Abstract

Effects of condition score (CS) at calving and concentrate supplementation over early lactation on milksolids production (MS), liveweight, CS change and intake were investigated in spring 1995. Differential feeding before calving resulted in high CS (HCS) and low CS (LCS) herds of 5.6 and 4.7 (P<0.001) respectively. After calving (10 August) the HCS and LCS herds were split (n=10) and either fed (+) or not fed (-) 3 kg DM/cow/day of rolled barley for 48 days. During the treatment period each herd was offered a similar pasture allowance of 22 kg/cow/day. A 27 day carryover period followed with no supplementation. Treatments were grazed separately throughout. During supplementation the liveweight gain (P<0.01) and change in CS (P<0.05) was greater for LCS than HCS. Cows on + concentrate gained more liveweight (P<0.01) than - concentrate. CS at calving had no effect on milk yield or composition. Concentrate increased (P<0.001) milk, fat and protein yields and protein %. Feeding 144 kg DM/cow of concentrate increased (P<0.001) milksolids by 16.5 kg/cow. No significant interaction occurred between CS at calving and concentrate but for HCS cows the response to feeding concentrates was 21.2 kg MS/cow compared to the response for LCS cows of 11.8 kg MS/cow. During the feeding period, pasture intake was greater (P<0.05) for LCS (12.5 kg/cow/day) than HCS (11.0 kg DM/cow/day). Concentrate had no effect on pasture intake. No treatment effect on pasture intake occurred in the carryover period. These results suggest, that at the pasture allowance post calving of 22 kg DM/cow/day, a CS at calving of 4.7 is adequate to sustain similar milksolids production in early lactation as cows calving with CS of 5.6.

CJ, Mudford, NA Thomson, and CW Holmes

Proceedings of the New Zealand Society of Animal Production, Volume 57, , 157-160, 1997