Growth of rearing calves in relation to lysine contents of milk replacer and calf starter and feeding frequency of milk replacer

Abstract

In two factorial feeding experiments with 90 and 102 rearing calves the effect of addition of extra lysine to the milk replacer in combination with a low and high lysine content of the calf starter on dry matter intake and weight gain was studied. Once or twice daily milk feeding was also compared. The calves received milk replacer up to the age of 8 weeks and calf starter and hay ad libitum from the 3rd week on. The experiments lasted to the age of 12 respectively 10 weeks. In the first experiment increasing the lysine content of the milk replacer from 14.5 g/kg to 18.5 g/kg had no effect on dry matter intake and weight gain. In the second experiment increasing the content of lysine to 17 g/kg resulted in higher intake of dry matter and higher weight gain, but only in combination with a calf starter with a low lysine content (6 g/kg). In the first experiment twice daily milk feeding resulted in higher intake of concentrate and higher weight gain as compared to once daily. In the second experiment this was only so if the starter had the lower lysine content. Increasing the lysine content of calf starter from 7 to 8.5 g/kg had no effect on dry matter intake and weight gain in the preweaning period in the first experiment. In the second experiment increasing the lysine content from 6 to 8.5 g/kg led to higher intake of concentrate and higher weight gain. This effect was only seen if the milk replacer had no extra lysine added. In the postweaning period there was no effect of increasing the lysine content from 7 to 8.5 g/kg (Exp. I). Increasing the lysine content from 6 to 8.5 g/kg led to higher dry matter intake and higher weight gain (Exp. II). These results are discussed in the light of the partial degradability of the concentrate protein in the rumen and the effect of duodenally available lysine on feed intake and weight gain.