Evaluation of dietary calcium level and source and phytase on growth performance, serum metabolites, and ileum mineral contents in broiler chicks fed adequate phosphorus diets from one to 28 days of age.

A total of 936 one-day-old broiler chicks (Ross 308) was used to evaluate the effects of dietary calcium (Ca) source (1.0 and 0.6% from Ca carbonate [CC], or 0.6% from Celtic sea minerals [CSM]) on broiler chick response to phytase supplementation (0, 500, or 2,500 FTU per kg of diet) in phosphorus (P) adequate diets. Birds were randomly assigned to 9 treatments, each replicated 8 times (4 repeats of male and 4 repeats of female birds; 13 birds per replicate) in a completely randomized design. Results showed that birds fed low Ca CC diets had significantly (P ≤ 0.05) lower body weight at 14 and 21 d; weight gain during 1 to 14 d; feed intake during 1 to 14 d and 1 to 28 d; and toe and tibia ash content, ileum ash, and Ca, and P contents at 28 days. Feed conversion ratio and feed intake between 21 and 28 d, and serum Ca, Fe, and alkaline phosphatase levels at 28 d of age were not affected by dietary Ca level. The negative influence of reducing the dietary Ca level on body weight and weight gain was less severe when CC was replaced with CSM, and birds fed the CSM diet had a significantly lower feed conversion ratio and higher tibia P content compared to CC. Phytase did not have a significant influence (P > 0.05) on most measured parameters, but significantly reduced ileum P and ash contents, especially at the higher level of 2,500 vs. 500 units of phytase per kg of diet. These results confirm that CSM has a valuable potential to improve feed conversion ratio, and that phytase was less effective in compensating for a significantly reduced dietary Ca level as it is for P.

Reproductive performance of breeder quails fed diets supplemented with L-cysteine-coated iron oxide nanoparticles.

The objective of this study was to investigate the effects of L-cysteine-coated iron oxide nanoparticles on reproductive performance in breeder quails. The five treatment diets consisted of (i) negative control diet not supplemented with iron, (ii) positive control diet supplemented with 60 mg/kg of Fe3 O4 and (iii) experimental diets supplemented with 0.6, 6 and 60 mg/kg of L-cysteine-coated iron oxide nanoparticles. A total of 100 seven-day-old quail chicks were weighed and randomly placed to five groups of five replicate cages. Four quails (one male and three females) were raised in each cage (50 × 15 × 17 cm). Egg production, feed consumption and egg weight were recorded daily and calculated on a hen per day basis. Egg components, fertility, hatchability and day-old chicks hatched from their eggs were measured at the end of the experiment. The percentage of egg production and egg mass of the 6 mg/kg Fe3 O4 -Cys NPs group were significantly higher than those of the control groups. Throughout the experimental period, the highest weekly egg weight was recorded for the 60 mg/kg Fe3 O4 -Cys NPs group. Fertility was improved by diet supplemented with iron, both FeSO4 and Fe3 O4 -Cys NPs. The breeder fed Fe3 O4 -Cys NPs had the highest day-old chicks weight. The results of this study showed that Fe3 O4 nanoparticles that were coated by L-cysteine could improve availability and utilization of iron in diet. Finally, it was proposed that Fe3 O4 -Cys NPs could be used as feed additives in quails.