36 International Poultry Production • Volume 24 Number 4
This Turkish study (Vet. Fak. Dergisi 63 25-29) was undertaken to assess theeffects of dietary sepiolite (0, 0.5 and 1.0%) on performance, egg quality, eggyolk cholesterol content and certain blood parameters in laying hens for 22weeks from 38 weeks of lay.Dietary sepiolite supplementation did not significantly affect feed intake,
egg production, egg weight and FCR. The values for egg breaking strengthand egg shell thickness were increased and egg yolk cholesterol wasdecreased at the 1.0% inclusion level. Dietary treatments did not significantlyaffect egg shape index, egg albumen index, egg yolk index and Haugh units.At the 1.0% level sepiolite reduced serum cholesterol and triglyceride butincreased total serum protein levels.
Sepiolite and egg quality
Changes in plumage colour in ducks Tyrosinase, encoded by the TYRgene, is the rate-limiting enzyme inthe production of the melanin pigment. In this Chinese study(Genet. and Mol. Res. 14 18623-18628) plumage colour separationwas observed.It was discovered that SNP
variations probably accounted fordifferences seen in feather colour.
Sulphur amino acids at peak lay This Chinese study (Chin. J. of An.Nut. 27 3720-3725) evaluated theeffects of different levels of sulphurcontaining amino acids (0.52 (control), 0.57, 0.61, 0.66 and 0.71%)on the performance of Jinghong layers during peak production andinvestigated optimal inclusion levelsfor sulphur containing amino acids.There were significant differences
in laying rate, daily egg production,average feed intake and averagedaily gain compared to the controlgroup.By quadratic regression curve
analysis the optimal dietary require-ment for sulphur containing aminoacids and digestible sulphur con-taining amino acids were 718 to 758and 681 to 719mg per day. The requirements for specific
amino acids are in the table below.
Age related carcase changesin turkeys This Polish study (Euro. Poult. Sci. 79103) looked at age related changesin the tissue composition of carcaseparts and the distribution of leanmeat, fat with skin and bones inturkey carcases from BUT Big 6turkeys between 2 and 20 (male)and 16 weeks (female).In the males between 2 and 20
weeks of age the percentage leanmeat in breast and legs rose by 3.4and 1.8% respectively, whereas similar figures for wings, back andneck were decreases of 2.8, 1.5 and1.0%. Similar figures were seen in thefemales. The content of skin with subcuta-
neous fat decreased considerably inneck and wing, especially in malesover 16 weeks and females over 12weeks of age. The smallest changesseen related to bones.
New rapid method forCampylobacter spp. detection This British paper (J. of Appl.Microbiol. 120 469-477) describesthe development of a rapid test forthe detection of thermotolerantcampylobacter in poultry faeces. This method is based on immuno-
magnetic separation and loop medi-ated isothermal DNA amplification(IMS/LAMP). This LAMP method is specific, as
Sulphuraminoacids
Digestiblesulphur
amino acids
Methionine Digestiblemethionine
(mg per day)
To maximiselaying rate
718 681 427 405
To maximise dailyegg production
728 690 433 410
As the industry’s search for the mosteffective alternatives to in-feed antibioticscontinues, one thing seems clear,promoting positive gut health in theanimal is essential to achieving optimalcost and performance. Gut health,described by Stephan Bischoff, is abalancing act that involves achievinghomeostasis in interactions between theanimal’s gut microbiome, immunefunction and nutritive processes.
Can enzymes be part of the solution?
An increasing number of trialsdemonstrate the impact nutrition has onthe animal’s gut health and performance.Enzymes are a key nutritionalconsideration and player in these effects.Exogenous enzymes are categorisedaccording to the substrates they target,exogenous xylanases target the solubleand insoluble arabinoxylans in cell walls.Use of xylanase has multiple benefits,from releasing encapsulated nutrientssuch as starch and protein from the cellsto reducing the viscosity of the digesta,both leading to improvements indigestibility (Choct, 2006). Non-starchpolysaccharide (NSP) content in animalfeed is one variable needing to bemanaged as it affects satiety, gut motility,nutrient digestion and absorption, as wellas changes in gut microbiota. Thebreakdown of NSPs by xylanase cancreate a positive environment forbeneficial bacteria to grow by reducingviscosity and producing small oligomers.Recent scientific studies shed light onenzymes’ effectiveness in maintaining astable gut environment by favouring hostand beneficial microflora and creatingspecific conditions detrimental to thegrowth of non-beneficial bacteria.
The mechanism of action behind theeffectiveness of enzymes differ in theupper and lower gastrointestinal tract(GIT). In the upper GIT, exogenousenzymes increase the digestibility ofnutrients, leading to a reduction in theavailability of indigestible substrate formicrobial growth. Furthermore, viscosityof the chyme is also reduced whenfeeding viscous grains such as wheat orbarley, increasing the passage rate ofdigesta. These conditions lead to areduced microbial population in the upperGIT, consequently reducing the threat ofproliferation of non-beneficial bacteria.While degrading viscous β-glucans andarabinoxylans from wheat and barley,small oligomers and free sugars areproduced and some of these are poorlyabsorbed in the upper intestinal tract.
ENZYMES: Alternative solutions for AGP free poultry production
For more information visit http://animalnutrition.dupont.com/home/or email us at [email protected]
Ajay Awati, Poultry Segment LeaderDanisco Animal Nutrition
(part of DuPont Industrial Biosciences)
These oligomers and sugars are utilisedby certain beneficial bacteria in the hindgut leading to increased volatile fattyacids (VFA) production and containmentof proliferation of non-beneficial bacteria.Choct et al (1999) found that VFAproduction was lower in an enzymetreated group in the ileum, while incontrast in the caecum VFA production ofthe enzyme treated group was higherthan the control. These results underlinethe earlier mentioned degradation of fibrefractions into smaller oligomers andsugars which are fermented further downthe tract in caecum. This shift can benefitintestinal health and microbial balance inthe lower GIT.
These effects were evident in severalpublished studies, showing higherperformance of the animals along withreduction of non-beneficial bacteria in theGIT. Amerah et al (2012), showed asignificant reduction in Salmonellaprevalence in broilers, when xylanasewas added to the diet. Some studies alsoreported positive effects of xylanaseinclusion on gut barrier function whenbirds were challenged by C. perfringens(Liu et al 2012).
Enzymes are known for their effects onthe anti-nutritional factors in the feed,however, their impact on the gutenvironment, and consequently on guthealth is receiving growing attention. The ability of enzymes to boost animalperformance, reduce feed cost andpositively affect the gut environment andhealth, support their use as an importantfeed additive in the post-AGP era.
Weight gain (g)
FCR (g/g)
Positive samples (%)
Challenged control 1800
2084 +284
2.01
1.78 -0.23
100
87.5 -12.5
Xylanase
Challenged control
Xylanase
Challenged control
Xylanase
36,37, research 19/05/2016 Week 20 15:20 Page 1
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