A multi-strain probiotic administered via drinking water enhances feed conversion efficiency and meat quality traits in indigenous chickens

摘要

Whereas the use of probiotics is commonplace in commercial production of improved chicken strains,little is known about the impact of these live microbial feed additives in indigenous chickens in South Africa. This study investigated the effect of a multi-strain probiotic(containing Bacillus safensis, Bacillus subtilis, Bacillus megaterium and Cupriavidus metallidurans, total bacteria number was 1.4 × 10~8 cfu/mL),administered via drinking water, on growth performance, blood parameters, and carcass and meat quality characteristics of Potchefstroom koekoek cockerels for a period of 12 weeks. A total of 140 fiveweek-old cockerels were randomly allocated to 4 experimental diets formulated to have similar energy and protein levels as follows: 1) negative control diet(CON;commercial chicken grower diet without both antibiotics and probiotics), 2) positive control diet(ANTIB;commercial chicken grower diet with antibiotics [0.05% Coxistac and 0.04% olaquindox] but no probiotics), 3) negative control diet plus 2.5 mL of probiotics per litre of water(PROB25) and 4) negative control with 5.0 mL of probiotics per litre of water(PROB50). There was a significant(P < 0.05) week and diet interaction effect on average weekly feed conversion efficiency. At 9 weeks of age, cockerels in PROB50 group had higher(P < 0.05) feed conversion efficiency than those in CON and ANTIB groups. However, 14-week-old cockerels in PROB50 group had lower(P < 0.05) feed conversion efficiency than those in ANTIB group. Treatments had no significant(P > 0.05) effect on overall feed intake, overall weight gain and haemato-biochemical parameters of cockerels. Gizzard and spleen weights were similar(P > 0.05) in PROB50, CON and PROB25 groups. Cockerels in PROB50 group had shorter(P < 0.05) small intestine than those in CON and PROB25 groups. Cockerels in PROB50 group had larger(P < 0.05) breast weight than those in PROB25 group.Cockerels in ANTIB and PROB50 groups had greater(P < 0.05) wing and thigh weights than those in CON and PROB25 groups. Shank weight was similar(P > 0.05) in PROB50, CON and ANTIB groups. Meat pH measured after 24 h of slaughter was the highest(P < 0.05) in CON and ANTIB groups followed by PROBO25 and PROB50 groups. Cockerels in CON group had lower(P < 0.05) cooking losses than those in ANTIB, PROB25 and PROB50 groups. It was concluded that probiotics can be used in place of prophylactic antibiotics in Potchefstroom koekoek cockerels.