Periparturient parasitism impacts on methane production
BACKGROUND: Since methane release by ruminants is directly related to feed intake, factors that influence feed intake, such as disease challenge, are likely to affect methane release. However, direct measurements of disease challenge on methane release are needed to account for the impact of disease per se. METHODS: Twin-rearing ewes were ad libitum fed pelleted lucerne from day-32 to day36 (day0 is parturition), and infected or not with 10,000 Teladorsagia circumcincta L3 every Mon- Wed-Fri (n=16). A third group of 16 ewes were fed at 80% of uninfected ewes’ feed intake during lactation. Feed intake was measured twice weekly. Ewe and litter bodyweight were assessed weekly. Staggered lambing allowed for four rounds of housing in one of six methane chambers for six days from day30 (two ewes per chamber). Methane release over the last 24 h was used for this analysis. RESULTS: Parasitism reduced feed intake and litter weight gain by 9 and 7%, respectively and increased maternal bodyweight loss (P<0.05). Whilst parasitism reduced daily methane production by 10% (P<0.05), methane yield was similar, averaging 10.6 g per kg intake. However, additional feed intake needed for delayed weaning at similar lamb weight and compensation of additional maternal bodyweight loss suggests that periparturient parasitism increases methane output per lamb weaned by 14%. Extrapolation of our findings to lambs using published pen and field studies would predict that methane costs of lamb parasitism could be considerably greater. CONCLUSIONS: Periparturient parasitism increases methane production arising from accounting for production losses, suggesting that ewe worm control can improve productivity and reduce environmental footprint of sheep production systems.
Other Titles/Title of Conference
13th ICOPA: International Conference of Parasitology, Mexico City, Mexico
International Congress of Parasitology