but have higher 3.5% fat-corrected yield. Neither treatment influenced variables nor fat production efficiency. spent less time idling rumination time, drinking water eating, animals water. Under conditions this experiment, we conclude that it possible reduce without negative cow performance. However, use resulted mitigated rise regardless frequency. external factors such as collective stimulation stage lactation must be surveyed further research.