An experiment was conducted to evaluate the influence of a novel microbial phytase on performance, tibia ash, and the content of phytate, phytate esters, and inositol in the gizzard of young broilers. Male Cobb 500 broilers (n = 1,680) were fed 1 of 7 experimental diets: positive control (PC) formulated to meet or exceed nutrient recommendations; PC plus dicalcium phosphate (PC+DCP) formulated to provide Ca and P at 0.10% above the PC; PC plus 500 U/kg of microbial phytase (PC+500); negative control (NC) with Ca and P reduced from the PC by 0.16% and 0.15%, respectively; and the NC plus phytase at 500 (NC+500), 1,000 (NC+1,000), or 1,500 (NC+1,500) U/kg. Diets were fed in crumbled form to 20 birds/pen and 12 replicate pens/diet from d 0 to 21. On d 21, 4 birds/pen were euthanized for collection of right tibias and gizzard digesta for determination of tibia ash and gizzard phytate. In general, broilers fed the NC diet had reduced (P ≤ 0.05) feed intake and BW gain compared with broilers fed diets supplemented with phytase, but not different than the PC or PC+DCP. Phytase supplementation in the NC diet improved (P ≤ 0.05) BW gain comparable with or above that of the PC. Feed conversion ratio was improved in broilers fed the NC+1,000 or NC+1,500 compared with broilers fed all other diets. Tibia ash was reduced (P ≤ 0.05) in broilers fed the NC compared with broilers fed all other diets, and phytase supplementation improved tibia ash comparable with the PC. Phytase supplementation reduced (P ≤ 0.05) phytate (inositol hexa-phosphate) concentration in the gizzard. Inositol concentration in the gizzard was higher (P ≤ 0.05) in birds fed NC+1,000 or NC+1,500 compared with all other diets and this was correlated with growth performance (P ≤ 0.05) rather than tibia ash (P > 0.05). Improvements in feed conversion ratio associated with superdoses of phytase may be attributed to phytate destruction and the provision of inositol.

This study evaluated the influence of inoculation of different nutrients into eggs of 18-d-old broiler embryos. On d 18 of incubation, before transferring, eggs were injected with a solution containing either maltose, a multivitamin supplement, zinc-glycine, glutamine, a mixture containing all these elements, or sodium chloride (control). After hatching, 2,400 male broiler chicks were placed in an experimental broiler house and distributed into 60 floor pens in a completely randomized design comprising a 2 × 6 factorial arrangement of treatments (2 egg weights × 6 solutions), for a total of 12 treatments. Birds and feed consumption were measured weekly. At 42 d of age, 3 birds per replicate pen were randomly selected for processing. Birds derived from heavier eggs had greater hatchability and hatching weight. At 42 d of age, birds from heavier eggs had higher BW, carcass weight, and breast meat weight. The livability of birds derived from heavy eggs was higher at 7 and 14 d of age. The in ovo inoculation of the nutrients to 18-d-old embryos did not influence live performance or carcass traits. The technique of in ovo inoculation of certain nutrients may be used in industrial poultry production, but further studies are required to define the best solutions or mixture of nutrients to be used.

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Nowadays, 70 % of global monogastric feeds contains an exogenous phytase. Phytase supplementation has enabled a more efficient utilisation of phytate phosphorous (P) and reduction of P pollution. Trace minerals, such as iron (Fe), zinc (Zn), copper (Cu) and manganese (Mn) are essential for maintaining health and immunity as well as being involved in animal growth, production and reproduction. Exogenous sources of phytase and trace elements are regularly supplemented to monogastric diets and usually combined in a premix. However, the possibility for negative interaction between individual components within the premix is high and is often overlooked. Therefore, this initial study focused on assessing the potential in vitro interaction between inorganic and organic chelated sources of Fe, Zn, Cu and Mn with three commercially available phytase preparations. Additionally, this study has investigated if the degree of enzyme inhibition was dependent of the type of chelated sources. A highly significant relationship between phytase inhibition, trace mineral type as well as mineral source and concentration, p < 0.001 was verified. The proteinate sources of OTMs were consistently and significantly less inhibitory than the majority of the other sources, p < 0.05. This was verified for Escherichia coli and Peniophora lycii phytases for Fe and Zn, as well as for Cu with E. coli and Aspergillus niger phytases. Different chelate trace mineral sources demonstrated diversifying abilities to inhibit exogenous phytase activity.

