Feed supplementation with sodium butyrate and phytase for laying quail

Introduction

Japanese quail egg production has experienced tremendous growth in recent years. Brazil is now one of world's major quail egg producers, with one of largest national quail flocks. Brazilian quail industry is supported by small and medium producers, typically with a chicken egg production background, and an entrepreneur spirit.

Virtually together with the expansion of this industry, consumers have become more and more concerned about the way their food is produced, emphasizing the potentially negative environmental impact of farm practices. This environmentalist vision is also growing in the Brazilian poultry industry, so that priority is now being given to the use of feed additives aiming to improve nutrient digestibility/absorption and, therefore, decreasing the excretion of potentially-polluting substances. Exogenous enzymes are one example of feed additives that enhance nutrient utilization by birds thus resulting in improved use of nutritional resources and minimizing nutrient excretion to the environment.

Organic acids are one additional group of feed additives that have attracted industry attention, since their use results in improved intestinal health (Van Immerseel et al., 2005), and increased nutrient absorption, thus improving animal performance and decreasing the amount of nutrients excreted to the environment. Some recent reports like that published by Liem et al. (2008) are identifying synergy between the use of enzymes and some organic acids in the production of broilers. Nevertheless, nothing is known about the effects of using exogenous enzyme-organic acid combinations in Japanese quail.

The objective of this study was to evaluate the effects of supplementing Japanese quail feeds with sodium butyrate alone or in combination with phytase after laying peak on dietary dry matter/crude energy metabolism.

Materials and Methods

The experiment was carried out in UFLA's poultry sector, using a conventional, laying quail house. Two hundred and forty (240) Japanese quail (Coturnix coturnix japonica) after laying peak were housed in cages at a stocking density of 144 cm²/bird (8 birds/cage). Birds were distributed using a completely-at-random design, with 5 treatments and 6 repetitions of 8 quail per experimental unit, under four 21-day evaluation periods, under a 5 x 4 factorial scheme (5 treatments x 4 time periods). The experimental feeds were formulated based on corn and soybean meal, in accordance with the recommendations published by Vilar et al. (2007). The chemical composition of feedstuffs was based on the Brazilian Tables (Tableas Brasileiras, Rostagno et al., 2005), supplemented or not with bacterial phytase and polypeptide-coated sodium butyrate.

Birds were fed twice per day, using trough-type feeders. Feed and water (nipple drinkers) were provided ad libitum. Lighting program provided 16 hours of light per day, from 5:00 AM to 9:00 PM.

Treatments were as follows: 1) Positive control (PC) feed, with no sodium butyrate (SB) or phytase; 2) Negative control (NC) feed with reduced nutritional levels, as per enzyme matrix; 3) NC+phytase, 4) NC+SB, 5) NC+phytase+SB. The NC feed had the following nutrient reductions: -0.40% crude protein, -0.12% available phosphorus, -0.15% calcium, -0.019% digestible lysine, -0.007% methionine, -0.014% digestible methionine + cystine, -0.013% digestible threonine, -0.003% digestible tryptophan, and -30 kcal metabolizable energy. Phytase and sodium butyrate levels were 500 FTU/kg feed and 0.015 g/kg feed, respectively.

Quail performance was measured in terms of egg production (%/bird/day), feed intake (g/bird/day) and feed conversion rate (FCR, g/g).

At experiment completion, a 3-day total excreta collection period started. Excreta were received in plastic-lined trays, placed underneath each experimental unit. The starting and ending points of the collection period were identified using ferric oxide as a marker, and excreta were collected twice per day, recording the feed intake and total excreta production during the period. Analyses were then performed in order to determine dry matter and crude energy in both excreta and experimental feeds, as per the methodology described by Silva and Queiroz (2002), allowing for the calculation of both dry matter metabolization coefficient (DMMC) and gross energy metabolization coefficient (GEMC) in the experimental feeds.

Results were analyzed using the SISVAR statistical software, in agreement with Ferreira (2000). Treatments were compared using Tukey´s test with 5% probability.

Results and Discussion

Quail performance is shown in Table 1. Feed supplementation with phytase and/or sodium butyrate had no effect (P>0.05) on egg production or feed intake. Nevertheless, FCR showed differences among treatments (P<0.05) since it was adversely affected in birds fed the sodium butyrate-supplemented feed, showing that when added alone to digestible methionine + cystine-reduced diets, the organic acid can affect FCR. The level selected for feed formulation can exceed birds' actual requirement during the post-peak laying stage, which blocked the possibility of reducing egg production in the quail fed the NC diet.

No effect was seen (P>0.05) of feed supplementation of phytase and sodium butyrate on DMMC or GEMC in the experimental feeds (Table 2).

Table 1. Performance of laying Japanese quail fed a sodium butyrate (SB)- and phytase-added ration

Treatment	Egg production (%)¹	Feed Intake (g/bird /day)¹	Egg weight (g)¹	FCR (g/g)
Positive Control (PC)	87.4	25.1	12.4	2.33 a
Negative Control (NC)	86.3	25.0	12.1	2.43 ab
NC+phytase	87.7	25.3	12.0	2.44 ab
NC+SB	86.3	25.3	12.2	2.47 b
NC+Phytase+SB	88.7	25.1	12.1	2.37 ab
CV (%)	9.6	9.9	10.1	14.2

^{Means followed by different letters in one same column are significantly different as per Tukey's test (P<0.05).
1 = (P>0.05); FCR = Feed conversion rate CV = coefficient of variation.}

Table 2. Apparent dry matter metabolization coefficient (DMMC) and crude energy metabolization coefficient (CEMC) of experimental feeds for Japanese laying quail fed the sodium butyrate (SB)- and phytase-supplemented feed

Treatment	DMMC (%)	CEMC (%)
Positive Control (PC)	79.18	84.25
Negative Control (NC)	77.38	82.91
NC+phytase	77.27	82.10
NC+SB	77.37	82.01
NC+phytase+SB	78.19	83.25
CV(%)	6.61	4.77

^{(P>0.05); CV = coefficient of variation.}

Conclusion

Supplementing the feed of Japanese, post-peak laying quail with sodium butyrate either alone or in combination with bacterial phytase did not result in improved laying performance. Further studies with these additives on laying quail performance are needed.

Acknowledgements

Gratitude is expressed to Minas Gerais Research Protection Foundation (Fundación Amparo a Pesquisa de Minas Gerais, FAPEMIG) for the financial resources granted (Protocol PPM054/09).

Bibliography

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Liem A, Pesti GM, Edwards HM. 2008. The effect of several organic acids on phytase phosphorus hydrolysis in broiler chicks. Poultry science 87:689-693.

Rostagno HS, Albino LFT, Donzele JL et al. 2005. Tabelas brasileiras para aves e suínos; composição de alimentos e exigências nutricionais. 2^a ed. - Viçosa: UFV, DZO. 186p.

Silva DJ & Queiroz AC. 2002. Análise de alimentos: métodos químicos e biológicos. 3.ed. Viçosa, MG: Editora UFV. 235p.

Van Immerseel F, Boyen F, Gatois I, Timbermont L. 2005. Supplementation of coated butyric acid in the feed reduces colonization and shedding of salmonella in poultry. Poultry science 84:1851-1856.

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