A DOSE TITRATION STUDY ON THE EFFECT OF VIRGINIAMYCIN ON SPECIFIC BLOOD PARAMETERS AND MILK QUALITY IN THE SOW

The present study investigates the changes in blood cholesterol and to tal lipids concentrations, as well as changes in milk fat, protein, la ctose and total solids content of sows after the long-term administrat ion of virginiamycin (VM) in the feed. Seventy-two (72) healthy Dallan d gilts, in 18 groups of four (2 + 2) siblings were used in total. The gilts of each group of siblings were randomly allocated to one of the following four dietary treatments: VM0 = negative control, virginiamy cin 0 mg/kg, VM20 = virginiamycin 20 mg/kg feed, VM40 = virginiamycin 40 mg/kg feed and VM60 = virginiamycin 60 mg/kg of feed. Treatments st arted at the age of 6 months covering three complete breeding cycles ( up to the third weaning). The first eight groups of siblings (eight gi lts per treatment/32 gilts in total) were used for blood sampling (blo od group), while the remaining 10 groups of siblings (10 gilts per tre atment/40 gilts in total) were used for milk sampling (milk group). Fe eds given at insemination, pregnancy and lactation did not contain any other antibacterial or performance enhancer. The results indicate tha t all three levels of VM supplementation of gilt/sow feed influenced c ertain blood parameters by increasing (P < 0.05) both cholesterol and total lipids concentrations on the 30th and 60th day of each pregnancy , at each farrowing and at each weaning. The effect of dietary VM I on these blood parameters remained constant throughout three consecutive parities. Moreover, the results indicate a beneficial effect of dieta ry VM on the milk quality of the sows during the third lactation by in creasing (P < 0.05) (i) the mean fat content, (ii) the mean protein co ntent, (iii) the mean lactose content and (iv) the mean total solids c ontent The highest (P < 0.05) levels in both blood and milk parameters were noticed at the inclusion level of 40 mg/kg of feed.