Effects of Xylanase and Protease Supplementation on Growth Performance, Meat Quality, Gut Health, Cecal Fermentation, and Bone Traits in Broiler Chickens
by
, , , , , , , and
Esin Ebru Onbaşılar
1,*
,
Sakine Yalçın
2,*,
Barış Batur
3,4,
Suzan Yalçın
5,
İhsan Berat Kılıçlı
6
,
Caner Bakıcı
3,
Buket Bakır
7,
Yeliz Kaya Kartal
8 and
Tevhide Sel
8 1
Department of Animal Husbandry, Faculty of Veterinary Medicine, Ankara University, 06110 Ankara, Türkiye
2
Animal Nutrition Science Association, 06420 Ankara, Türkiye
3
Department of Anatomy, Faculty of Veterinary Medicine, Ankara University, 06110 Ankara, Türkiye
4
The Graduate School of Health Sciences, Ankara University, 06110 Ankara, Türkiye
5
Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, Selçuk University, 42003 Konya, Türkiye
6
Faculty of Veterinary Medicine, Ankara University, 06110 Ankara, Türkiye
7
Department of Histology and Embryology, Faculty of Veterinary Medicine, Tekirdağ Namık Kemal University, 59030 Tekirdağ, Türkiye
8
Department of Biochemistry, Faculty of Veterinary Medicine, Ankara University, 06110 Ankara, Türkiye
*
Authors to whom correspondence should be addressed.
Animals 2026, 16(3), 465; https://doi.org/10.3390/ani16030465
Submission received: 20 December 2025
/
Revised: 22 January 2026
/
Accepted: 30 January 2026
/
Published: 2 February 2026
(This article belongs to the Section Poultry)
Simple Summary
In modern broiler production, rapid growth may challenge skeletal development due to limitations in nutrient utilization rather than inadequate mineral supply. This study evaluated the effects of dietary xylanase and protease supplementation, applied individually or in combination, on growth performance, intestinal characteristics, meat quality, gut health, and bone development in broiler chickens. Enzyme supplementation mainly enhanced growth performance during the 22–42-day period, which was associated with reduced intestinal viscosity and improved digestive efficiency. Breast meat composition and antioxidant status were not affected by the dietary treatments. Despite identical dietary calcium and phosphorus levels, enzyme-supplemented broilers exhibited improvements in bone development, including increased bone size, weight, and structural robustness, particularly in the femur and lower leg bones. These responses likely reflect enhanced nutrient utilization rather than changes in mineral intake. Overall, dietary xylanase and protease supplementation represents a nutritional strategy to support growth performance, gut function, and skeletal integrity in fast-growing broiler chickens.
Abstract
This study investigated the effects of dietary xylanase and protease supplementation, applied individually or in combination, on growth performance, intestinal characteristics, gut fermentation, meat quality, and skeletal traits in broiler chickens. A total of 540-day-old male broiler chicks were allocated to six experimental groups and fed a control corn-soybean meal-based diet or diets supplemented with xylanase, protease, or a xylanase–protease combination. Enzyme supplementation significantly improved body weight gain and feed efficiency, particularly between days 22 and 42, and reduced intestinal digesta viscosity. Improvements in gut morphology were reflected by increased villus height and villus-to-crypt ratios, accompanied by higher cecal total volatile fatty acid concentrations, increased Lactobacillus populations, and reduced coliform counts. In contrast, breast meat physicochemical composition and antioxidant status were not affected by dietary treatments. Skeletal development was positively influenced, with improvements observed in selected morphometric and structural bone traits. Overall, dietary xylanase and protease supplementation enhanced broiler performance and skeletal development primarily through improved digestive efficiency and favorable modulation of gut morphology, microbial ecology, and intestinal fermentation, without adverse effects on meat quality.
