Effect of supplementation of synbiotic plus betaine and selenium on behavior and performance of broilers stocked at high stocking density pens

Abstract

This experiment aimed to examine the effect of synbiotic plus betaine and selenium supplementation on the behavior, blood profile and performance of broiler chickens reared at stocking density pens. For 21 days, a total of 330 broilers with body weight of 929.67 ± 21.15 g were randomly assigned to 35 experimental units (pens) with a normal stocking density (NSD) of 9 birds/m2 as a positive control and high stocking density (HSD) of 15 birds/m2. A total of 7 treatments were applied, consisting of 1 NSD treatment (CONTR-) and 6 HSD treatments, i.e., CONTR+ (positive control); SYN (1% synbiotic), BET (betaine 2 g/kg feed), SYNBET (synbiotic 1% + betaine 2 g/kg feed); SE (selenium 0.4 mg/kg feed); SYNSE (1% synbiotic + selenium 0.4 mg/kg). Parameters including behavior, blood profile and performance were measured at week 4 (d 28) and week 5 (d 35). The results showed that the supplementation of synbiotic, betaine, selenium, or their combination improved (P< 0.05) the behavior, blood profile (eritrocytes, hemoglobin) and performance of broiler chickens at high stocking densities. The conclusion of the study was synbiotic plus betaine (SYNBE) supplementation can improve behavior and produce the best performance in broilers reared at high stocking densities.