Effect of different phosphorus levels on the performance and egg quality of laying hens fed wheat- and maize-based diets

Abstract

A high or low level of available phosphorus (AP) in a laying hen's diet may adversely affect the bird's performance and reduce the eggshell quality (Harms, 1982;Bar and Hurwitz, 1984). Nys (1999) reported that 0.3% AP allows normal performance and bone integrity of hens. Excess dietary P is not only detrimental to the bird, but also it reduces the availability of other divalent cations and phytin phosphorus by reducing phytate hydrolysis (Ballam et al., 1985), which subsequently leads to environmental pollution. The amount of phosphorus in the eggshell is around 22 mg. In 1994, the National Research Council (NRC) estimated a requirement of 250 mg of AP per hen per day. This value was significantly lower than the preceding recommendation of 350 mg AP published by the NRC (1984). The dietary calcium (Ca) requirement was also reduced from 37.5 to 32.5 g/kg. Summers (1995) suggested that a maize-soybean meal diet containing 0.2% AP gave similar performance in layers up to 32 weeks of age as a similar control diet containing 0.4% AP. In layers older than 32 weeks, although the shell quality and average egg weight were similar, egg production was significantly reduced with the lower P diet. No differences between the 0.4 and 0.3% AP diets were noted for any of the production variables measured. Composition of the diet, rearing method, age of the bird and season are known to influence the P requirement (Rao et al., 1999). The required level The effects of diet type (wheat-or maize-based) and concentration of available phosphorus (AP; about 4, 3 and 2 g/kg) on the parameters of hen performance and egg quality as well as shell calcium (Ca) and phosphorus (P) contents were examined. Two experiments were carried out in which 240 and 120, respectively, older ISA Brown hens were housed in enriched cages. The interaction of diet type and AP concentration was ascertained for all evaluated characteristics except the amount of Ca and P deposited in shells in the first experiment. In the second experiment, the interaction of diet type and AP concentration was found for feed intake, egg weight, shell thickness and weight as well as the albumen quality parameters. Furthermore, Ca deposition in shells increased (P < 0.001) with the wheat diet. Hens fed a maize-based diet (P < 0.001) laid heavier eggs. The highest level of AP (4.1 g/kg) in the wheat-based diet significantly (P < 0.001) decreased albumen height, albumen index and Haugh units (HU). These trends were the same in both experiments. The results indicate that 0.27% AP in wheat-based diet and 0.30% AP in maize-based diet are adequate for hens with the intake 115 g of feed with 3.5% of Ca without a negative impact on performance or egg quality.

The effect of non-phytate phosphorus and phytase levels on performance, egg and tibia quality, and pH of the digestive tract in hens fed higher-calcium-content diet

“…The high AP level of 3.0 g/kg (unlike the lower levels of 2.1 and 1.7 g/kg) increased the egg production and egg mass production. This finding is consistent with the findings of Skřivan et al (2010), who showed that AP levels of 2.7 g/kg in a wheatbased diet and 3.0 g/kg in a maize-based diet are adequate for hens with an intake of 115 g of feed with 35 g/kg of Ca and without F addition and do not have a negative impact on performance or egg quality. The treatment with 2.1 g/kg NPP yielded results for hen-day egg production and egg mass production similar to those obtained with the diet with 3.0 g of NPP/kg, with or without F. Ahmadi and Rodehutscord (2012) stated that on the basis of an evaluation using a full quadratic model, maizesoybean meal-based diets containing 2.2 g/kg of NPP without supplemental F resulted in high egg production, egg mass, and feed efficiency in hens.…”

“…From previous experiments by Skřivan et al (2010) and Englmaierová et al (2012) it is evident that a higher concentration of NPP (4.1 and 3.7 g/kg) in the diet has a negative effect on the hen-day egg production, feed intake, and feed conversion ratio. Thus, in the present study, lower levels of NPP were chosen.…”

“…However, this is often at the expense of optimal skeletal integrity (Wilkinson et al, 2011). For good growth performance and egg quality, Skřivan et al (2010) recommend 2.7 g/kg of available phosphorus (AP) in a wheat-based diet and 3.0 g/kg of AP in a maize-based diet for hens with an intake of 115 g of feed containing 35 g/kg Ca. According to analyses of the model, Ahmadi and Rodehutscord (2012) showed that diets based on corn and soybean meal containing 2.2 g/kg of nonphytate P (NPP) without supplemental F resulted in high egg production, egg mass, and feed efficiency in layers.…”

Efficacy of contrast levels of non-phytate phosphorus and Aspergillus niger phytase in hens fed wheat-maize-based diets

“…In the current study, a higher concentration of P in the diet decreased the hen-day egg production, feed intake, and feed conversion ratio. The higher level of P that we chose was the same as in the experiments of Skřivan et al (2010), in which an identical negative effect of excessive P was observed. In addition, F mobilises phytate, Ca, and other nutrients.…”

“…However, de Faria et al (1999) observed decreases in the egg production, egg weight, and egg mass without alterations in the eggshell quality characteristics in hens fed diets containing 0.35% of total P as opposed to 0.55% of total P. Sohail et al (2001) observed a reduction of egg production (by 8.5 and 6.8%) and feed consumption due to decreases in the non-phytate phosphorus (NPP) from 0.40 and 0.25% to 0.09%. Based on the findings of Skřivan et al (2010), 0.27% of available phosphorus (AP) in a wheat-based diet and 0.30% of the AP in a maizebased diet are adequate for hens having an intake of 115 g of feed containing 3.5% Ca without a negative impact on the performance or egg quality. According to a study by Rodrigues et al (1998), levels of 0.35 and 0.25% of AP for the initial and final laying phases were adequate for laying hen performance and egg quality during the second production cycle.…”