The production performance of Holstein and Fleckvieh x Holstein cows in an intensive feeding system

[摘要] ENGLISH ABSTRACT: The aim of the study was to determine the effect of crossbreeding using Fleckvieh sires on Holstein cows on milk production and reproduction parameters, veal and beef production and growth parameters of heifers in an intensive feeding system.The study was conducted at the Elsenburg Research Farm using Fleckvieh x Holstein (FxH) and Holstein (H) cows, bull calves and heifers. Twenty four heifers from both genotypes were initially sourced from a commercial dairy farm and reared to first calving at Elsenburg. Male and female progeny from these cows were subsequently included in the trial. Holstein cows and heifers were inseminated with H semen and FxH cows and heifers were inseminated with Fleckvieh semen. Similar standard management practices with regards to feeding of dairy cows, heifers and bull calves were followed for both genotypes.Production parameters, corrected for a 305-day lactation period, did not differ, being 6330±117 vs. 6108±97 kg milk, 252±4.7 vs. 251±3.9 kg fat and 202±3.5 vs. 200±2.9 kg protein for H and FxH cows, respectively. Protein and fat percentages differed between genotypes being 3.20±0.02 vs. 3.3±0.02% and 3.98±0.03 vs. 4.13±0.0.02% for H and FxH cows, respectively. Using a dual-purpose breed in a crossbreeding programme on Holstein cows did not reduce the production performance of crossbred cows.Some fertility parameters of H vs. FxH cows differed significantly, i.e. the interval from calving to first service being shorter for FxH vs. H cows at 86.2±5.3 vs. 104.7±5.0 days, respectively. However, days open tended to differ between genotypes being 153.1±6.8 and 135.3±7.1 for H and FxH cows, respectively. The number of services per conception did not differ between genotypes being 2.24±0.14 and 2.30±0.15 for H vs. FxH cows, respectively. While more FxH cows conceived within 100 days after calving in comparison to H cows, being 37±6 and 48±6%, respectively, the proportion of cows conceiving within 200 days post partum did not differ between genotypes, being 76±4 and 81±4% for H and FxH cows, respectively. Fertility parameters for H vs. FxH heifers did not differ, i.e. age at first insemination was 15.4±0.30 vs. 15.5±0.33 months, age at conception 17.2±0.35 vs. 17.3±0.34 months and age at first calving 26.4±0.37 vs. 26.5±0.24 months of age, respectively.The birth weight (BW) of FxH and H heifers did not differ, being 37.70.65 vs. 37.40.71 kg respectively, while the average daily gain (ADG)(determined with a linear regression fitted to obtain individual ADG's) of FxH heifers was significantly higher than that of H heifers, being 0.8130.021 vs. 0.6960.017 kg/day. However, the live weight, stature, girth circumference and age at first calving of heifers did not differ between genotypes.Bull calves were divided into four groups, the treatments being genotype (H or FxH) and marketing age, i.e. veal (marketed at a live weight of about 200 kg for a carcass weight not exceeding 100 kg) and as beef marketed as steers at 18 months of age. Veal calves were reared in an intensive feeding system while steers were put on kikuyu pasture. For steers reared to 18 months of age, birth weight (BW), live weight (LW) at 18 months of age and ADG did not differ between H and FxH steers, being 38.3±1.3 and 41.2±1.3 kg, 450±16 and 468±20 kg and 0.741±0.022 and 0.778±0.023 kg per day, respectively. For veal calves, the BW, LW at marketing and ADG did not differ between H and FxH, being 39.6±0.70 and 41.4±0.91 kg, 203±1 and 198±2 kg and 0.929±0.020 and 0.953±0.021 kg, respectively.In conclusion, with the exception of fat and protein percentages, milk production parameters did not differ between H and FxH cows while some fertility parameters differed between genotypes. Crossbred cows showed a positive internal growth rate of 9.4% while H showed a negative internal herd growth of about 5% over the trial period.

[发布机构] Stellenbosch University