THE EFFECTS OF HALOFUGINONE AND SALINOMYCIN, ALONE AND IN COMBINATION, ON LIVE PERFORMANCE AND SKIN CHARACTERISTICS OF FEMALE BROILERS - INFLUENCE OF A HIGH-PROLINE DIET SUPPLEMENTED WITH ASCORBIC-ACID AND ZINC

Live performance and carcass quality of female broilers were evaluated under four coccidiostat programs (CP) and two feed treatments. The CP consisted of halofuginone (H) and salinomycin (S), fed either continu ously (HH and SS) or in rotational programs (HS and SH), during the st arter (1 to 21 d) and grower (22 to 35 d) periods, respectively. All g roups received an unmedicated withdrawal feed from 36 to 42 d. Feed tr eatments consisted of a control and a fortified diet high in proline a nd supplemented with additional ascorbic acid and zinc (50 birds per p en; 4 pens per feed; 8 pens per CP). In addition to live performance a nd skin puncture strength, carcass quality attributes following proces sing (at 43 d of age) were assessed. No CP by feed interactions were d etected for any of the variables measured. The CP treatments did not d iffer for live performance. Birds on fortified feed were heavier at 21 d (P <.001) and had an improved feed conversion at 42 d (P< .05). Ski n puncture strength was significantly reduced for the birds fed H, eit her in continuous (HH) or rotational programs (HS and SH). Skin sores- scratches and tears were lowest for the SS and SH groups. The HH Treat ments resulted in fewer grade A carcasses (P < .001). Halofuginone, wh en fed continuously or in the starter feed, affected carcass quality o f broilers. Higher dietary proline or supplementation with ascorbic ac id and zinc did not appear to alleviate the effects of halofuginone on skin qulity.