No abstract

An experiment was executed to test the hypothesis that supplementation of dietary threonine ( d-Thr ), above NRC recommendation to diets containing poorly digestible protein source ( PS ) may compensate its detrimental effects on overall performance of broilers. In total, nine hundred 1-day-old mixed sex broilers (Ross-308) were randomly distributed over 6 (2 × 3) experimental diets comprising 5 replicates of 30 broilers each for 35 d. The experimental diets contain either soybean meal ( SBM ) or canola meal ( CM ) with 3 levels (100, 110, and 120% of NRC recommendation) of d-Thr. During the course of the trial (0 to 35 D), interactions ( P < 0.05) between PS and d-Thr were observed for feed intake ( FI ), body weight gain ( BWG ), feed conversion ratio ( FCR ), carcass, and gut health parameters. The broilers fed recommended level (100%) of d-Thr had 7 and 5% poorer FCR compared with those fed diets with 110 and 120% d-Thr, respectively. For villus height ( VH ), an interaction ( P = 0.007) was found between PS and d-Thr level. Broilers consuming SBM diets had 22% longer villi, 10% deeper crypts, and 30% greater VH to crypt depth ratio ( VCR ) compared to those fed CM. The broilers fed 110% d-Thr diets had 9% lower crypt depth ( CD ) and 15% greater VCR compared with those fed diets containing NRC recommended levels. CM resulted in 9% lower protein digestibility with lower ( P < 0.05) of some AA, whereas it was improved by 7% in broilers fed 120% d-Thr supplemented diets. The bursa and spleen weights were positively affected ( P < 0.001) by PS. Threonine supplementation (10%) resulted in 25% greater thymus, 18% heavier bursa, and 30% greater infectious bursal disease titer. In conclusion, supplementation of d-Thr, above NRC recommendation, resulted in a better growth performance and carcass traits, improved ileal digestibility of protein and amino acids, better gut health, and immunity in broilers.

The aim of present study was to determine the effects of supplementation of either synbiotic or probiotic on growth performance and carcass characteristics, gut health, cecal microbiota prolife and apparent ileal digestibility of protein, amino acids, and energy in broilers. Two hundred and forty-day-old straight-run broilers (Ross 308) were allotted randomly to 1 of 5 dietary treatments including basal diet (control), supplemented with either synbiotic (Nutromax P) or probiotic (Actera), each at 0.5 and 1 g/kg of the diet for 5 weeks. The overall findings of the study indicated better (p < 0.05) growth performance of broilers by synbiotic supplementation (1 g/kg) compared with those fed probiotic (1 g/kg) supplemented and control diets. The broilers consuming diet supplemented with 1 g/kg synbiotic has an increased carcass yield in comparison with those fed control diet. The findings of gut health indicated significantly increased villus height and goblet cells, by synbiotic supplementation (1 g/kg), compared with control diet in broilers. The broilers fed 1 g/kg synbiotic supplemented diets had 18% increased protein, 9 to 31% higher amino acid, and 34% better energy digestibility, whereas 8.4% decreased protein digestibility in broilers fed probiotic (1 g/kg) supplemented compared with control diet in broilers. The broilers fed synbiotic (1 g/kg) supplemented diets had increased cecal Lactobacillus and decreased Salmonella, E. coli, and Clostridium count compared with those fed control diet. In conclusion, synbiotic supplementation (1 g/kg) resulted in improved production performance, balanced cecal microbial composition, and better digestibility of nutrients in broilers compared with those fed control and diets supplemented with probiotics.

This study was conducted to evaluate the impact of selenium sources on egg and hatching traits of native Aseel chicken. Selenium-treated 21-weeks-aged 84 pullets and 12 cockerels from Lakha, Mushki, Peshaweri and Mianwali varieties (21 pullets and 3 cockerels per variety) were divided into three treatment groups A, B and C (7 pullets and 1 cockerel per group). Group A and B were experimental and C was control. Ration for group A was included 0.3 mg/kg Se-yeast, B was included 0.3 mg/kg sodium selenite and C with No selenium. Se-yeast supplementation presented increased egg weight, shell thickness, yolk index, Haugh units; enhanced egg length, breadth, volume, shape index and surface area; decreased dead germ%, dead in shell%, clear egg% and enhanced hatchability%, the hatch of fertile% and chick weight. Present study concluded that Se-yeast is a superior supplement in improving egg quality, geometry and hatching features of indigenous Aseel varieties.

There has been an upsurge of interest in the phytobiotics coincident with the onset of the potential ban on the use of antibiotic growth promoters (AGPs) in the broiler industry and because many kinds of nutraceuticals play an important role in improving growth performance, feed efficiency, and gut health of broilers. In the previous years, significant biological activities of essential oils (EOs) belonging to phytobiotics were observed, including anti-bacterial, antifungal, antiviral, and antioxidant properties. We found new perspectives on the roles of EOs, particularly extracts from the Apiaceae family, which is one of the largest plant families, in potential replacement of AGPs, and on the chemical composition involved in regulating microorganism activity and oxidative damage. Furthermore, the positive effects of EOs on broiler production and the possible mechanisms inducing the involvement of gut health and growth performance have been studied.