Early New Zealand Studies:

An evaluation of the performance of crossbred calves from ten common breeds, conducted by the New Zealand Ministry of Agriculture and Fisheries, during the 1970s at the Ruakura Agricultural Centre at Hamilton, New Zealand.

Ten sire breeds were evaluated over a period of five years by the New Zealand Ministry of Agriculture and Fisheries. Approximately a dozen sires from each breed were used over a mixture of 1,500 Angus and 500 Hereford cows, with data being collected on some 4,500 progeny. Unlike the studies conducted by the United States Department of Agriculture at its Meat Animal Research Centre in Nebraska, where the animals were often grain fed, the New Zealand study was conducted on pasture alone in three different locations, thus more closely resembling Australian beef producing conditions .

In the first phase of the study, the survival and performance of the crossbred progeny was evaluated up until 13 months of age, and is summarised in the first two tables below:

Regarding the South Devon crosses, the following points should be noted:

1. Calving difficulty (7%) was half that experienced with the big European breeds (10-15%).

2. 95% of all South Devon cross calves were weaned, significantly more than those of European origin (90%).

3. The average daily weight gain to weaning of the South Devon cross calves was intermediate between that of the European and British breeds, but significantly better than that of the Limousin cross calves.

4. The yearling weight of the South Devon cross calves, was significantly greater than those of the British crosses, but not significantly different to those of the European crosses.

In the second phase of the study, the male calves were grown out on pasture and then slaughtered - approximately 1350 at 20 months of age and another 550 at 31 months of age. Following slaughter, the carcases were analysed for the following traits: pre-slaughter weight, hot carcase weight, dressing percentage, grade (New Zealand Meat Producers' Board, 1975), fat depth, and eye muscle (M.longissimus) area.

The following two tables summarise the findings from those animals slaughtered at 20 months of age.

The following two tables summarise the findings from those animals slaughtered at 31 months of age.

Regarding the South Devon crosses, the following points should be noted:

1. At both ages of slaughter (20 & 31 months), the pre-slaughter and hot carcase weights were not significantly different to those of the European crosses, but were significantly heavier than those of the British crosses.

2. Whereas the European crosses had a significantly greater eye muscle area than their British counterparts, what they had in muscle, they lacked in subcutaneous fat. The reverse was the case in the British crosses - less eye muscle area but greater subcutaneous fat. In the case of the South Devon crosses, their eye muscle area and subcutaneous fat tended to be intermediate between those of the European and British crosses. Thus the South Devon crosses exhibited the ability to grow and to fatten while at the same time expressing adequate muscle.

3. As yearlings, the South Devon cross carcases graded intermediate between those of the British crosses (good) and those of the European crosses (less good). At older ages, however, the South Devon cross carcases graded the best of all the beef breed crosses.

While the European sires tended to produce crossbred calves with higher hot carcase weights, they also had a higher percentage of calves that did not survive to weaning. This latter tended to negate the economic advantages of the former. In concluding their study, the researchers attempted to rank the sire breeds in terms of the weight of carcase obtained at 20 months per cow calved. This was then related to a value of 100 which was given to the Hereford x Angus cross. The results are summarised in the following table:

Conclusions:

As a sire, the South Devon has characteristics intermediate between those of the large, later-maturing, European breeds, and the smaller, earlier-maturing, British breeds. When used in a cross-breeding program, it has the potential to provide the greatest economic returns as judged by the quantity and quality of beef produced per cow joined.

References:

Baker RL, Carter AH, Morris CA, Johnson DL. Evaluation of eleven cattle breeds for crossbred beef production: performance of progeny up to 13 months of age. Animal Production 1990; 50: 63-77.

Morris CA, Baker RL, Carter AH, Hickey SM. Evaluation of eleven cattle breeds for crossbred beef production: carcass data from males slaughtered at two ages. Animal Production 1990; 50: 79-92.