Voluntary Intake of Forage by Holstein Cows as Influenced by Lactation, Gestation, Body Weight, and Frequency of Feeding

Prediction of the voluntary intake of food by dairy cows: 1. Stall-fed cows in late pregnancy and early lactation

“…The non-significant effects of age in all models are similar to the limited reports in the literature (Trimberger et al, 1963;Johnson et al, 1966).…”

“…Trimberger, Gray, Johnson, Wright, Van Vleck and Henderson, 1963;Davenport, 1964;Conrad et al, 1964). The apparent discrepancy between these two views may be due to the range of data analysed and not to the effect of live weight on intake; for example, and Johnson et al (1966) used cattle with weight ranges of about 400 and 570 Ib, respectively, while Conrad et al (1965) recorded a weight range of about 850 Ib. In the present analyses the coefficient of variation for live weight was of the order of 10 to 12% in all sets, but this was apparently not large enough to produce significant differences in feed intake.…”

“…Blaxter, 1950-51;Blaxter and Wilson, 1962;Conrad et al, 1964;Johnson et al, 1966). Conrad et al (1964) distinguished between a phase of increasing dry-matter intake with increasing dry-matter digestibility up to 66-7% and a phase of decreasing intake at higher levels of digestibility.…”

“…These factors include measurements which reflect energy expenditure such as milk yield, live weight and live-weight gain (e.g. Wallace, 1956;Holmes, Jones, Drake-Brockman and White, 1965), together with assessments of feed quality such as hay/concentrate ratios or digestibility (Conrad, Pratt and Hibbs, 1964) or weights of concentrates offered (Davenport, 1964;Johnson, Trimberger, Wright, Van Vleck and Henderson, 1966).…”

Milk production from grazed temperate grassland

“…It is not always possible accurately to estimate the effect of pregnancy on intake because of the confounding effects of growth in heifers and of lactation in cows. Stall feeding experiments with dairy cows, however, indicate a 12-15% decline in intake during the last 6 weeks of pregnancy (Campling, 1966;Johnson et al 1966;Curran et al 1967). Although the fetus occupies an increasing volume of the abdominal cavity leading to a reduction in the volume of rumen digesta, the reduction in intake in late pregnancy is not confined to diets limited in intake by physical factors (Forbes, 1970;1971).…”