The effect of winter feeding level on subsequent grazing behaviour and herbage intake of Charolais heifers

Abstract

Two groups of eight Charolais heifers were used to examine the effect of feeding level during the post-weaning winter on the grazing behaviour and herbage intake over three periods during the first 2 months of grazing. The winter diets (L and H) were given to achieve a mean difference of 50 kg between groups at turn-out. The heifers were set-stocked together on a hill pasture where sward height was maintained at 12 cm. The -winter live-weight gains were 0-31 and 0-70 (s.e. 0-032) kg/day for L and H heifers respectively, and spring gains 1-94 and 1-66 (s.e. 0-082) kg/day respectively. Intakes increased throughout the spring grazing for both groups. Absolute intakes were lower for L than for H heifers only during the first period (P < 0-05). Intake per kg live weight was higher in L than in H heifers (23-0 v. 21-1 (s.e. 0-54) (434, (s.e. 12-9) mg OM), while bite weights ofL heifers only reached those of H heifers in the last period. Bite weight was linearly related to live weight. Bite rates were not different between groups, but L heifers compensated for lower bite weight by grazing longer and they increased their grazing time after turn-out faster than H heifers. Grazing time was mainly responsible for higher relative intakes in L heifers, and thus, partly, for compensatory gain observed. g organic matter (OM) per kg live weight). Bite -weights of H heifers were constant throughout

Performance and meat quality of native and continental cross steers grazing improved upland pasture or semi-natural rough grazing

“…Biting rate has been found to increase and grazing time to decrease (Hodgson and Jamieson, 1981;Cazcarra and Petit, 1995b) with age and weight of cattle. Other work with Charolais heifers of a similar age found those with a lower live weight grazed longer but tended to have a lower bite rate (Cazcarra and Petit, 1995a). In contrast, during Experiment 1 the older, heavier WB steers spent a higher percentage of time grazing than the CX steers, and as there was no differences in bite rate, there was a corresponding increase in eating prehensions.…”

“…In contrast, during Experiment 1 the older, heavier WB steers spent a higher percentage of time grazing than the CX steers, and as there was no differences in bite rate, there was a corresponding increase in eating prehensions. This could potentially have led to a higher intake (Cazcarra and Petit, 1995a), which in turn could account for the higher growth rates of the WB steers at this age. However, at 20 months of age the only significant effect of genotype on grazing behaviour was a higher chewing rate for the WB steers, and there was no indication of a potential difference in intake, which is in keeping with the similar growth rates of the two breeds at that time.…”

Effect on upland beef production of incorporating winter feeding of red clover silage or summer grazing of Molinia‐dominated semi‐natural pastures

“…An alternative approach to managing this type of livestock is to ration cattle to achieve the moderate liveweight gains through the winter in order to exploit compensatory growth in summer (Cazcarra and Petit, 1995). Previous work has demonstrated that compensatory growth can occur in cattle even when herbage allowance or sward height restricts intake (Wright et al, 1986), and a negative association between winterfeeding level and summer liveweight gain has been identified on a range of upland pasture types .…”