Restriction of dietary digestible lysine allowance in grower phase reduces the occurrence of white striping in broiler chickens

Abstract

Dietary lysine (Lys) or metabolizable energy (ME) and amino acid (AA) density were reduced during different growth phases to prevent the occurrence of white striping (WS) in broiler chickens. The study consisted of a 49-day rearing experiment involving a total of 390 one-day-old Ross 308 male broiler chickens randomly distributed into 5 experimental groups comprising of 30 replicate pens (13 chickens/pen). One group served as control group fed diets according to the nutrient requirements. Two groups were fed 15 % low digestible lysine (dLys) in grower (GRO low Lys) or grower and finisher diets (GF low Lys). Other groups received 5% low ME and AA density in grower (GRO low ME AA) or grower and finisher diets (GF low ME AA). Lowering dLys suppressed the growth performance during the respective growth phases. BW gain was lower in GF low Lys group than control group (P = 0.010). Broilers in GRO low Lys and GF low Lys groups had lower FI at d 0−49 than those in control group (P = 0.006). Birds in control, GRO low Lys, and GRO low ME AA groups showed better FCR (P < 0.001). Slaughter weight was lower in GF low Lys group than other groups (P = 0.003). Carcass yield was lower in GRO low Lys and GF low Lys groups in comparison with control group (P = 0.004). Breast yield was lower in GF low Lys group whereas broilers fed GRO low Lys diets had lower breast yield than those in control group (P < 0.001). Meat quality was similar among the treatments except drip loss that was lowest in broilers in control group compared with other groups (P = 0.001). Crude protein increased (P = 0.045) whereas crude fat content of breast meat decreased (P = 0.006) in broiler chickens fed low dLys diets. Feeding low dLys diets reduced the incidence and severity of WS compared with other groups (P < 0.001). It is concluded that reducing the dietary dLys levels during grower phase reduced the development of WS in broiler chickens without affecting the overall growth performance.