High-energy diets for reproductive rabbit does: effect of energy source.
2003
Pascual, J. J. | Cervera, C. | Blas, E. | Fernández-Carmona, J.
The main energy diets developed and evaluated in recent decades for reproductive rabbit does are reviewed, with the emphasis on the effect of the energy source (animal fat, vegetable oil, and cereal starch) used. During gestation, energy supplementation of diets usually produces a decrease in feed intake due to energy intake regulation, but in some cases females are unable to regulate their feed intake with high-starch diets, leading to excessive energy intake. This overfeeding can cause fattening of does, sometimes related to greater pup mortality at birth. During lactation, reproductive rabbit does clearly increase their energy intake when fed with fat-enriched diets. This energy supplement is mainly utilized to increase their milk energy production (higher milk yield with a higher energy content), and higher litter growth and survival is consequently observed with fat-enriched diets. However, higher milk yield of these does is usually related to a greater negative energy balance and lower fertility values. In lactating does given cereal starch-enriched diets, primiparous rabbit does, whose voluntary intake is physically limited, usually show a higher energy intake, whereas multiparous does even decrease their energy intake. In any case, milk yield and composition of does given starch-enriched diets are not improved and may even worsen, negatively affecting litter performance and survival. However, does fed high-starch diets frequently present better energy balance during lactation as a consequence of their lower milk yield (lower lactation strain). Therefore, the addition of animal fat to the diet seems to improve the utilization of ingested energy for milk production, whereas the inclusion of higher dietary starch content can decrease the negative energy balance that reproductive rabbit does usually experience. The results obtained with vegetable oil-added diets are between those observed for animal fat- and starch-supplemented diets, showing similar milk production and litter performance but with lower body reserve depletion.
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