A new guide to dairy heifer replacement growth rates, designed to help all producers achieve those targets, will be launched by Volac at Livestock 2012.
The guide explains why growth rate targets throughout the entire rearing period are essential to achieving target age and weight at first calving. It provides recommended target weights at specific ages and to ensure they are met, advises producers to regularly monitor their calves by measuring growth rates using weigh scales or alternatively using a weigh band to measure heart girth, which is closely correlated with weight and noted for providing a reliable measure.
“Growth has a direct effect on age at first calving,” explains guide author, Volac’s Dr Jessica Cooke. “Heifers must be in calf at 15 months of age if they are to achieve most farmers’ aim – first calving at 24 months in order to help increase each animal’s productive lifetime. However, a Royal Veterinary College survey found that only 67% of heifers held to first service and that they require an average 1.4 services for each conception. Consequently, we recommend setting growth rates to help ensure heifers have adequate body size for first service at 13 months of age.”