Reducing kid loss: Select and protect - phase 1

Summary

Reproduction is an important underlying factor limiting sustainable supply of goats in Australia. Goats are produced in many of the same areas of Australia as sheep are, yet, while there is a comprehensive knowledge of the reproductive performance of sheep, there are few Australian-specific reports on goat reproduction, disabling any capacity to assess the extent and impact of reproductive wastage in the industry.

As part of this project, farm-scale modelling was undertaken, and for the first-time attempts were made to model the goat using the GrassGro DSS – an agriculture decision support software. The lowest reproduction rates observed in this study were insufficient to maintain a self-replacing herd without retaining does to an older age. However, four in ten of the herds observed had high marking rates per doe scanned, indicating a substantial opportunity for improvement in the goatmeat sector.

Objectives

This project aimed to establish a baseline understanding of reproductive wastage, causes and costs of reproductive wastage in the Australian goatmeat industry and make recommendations to effectively address reproductive wastage, including additional RD&A requirements.

Key findings

• Review of literature has revealed that the goat breeding season is typically between March and September, although NSW and Queensland producer perceptions of the breeding season suggest it can range between December and May.
• The age at puberty depends on liveweight, nutrition, season of birth and breed. The number of ova shed per ovulation is influenced by breed and liveweight, but also by age and body condition. Ova shed can be up to 40% higher at the peak of the natural breeding season than outside the breeding season and is improved by pre-ovulatory nutrition. Mating success is also affected by season, nutrition, age and breed.
• Reproductive wastage post-ovulation can be affected by embryonic mortality, which is a common source of reproductive wastage, and the levels in goats are similar to sheep. In contrast, foetal losses appear to be higher in goats than in sheep, with susceptibility to abortion storms from around days 90–120 of gestation.
• Perinatal loss is a major source of reproductive wastage in goats, although there is limited data for Australian commercial herds. KIDPLAN data suggests mortality-to-weaning averages 20%, with notable variation, and is affected by environment, litter size, nutrition and breed effects.
• In Australia, producers report predation as a key cause of perinatal mortality.
• The on-farm reproduction study revealed fertility rates averaged 71%, with 1.65 foetuses per pregnant doe, and 65% kid survival. Doe survival was reasonable, averaging over 95%. When compared to adults, maiden doe performance was lacking, with lower fertility and higher doe and kid mortality.
• The effect of the intense drought of 2019 was apparent in the study, with the uncertainty about carrying capacity being a barrier to engagement for many producers. Some producers expressed concerns that their nannies were not breeding due to the difficult conditions. The drought impacted on the herds with the lowest reproduction rates observed, where undernutrition impacted on some herds during kidding.

Benefits to industry

At the industry scale, decreasing kid loss from 30% to 20%, at a fertility rate of 95% would increase the value of the managed meat goat sector by approximately $786,710.

MLA action

• In December 2020, MLA conducted a webinar with AgCommunicators focusing on kid loss.
• Phase 2 of this project is in development - please contact MLA if you wish to receive further information.
• Case studies from this project will be featured in the Goats On The Move newsletter throughout 2021.

Future research

• The development of management packages that establish weight and condition score targets for maidens and adult does requires further investigation.
• Further research needs to closely examine sources of reproductive wastage, such as the factors affecting fertility, foetal losses and the stages at which the losses are occurring and why.
• Management solutions to need to be developed improve kid survival, including quantifying the role of, and solutions to, predation.
• Future opportunities should consider the need to validate the GrazPlan sheep model for use with goats.