Effects of Humic Acids on Poultry Under Stress Conditions

Abstract

The transportation of chickens from the poultry farm to the slaughterhouse causes stress conditions that influence the oxidative status of the whole organism and subsequently change the organoleptic properties of the meat delivered to the consumer. The aim of this work was to investigate how administering 0.6% humic acids to broiler chickens for a period of 42 days affects the level of selected enzymes directly involved in oxidative stress elimination. For the most objective estimation of the oxidative state, parameters were determined in liver and kidney mitochondria, and in the blood plasma. With regards to the chelating properties of humic acids, our interest was in monitoring the effects on the distribution of the transition metals Fe, Zn, Cu, Mn, which serve as cofactors of antioxidant enzymes. We have found that, under normal conditions, 42 days of humic acid administration do not cause significant metal redistribution. It has a significant effect on Se excretion, according to the pronounced deposition of Se in kidney tissue, without significantly increased activity of the corresponding enzyme. This led to compensation by changes in other antioxidant enzyme activities. This is a noteworthy finding, especially after administration of longer than 42 days. In conditions caused by sudden stress, according to the detected element levels, it is possible to expect a better response in the case of humic acid administration. The effect of humic acid supplementation appeared to be organ-specific and may ultimately be beneficial for the chickens' health, stress elimination and, finally, the quality of the meat.

Effect of the Addition of Humic Substances as Growth Promoter in Broiler Chickens Under Two Feeding Regimens

“…In broilers supplemented with increasing dietary FA, increased superoxide dismutase and glutathione peroxidase activity and decreased malondialdehyde levels in the blood were also found in a recent study [40]. In broilers supplemented with HS and subjected to transportation stress, increased superoxide dismutase activity in the mitochondria of the liver compared to the control group was also observed [12]. The activities of glutathione reductase followed the same trend.…”

“…In rats supplemented with HS, higher nitrogen retention has also been observed [39]. Recently, in FA-fed broilers [40] higher activities of the digestive enzymes amylase, lipase, and protease were reported, which agrees with the increased length of the mucosal villi of the jejunum and the increased gut length due to dietary inclusions of HS in broiler [12,41]. However, these findings do not agree with the lack of effects of EHS on nutrient use in our research.…”

“…These findings did not agree with the lack of effect of the EHS on the antioxidant status and index of lipid peroxidation in the breast muscle and the meat quality variables of this study. In our research, the antioxidant status of breast meat was measured, rather than in blood, because the meat is the final product for human consumption, and the antioxidant status of the meat may influence the shelf life and other variables such as meat color, flavor, and tenderness [12,44].…”

“…In broiler chickens, improvements in body weight, feed conversion, the ash content of the tibia, and the retention of ashes, nitrogen, and energy as well as reduced crypt depth and increased length of the villi of the jejunal mucosa due to the inclusion of HS have been reported [4,8]. Increased antioxidant activity in birds reared under normal and stress conditions [11,12] and lower Escherichia coli counts in the digesta of the small intestine have also been reported in broilers added with HS (50). However, contrasting results have also been found.…”

Multiple factorial analysis of physicochemical and organoleptic properties of breast and thigh meat of broilers fed a diet supplemented with humic substances

“…Supplying poultry meat of adequate quantity and quality to meet public demand is a major objective of the broiler industry ( Esenbuga et al., 2008 ). From the perspective of the consumer, poultry is a very attractive and essential element in the human diet because of its nutritional, dietetic, and sensory properties, and its rapid culinary preparation ( Vašková et al., 2018 ).…”