The effects of a grain source (corn grain (CG) vs. barley grain (BG)) and starter protein content (19% vs. 22% CP, dry matter basis) on growth performance, digestibility, ruminal fermentation, and blood metabolites were evaluated in Holstein dairy calves. Forty 3-day-old female calves with a starting body weight of 39.3 kg were subjected to four treatments in a completely randomized design with two by two factorial arrangements. Treatments were: (1) CG + 19% CP (CG-19CP); (2) CG + 22% CP (CG-22CP); (3) BG + 19% CP (BG-19CP); and (4) BG + 22% CP (BG-22CP). All calves were weaned at 59 days of age and remained in the study until 73 days of age. Starter and total DM intake were not affected by grain source and dietary protein content (p > 0.05). The average daily gain and feed efficiency were improved, and ruminal total short-chain fatty acid, propionate, and butyrate concentrations were increased in BG calves compared to CG calves (p < 0.05). The ruminal concentrations of ammonia nitrogen (d 71; p = 0.02) and acetate (d 35; p = 0.02) were increased in CG fed calves compared to BG. The greatest wither height (p = 0.03) and blood insulin concentration (p = 0.03) were seen in BG-22CP treatment. In conclusion, BG has marginal benefit in the height of calves when fed with diet containing 22% CP which may be recommendable in replacement heifer rearing programs.

Context: Dietary manipulations such as reductions in protein or the addition of bioactive feed additives might alleviate the adverse effects of high ambient temperature in poultry. Aims: The effects of dietary crude protein (CP) and phytonutrient mixture (PM) on growth performance and physiological responses were evaluated in broilers under circular heat stress (HS). Methods: In total, 420 1-day-old broiler chickens were randomly distributed to seven treatments in a factorial arrangement (3 × 2), with three levels of CP (normal, medium (95% of the normal CP content) and low (90% of the normal CP content)) and with or without the addition of PM (mixture of 5 mg/kg carvacrol, 3 mg/kg cinnamaldehyde, and 2 mg/kg capsicum oleoresin). The thermoneutral control (TNC) birds were housed in a thermoneutral chamber and fed with a normal-CP diet without PM supplementation. The other six groups were kept in a HS chamber (33°C) for 8 h (1000 hours to 1800 hours). Key results: After 6 weeks, feeding broiler chickens with low-CP diets had adversely affected growth performance and intestinal protease activities, while mortality rate, heterophile to lymphocyte ratio, and serum cortisol concentration of the low-CP group were lower (P < 0.05) than those of the high-CP group. Dietary PM supplementation also positively influenced (P < 0.05) average daily gain, feed conversion ratio, intestinal lipase and trypsin activities and serum T4 concentration. There were the CP × PM interactions (P < 0.05) for jejunal villus height and villus surface area, indicating that the effect of PM on these responses was more marked at the lower dietary CP contents. Conclusions: Supplementation with PM can ameliorate the detrimental effects of HS on productive performance and digestive enzyme activities in broilers. The PM supplementation could improve intestinal morphology when applied to the diets of heat-stressed broilers with lower CP contents (95% and 90% of the recommendations). Implications: Although growth performance was reduced by feeding low-CP diets (90% of the normal CP content), a beneficial effect was observed on the stress indicators of broilers grown in HS conditions. Dietary supplementation of PM might also be an effective strategy to alleviate the adverse effect of HS.

Fifteen fertile rams (live weight 55.9 ± 1.21 kg, and 2.5-3 years old) were randomly allotted to three diets consisting of 0 (Control), 12.5 (PBP-12.5), and 25 % (PBP-25.5) pistachio by-products (PBP) in dry matter. Sperm motility parameters were detrimentally affected in animals feeding on PBP-25% diet (P<0.05). Sperm concentration of C17-1, C22-6-n-3, C18-2-Cis and C22-6 n-3 fatty acids decreased but that of C18-0 and C18-1-Cis fatty acids increased at the highest level of dietary PBP. The results indicated that 12.5% PBP in dry matter, as a cheap by-product, may be included in the ram diet for extended periods without any discernible detrimental effects on sperm characteristics. However, fertility trials need to be performed to substantiate this conclusion.