Nutritional Vitamin and Meat Quality of Broilers

INTRODUCTION

Recent studies have shown vitamin levels above minimum requirements may optimize genetic potential and improve immune status. Optimum Vitamin Nutrition (OVN^TM) is a new concept in animal nutrition that aims to better production and meat quality. The objective of this study was to evaluate the effects of different vitamin levels (NRC and OVN^TM) in broiler diets on productive parameters and meat quality.

MATERIALS AND METHODS

A total of 3,840 1-d-old Cobb-500 chicks were assigned to two treatments with 12 replicates (floor pens) of 160 birds each in a randomized block design. The rearing period was 44 days. Pelletized feed was supplied ad-libitum. The treatments (Table 1) were T1: vitamin levels according to NRC (1994) and T2: OVN^TM vitamin levels according to DSM Nutritional Products (Basel,Switzerland recommendations (DSM, 2004). The experimental diets were based on corn, soybean meal, steam deactivated full fat soybean and meat and bone meal. Diets were formulated according to the standards of Granja Tres Arroyos Company. At the end of the rearing period animal performance parameters (feed intake, body weight, daily weight gain, feed conversion ratio and European production efficiency factor (EPEF)) were analyzed. Meat quality (water retention capability, pH, hardness, TBARS and α-tocopherol content) was determined using a factorial arrangement, 2 treatments x 3 conservation times (1, 4 and 7 days).

pH: pHmeter Testo 230 with electrode for meat and automatic temperature compensated. (Boccard et al., 1981)

Hardness: Warner Bratzler shear over INSTRON mod. 4442 equipment. Cylindrical samples (Ø:1 cm), cell of50 kg, blade speed: 90 mm/min. Charge=maximum force at time of cutting (kgf).

Water retention capability: Through pressure between plates. (Grau and Hamm, 1957)

Lipid oxidation: Estimated by TBARS (Thiobarbituric Acid Reactive Substances) (Gray, 1978; Melton, 1983; Robards et al., 1988). Data is shown as μg of malonaldehide per Kg of meat.

Alpha-tocopherol: Determinates at day 1 of conservation from frozen chicken meat. Samples were extracted with hexane and separated by HPLC with fluorescence detection (λexc 296 nm- λem 330 nm). Calibration curve was performed with the standard of alpha-tocopherol (Merk,Germany).

Data was subjected to ANOVA. Means separation was performed using Duncan’s multiple range test (Balzarini et al., 2008). Statistical significance was considered at p≤0.10.

Table 1. Vitamin level per metric ton of feed

Effects of Nutritional Vitamin Levels on Performance and Meat Quality of Broilers - Image 1

RESULTS AND DISCUSSION

Animal performance results are summarized in Table 2 and meat quality in Table 3.

Table 2. Animal performance results at 44 days old

Effects of Nutritional Vitamin Levels on Performance and Meat Quality of Broilers - Image 2

At the end of the rearing period (44 days) chickens from OVN^TM treatment were 1.86% heavier than NRC chickens (p≤0.10) and tend (p≤0.15) to have better EPEF and BW/FCR ratio.

Table 3. Meat quality of breast at different conservation times

Effects of Nutritional Vitamin Levels on Performance and Meat Quality of Broilers - Image 3

The OVN^TM treatment reaches the highest level of alpha-tocopherol in frozen meat, giving a differentiated quality product.

The higher presence of antioxidants such as alpha-tocopherol in poultry meat not only helps to preserve their organoleptic characteristics (Kennedy et al., 2005), but also this benefit is transferred to the consumer with the consequent improvement in oxidative status and health. (Di Mascio et al., 1991; Diplock, 1991)

No differences were observed in crude pH, cooked pH and hardness; but an improvement (10.6%) was observed in the water retention capability with OVN^TM.

The meat quality (water retention capability and pH) decreased with the conservation time.

CONCLUSIONS

Chickens from OVN^TM treatment were 1.86% heavier than NRC ones.

The OVN^TM treatment reaches 156% more α-tocopherol content than NRC.

The OVN^TM treatment increases the oxidative protection and water retention capability.

No differences were observed in crude pH, cooked pH and hardness.

In conclusion, optimal vitamin supplementation could be successfully used to improve broiler performance and meat quality.

BIBLIOGRAPHY

BALZARINI, M.G., GONZALEZ, L., TABLADA, M., CASANOVES, F., DI RIENZO, J.A. and ROBLEDO, C.W. (2008). Infostat. Manual del Usuario, Editorial Brujas, Córdoba, Argentina.

BOCCARD, R., BUCHTER, L., CASTEELS, E., COSENTINO, E., DRANSFIELD, E., HOOD, D.E., JOSEPH, R.L., MACDOUGALL, D.B., RHODES, D.N., SCHÓN, I., TINBERGEN, B.J. and TOURAILLE, C. (1981) Procedures for measuring meat quality characteristics in beef production experiments. Report of a working group in the commission of the European communities' (CEC) beef production research programme. Livestock Production Science, 8(5): 385-397.

DI MASCIO, P., MURPHY, M.E. and SIES, H. (1991) Antioxidant defense systems: the rol of carotenoids, tocopherols and thiols. American Journal of Clinical Nutrition53(1): 194S-200S.

DIPLOCK, A.T. (1991) Antioxidant nutrients and disease prevention: an overview. American Journal of Clinical Nutrition53(1): 189S-193S.

DSM. (2004) Vitamin Supplementation Guidelines. [Online]. Available: http://www.dsm.com/en_US/downloads/dnpsa/Vitamin_supplementation.pdf. [Accessed 15 August 2011].

GRAU, R. and HAMM, R. (1957) Über das Wasserbindungsvermögen des Säugetiermuskels. II. Mitteilung. Über die Bestimmung der Wasserbindung des Muskels, Zeitschrift für Lebensmitteluntersuchung und -Forschung A105(6): 446-460.

GRAY, J.I. (1978) Measurement of lipid oxidation: A review. Journal of the American Oil Chemists' Society55(6): 539-546.

KENNEDY, O.B., STEWART-KNOX, B.J., MITCHELL, P.C. and THURNHAM, D.I. (2005) Vitamin E supplementation, cereal feed type consumer sensory perceptions of poultry meat quality. British Journal of Nutrition93(3): 333-338.

MELTON, S.L. (1983) Methodology for following lipid oxidation in muscle foods. Food Technology37(7): 105-111.

NRC, National Research Council. (1994) Nutrient requirements of poultry, in: Nutrient requirements of domestic animals,Washington,DC, National Academic of Science.

ROBARDS, K., KERR, A.F. and PATSALIDES, E. (1988) Rancidity and its measurement in edible oils and snack foods. A review. Analyst113(2): 213-224.