Effects of dietary organic and inorganic zinc and copper supplements on performance, footpad dermatitis, carcass characteristics, and blood profile of broiler chickens

The aims of this study was to determine the effect of organic and inorganic Zn and Cu supplements on performance, footpad dermatitis (FPD), carcass characteristics and blood profile in broiler chickens. A total of 336 one-day-old Ross 308 broiler chicks were distributed into 24 floor pen and reared for 42 days. A basal mineral premix (without Zn and Cu) was supplemented with organic or inorganic Zn and Cu to meet 100% (i.e., 110 and 16 mg/kg of the mineral premix, respectively) or 50% (i.e., 55 and 8 mg/kg of the mineral premix, respectively) of the recommended levels. Six dietary trace mineral premix were formed with inclusion of 1) inorganic Zn and Cu at the level 100%, 2) organic Zn and Cu at the level 100%, 3) inorganic Zn and Cu at the level 50%, 4) organic Zn and Cu at the level 50%, 5) organic Zn at the level 50% and inorganic Cu at the level 100%, and 6) inorganic Zn at the level 100% and organic Cu at the level 50%. Results indicated that organic Zn and Cu supplementation improved (P< 0.05) body weight gain and feed conversion ratio than inorganic form. However, the incidence and severity of FPD were significantly lower in broilers received only organic Zn and Cu than those of birds under inorganic Zn and Cu at the level 50%. Broilers fed lower level of inorganic Zn and Cu supplement showed the lowest breast yield compared to the other treatments. In contrast to the alkaline phosphatase enzyme, serum cholesterol concentration decreased (P< 0.05) in broiler chickens received organic Zn when compared to the supplementing of inorganic Zn and Cu at the level 50%. The results showed that organic Zn and Cu, as a proper alternative to inorganic forms, are useful to improve performance and health of broilers

Effects of Feeding Levels of Starter on Weaning Age, Performance, Nutrient Digestibility and Health Parameters in Holstein Dairy Calves

To evaluate the effects of feeding four different levels of starter in male Holstein dairy calves, a completely randomized study was conducted, using 28 calves with initial body weight of 40.5±2.4 kg. The animals were fed iso-nitrogenous starter and were weaned when they consumed 350, 500, 650 and 800 g/d of starter for 3 d consecutively. Starter and water were available ad-libitum throughout the experiment. Body weight at pre-weaning (less than 5 wk) and post-weaning (8 wk) was lower in calves that received 350 g/d of starter than in the other treatments (p0.05). Dry matter, organic matter and crude protein digestibilities were lower in calves that received 350 g/d of starter compared with other treatments (p0.05).Treatments had no significant effect on time of starting rumination, respiratory score, and days of drug administration for pneumonia. There were no meaningful differences in feces, fecal odor scores, body temperature, and days of drug administration for diarrhea among all treatments (p>0.05). Total dry matter intake at the end of experiment showed no significant difference among calves fed 600 and 800 g/d of starter, but calves fed 350 and 500 g/d of starter showed more dry matter (DM) intake than calves in the 600 and 800 g/d groups (p<0.05)