338
Total mixed ration vs. component feeding does not improve individually-fed high-producing cow performance: Common wisdom challenged
The objective was to determine effects of total mixed ration delivery vs. component feeding in high-producing lactating cows in a noncompetitive housing environment. Four multiparous (665 ± 65 kg body weight; 67 ± 20 days in milk; mean ± SD) and four primiparous (583 ± 43 kg body weight; 85 ± 36 days in milk) lactating Holstein cows housed in free individual boxes (4 ×3 m) were used in a cross-over design experiment with two 25-d periods. Each period had 20-d of adaptation. Cows received a single diet, based on barley grain and a mixture of corn silage and alfalfa hay, prepared and presented as either total mixed ration (TMR) or component forage and concentrate (CFC). The forage to concentrate ratio was 50:50 (dry matter basis), permitting 5-10% daily orts. Fecal and urine samples from individual cows were collected daily for the last 5-d of each period. Cows were milked twice daily at 0500 and 1700 h. Data were analyzed using Mixed Models with fixed effects of treatment, parity and their interaction, and random effects of period and cow within parity. Feeding TMR vs. CFC did not affect (P>0.10) dry matter intake (21.0 vs. 21.2 kg/d), milk yield (35.1 vs. 35.3 kg/d), and milk contents of fat (3.3 vs. 3.2%), protein (3.0 vs. 3.03%) and lactose (4.9 vs. 4.8%). As a result, total daily milk solids production was not affected. Daily durations of eating (340 vs. 320 min/d), ruminating (300 vs. 300 min/d), and total chewing (660 vs. 620 min/d) were similar (P>0.10) between TMR- and CFC-fed cows, respectively. The first meal length (FML), starting from feed delivery until the first non-eating bout of ≥20 min, was 115 min in the TMR-fed cows and totally 152 min in the CFC-fed cows (P<0.01). Urine (8.0 vs. 8.1) and fecal (6.2 vs. 6.0) pH were unaffected by TMR vs. CFC delivery (P>0.10). Therefore, the results suggest that under a noncompetitive housing and feeding environment, feeding a high-producing diet as TMR vs. CFC does not affect production and intake behavior of lactating Holstein cows.
Keywords: Feeding system, dairy cow, milk production