Animal. 2016 Oct;10(10):1609-18. doi: 10.1017/S1751731116000598. Epub 2016 Apr 20.
- 11INRA,UMR 1248 AGIR,F-31326 Castanet Tolosan,France.
- 22INRA,Génétique, Physiologie et Systèmes d'Elevage (GenPhySE),F-31326 Castanet Tolosan,France.
- 33Université de Perpignan,IUT,F-66962 Perpignan,France.
- 44ITAB,F-49105 Angers,France.
Abstract
Organic agriculture is developing worldwide, and organic rabbit production has developed within this context. It entails raising rabbits in moving cages or paddocks, which enables them to graze grasslands. As organic
farmers currently lack basic technical information, the objective of
this article is to characterize herbage intake, feed intake and the
growth rate of rabbits
raised on grasslands in different environmental and management contexts
(weather conditions, grassland type and complete feed supplementation).
Three experiments were performed with moving cages at an experimental
station. From weaning, rabbits
grazed a natural grassland, a tall fescue grassland and a sainfoin
grassland in experiments 1, 2 and 3, respectively. Rabbit diets were
supplemented with a complete pelleted feed limited to 69 g dry matter
(DM)/rabbit per day in experiment 1 and 52 g DM/rabbit per day in
experiments 2 and 3. Herbage allowance and fiber, DM and protein
contents, as well as rabbit intake and live weight, were measured
weekly. Mean herbage DM intake per rabbit per day differed significantly
(P<0.001) between experiments. It was highest in experiment 1 (78.5 g
DM/day) and was 43.9 and 51.2 g DM/day in experiments 2 and 3,
respectively. Herbage allowance was the most significant determinant of
herbage DM intake during grazing, followed by rabbit metabolic weight
(live weight0.75) and herbage protein and fiber contents. Across
experiments, a 10 g DM increase in herbage allowance and a 100 g
increase in rabbit metabolic weight corresponded to a mean increase of
6.8 and 9.6 g of herbage DM intake, respectively. When including
complete feed, daily mean DM intakes differed significantly among
experiments (P<0.001), ranging from 96.1 g DM/rabbit per day in
experiment 2 to 163.6 g DM/rabbit per day in experiment 1. Metabolic
weight of rabbits
raised on grasslands increased linearly over time in all three
experiments, yielding daily mean growth rates of 26.2, 19.2 and 28.5
g/day in experiments 1, 2 and 3, respectively. The highest growth rate
was obtained on the sainfoin grassland despite lower concentrate
supplementation. Thus, it seems possible to reduce complete feed
supplementation without reducing animal performance. This possibility
requires improving our knowledge about organic rabbit production systems and especially grazing and animal health management.
KEYWORDS:
agroecology; grazing; herbage allowance; organic agriculture; rabbit