The research, undertaken by Dr Sarah Legge as part of her PhD study with the Dairy Up team at University of Sydney, has found that under-performing calves could be identified from day five in the feeder system.
“The findings provide the basis to develop early alert systems for calves being reared with automatic calf feeders,” Dr Legge said.
The study found strong associations between the performance of female dairy calves at weaning and their subsequent performance as lactating animals.
A consistent weaning weight of about 80kg/head translated to higher production, especially in lactation one and two, and a longer life in the herd.
The research found up to 60kg variation in weaning weight with automated feeders, despite a very low mortality rate.
A subsequent study looking at the association between weaning weight and future yield and number of lactations in 1400 calves in a NSW dairy herd found that weaning weight was more strongly associated with survival in the herd than birth weight.
“For example, a calf with a weaning weight of 50kg had a 17 per cent likelihood of lasting three or more lactations in the herd, compared with 40 per cent for a calf with a weaning weight of 100kg,” Dr Legge said.
“Weaning weight and cumulative consumption at day five had a significant impact on total lifetime milk production.”
Further modelling investigated the effect of pre-weaning factors on removal from the herd, using a dataset from more than 14,000 animals from the same herd.
Dr Legge said birth weight, weaning weight and days in milk significantly influenced the likelihood of a cow being removed, with cows with a lighter weaning weight more likely to be removed from the herd early.
The research arose from a farmer’s observation of a relatively large, unexplained variability in the size of calves at weaning.
Despite uniform management and adherence to best practice standards, the farmer was concerned that calves with problems were not always identified early enough for intervention or prevention of issues and was unsure of the impact of this variability on lifetime productivity and profitability.
Dr Legge said the findings were an example of the huge opportunity to use data from modern technologies such as automated calf feeders to improve farm management.
“On-farm records and the automatic feeders provided a rich data set including birth dates, weights at various ages, health indicators and feed intake.”
For more information, go to: https://www.dairyup.com.au
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