1833
Feed intake and Feeding Behavior of lactating dairy cows were affected by dietary fatty acid profile
There are quite rare data regarding effects of dietary fatty acid profile on feeding and chewing behavior. The aim of this study was to evaluate the milk fatty acid profile in early lactating dairy cows supplemented with protected unsaturated fatty acids sources and prilled source of palm fatty acids. Twenty four multiparous Iranian Holstein cows individually were assigned to diets with different fatty acid profiles and supplemented through 30 days prior to expect calving date to 50 days in milk. Dietary treatments consisted of (1) Prilled Pam fatty acids (PO) [Energizer RP10 ®, 2 & 2.25 % DM in pre- and postpartum, respectively]; (2) Ca-salts of sunflower oil (SO) [Persia Fat®- SO]; (3) Ca-salts of fish oil (FO) [Persia Fat®- FO] and (4) equal amounts of Persia Fat®- FO & Persia Fat®- SO. Calcium salts were supplemented as 2.2 and 2.5% of dietary DM in pre- and postpartum period, respectively. All rations contained identical forage and concentrate components. Feeding behavior was continuously monitored for 5 consecutive days in 15, 30 and 45 days in milk using video recordings. Data were analyzed using PROC MIXED of SAS 9.1 with repeated measures in time function. Dry matter intake for PO was less than Persia Fat® with different FA profiles (20.17 vs. 23.56, 22.25 and 2.53, for treatments 1 to 4, respectively, P<0.05). Supplementation of palm fatty acids decreased meal number, meal length and time to consume 1 kg of DM or NDF, but amount of feed intake in each meal was not affected. Time interval between meals was numerically increased (P>0.05) by supplementation of PO (2.74 vs. 2.28, 2.51 and 2.53, for treatments 1 to 4, respectively).The PO treatment increased time spent ruminating in each bout, but increased rumination bout intervals. Total number of rumination bouts was not affected by fat supplement type. Total rumination time (660.48 min vs. 587.86, 584.8 and 73.75, for treatments 1 to 4, respectively) and rumination per kg of DM (32.74 min vs. 24.95, 26.28 and 25.47, for treatments 1 to 4, respectively) and NDF (102.39 min vs. 78.02, 82.21 and 79.62, for treatments 1 to 4, respectively) were increased for PO than PUFA supplemented cows. We conclude that saturated fat supplement suppress DMI via increase time spend to consume or rumination feed.
Keywords: Palm oil, PUFA, Rumination