Whole citrus fruits in total mixed rations for Mediterranean milking ewes. Milk production and composition

Autores UPV
Año
Revista Options Mediterraneennes. Serie A: Seminaires Mediterraneens

Abstract

A total of 48 lactating ewes, belonging to 2 different Mediterranean breeds ¿Guirra (rustic native breed) and Manchega (mixed aptitude breed)¿ were used to evaluate the effect of the inclusion of whole citrus fruits (WCF) in their rations. Four iso-energetic and iso-protein total mixed rations were formulated containing fresh WCF at 0, 10, 20 and 30% replacing dry-rolled barley and pelleted beet pulp on a DM basis. The milk yield and composition were obtained once a week at morning and afternoon milking. Total milk yield values observed for 30% WCF group were 12% higher than for the others. Also, a reduction of the milk fat content with the inclusion of WCF was observed, being 8.2, 7.95, 7.69 and 7.1% for 0, 10, 20 and 30% WCF groups (P<0.05). Milk protein content was maximum for ewes on 10% WFC ration (6.4%) and minimum for 30% WCF group (6.0%; P<0.05), due to the lower milk casein content of 30% WCF group (-0.3% respect to 0 and 10% WCF groups; P<0.05), while soluble protein content was similar for all the groups (mean: 1.17%). Throughout the experimental period, a reduction of 6% fat corrected milk (6%FCM) production was observed with all the rations (-35 ml per week), but it was steeper for 20 and 30% WCF groups than for the other 2 groups. In conclusion, WCF could contribute to diminishing dependence of high-milking ewes on grains without affecting the milk output, however further studies related to WCF effect on body condition and on the capacity of lactating animals to mobilize body reserves should be made.