The findings challenge long-held beliefs about the weaning-feeding process and fit nicely into a rapidly expanding value-based marketing approach in which meat quality rather than average cattle weight drives the payments made to producers. Producers for years have weaned their animals at seven months and let them forage in pastures for up to a year before feeding a corn-based finishing diet.
The researchers latest study, published in the July issue of the Journal of Animal Science, documents changes in meat-fat composition over two production seasons using the two approaches. It also confirms their preliminary findings about the possible advantages of early weaning of cattle.
"This study shows that we can produce high-quality beef that consumers desire, while at the same time reducing the amount of waste fat that must be discarded," said Larry L. Berger, a professor of animal sciences. "Our approach gives farmers an alternative production system in which they can improve the quality of the meat and get a better economic return off the animals."
Bergers team analyzed two groups of Angus-Simmenthal heifers from the same genetic line. One group (16 animals) was weaned and put to pasture in the traditional way before getting the finishing diet. Thirty-two animals born the next year were weaned early and put on the finishing diet.
Ultrasound readings taken at regular intervals let researchers see changes in both intramuscular fat and subcutaneous rib fat. Intramuscular fat, or marbling, is a barometer of beef juiciness and flavor. Subcutaneous fat is waste and is removed before meat cuts hit store shelves.