Effects of feeding different TMR in early and late lactation on milk production, nutrition, body weight and economic parameters in primiparous Holstein cows
2015
Nakamura, M. (NARO Hokkaido Agricultural Research Center, Sapporo (Japan)) | Nakajima, K. | Hayasaka, K.
We evaluated the effects of feeding different total mixed rations (TMR) in early and late lactation on milk production, nutrition, body weight and economic parameters in primiparous dairy cows. Postpartum, 18 primiparous dairy cows were assigned to management groups 1 (n = 9) or 2 (n = 9). All cows were fed TMR ad libitum for 305 days. Group 1 cows were fed TMR consisting of grass silage, concentrate and soybean meal (TDN 72%, CP 18%) for the full lactation period. Group 2 cows were fed this same TMR in early lactation (weeks 1 to 21) but were then switched to another TMR consisting of glass silage and concentrate (TDN 69%, CP15%) in late lactation (weeks 22 to 43). Cows in group 2 showed lower average milk yield, dry matter intake, milk protein percentage and lactation persistency (=240 days in milk -60 days in milk + 100) in late lactation. Moreover, body weight and body condition score on dry-off day were significantly lower in group 2 cows than in group 1. Average body weight gain over the full lactation in group 2 cows was smaller than standard body weight gain predicted by the Richards growth curve, and these cows showed malnutrition in late lactation. The feed cost of milk production was higher in group 1 than in group 2, but the net income (per-cow milk income minus the costs of concentrate, soybean meal and silage in this group) was 14,000 yen higher over the full lactation. Feeding of a higher TDN and CP ration over the full lactation improved nutritional status and milk production in primiparous dairy cows.
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