The objective of this study was to investigate the effect of dam breed from dams with varying proportions of Friesian and Jersey genetics on growth traits and carcass characteristics of their 24-month-old beef-cross-dairy-breed heifer and steer progeny in a pastoral-based system.Ĭalves were collected from their dams within 24 h of birth and artificially reared at one of two sites within the same farming complex. However, as the percentage of Jersey genetics in the national dairy herd increases, the potential for excessively yellow fat from Jersey genetics of the dam could be a disadvantage for farmers. In terms of carcass composition, Jersey cattle are more similar to British beef breeds than Friesian cattle, as they have similar proportions of bone, muscle and fat. Over 60 years of research confirms there is no difference in growth potential, saleable meat yield, primal cut yield or meat quality between New Zealand dairy breeds and British beef breeds under similar management. This is not supported by the scientific literature. There is a widely held belief that animals of dairy origin are inferior beef animals compared to the traditional British beef breeds. Straightbred Jersey cattle have yellower fat than Friesian cattle, although yellowing was not an issue in beef-cross-dairy-breed steers with only a quarter Jersey genetics. Previous literature has reported progeny of Jersey dams to be slower growing than those of Friesian dams, and as the proportion of Jersey genetics increases, dams produce smaller and slower growing progeny with lighter carcasses. In the New Zealand carcass classification system, yellow fat can incur a price penalty. Ĭalf rearers and beef finishers prefer calves with Friesian markings to those with Jersey markings as cattle with Jersey genetics are expected to have poor growth rates and greater incidences of excessively yellow carcass fat. Two-thirds of the annual beef kill in New Zealand originates from the dairy industry (per head), so the increase in crossbred cows in the national dairy herd inevitably results in an increase in Jersey genetics entering the beef herd from retention of dairy-origin calves for beef finishing.
This equates to over a two-fold increase in the proportion of Friesian–Jersey crossbred cows in the dairy herd in the last 23 years to benefit from increased milk production through hybrid vigour. The breed composition of New Zealand dairy herds has shifted from 57% Friesian, 16% Jersey and 19% Friesian–Jersey crossbred in 1998 to 33% Friesian, 8% Jersey and 49% Friesian–Jersey crossbred in 2020. The progeny of JX dams had yellower fat than all other dam breed groups and a greater incidence of excessively yellow fat (fat score ≥ 5). Carcass weight was greatest for progeny of F dams (286 kg, compared with 279, 275 and 276 for progeny of FX, FJ and JX dams, respectively). Calves born to F dams took 93 days to reach a weaning weight of 100 kg, whereas those from FX, FJ and JX dams took 99, 101 and 102 days, respectively. At each point measured, liveweight was greatest for calves born to F dams. Carcass characteristics were also recorded. Liveweights of 142 heifers and 203 steers from Friesian (F), Friesian-cross (FX), Friesian–Jersey (FJ) and Jersey-cross (JX) dams were recorded at birth, weaning, as yearlings and at slaughter.
The aim of this study was to investigate the effect of dam breed from dams with varying proportions of Friesian and Jersey genetics on growth traits and carcass characteristics of their 24-month-old beef-cross-dairy-breed heifer and steer progeny.
Limited literature is available on the effect of dam breed on the performance of beef-cross-dairy-breed progeny. The recent increase in Jersey genetics in the dairy herd will inevitably result in an increase in Jersey genetics entering the beef herd from retention of dairy-origin calves for finishing. Approximately two thirds of the annual beef kill in New Zealand originates from the dairy industry.