Effect of replacing barley grain with cork oak acorn (Quercus Suber L.) on digestibility, nitrogen balance and growth of goat kids.

Oak acorn has been studied as an alternative energy source, replacing some grain in rabbit, broiler and sheep concentrate diets. However, the impact of oak acorn supplementation on diet utilisation by goats has not been studied. Such research would be useful in the Mediterranean mountainous areas because of the availability of oak acorn in bulk (October-January) and their use in the smallholder farming system goats. This study examined the effect of replacing barley grain with cork oak acorn (Quercus Suber L.) on apparent digestibility in vivo, nitrogen (N) balance and growth of goat kids. Voluntary intake of acorn was studied. Ten Boer kids ( 26.5 ± 0.5 kg ) were individually housed in metabolism cages and were randomly divided into two equal groups. Kids in each group received individually 500 g oat hay and 600 g of concentrate containing barley grain (control diet) or oak acorn (experimental diet). The digestibility and growth experiment lasted 60 days. In the following 3 weeks, voluntary intake of acorn containing concentrate was measured on kids receiving experimental diet. Digestibility coefficients of dietary constituents (DM, OM, and CP) were reduced (P<0.001) as a result of acorn substitution for barley. Nitrogen retention (g/day) was positive for acorn diet (4.94 g) but lower (P<0.001) than for control diet (8.74). No differences (P>0.05) in CF digestibility and daily gain were observed between the two groups of kids. Voluntary intake of acorn containing concentrate reached 1400 g/day without any observable toxicity sign. In conclusion, complete substitution of barley grain with cork oak acorn did not affect performance of growing kids. This alternative could decrease the cost of animal origin products. [ABSTRACT FROM AUTHOR]