A Meat & Livestock Australia-funded study in northern Australia has found no single factor contributes to the number of ‘poor doers’ in a mob.
Across northern Australia, post-weaning liveweight gain in cattle varies widely, even within individual herds managed under similar conditions.
The study, conducted by the Northern Territory Department of Primary Industry and Fisheries and AusVet Animal Health Services, aimed to identify reasons for variation in liveweight gains within herds.
In many cases, the growth rates of the best performing animals were limited by the digestibility of their base diet; but a major change to base diet is not feasible or economical when the enterprise is based on native pastures.
Stage one: number crunching
During the first stage of the project, data was examined from the cattle herds. The data revealed a number of factors explaining variation in weaning weight and post-weaning weights:
Stage two: observation
The second stage of the project made observations on 11 commercial Northern Territory properties.
The study collected data on:
• growth traits (liveweight, hip height and body condition score)
• temperament traits
• adaptive traits (tick score, buffalo fly count, lesion score for buffalo flies, HGP implant timing and status, faecal egg count, faecal oocysts count)
• disease status (pestivirus, bovine ephemeral fever anaplasmosis)
• husbandry procedures
Additional small, nested studies (measurements for a subset of animals from some or all properties) included biochemistry and serology testing on serum samples, parasite testing on faecal samples and faecal near infrared spectroscopy testing.
Major findings from stage two include:
• The best performers for the next year were weaners that were heavier and taller than average (based on liveweight at the final observation), i.e. additional height at weaning provided a long-term weight benefit
• The worst performers for the next year were weaners that were lighter and shorter than average
• The second best performers for the next year were weaners that were heavier and shorter than average (based on liveweight at the final observation)
Source: Meat & Livestock Australia
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