Feed intake, lactation performance, blood metabolites and fertility in early lactation dairy cows grazing a timothy pasture

Abstract

The present study was conducted to investigate feed intake, milk yield, milk composition, blood metabolites and fertility in early lactation dairy cows grazing a timothy pasture. Fourteen multiparous Holstein cows that calved between 20 May and 19 July were used over a 3‐year period. The stocking rate was 3.6–4.3 cow/ha. Concentrates were fed separately at 9.5–11.5 kg/day per cow (dry matter basis) from 1 to 13 weeks postparturition. Herbage intake was estimated using chromium oxide as an indigestible marker. The mean contents of crude protein, total digestible nutrients and neutral detergent fiber of pasture during the 3‐year study period were 22.3%, 71.8% and 51.7%, and those of total diet were 18.9%, 77.3% and 40.3%, respectively. The mean herbage dry matter intake was 13.0 kg/day from 2 to 13 weeks postparturition during the study, total dry matter intake was 23.7 kg/day, the total digestible nutrients sufficiency rate was 105%, milk yield was 39.7 kg/day, and milk fat percentage was 3.30%. The decrease in bodyweight postparturition was slight. Urea nitrogen concentrations in serum were below 18.3 mg/dL. The mean days to first estrus and days open were 36 and 104 days, respectively. These results indicate that energy deficiency, decrease in bodyweight and fertility in early lactation barely occur when high producing dairy cows are fed enough grazing grass and suitable concentrates.

Conception of Jersey cattle in Turkey

“…The time of high protein, the rapid rate of passage and the low dry matter content in spring pasture coincides with the time of the breeding in late-rainy or early-dry season may be some of the possible reasons for an improved overall CR to first-service of heifers and primiparous inseminated during dry season compared to those inseminated during rainy season (O'Callaghan and Boland 1999;Doepel et al 2002;Coffey et al 2004;Ohgi et al 2006). A similar situation may occur in Black Sea Region of Turkey, when cows are grazing immature pastures.…”