IS THEIR MERIT IN CROSSBREEDING?

Discipline: breeding;

Crossbreeding in dairy cattle remains controversial, one reason being milk yield may be reduced. With all factors affecting profitability, milk yield per cow is the most important and therefore the emphasis on yield in breeding programs. However, yield is often associated with reduced re-conception, longevity and immunity, and increased calving interval. These factors are low in heritability and as a result selection progress is slow. Therefore, crossbreeding may be an alternative as the effect of heterosis will be beneficial. The viability of crossbreeding Jerseys with Fleckvieh was investigated by the authors referenced below. Since Fleckvieh have similar milk yields as Jerseys, the effect on profitability may be accounted for.

The authors were concerned about slow growth rate in Jersey heifers, unsatisfactory cow fertility and the reduced disease resistance observed and consequently investigated whether these parameters can be improved by crossing Jerseys with the dual purpose Fleckvieh. In the study the production and reproductive performance of Jersey and Fleckvieh × Jersey (F×J) cows were compared in a pasture-based system.

Milk production parameters were compared using standard milk recording procedures. Milk, fat and protein production was adjusted to 305 days per lactation and corrected for age at calving. Heifers were inseminated at 13 months of age and cows 40 days post-calving.

F×J cows produced significantly more milk than Jersey cows (6140 and 5400 kg milk, respectively). Similarly, fat and protein yields were significantly higher in F×J (272 and 201 kg, respectively) than in Jersey cows (246 and 194 kg, respectively). Fat and protein percentages did not differ significantly, being 4.61 % fat in the Jersey compared to 4.47 % fat in the F×J. The mean interval from calving to first insemination was shorter for F × J cows, being 77 days compared with 82 days for Jersey cows. A larger proportion (0.70) of F × J cows was inseminated within 80 days post calving, compared with Jersey cows (0.54). Furthermore, the proportion of cows confirmed pregnant by 100 days in milk was higher for F × J cows in comparison with Jersey cows, being 0.79 and 0.66, respectively. It was concluded that the improvement in reproductive performance and milk production observed after crossbreeding may be attributed to breed complementarity and heterosis.

Comments: The results are promising and could provide an alternative to struggling Jersey herds. However, further investigations are required and it should be realized that the complementarity and heterosis benefits are expected to be lower in F2 and further generations. Repeated crossing may therefore be required. 

S. Goni, C.J.C. Muller, J.A. Botha, B. Dube & K. Dzama, 2017. Production and reproductive performance of Jersey and Fleckvieh × Jersey cows in a pasture-based system. In; Proc. of the SALHC, Champagne Sports Centre, Winterton, KZN, 5-7 June 2017.