The performance of early-weaned calves offered concentrates or artificially dried grasses

Abstract

In two experiments dried grass cobs or concentrate were offered to calves for 20 weeks after weaning. In Experiment 1 the grasses were harvested in the autumn and in Experiment 2 in the spring. Within each experiment three grasses differing in quality and two levels of concentrate were compared. Dry-matter intake of the dried grasses highest in digestibility was lower than that of medium digestibility grass, and hardness of package, palatability and mould infestation were implicated as possible causal factors. Live-weight gains by calves were closely correlated with digestible organic matter (DOM) intake. There was no significant difference between spring harvested grasses and concentrate in efficiency of utilization of DOM for live-weight gain but autumn grasses were used less efficiently than concentrate. At similar rates of gain the replacement value (dry-matter basis) of dried grass for concentrate averaged 142 : 1.

Intake and live-weight gain by British Friesian calves offered different ratios of dried grass and concentrates

“…With increasing dried grass content, since DOM content per kg DM declines linearly, DM requirement increases linearly. Regression analysis of DM requirements against dried grass content indicated a replacement value of dried grass for concentrates of 1*36 : 1, this is similar to the ratio of 1*42 : 1 reported previously (Marsh, 1974). Therefore, within this type of feeding regime it would only be economic to incorporate dried grass into the concentrate pellet when its purchase price is less than 73-5 % of a cereal/protein concentrate on a drymatter basis.…”

“…Dried samples of offered feeds were bulked over fortnightly periods, milled and kept for chemical analyses. Moduli of fineness and uniformity of dried grass pellets (E) and of the dried grass meal used in treatments B, C and D, were determined by a process described elsewhere (Marsh, 1974).…”

“…Although intake of dried grass by calves can be increased by packaging (Lonsdale and Tayler, 1971;Wilkins, Lonsdale, Tetlow and Forrest, 1972) daily gains do not always reach those recommended for calves in a semi-intensive beef system (Harte and Lawlor, 1972;Marsh, McCullough and McKeown, 1973). A recent study showed that season and stage of growth of herbage at harvest were important factors affecting the variation in intake and daily gain from packaged dried grass (Marsh, 1974) and, since grass for drying is harvested throughout the growing season and at different stages of growth, its nutritive value is unlikely to be maintained at a constant and high level. Therefore if the recommended daily rates of gain of 0-77 kg (Baker, Kilkenny, Spedding and Tayler, 1971) for calves in a semi-intensive beef system are to be obtained, lower quality dried grasses are likely to require supplementing with an energy-rich concentrate.…”

A Comparison Between Spring and Autumn Pasture for Beef Cattle at Equal Grazing Pressures

“…Several studies with artificially-dried grass have also shown that spring-harvested herbage supported greater levels of production from dairy cows (2,6), beef cattle (1) and calves (8,9). Such advantages might not necessarily appear with beef cattle under grazing conditions and any differences that have occurred at pasture could be a result of confounding factors associated with season.…”

The effect of concentrate, barley and dried grass on the voluntary intake of different silages

“…The mean moduli of fineness and uniformity, determined using the method described by Marsh (1974), were 1-0 and 0 : 2 : 8 and the mean density was 1-05 g/ml. The concentrate mixture, which was formulated to have a crude protein content similar to that of the dried grass, contained 69-5 % milled barley, 27-5 % extracted soya bean meal and 3 % minerals and vitamins.…”