Farm Table says:
A Genetic Approach
What is the Problem?
The main source of pasture contamination with infective strongyle eggs is from feces of calves, especially weaners.
This study aimed was to demonstrate that enhanced parasite resistance in cattle herds can be established and maintained via genetic selection without compromising enterprise profitability.
Potential Outcomes would include:
- increased usage of genetic selection (via sire EBVs) for enhanced parasite resistance within breeds
- decreased reliance on chemical control of internal parasites
- improved productivity and profitability of beef enterprises
What did the research involve?
Angus cattle were sampled from 8 herds with strong genetic links to the Temania Angus stud enterprise.
Samples were collected manually from the rectum of each animal and the sample container was labeled with either animal identity or sample number related to animal identity.
3.3 Statistical Analysis
-Following deletion of animals with incomplete records or when sires were represented fewer than four times, 2556 records were included in the data set.
– All analyses were conducted using the GenstatV13.1 (VSN international).
What were the key findings?
4.1 Fixed Effects
As expected there was a wide variation in FEC due to time collected and location.
4.2 Random Effects
Sire Effects (Estimated Breeding Values)shows the predicted sire EBVs and 95% confidence intervals for progeny of each of the 99 sires represented in the study.
4.3 Heritability Analysis of fourth-root EBVs estimated a heritability of 0.4085 with a standard error of 0.0965.
4.4 Effect of Enhanced Parasite Resistance on Production Traits Dollar index values for Long Fed/CAAB26 showed little variation between the animals with the highest 10% and the lowest 10% of Parasite Resistance EBVs.
This study has developed preliminary estimated breeding values (EBVs) for internal parasite resistance in 99 Angus sires across southeastern Australia. Breedplan offers the ability to monitor developments in enhanced resistance to parasites alongside continuing genetic gains in the production traits.