Effects of feeding ensiled sliced oranges to lactating dairy sheep

Abstract

Ninety six lactating ewes of the Sfakian dairy sheep breed, divided into two equal groups were used. Three kilograms (79.5%) sliced orange silage mixture with by-products were offered daily to the animals as experimental treatment, replacing part of the maize grain/soybean meal/oat hay ration given to the controls. Microbiological and chemical analyses of silage showed that ensiling high moisture materials such as whole oranges is feasible. Silage pH from 4.1 before, dropped to 3.7 after ensiling. Colony forming units of yeasts and fungi in silage were approximately 200-fold lower at the end of the ensiling process. Silage DM was 16% lower at the end of ensiling (25.0 versus 21.0%). Orange silage mixture composition was CP 13.4, crude fibre 13.4, fat 2.3, ash 7.93, Ca 0.99 and P 0.7% on DM basis and proved palatable to sheep particularly due to its pleasant odour. Milk yield and composition were measured for a 6-week period. Overall daily milk yield was 12% higher for controls (769.0±28.9 g versus 680.0±21.0 g, P<0.05) but the situation was reversed for the last third of the lactation period. However, 6% fat corrected milk yields (821.0±31.8 versus 832.0±28.5) did not differ significantly. Ewes fed orange silage had 16% higher fat content in milk ( P<0.05). Treatment differences in ewes’ body weight were not significant during the experimental period. Results show that the inclusion of ensiled sliced oranges to diets of lactating sheep is a viable proposition.