The influence of calf rearing methods and milking methods on performance traits of crossbred dairy cattle in Thailand - 3. Calf performance

Abstract

The experiment to investigate the effect of restricted suckling (RS) and bucket rearing (BR) involved 40 calves from crossbred dairy cows with 75 % or 87.5 % Holstein-Friesian (HF) genes from 4 days after birth to weaning at 84 days of age. From days 4 to 84 of age restricted suckling calves were allowed to suckle their dams up to 15 minutes post milking. Bucket reared calves were fed a total of 236 kg whole milk and received concentrate supplementation after day 56. All calves were kept indoor, received Brachiaria ruziziensis grass ad libitum from day 56 and had free access to water. RS calves exhibited no losses and only 3 illnesses, whereas three BR calves died and nine developed illnesses. Up to 84 days of age RS calves had a highly significant faster average daily gain (ADG) than BR calves (620 g vrs. 390 g) and a significant larger heart-girth. RS and BR calves had an estimated adjusted daily metabolisable energy (ME) intake from milk of 18.9 ME and 12.6 ME and from the whole ration of 18.9 ME and 14.3 ME, respectively. Intake of milk fat, milk protein, Ca and P were highly significant higher in RS calves. Total protein intake from the whole ration was higher in BR calves. The daily intake of 18.9 MJ and 14.3 MJ ME for RS and BR calves exceeded the need for the realised ADG of 620 g and 390 g (average demand: 16.3 and 11.8 MJ ME) which suggest an oversupply of energy. Demand calculation for protein of 115 g and 103 g crude protein for RS and BR calves corresponded to an intake of 107.7 g and 118.9 g crude protein, respectively. This indicates that the efficiency in utilisation of crude protein seems to be grossly underestimated in suckling calves. Restricted suckling has been demonstrated to be an efficient method for calf rearing.