Effect of level of concentrate fed once or twice daily on the milk production of cows grazing tropical pasture

Abstract

A group of 40 Holstein-Fresian cows grazing tropical pastures were supplemented from 14 days after calving with a grain-based concentrate containing 15% protein. Concentrate was given at nil, 2, 4, 6, and 8 kg/cow. day fed once daily after morning milking, and 4, 6, and 8 kg/cow.day in 2 equal feeds, after morning milking and before evening milking. The experimental period was 250 days for cows fed once daily and 150 days for those fed twice daily. Over 250 days of lactation, the milk yield of cows fed once daily was significantly increased with increasing grain feeding, from 12.8 kg/day for the nil group t o 20 kg/day for the 8 kg group. Milkfat percentage was lower (P<0.05) for cows given 8 kg grain concentrate daily than for those given 2-4 kg, and total fat yield increased (P<0.1) with up to 4kg/cow.day. Protein percentages were similar across treatments, and protein yield increased (P<0.05) with grain level. Lactose percentage was increased (P<0.05) with concentrate feeding, and lactose yield increased (P<0.05) with increasing concentrate level. Fat-corrected milk (FCM) increased (P<0.05) from 3046 kg at nil concentrate to 4465 kg at 8 kg/cow. day. Over the first 150 days of lactation, milk yield increased from 19.5 kg/day for cows fed once daily to 21.7kg/day for those fed twice daily. Milkfat and protein percentages were similar. Greatest responses to twice-daily feeding occurred at 6 kg concentrate/cow.day. It was concluded that total milk yield increased linearly to 8 kg concentrate/cow.day, but FCM yield was at a maximum at 6 kg concentrate1cow.day. There were advantages in feeding 6 kg concentrate twice daily.

Evaluation of a Mobile Computerized Grain Feeder for Lactating Cows Grazing Grass Pasture

“…No previous research has evaluated the feeding of grain more than twice daily for cows on pasture, and no previous study has evaluated the amount of grain fed in this study. During early lactation, twice daily feeding versus once daily feeding of up to 8 kg/d of grain with tropical pastures resulted in increased milk yield (21). Neither our study nor the study of McLachlan et al ( 2 1 ) evaluated data on rumen fermentation to know whether it was altered by feeding frequency.…”

Effect of cereal-based concentrates on productivity of Holstein–Friesian cows grazing short-rotation ryegrass (Lolium multiflorum) or kikuyu (Pennesitum clandestinum) pastures

“…Thus, various reviews and studies (Davison et al, 1985;Kellaway and Porta, 1993;McLachlan et al, 1994;Robiana et al, 1998;Walker et al, 2001;Bargo et al, 2003) all suggest 4 to 5kg/cow/day as the maximum amount fed before a decline in response was observed. Walker et al (2001) compared their results with other studies and clearly showed an excellent milk response to the first 3-4kg concentrates fed and then a variable drop with some negative increments as concentrate fed increases.…”

Predicting Immediate Marginal Milk Responses and Evaluating the Economics of Two-Variable Input Tactical Feeding Decisions in Grazing Dairy Cows

“…There are numerous and complex interactions that influence the immediate marginal milk response to supplements. Factors such as season, the nutritive characteristics of pastures, pregrazing pasture mass and allowance of pasture on offer [4,15,18,37], amount of pasture consumed [4,18], amount and type of supplement consumed, nutritive characteristics of the supplement [4,5,18,23], amount of substitution [15,18] and animal and management factors, such as stage of lactation [5], body condition score [19], frequency of feeding [38] and genetic merit of cows [39], have all been shown to influence milk production when supplements are fed.…”

“…In the present analysis, milk yields from animals lighter than 400 and heavier than 600 kg are largely untested, as are milk yields from cows beyond 270 days in milk. The influence of the genetic merit of cows [38] is also not captured in this model. Empirical models of this kind, developed on, and calibrated to, a wide diversity of experimental data collated from different locations in different decades, cannot detect and reliably represent the minutiae of biological processes.…”