Enzymes could be beneficial when feeding rapeseed meal in broiler rations
Take Home Message: For broilers fed diets high in rapeseed meal, include enzymes to enhance performance
Non-starch polysaccharide (NSP)-degrading and phytase enzymes incorporated in rapeseed meal based broiler diet could be beneficial. That was the finding of a trail, carried out by Iranian scientists, which was presented to delegates at the British Society of Animal Science’s annual conference.
The study showed that levels of rapeseed meal had adverse effects on performance, but that the addition of an enzyme was an effective method to overcome the ‘anti nutritional’ factor of rapeseed meal.
In comparison to 44% crude protein of soybean meal, the protein content of rapeseed meal is between 35% and 40% and has a physiologically suitable amino acid combination in animal nutrition. But rapeseed meal also contains nutritionally unfavourable substances such as glucosinolates, sinapin, tannin, phytate and non starch polysaccharides (NSPs).
Enzymes have the potential to be used in diets contain anti-nutritional factors that hinder nutrient availability. NSPs include cellulose, B-glucans, arabinoxylans, and pectins that may increase viscosity of digesta and cause a decrease in nutrient digestibility and performance of broiler chickens.
Phytase activity from digestive secretions, some feed ingredients, resident bacteria, exogenous microorganisms, or both resident bacteria and exogenous microorganisms is present in the digestive tract of broiler chickens, but its efficiency at a practical level is very low.
The Iranian study set out to investigate the replacement value of soyabean meal with locally grown rapeseed meal and two types of enzymes (NSP degrading and phytase) on performance of broiler chickens.
Three levels of soyabean meal protein were replaced with rapeseed meal protein and two levels of Phytase enzyme and two levels of a dietary NSP-degrading enzyme were added to the diets during starter (seven to 21 days of age) and grower (21 to 42 days of age) periods.
A total of 360 Ross broilers were used in a completely randomised trial with 12treatments, three replicates and 10 birds per replicate. Feed consumption and body weight gain of chicks were recorded four hours after the removal of feed and the feed conversion ratio (FCR) calculated at end of every week.
And the results indicated that feed intake, liveweight gain and feed efficiency were significantly decreased by increasing rapeseed mean in the diet.
The liveweight gain and feed intake of broiler were significantly increased by the addition of Grindazyme, but were not affected by supplementation with Phytase in the diet. But broilers fed diets containing phytase had a higher feed intake and liveweight gain compared to broilers fed the control ration.
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