The effect of dietary phytase supplementation at different levels on tibial bone characteristics and strength in broilers

The influence of various levels of supplemental phytase on P and Ca availability was investigated using morphometric indices and the bone strength of tibiotarsi in broilers. Forty tibiotarsi were used from the Ross 308 male broilers fed corn-soybean meal based diets. Dietary treatments were: 1) Control: diet with DCP, 2) Negative control: control diet without DCP, 3) Control diet + 300 U of phytase/kg, 4) Control diet + 500 U of phytase/kg, 5) Control diet + 700 U of phytase/kg. There were no significant differences among the groups in the mean for tibiotarsal weight and length and also for the thickness of the medial wall. However, 300 U/kg diet with phytase supplementation had a greater influence on the tibiotarsal weight/length index and the robusticity index when compared to those of broilers in both control groups, and the thickness of the lateral wall and tibiotarsal index among all the groups (P<0.05). The percentages of tibia ash were improved by the addition of dietary phytase. Phytase supplementation slightly improved tibia breaking stress and the modulus of elasticity in broilers. Increasing phytase levels from 300 to 700 U of phytase/kg of diet provided no additional benefits for tibiotarsal bone characteristics and strength in broilers

The effects of dietary humate supplementation on broiler growth and carcass yield

The growth-promoting effect of Farmagulator DRY(TM) Humate (FH) on live performance, carcass weight, and the abdominal fat pad of broilers was studied during different feeding periods. Four hundred, 1-d-old straight-run birds were randomly distributed to 20 floor pens of an environmentally controlled house. Four dietary regimens were replicated in five pens, each containing 20 chicks, as follows: 1) birds received no added FH in the starter or grower (NAFH), 2) birds received FH from 0 to 21 d (FH0-21), 3) birds received FH from 22 to 42 d (FH22-42), 4) birds received FH from 0 to 42 d (FH0-42) in the starter and grower diets, respectively. The FH was added to the diets at 2.5 kg/per ton of feed. Starter and grower diets were formulated to meet the minimum NRC requirements for broilers and were provided as a mash feed. Body weights at 21 d were not affected by the dietary regimens. At 42 d, body weights and feed conversions of broilers were significantly affected by the dietary humate treatments. Birds fed FH22-42 weighed more than the NAFH, whereas the FH0-21 and FH0-42 were intermediate and not different from the other treatments. Feed:gain was lower for the FH22-42 and FH0-42 treatments compared to the NAFH. There was no difference in carcass yield or abdominal fat pad percentages due to feeding FH. Feeding FH during the grower period had the most beneficial effect in terms of growth and feed conversion on broiler performance

Effects of dietary supplementation with organic acids and zinc bacitracin an ileal microflora, pH and performance in broilers

An experiment was conducted to determine the effects of an organic acid combination (Acid Lac Dry: lactic, fumaric, propionic, citric and formic acid) and/or zinc bacitracin on the body weight gain, feed efficiency, microflora and pH in the ileum content of broiler-type chicks. Ross PM3 broiler chicks were placed in an experimental design that consisted of four dietary treatments with 48 broilers in each group. One-day-old chicks were fed either a control diet or a similar diet supplemented with 3 g/kg Acid Lac Dry, 0.1 g/kg zinc bacitracin or both additives in combination during a 42-d feeding trial. Acid Lac Dry+zinc bacitracin supplemented diet, significantly (P<0.05) increased body weight at 3 weeks of age but not at 6 weeks of age when compared with control and Acid Lac Dry supplemented diets. The best feed to gain ratio was obtained in group fed Acid Lac Dry+zinc bacitracin supplemented diet during this experiment. Carcass weight and dressing percentage were not affected by any treatment. Mean ileal pH was significantly (P<0.05) higher in group fed the additives in combination than the animals treated with either Acid lac Dry or zinc bacitracin. However, the combination had the lowest number of Enterobacteriaceae in the intestinal material

The effect of various weighing procedurs on broiler performance evaluation

This study was caried out to determine the effects of weighing, after 0 or 18 hours of starvation period of chicks and at intervals of 1 or 2 week or at the end of starter and finisher period on the live weight and feed convertion rate of broilers

