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

Abstract

A 2 × 2 factorial design experiment examined the effect of dietary non-phytate phosphorus (NPP) (1.3 and 4.0 g/kg) and 3-phytase (F) (0 and 150 FTU/kg) on the performance indicators of hens, physical parameters of eggs, phosphorus (P) content of the eggshells, and the pH of the digestive tract of laying hens. Two hundred and forty hens (ISA Brown) were housed in enriched cages and fed a wheat-maize-based diet. A significant effect of both NPP and F was found for the yolk colour (P = 0.016) and shell thickness (P = 0.038). The F supplement or higher level of NPP alone and in combination increased the value of the yolk colour and shell thickness. The supplementation of the basal diet with F significantly increased the laying performance, especially with regard to the egg weight and feed conversion ratio. The higher dose of NPP had a negative effect on the egg production, feed intake, and feed conversion ratio. The lower level of NPP (1.3 g/kg) decreased the internal egg quality and shell quality, except for the shell strength. In contrast, the addition of 3-phytase to the diet increased the shell thickness and shell weight. The P content in the eggshells was not influenced by the dietary treatment. The higher level of NPP or F increased the pH in the gizzard to a value suitable for F activity. The hens fed a diet containing 1.3 g/kg NPP achieved a higher performance; moreover, the F supplement at 150 FTU/kg increased the external quality of the eggs.Keywords: laying hen; egg production; feed intake; eggshell quality; pH Mineral phosphorus (P) is important for proper bone development, formation of eggshells, and metabolism of laying hens. Approximately 20-50% of plant P is available in a poultry diet, and the rest is present in the form of phytate. Phytate P is biologically less available to poultry due to either insufficient quantity or the lack of secretion of phytase (F), which hydrolyses phytic acid in the digestive tract (Ravindran et al., 1995;Sebastian et al., 1998).As shown by the results of Swiatkiewicz et al. (2010), reducing the dietary levels of Ca (from 3.70 to 3.25%) and P (from 0.65 to 0.60%) significantly decreased the percentage of the eggshell, thickness, density, and breaking strength of the eggshell. 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 an...

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

“…Coincidently, Wilkinson et al (2011) showed that dietary Ca reduced the efficacy of F, which resulted in decreased phytate-P and increased phosphorus excretion and facilitating the formation of mineral-phytate complexes. Consistently with results of Englmaierová et al (2012), the high and medium levels of P increased the pH in the gizzard to a level suitable for F activity.…”

“…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.…”

Effect of dietary magnesium, calcium, phosphorus, and limestone grain size on productive performance and eggshell quality of hens

“…A high dietary concentration of NPP is related to the decrease of productive performance of layers. Englmaierova et al (2012) found that the hens fed a diet with only 1.3 g/kg NPP achieved a higher performance than the hens with 4.0 g/kg NPP in the diet.…”

Effect of suboptimal levels of non-phytate phosphorus and exogenous phytase on precaecal digestibility of phosphorus and calcium in laying hens

“…At lower levels of NPP, phosphorus is more effectively utilized than from diets with higher levels of NPP. This can explain why the performance of layers is the same or higher when using the lower levels of NPP in the diets (Englmaierova et al 2012). Gao et al (2013) used an even lower NPP level (1.0 g/kg, total phosphorus 3.4 g/kg) than in this study, and they also reported a higher coefficient of apparent ileal digestibility of phosphorus from this diet (0.506) compared with phosphorus digestibility from diet with total phosphorus 5.7 g/kg and 3.2 NPP g/kg (0.474).…”

“…The results of many short-and long-term experiments indicate that the NPP requirements of laying hens may be even lower than the National Research Council (1994) recommendation (Keshavarz and Nakajima 1993;Van der Klis and Versteegh 1996;Gordon and Roland 1997;Parsons 1999). Englmaierova et al (2012) found that hens fed a diet that contained 1.3 g/kg NPP achieved a higher performance than those with 4.0 g/kg of NPP in the diet.…”