Abstract #M18

# M18
Effect of timing of feed delivery on feeding behavior and productivity of dairy cows.
Meagan T. M. King*1, Robin E. Crossley1, Trevor J. DeVries1, 1Department of Animal and Poultry Science, University of Guelph, Guelph, ON, Canada.

The objective of this work was to assess the effect of timing of feed delivery on behavior and productivity of cows milked 3×/d. Twenty-four lactating Holstein dairy cows (7 primiparous and 17 multiparous), milked 3×/d (at 1400, 2100, and 0700 h), were individually exposed to each of 2 treatments (over 21-d periods) in a replicated crossover design. Treatments were the manipulation of timing of TMR delivery, 2×/d, in relation to milking time: (1) feeding at milking time (at 1400 and 0700 h) and (2) feeding halfway between milking times (at 1730 and 1030 h). Milk production, feeding, and rumination behavior were electronically monitored for each animal for the last 7 d of each treatment period. Milk samples were collected for 2 of the last 4 d of each period for milk component analysis. Data were then summarized across treatment period by cow and analyzed in a general linear mixed model. With a feed delay, DMI was lower (26.3 vs. 27.6 kg/d; SE = 0.6; P = 0.04). Although there was no difference in feeding time (230.2 min/d), cows fed with a delay consumed their feed slower (0.12 vs. 0.13 kg DM/min; SE = 0.003; P < 0.001) and had more meals (10.1 vs. 9.2 meals/d; SE = 0.3; P = 0.02), which were smaller in size (2.8 vs. 3.1 kg/meal; SE = 0.1; P = 0.008) and shorter (27.9 vs. 30.8 min/meal; SE = 1.3; P = 0.03). Rumination time (8.7 h/d) and lying time (9.9 h/d) were similar between treatments. Cows without fresh feed at their 1400 h milking stood for less time following that milking (72.2 vs. 86.4 min; SE = 6.9; P = 0.045), however, no differences in this latency to lie down were seen for either of the other 2 milking times. Milk yield (46.3 kg/d), milk fat content (3.65%), milk protein content (2.90%) were similar between treatments. Given the difference in DMI and no change in yield, with a feed delay, efficiency of production was improved (1.80 vs. 1.69 kg milk/kg DMI; SE = 0.04; P = 0.01). These data suggest that moving the timing of feed delivery away from milking resulted in cows consuming their feed more slowly in smaller, more frequent meals, contributing to an improvement in efficiency of production.

Key Words: feed delivery, meal pattern, behavior