Investigation of the Effects of Using Natural Fermented Lactic Acid Bacteria as Probiotics on Fattening Performance, Blood Parameters, and Intestinal Microflora in Broiler Chickens Under Heat Stress
by
, , ,
Sadık Serkan Aydin
1,*,
Mehmet Avci
1,
Nurcan Kirar
1,
Ahmet Oruç
2,
Mehmet Savrunlu
3 and
Aydin Daş
4 1
Department of Animal Nutrition and Nutritional Disease, Faculty of Veterinary Medicine, Harran University, 63200 Şanlıurfa, Turkey
2
Department of Livestock, GAP Agricultural Research Institute, 63040 Şanlıurfa, Turkey
3
Şanliurfa Food Control Laboratory, Ministry of Food, Agriculture and Livestock, 63100 Şanlıurfa, Turkey
4
Department of Animal Husbandry, Faculty of Veterinary Medicine, Harran University, 63300 Şanlıurfa, Turkey
*
Author to whom correspondence should be addressed.
Vet. Sci. 2026, 13(5), 488; https://doi.org/10.3390/vetsci13050488
Submission received: 29 April 2026
/
Accepted: 16 May 2026
/
Published: 18 May 2026
(This article belongs to the Special Issue Feed Fermentation and Animal Health: Nutrition and Metabolism)
Simple Summary
This study evaluates the effects of a naturally fermented probiotic prepared from meadow grass supplemented with molasses and a commercial probiotic on growth performance, blood parameters, and intestinal microflora in broiler chickens under normal and heat stress conditions. The poultry industry is a major contributor to global food production, and broiler chickens are highly valued for their rapid growth and efficient feed utilization. However, heat stress remains one of the most critical challenges, particularly in regions with high ambient temperatures or inadequate ventilation, leading to reduced productivity, impaired physiological functions, and disrupted intestinal health. Nutritional strategies such as probiotic supplementation have gained increasing attention as sustainable approaches to mitigate these negative effects. In particular, naturally derived probiotics obtained from plant-based fermentation processes offer a low-cost, environmentally friendly, and practical alternative to conventional commercial products. By evaluating these alternatives under both normal and stress conditions, this study contributes to the development of sustainable and effective strategies to improve poultry health and production efficiency.
Abstract
Heat stress is a major environmental challenge in poultry production, negatively affecting growth performance, physiological functions, and intestinal health in broiler chickens. This study aimed to investigate the effects of probiotics prepared from meadow grass with molasses (PJFM) and commercial probiotics (TP) on fattening performance, blood parameters, and intestinal microflora in broiler chickens under heat stress. A total of 240 one-day-old Ross 308 broiler chicks (initial body weight: 46.72 ± 0.18 g) were used in a 42-day trial. The chicks were divided into six groups of 10 birds each, with four replicates. The study groups were divided into six groups: control (TNC) under normal environmental conditions (TN), PFJM (TNPJFM) and commercial probiotic (TNTP) supplemented in their drinking water, and control (HSC), HSPFJM, and HSTP under heat stress (HS) conditions. Temperature (34.5–36.2 °C) was applied for 42 days. Lactic acid bacteria (LAB) were 1.2 × 1012 cfu/mL in PFJM, and Lactiplantibacillus plantarum was the predominant species. Probiotics were added to the chicks’ drinking water at 0.5 mL/L. The control groups’ water was free of probiotics. This study revealed a decrease in body weight and body weight gain and a worse feed conversion ratio in the HSC group. The lowest carcass weight under heat stress was in the HSC group, and the highest was in the HSPFJM group. The lowest gizzard and highest bursa Fabricius percentages were in the probiotic-containing groups. Blood glucose and uric acid decreased in the HSPFJM group. In the HSC group, lactic acid bacteria (LAB) decreased, while E. coli, total mesophilic aerobic bacteria (TAB), enterobacteria, and yeast increased. In the probiotic-supplemented groups, LAB increased, while E. coli, yeast, and enterobacteria decreased. The study results suggest that PJFM supplementation may positively impact intestinal health in chickens exposed to heat stress, supporting growth performance and health parameters.
Keywords:
heat stress; probiotic; cecum microbiology; broiler
