Effect of Multi-Enzyme Preparation on Growth Performance and its Matrix Values Validation in Broiler

Non-starch polysaccharides (NSPs) are major components of dietary fibre found in feed ingredients that consist of both soluble and non-soluble polysaccharides. NSPs possess antinutritive properties that can hinder bird performance and alter gut physiology. These antinutritive properties include high gut viscosity, encapsulation of starch and amino acids, sticky droppings, modification of gut physiology, and an overall reduction in bird performance. Feed enzymes containing multiple components targeting different NSPs can effectively eliminate these negative impacts (Woyengo and Nyachoti, 2011). In addition, another major antinutritional factor in the form of phytic acid (phytate) is also widely presented in cereal ingredients, representing the predominant portion (60 – 80%) of the total phosphorus. Phytate is a complex of Ca or Mg with myo-inositol and binds with phosphorus and other important nutrients and thereby decreases their availability. As an efficient enzyme to hydrolyse phytate, phytase has become an essential additive in poultry feed since the early 2000s (Dersjant-Li et al., 2015). As all plant-based feed ingredients contained protein, polysaccharides and other nutrients encapsulated in cell wall, it is meaningful to examine the interaction between carbohydrase and phytase in poultry diets. Early research in poultry suggested such interaction did exist and the degree of interaction seemed to be related to the main ingredients used in the feed formulation (Schramm et al., 2017). For instance, a study using fast growing broilers reported additional daily weight gain and improved feed conversion ratio following the supplementation with multi-NSPase (enzymes targeting on NSPs) to the corn-soya diets that already contained high dose phytase (1000 FTU/kg) (Schramm et al., 2017).

This study was designed to examine the effect of multi-enzyme preparation (MEP) containing both carbohydrase and phytase, and compared the efficacy of different phytases in the feed which already contained a premium carbohydrase. The precise estimation of matrix values of this MEP in corn-DDGS-SBM based broiler diet was also explored.

The trial was carried out at the experimental farm of PT Malindo Feedmill Tbk in Indonesia. 3900 birds (Ross 308) were divided into 6 treatments with 10 replication per treatment and 65 birds per floor pen, with randomised complete block design (RCBD). Each experimental unit contained 65 birds and the male:female ratio was close to 50:50. The following enzyme preparations were used in this trial: Rovabio® Advance Phy T (Enzyme product A) contains mainly xylanases, beta-glucanases and arabinofuranosidases combined with 6-phytase (Adisseo France S.A.S). Rovabio® T-Flex (Enzyme product B) contains mainly xylanases, beta-glucanases and arabinofuranosidases (Adisseo France S.A.S), and phytase A is a modified Escherichia coli 6-phytase expressed in Trichoderma reesei (United Kingdom). The trial design was shown in Table 1 and the standard diet specifications were shown in Table 2.

A three-phase feeding program was applied in the current trial, including starter feed from 0-10 days, grower feed 11-21 days, and finisher feed 22-35 days, which was mainly based on ROSS 308 nutrition specifications. The starter feed was produced as fine crumble (1-1.5 mm), grower feed as crumble (1.8-2 mm), and finisher as pellet (3 mm). The pelleting temperature was ranging from 80 oC to 85o C with conditioning time at 40 seconds. The feeds for all treatments were manufactured and packed in 50 kg bags. The main ingredients in all feeding phases contained corn, corn DDGS, and soybean meal (SBM).

Proximate analysis of feed samples from all the six groups for starter, grower and finisher diets were done at Adisseo laboratory in Singapore (Adi-lab) using NIR machine (Bruker MPA - 2I050105, Germany).

Live weight and feed intake were recorded on D10, D21 and D35 on per pen bases, and depletion was recorded daily. FCR and average daily gain (ADG) were analysed for all the three phases and throughout the whole phase from D0 to D35. Performance index (PI) was also calculated on D35.

Table 4 - Effects supplementation enzymes in broiler performance parameter in each phase¹.

Table 4 shows the results of key growth performance indicators for starter (0-10 day), grower (11-22 day) and finisher (22-35 day) periods. As expected, results in T1 showed that birds can reach their genetic potential in each stage compared with the breeder standard, indicating sufficient nutrients and appropriate trial management level. Using Enzyme product A as on-top application (T2) brought significant improvements for BW, ADG and FCR (P < 0.01) when compared with T1 in the starter period. While in the grower phase this effect tended to attenuate, until the finisher period there were almost no significant differences for all the key growth indicators observed (Table 4). The results are supported by the previous findings that 1-2 weeks after hatching the digestive systems are not well developed, and bone development requires critical nutrients supply, especially calcium and phosphorus (Sklan, 2001; SanchezRodriguez et al., 2019) in poultry. As shown in Table 3, the reformulation successfully reduced the total phosphorus and crude fat level in T3 to T6, leading to the elevated risk of delaying the body development of birds. This creates the opportunity for both carbohydrase and phytase to help eliminate the anti-nutritional factors in the feed, and release more essential nutrients for birds in the early developmental stages. Also, enzyme treatments in T3 to T6 all restored the growth parameters to the T1 level, regardless of the reformulated nutrients levels and enzyme applications in all three phases. However, there was a tendency for the major reduction of all three key nutrients in T5 and T6 to induce nutritional deficiency stress in both the starter and finisher phases, which is correlated with the highest FCR among all the treated groups. In particular, FCR in both T5 and T6 was significantly affected compared with T1 (P < 0.01) in the grower phase. This may be due to the imbalanced nutrients caused by the aggressive downspec when the birds need to deposit proteins in organs, therefore reaching the limit of enzyme application to rebalance the diets.

As shown in Table 5, throughout the whole phase (0-35 day) on top application of Enzyme product A (T2) can also bring significant improvement for final BW (P = 0.002), ADG (P = 0.002) and FCR (P < 0.001) compared with T1, with no significant difference (P = 0.35) in feed intake. Feed utilisation was optimised by this effective MEP Enzyme product A throughout the whole growing phase, with feed intake being the same or less but with birds gaining more weight. In addition, we observed no significant difference for the growth parameters between T3-T6 and T1. However, T4 with 60 kcal/kg AME, 3% dAA and 0.18% Ca/avP nutrients reduction and Enzyme product A treatment delivered the most economical solution, showing the lowest FCR among all the treated groups. In this case, it is estimated that the optimal matrix value of Enzyme product A in corn-DDGS-SBM based broiler diet in practice can be starting from T4 down-spec and fine-tuned accordingly. Finally, T5 and T6 delivered very close results, meaning Enzyme product A can work as well as the top tier carbohydrase and phytase combination.

In conclusion, the results demonstrated Enzyme product A was able to reverse the negative effect of both moderate and aggressive reformulations in broiler diets. Also, the carbohydrase and phytase in Enzyme product A had a clear synergetic effect to release more nutrients in broiler feed thus reducing feed cost. A reliable matrix value of Enzyme product A was also validated and recommended as a solid basis for its practical application in broiler feed.