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RESEARCH ARTICLE

Effects of dietary acidifier supplementation on broiler growth performance, digestive and immune function indices

Irida Palamidi A , Vasileios Paraskeuas A , Georgios Theodorou B , Renata Breitsma C , Gerd Schatzmayr D , Georgios Theodoropoulos E , Konstantinos Fegeros A and Konstantinos C. Mountzouris A F
+ Author Affiliations
- Author Affiliations

A Department of Nutritional Physiology and Feeding, Agricultural University of Athens, Iera Odos 75, 11855, Greece.

B Department of Animal Breeding and Husbandry, Agricultural University of Athens, Iera Odos 75, 11855, Greece.

C Biomin Holding GmbH, Industriestrasse 21, 3130 Herzogenburg, Austria.

D Biomin Research Centre, Technopark 1, 3430 Tulln, Austria.

E Department of Anatomy and Physiology of Farm Animals, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece.

F Corresponding author. Email: kmountzouris@aua.gr

Animal Production Science 57(2) 271-281 https://doi.org/10.1071/AN15061
Submitted: 4 February 2015  Accepted: 14 September 2015   Published: 18 February 2016

Abstract

The effect of dietary acidifier (AC) supplementation in combination or not with avilamycin (AV) was evaluated on broiler performance, nutrient digestibility, gizzard pH, activity of digestive enzymes and relative expression of cytokines. A 2 × 2 factorial experimental design with inclusion of AC (0 and 1 g/kg of diet) and AV (0 and 2.5 mg/kg of diet) as the main factors was implemented. Subsequently, 544-day-old male Cobb broilers were allocated in four treatments (i.e. C – no additions, AC; AV and ACAV), each having eight replicates of 17 broilers, for 6 weeks. Overall bodyweight gain (BWG) was improved (PAC = 0.035) by AC addition. BWG and feed conversion ratio were improved (P ≤ 0.05) by AV addition in all growth periods and overall. Dry matter, organic matter digestibility and energy retention were improved by AC (PAC = 0.050, PAC = 0.045 and PAC = 0.020, respectively), or AV (PAV = 0.018, PAV = 0.013 and PAV = 0.012, respectively). In addition AV supplementation improved digestibility of ether extracts (PAV = 0.022) and crude protein (PAV = 0.042). Pancreatic trypsin activity was lower in AC (PAC = 0.027) or AV (PAV ≤ 0.001) supplemented diets. An AC × AV effect on gizzard pH (PAC × AV = 0.034) was noted. Expression of interferon-γ (PAV = 0.010), interleukin (IL) 18 (PAV = 0.048) and inducible nitric oxide synthase 2 (PAV = 0.035) in spleen were downregulated by AV. An upregulation of IL10 (PAC × AV = 0.018), IL18 (PAC × AV = 0.002) and IL22 (PAC × AV = 0.030) in the caecal tonsils was shown for the combined ACAV supplementation. In conclusion, dietary AC supplementation improved performance, nutrient digestibility and energy retention, irrespective of AV inclusion. This study has provided evidence for potential links between digestive and immune function indices with growth performance improvements.

Additional keywords: broilers, cytokines, digestibility, digestive enzymes, organic acids.


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