تاثیر مصرف پیاز بر عملکرد تولیدی و فراسنجه های بیوشیمیایی و خون‌شناسی گوساله‌های پرواری

Effect of onion feeding on biochemical and hematological Parameters and performance of fattening calves

Introduction: Onions are herbaceous plants from the Alliaceae family, that all have important dietary and medicinal properties. The average cultivated area of onion in Iran is 61500 ha; however up to 40% of the onions produced may are culled when production exceed market demand (Diani et al. 2021). Feeding cull onion bulbs to livestock is one method to cull onion disposal that may benefit both livestock and onion producer (Fredrickson et al, 1995). Livestock easily consumes onion often preferred to high quality roughages or grains (Keyvanlou et al. 2011). However, the sulfur compounds of the onion have hemolytic activity in high levels. Onions have also, fungicidal and bactericidal properties may alter rumen microbial population (Fredrickson et al. 2011). Studies examining onion toxicity have generally focused on lab animals, broiler or sheep; however, few studies on calves health and productivity are available. This experiment examine the effects of short-term onion feeding on hematological and biochemical parameters and performance of calves.
Material and methods: Ten Holstein-Sarabi calves weighing 123.6±5.46 kg designed to one of the two control or control+onion supplemented diets based on a completely randomized design for eight weeks. Onions was prepared daily by chopping and mixing with concentrate portion of diet to provide 10% onion dry matter basis. 10 ml venous blood was taken from fastened calves for biochemical and hematological analyze at the end of experiment. Weighting was conducted once per four week and daily feed and water intake was recorded individually. Data were analyzed using SPSS version 18. The experiment was conducted in a completely randomized design with two treatments and five repetitions: Y_ik=μ+T_i+e_ik . Biochemical and hematological parameters and performance of calves were analyzed using the general procedure of multivariable linear model and the average weight of animals during the experiment using data repeated in time. The non-parametric Mann-Whitney test was used to compare the results of the white blood cells differential test.
Results and discussion: Statistic analysis revealed calves fed onion diets had significantly (P<0.01) high values of Glucose, Cretinine, Calcium, and low Uric acid when compared to control. Hematological parameters of onion fed calves hadn’t significantly difference from control group, while count of monocyte were significantly increased and the proportion of eosinophil and basophil were significantly decreased (P<0.05). Mean daily weight gain and feed conversation of onion fed calves was significantly higher than control, while mean body weight and dry matter intake and water intake wasn’t changed. Regulation of hypoglycemic activity is considered one of the important effects of onion that have frequently shown in diabetic animal models (Kumari et al. 1995, Babu et al. 1997, Fallah Huseini et al. 2006, Akash et al. 2014). Sulfur compounds including S-methylcysteine and flavonoids such as quercetin are mainly responsible for the hypoglycemic activity of Allium cepa. These component induce hypoglycemia by inhibiting a-glucosidase, improving insulin secretion, reduce insulin resistance and maintaining glucose tolerance (Akash et al. 2014). Khaki et al. (2010) reported, onion had lowering effect in serum insulin level in healthy animals, contrary to what happens in diabetic animals. This may explain why the serum glucose level increased in onion fed calves in recent experiment. Onion have not significant impacts on blood lipid profile of calves in this experiment unlike previous studies (Kumari et al. 1995, Babu et al. 1997, Akash et al. 2014, Amiri et al. 2019, Dayani et al. 2020). The lack of a sufficient time for any significant changes in metabolic pathways may be the reason. Decrease in serum uric acid level (P=0.06) in onion fed calves in this experiment is in agreement with Haidari et al. (2008) study and in conflict by Ghiasi et al. (2014b). Inhibitory effect of onion in serum uric acid level may be one of the therapeutic approaches to treat gout (Haidari et al., 2008). Onion couldn’t lower serum urea value in current experiment and significantly increased serum creatinine level. Creatinine builds up in the blood in kidney disease, but its changes was in normal range yet. Dietary inclusion of onion improved hematological parameters as well as proportion of lymphocytes, neutrophils and monocytes of calves in accordance with the other reports (Tatfeng and Enitan 2012, Samson et al. 2012, Barzegar Khandouzi et al. 2014). Postulated mechanisms of action supposedly revolve around onion stimulatory effects on some cytokines, their role in iron bio-availability, and presence of some vitamins, essential amino acids and phytochemicals (Lampe et al, 1999). Effects of onion on leucopoiesis may be attributed to its ability to stimulate production of some colony stimulating factors (Samson et al, 2012). The significant reduction in proportion of eosinophil and basophil in this experiment may be due to release and consumption these cells followed by releasing the allergens from onion. The significant increase observed in weight gain and feed conversion ratio of calves fed onion in this present study, concur with that of previous researchers reported for broiler and lambs (Aji et al. 2011, An et al. 2015, Amiri et al. 2019). The herbal products and spicy have been used in animal feed as digestion stimulants and growth promoters (Frankic et al. 2009). Mitigate methane emissions in ruminants is also expected.
Conclusion: Feeding 10% onion based on total dry matter of diet had not only negative effect on biochemical and hematological parameters of growing Holstein-Sarabi calves but also increased serum glucose and calcium levels and blood monocyte percentage, and significantly improved daily weight gain and feed conversion ratio. Therefore, it seems that feeding this level of onion in fattening calves is harmless and even beneficial in the conditions of falling onion prices.
Keywords: Biochemical parameters, Calves, Hematological parameters, Onion, Production performance