Effect of dietary β-mannanase on productive performance, egg quality, and utilization of dietary energy and nutrients in aged laying hens raised under hot climatic conditions.

Moon Chan Kim,Do Yoon Koo,Hyeon Seok Choi,Dong Yong Kil,Franco Martinez Pitargue,Jong Hyuk Kim

doi:10.5713/ajas.17.0269

Moon Chan Kim, Do Yoon Koo + Show 4 more

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https://doi.org/10.5713/ajas.17.0269

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Abstract

ObjectiveThe objective of this experiment was to investigate the effect of dietary β-mannanase on productive performance, egg quality, and utilization of dietary energy and nutrients in aged laying hens raised under hot climatic conditions.MethodsA total of 320 84-wk-old Hy-line Brown aged laying hens were allotted to one of four treatments with eight replicates in a completely randomized design. Two dietary treatments with high energy (HE; 2,800 kcal/kg nitrogen-corrected apparent metabolizable energy [AMEn]) and low energy (LE; 2,700 kcal/kg AMEn) were formulated. Two additional diets were prepared by adding 0.04% (MN4) or 0.08% β-mannanase (MN8) to LE treatment diets. The feeding trial was conducted for 28 d, covering a period from July to August in South Korea. The average daily room temperature and relative humidity were 29.2°C and 83%, respectively.ResultsProductive performance, egg quality, and cloacal temperature were not influenced by dietary treatments. The measured AMEn values for MN8 diets were similar to those for HE diets, which were greater (p<0.05) than those for LE and MN4 diets. However, the AMEn values for MN8 diets did not differ from those for LE and MN4 diets.ConclusionThe addition of β-mannanase to low energy diets increases energy values for diets fed to aged laying hens. However, this increase has little positive impacts on performance and egg quality. These results indicate that dietary β-mannanase does not mitigate the heat stress of aged laying hens raised under hot climatic conditions.

Highlights

High environmental temperature and humidity lead to an adverse effect on livestock production and health, with poultry being the most sensitive of livestock animals to the heat stress owing to low ability to dissipate body heat load [1]
Productive performance, including final body weight (BW), hen-day egg production, egg weight, egg mass, feed intake, feed conversion ratio (FCR), and soft-broken egg production, of aged laying hens raised under hot climatic conditions was not affected by dietary treatments (Table 2)
Dietary β-mannanase has been known to increase nutrient digestion and utilization in the small intestine of animals, and decrease the amounts of fermentable nutrients reaching the hindgut of animals [24,25,26]

Summary

Introduction

High environmental temperature and humidity lead to an adverse effect on livestock production and health, with poultry being the most sensitive of livestock animals to the heat stress owing to low ability to dissipate body heat load [1]. Dietary nonstarch polysaccharides (NSPs) are recognized to be the major components showing various anti-nutritional actions such as decreased nutrient digestion and absorption in the small intestine [4]. This decreased utilization of nutrients in the small intestine is related to increased fermentation in the lower part of the gastrointestinal tract (GIT) of poultry [5]. Choct et al [6] reported that high intake of soluble NSPs greatly increased the small intestinal fermentation of broiler chickens. It is expected that decreased intake and/or increased utilization of NSPs in the GIT may decrease heat production of chickens because fermentative heat production www.ajas.info

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