Phytate is not only an unavailable source of phosphorus (P) for broilers but it also acts as an anti-nutrient, reducing protein and mineral absorption, increasing endogenous losses and reducing broiler performance. The objective of this study was to investigate the anti-nutritional effects of phytate by including high levels of phytase in diets not severely limited in available P. A total of 768 male Arbor Acres broilers were distributed in six treatments of eight replicate pens of 16 birds each consisting of a positive control diet (PC), positive control with 500 FTU/kg phytase, negative control (NC) diet with lower available P and calcium (Ca) levels and the same NC diet with 500, 1,000 or 1,500 FTU/kg phytase. Body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR) and mortality were determined at 21 and 35 d of age while foot ash was determined in four birds per pen at 21 d of age. FI, FCR and foot ash where not affected by the lower mineral diets at 21 d of age nor by the enzyme inclusion but broilers fed lower Ca and available P diets had lower BWG. At 35 d of age no difference was observed between broilers fed the positive or NC diets but broilers fed 500, 1,000 and 1,500 FTU/kg on top of the NC diet had better FCR than broilers fed the positive control diet. When compared to birds fed a diet adequate in P, birds fed the same diet included with 500, 1,000 and 1,500 FTU/kg of phytase in marginally deficient available P and Ca diets had an improvement of performance. These results support the concept that hydrolysing phytate and reducing the anti-nutritional effects of phytate improves bird performance on marginally deficient diets that were not covering the P requirement of birds.

An experiment was designed to determine the influence of fibre and betaine on the development of the intestine, liver and pancreas of broilers from hatch to 14 d of age. A total of 250-day-old Cobb 500 male broilers were allocated to 16 cages with 15 broilers each. Treatments were arranged in a 2 × 4 factorial design, consisting of 2 feed formulations (low and high fibre diets) and 4 levels of betaine (0, 1, 3 or 5 kg/t). At hatch, 10 birds in total were euthanised, and samples of the liver, pancreas, yolk sac and intestine were collected for reference of the analysed parameters before the start of the trial. On d 4, 9 and 14, 5 birds per cage (10 birds per treatment) were selected, euthanised and treated as the same as the birds at hatch. Villus height and width and crypt depth were determined on the duodenum samples, and absorptive area was calculated. The number of enterocytes in mitosis at the villus was determined by a positive reaction to antibody for Ki67 protein, and fused villus was evaluated visually. The relative weight of the yolk sac reduced ( P < 0.05) as birds aged while the intestine and liver reached a maximum ( P < 0.05) at around d 4 and the pancreas at d 9. Birds fed the high fibre diet had greater feed intake, lower relative weight of the pancreas and higher villus ( P < 0.05) than birds fed the low fibre diet. Villus width increased ( P < 0.05) at 4 d of age, and this was associated with fused villus. Betaine inclusion reduced ( P < 0.05) villus width, increased ( P < 0.05) villus size and absorptive area, and reduced ( P < 0.05) the number of enterocytes with positive reaction for the antibody Ki-67. Betaine inclusion reduced the width and increased the absorptive area and the villus height of the duodenum of birds up to 14 d of age. The higher fibre diet increased feed intake and villus height, yet reduced pancreas relative weight, while not affecting body weight gain. This response was possibly due to a dilution effect of the fibre, reducing nutrient absorption and consequently stimulating villus growth to improve absorption rates.

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