INTRODUCTION
Poultry industry present and future is focused on becoming a sustainable industry, on one side by decreasing the consumption of ingredients used also as human food, by increasing the use of alternative feedstuffs, and also by developing technologies to allow an increase on the digestible fraction of the feed, to diminish environmental pollution, for example exogenous enzymes addition to the feed. In the case of feeding laying hens, the most common ingredients worldwide are corn and soybean meal (SBM), both ingredients are also used as human food, either directly as corn or by applying food technology to develop several foods form the soy protein. Then the possibility of using sorghum and DDGS as source of energy and also addition of alternative protein sources such as canola is very attractive, however, the presence of high fiber levels in DDGS and Canola is a concern. Regarding the addition of exogenous enzymes to the feed, there are available phytase, carbohydrase and protease activities; however, a question rises regarding the right feed formulation matrix values when using combinations of different feed enzyme activities.
MATERIAL & METHODS
The present study was performed at the Poultry research, teaching, and extension center (CEIEPA) from the Veterinary Medicine College (FMVZ), from Universidad Nacional Autónoma de México (UNAM). CEIEPA is located inMéxico City, at 2,300 m above the sea level, 19° 18´ north latitude & 99° 02´ west longitude. Weather is sub-humid temperate with summer rains.
The trial was done at an experimental open hen house with curtains, 480 32-wks-old Bovans White hens, where randomly allocated to 4 treatments with 4 replicates of 10 cages with 3 hens each, to get 30 hens per replicate. Cage dimensions were as follows: front; 30 cm, deep; 40 cm, & height; 40 cm. Feed and water were provided ad libitum. The experimental treatments (Table 1) where as follows: T1 Control feed with 10% DDGS, formulated to fulfill Bovans White hens’ nutritional requirements, added with 111 ppm phytase enzyme (RONOZYME® P). T2 as T1 + 300 ppm carbohydrase enzyme activity (RONOZYME® Blend 25). T3 as T1 + 150 ppm protease enzyme activity (RONOZYME® ProAct). T4 + 300 ppm Ronozyme Blend 25 + 150 ppm Ronozyme ProAct.
Table 1. Experimental feeds composition.
Enzyme addition was performed by applying feed formulation matrix for all feed enzyme products as follows; Ronozyme P; Ca & Av. P, 0.1%, ME, 45 kcal/kg, CP, 0.105%, Lys, 0.008%, SAA, 0.005%, Thr, 0.007%, Trp, 0.007%, & Arg, 0.009. Ronozyme Blend 25; ME, 70 kcal/kg, CP, 0.09%, Lys, 0.013%, SAA, 0.006%, Thr, 0.008%, Trp, 0.003%, Val, 0.01%, Ile, 0.009, & Arg, 0.015. Ronozyme ProAct; CP, 0.62%, Lys, 0.007%, SAA, 0.019%, Thr, 0.038%, Trp, 0.005%, Val, 0.03%, Ile, 0.022, & Arg, 0.025. Experiment lasted 11 weeks. Data was analyzed as CRD and when effect of treatment was significant (P < 0.05) LSD analysis was performed (Stell & Torrie, 1980).
RESULTS & DISCUSION
Experimental results are showed in tables 2, & 3.
Table 2. Effect of different feed enzyme combinations on laying hen performance
Table 3. Effect of different feed enzyme combinations on egg production cost.
As it can be seen, addition of Ronozyme ProAct, or the combination of Ronozyme ProAct yielded a higher egg production (P < 0.02) compared to control feed. Feed intake was significantly (P < 0.01) higher for hens fed Blend 25 + ProAct than hens fed the control diet. Hen feed conversion & egg weight, were not affected (P > 0.05) by treatment. Egg mass was significantly (P < 0.017) higher for hens fed Blend 25 + ProAct than hens fed TRT 1. Under the experimental conditions of the present trial, hens fed Ronozyme Blend 25 or the combination Ronozyme Blend 25 + Ronozyme ProAct, showed a significant (P < 0.01) lower egg production cost than hens fed control feed.
The combination of Ronozyme Blend 25 + Ronozyme ProAct produced higher hen feed intake, this may be one of the reasons behind the positive effect on egg production, both as percentage and egg mass produced per hen. This synergistic effect may be explained by the fact that Ronozyme Blend 25 has carbohydrase enzymes activity, that work on the feed fiber fraction, whereas, Ronozyme ProAct is a protease. One of the main concerns that stop poultry producers to increase the use of alternative feed ingredients is that by increasing the amount of dietary fiber, nutrient digestibility goes down, and this translated to field production means poor feed conversion rates. It is well documented that egg production is affected mainly by hen daily energy intake and in second place by the amount of protein consumption, Lesson et al., 2005. When feeding high dietary fiber feeds to hens, fiber acts as a physical barrier, referred also as a cage effect, keeping part of the feed protein fraction away from the action of protease enzymes. In this trial it seems that the amount of dietary fiber, acted as limiting factor on the hen’s feed intake, and by adding the carbohydrase & protease enzyme activities, the hens in treatment 4, were able to increase their nutrient intake and get a direct effect on egg production numbers.
CONCLUSION
Under the experimental conditions of the present trial, the addition of Ronozyme P (phytase enzyme) in combination with Ronozyme Blend 25 (carbohydrase enzymes) and Ronozyme ProAct (protease enzyme), yielded a significant increase on feed intake and egg production, compared to the control diet, added only with Ronozyme P.
REFERENCES
LEESON, S., & SUMMERS, J.D. (2005) Commercial poultry nutrition. 3rdEd.University Books.GuelphOntario,Canada.
STELL, G.D.R., & TORRIE, J.H. (1980) Principles and procedures of statistics. A biometrical approach. 2nd Ed. McGraw-Hill Inc.
