724. Levels of feeding of concentrates for dairy heifers before and after calving

Abstract

1. Two levels of steaming-up and two levels of concentrates feeding during the first 84 days of lactation have been compared in a 2 x 2 factorial experiment over three winter seasons, using fifty-two Shorthorn and thirty-six Friesian heifers. The levels of steaming up were 2 cwt. and ½ cwt. of concentrates fed over the last 21 and 14 days of pregnancy, respectively. The levels of concentrates during lactation were 5 and 3 lb. per 10 lb. milk per day. Roughages were fed for maintenance. After the 84th day of lactation all animals were given the same treatment for the remainder of the lactation. Milk yield, milk composition and live weight were measured throughout the lactation.2. The treatments were annotated as HH, HL, LH and LL, the first letter indicating level of steaming-up and the second the level of concentrates feeding in the first 12 weeks of lactation.3. Mean milk yields were as follows:4. The LH treatment reqiuird 3 cwt. more concentrates than HL to produce the same amount of milk.5. The response to additioal concentrates on the LH treatment after calving was l lb. additional milk per l lb. additional starch equivalent.6. Butterfat percentages were higher (3·69%) in both groups on low-lactation feeding than in the two groups on high-lactation feeding (3·43%). The HL group (i.e. the group that received high steaming-up and low-lactation feeding) combined high milk yield with a higher butterfat percentage, and at current milk and feedingstuff prices and under the conditions of the trials, this group showed a greater cash return than the groups on the other three treatments.

The growth rate of heifers in a dairy herd

“…RIDLEB, W. H. BROSTER AND A. S. FOOT published elsewhere (Broster, Ridler & Foot, 1958). The influence of the two levels of feeding before calving on the weight of the calf at birth, on its subsequent growth rate and on the loss of weight at parturition have now been examined.…”

The effect of level of concentrate supplementation given with grass silage during the winter on the total lactation performance of autumn-calving dairy cows

“…In the literature the effects of concentrate input on milk fat content have been variable with numerous reports suggesting that level of concentrate supplementation did not affect this milk component. However, Broster, Ridler & Foot (1958) reported significant reductions in milk fat content when concentrate levels were increased while Gleeson (1970) reported an increase in milk-fat content when concentrates were added to the diet of cows under nutritional stress. It would seem that, while both very low and very high levels of supplementa-tion may influence milk fat content, within the range in the present study there was unlikely to be any marked effect of supplementation.…”

The effect of pre-partum feeding of heifers on milk composition

“…In an experiment with 88 heifers Broster, Ridler & Foot (1958) found no significant difference in the fat percentage when a pre-partum intake of about 2 cwt of concentrates was compared with an intake of about \ cwt. In the same experiment, however, a significant difference in fat percentage in favour of the lower plane of post-partum feeding was found where 5 lb concentrates/gal milk were compared with 3 lb/gal in the first 12 weeks of lactation.…”