Effects of dietary supplementation of citric acid, copper, and microbial phytase on growth performance and mineral retention in broiler chickens fed a low available phosphorus diet

An experiment was conducted to study the effects of microbial phytase (PHY), citric acid (CA), and Cu proteinate supplementation in broilers (13 to 42 d of age) fed a low available P diet (0.25%) on growth performance, carcass characteristics, blood parameters, and mineral retention. A 2 x 2 x 2 factorial arrangement of treatments was used to evaluate 2 levels of PHY (0 and 750 phytase units/kg of diet), Cu (0 and 250 ppm), and CA (0 and 3%). The CA and Cu supplementation as well as their interaction significantly affected BW and BW gain (P < 0.05), with birds fed supplemental CA having better BW gain when fed the Cu-supplemented diet. A significant Cu x CA interaction (P < 0.05) was observed for tibia weight, in which CA supplementation resulted in increased tibia weight when birds were fed a diet not supplemented with Cu. Interaction effects between PHY and Cu were noted for tibia ash (P < 0.01) and tibia P (P < 0.05), with Cu + PHY supplementation being superior to the other treatments for tibia ash. However, tibia P was greater for the individual effects of both Cu and PHY compared with the combined effect of both additives. There was a significant interaction (P < 0.01) of PHY and CA supplementation with tibia ash percentage, in which the tibia ash (%) increased with combinations of PHY and CA. Supplementation with Cu also resulted in significantly lower cholesterol levels in the thigh muscle (P < 0.05) and serum of birds (P < 0.05). Regarding the main effects of microbial phytase (P < 0.01) and CA (P < 0.05), supplementation increased the P retention with both additives. Therefore, when a low available P diet is used after 13 d, supplementing these additives in the formulation should be considered

Influence of different dietary copper sources on eggshell quality and phosphorus retention in laying hens

The effects of dietary supplementation with phytase (PHY) and prophylactic levels (250 mg/kg) of Cu from various Cu sources (Cu sulfate, Cu lysine, and Cu proteinate) on eggshell quality and P retention of layers that were fed low available P (aP) diets (0.11%) were assessed. In the first experiment, 120 Lohmann Brown hens, 40 wk of age, were assigned to 5 dietary treatments to evaluate eggshell quality (8 replications per treatment and 3 birds per replication). At 45 wk of age, 8 chickens in each treatment were placed in metabolic cages individually and subjected to the same treatments as in experiment 1 to determine P retention. No significant differences were observed among the treatments in terms of eggshell thickness, eggshell weight, percentage of damaged eggs, and specific gravity at the end of the first experiment. Feed consumption of the hens fed the Cu lysine diets was significantly less than feed consumption of hens fed diets that were not supplemented with Cu and hens fed diets supplemented with Cu proteinate in the second experiment (P < 0.01). The inclusion of PHY to a low-aP (0.11%) diet effectively supported and allowed almost the same eggshell quality and P retention compared with the high-aP (0.24%) diet. Therefore, feeding diets low in P (0.11% aP) together with 300 units of PHY and Cu from 3 different sources in the current experiment did not result in any decrease in eggshell quality. However, the use of supplementary Cu to provide 250 ppm from Cu lysine in laying hen diets that contained 0.11% aP and 300 units of PHY was concluded to decrease P retention (P < 0.05)

Effect of different enzyme supplementation on the performance and ileal pH of broilers fed wheat-and barley-based diets

This experiment was conducted to study the effects of different enzyme supplementation to wheat-and barley-based diets on the live weight gain, feed efficiency, dressing percentage and ileal pH of broiler chickens. Two hundred fourtyfive, day-old Ross-PM3 chicks were randomly assigned to a control and four treatment groups. Starter (1 to 21 days old) and grower (22 to 42 days old) diets were given without (control) or with different enzyme preparations, which are Avizyme 1200 (1000 mg/kg), Kemzyme Dry (500 mg/kg), Roxazyme-G (200 mg/kg) and Wheatzyme (700 mg/kg)