Alaa Mohammad, Abdel Razek Abeer Hamada, Tony Mohamed Ahmed, Yassin Aya Mohye, Warda Mohamad, Awad Mohamed Ahmed, Bawish Basma Mohamed
Department of Veterinary Hygiene and Management, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt.
Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Cairo University, Giza, 12211, Egypt.
Acta Vet Scand. 2024 Dec 18;66(1):62. doi: 10.1186/s13028-024-00782-6.
Rearing poultry under stressful high stocking density (HSD) conditions is a common commercial practice to increase profitability, despite its negative effects on broiler physiology and welfare. Many feed additives are used to alleviate the negative impact of such practices. This study investigated the ameliorative effects of guanidinoacetic acid (GAA) on growth performance, ingestive behavior, immune response, antioxidant status, stress indicators, and intestinal histomorphometry of broilers subjected to HSD. A total of 364 male broilers were randomly allocated into four treatments with 7 replicates each in a 2 × 2 factorial arrangement: two stocking densities (SD) (10 and 16 birds/m) and two GAA levels (0 and 0.6 g/kg feed).
Body weight, weight gain, feed intake, feed conversion ratio, production efficiency factor, dressing yield, and ingestive behavior were negatively affected by HSD, whereas the mortality rate was unaffected (P > 0.05). GAA improved the overall growth performance and dressing percentage (P < 0.05). In the HSD group, the immune response decreased at d 21 (P < 0.05). Creatine kinase, glutathione peroxidase (GPX), superoxide dismutase, catalase, triglycerides, and villus length and width (ileum) were reduced, whereas corticosterone (CORT) was increased (P < 0.05). Moreover, GAA increased the hemagglutination-inhibition titer at 21 days and the levels of lactate dehydrogenase, GPX, and catalase and decreased the levels of creatinine, alanine aminotransferase, nitrite, triglycerides, and CORT (P < 0.05). SD and GAA did not affect malondialdehyde or other biochemical parameters (P > 0.05).
Dietary GAA supplementation can improve productivity and antioxidant status and reduce stress in broilers reared in a HSD environment.
尽管在高饲养密度（HSD）这种应激条件下饲养家禽对肉鸡生理和福利有负面影响，但这是提高盈利能力的常见商业做法。许多饲料添加剂被用于减轻此类做法的负面影响。本研究调查了胍基乙酸（GAA）对处于HSD条件下肉鸡的生长性能、摄食行为、免疫反应、抗氧化状态、应激指标和肠道组织形态计量学的改善作用。总共364只雄性肉鸡被随机分配到四个处理组，每组7个重复，采用2×2析因设计：两种饲养密度（SD）（10只和16只/m²）和两种GAA水平（0和0.6 g/kg饲料）。
HSD对体重、体重增加、采食量、饲料转化率、生产效率因子、屠宰率和摄食行为有负面影响，而死亡率不受影响（P＞0.05）。GAA改善了总体生长性能和屠宰率（P＜0.05）。在HSD组中，第21天时免疫反应下降（P＜0.05）。肌酸激酶、谷胱甘肽过氧化物酶（GPX）、超氧化物歧化酶、过氧化氢酶、甘油三酯以及绒毛长度和宽度（回肠）降低，而皮质酮（CORT）升高（P＜0.05）。此外，GAA提高了21天时的血凝抑制效价以及乳酸脱氢酶、GPX和过氧化氢酶的水平，并降低了肌酐、丙氨酸转氨酶、亚硝酸盐、甘油三酯和CORT的水平（P＜0.05）。SD和GAA对丙二醛或其他生化参数没有影响（P＞0.05）。
在HSD环境中饲养的肉鸡日粮中添加GAA可提高生产性能和抗氧化状态并减轻应激。
