The effects of crude glycerin used in broiler mixed feeds on performance, small intestine histopathology and foot pad lesions

This study aims to use crude glycerin as an alternative energy source by reducing amount of corn in broiler mixed feeds. It also examines the effects of different crude glycerin (CG) amounts on broiler chickens' parameters at different ages, contributing to the literature and future studies. The study used 350 Cobb500 broiler, 43g on one-d-old. The chicks were randomly distributed into seven groups of five replicates, each with ten chicks. Treatments were Group I (Control, 0%CG 1-42d), Group II (5%CG 5-21d+0%CG 22-42d), Group III (0%CG 5-21d+5%CG 22-42d), Group IV (5%CG 5-42d), Group V (10%CG 5-21d+0%CG 22-42d), Group VI (0%CG 5-21d+10%CG 22-42d), Group VII (10%CG 5-42d). Feeds are isonitrogenic and isocaloric. Crude glycerin has 3595 kcal/kg AMEn, 87.48% glycerol, 6.8% moisture, 4% ash, 1.7% matter organic nonglycerol. The study analyzed live weight, feed consumption, live weight gain, feed conversion ratio, fecal moisture, blood parameters, footpad dermatitis, internal organ weights, breast-drumstick pH, color value, chemical properties, tibia ash- dyschondroplasia, Enterobacteria, Coliform, total aerobic bacteria counts in the intestine, villus, crypt, epithelial cell thickness measurements of the ileum, economic analysis. According to the results of the research, 5%, 10%CG 11, 22 days increases live weight compared to the control group. Feed consumption increases in 10%CG 11-21, 5-21 days (P<0.05). In all periods, 5%CG consumption resulted in higher live weight gain (P<0.05) compared to those consuming 0%CG, which was insignificant (P>0.05) in those consuming 10%CG. Feed conversion ratio is better in 5%,10%CG 5-10, 5-21 days (P<0.05). 10%CG increases excreta moisture, 5%CG causes less moist excreta (P<0.05) than the control group. As consumption increased, serum triglyceride, drumstick pH decreased, footpad dermatitis degree-score-incidence, heart-liver-pancreas-intestine weight, CP, EE in breast-drumstick muscles increased (P<0.05). 10%CG reduces drumstick-pH (P<0.05). The redness of the drumstick decreases with increasing consumption (P<0.05). With the increase in consumption, there's an increase in coliform count (P<0.05). As consumption increased, villus height, crypt width increased, villus width, crypt depth decreased, the villus surface area, villus height/crypt depth ratio increased (P<0.05). The increase in consumption increases the daily feed cost in all periods. Except for the 5-10 days, the cost for 1 kg of live weight increases as the crude glycerin rate increases. This is least in those consuming 5% CG in 5-10d (P<0.05). Results show that, if the mixed feed is prepared balancedly, crude glycerin can be used as an alternative energy source in broiler mixed feed up to 10% without compromising performance and health.