| چکیده انگلیسی مقاله |
Extended Abstract
Introduction: Zinc (Zn) is one of the most important minerals for the health and productivity of growing calves; Because this mineral is important for metabolism, growth, immune and defense system and antioxidant status. Also, this element is known as an anti-inflammatory and anti-diarrheal agent. In addition, Zn in enzymes acts as a structural component away from the active site, a proton donor in the active site, and an atomic bridge between the substrate and the enzyme. Zn has an essential role in the regulation of many metabolic processes, and its deficiency results in low appetite consequently decreased feed intake. Therefore, is of strong interest for producers, feed manufacturers, veterinarians and scientists. The National Research Council (2021) recommended 70 mg/kg Zn for calves at 30 days of age. While, the amount of this element in soil of many regions of Iran is commonly low. Therefore, the plants that grow in these soils have a low level of zinc concentration, and when they are consumed as animal feed, it can cause a wide range of complications due to zinc deficiency, of which abnormality in growth is one of the most obvious signs. Zn supplementation may improve the health and performance of suckling calves. However, the use of high concentration of zinc in the diet may affect the digestion, absorption and use of other nutrients in the diet and potentially lead to environmental pollution due to the excess excretion of zinc in the feces, so the use of zinc sources with above bioavailability has a special place. Recently, organic and hydroxy forms of mineral in animal feed supplements have attracted substantial interest of feed manufacturers and animal producers. Because they have higher bioavailability of Zn compared to inorganic salts. The aim of this study was to evaluate the effect of Zn sulfate, organic Zn and Zn hydroxychloride on performance, growth and blood parameters in Holstein suckling calves.
Material and Methods: This study was conducted using 40 Holstein suckling calves from 7 to 77 days of age in a completely randomized design. Each treatment had the same numbers of male and female calves. Treatments include:1) basal diet without zinc supplement (containing 53.29 mg Zn /kg DM); 2) basal diet+20 mg Zn /kg DM as organic Zn; 3) basal diet+20 mg zinc /kg DM as Zn hydroxychloride and 4) basal diet+20 mg Zn /kg DM as Zn sulfate. Calves were kept in individual stalls and had ad libitum access to water and Starter. During the experiment, the calves were fed with two meals of milk at 8:00 and 16:00 at the rate of 2 kg per meal. The dry matter intake, daily gain and feed conversion ratio in calves were determined. Blood samples were taken from the jugular vein at the 7, 43 and 77 days of age almost 4-5 hours after the morning feeding. The collected blood was poured into two separate tubes, one containing heparin to obtain plasma and the other without heparin to obtain serum. Plasma and serum samples were kept at minus 80 degrees Celsius until the measurement of the studied parameters. Blood concentrations of calcium and phosphorus, aspartate aminotransferase, alkaline aminotransferase, alanine aminotransferase, superoxide dismutase, creatine phosphokinase and lipid parameters (triglyceride, cholesterol, High-density lipoprotein, Low-density lipoprotein and very low-density lipoprotein) were measured using the commercial kits. Mindray BS-800 Chemistry Analyzer - BS-800 was used to measure the amounts of Zn, iron and copper in blood. Data were analyzed in a completely randomized design using SAS.
Results: The results showed that there were no significant differences between treatments for daily weight gain and dry matter intake at the 21, 35, 45 and 63 days of age (P>0/05). But at 77 days of age, daily weight gain and feed intake in calves received Zn supplements as Zn sulfate, Zn hydroxychloride and organic Zn were significantly higher than control group (P<0.05) Although there was no significant difference between different sources of Zn supplemented to groups (P>0/05). Body weight and feed conversion ratio of calves during the suckling period were not affected by Zn supplementation (P<0.05). There was significant increase in the serum Zn and Alkaline phosphatase concentrations of supplemented calves in the form of Zn sulfate, Zn methionine and Zn organic compared to the control group (𝑃<0.05). Serum concentrations of Iron, copper, calcium and phosphorus, aspartate aminotransferase, alanine aminotransferase, creatine phosphokinase and lipid parameters (triglyceride, cholesterol, High-density lipoprotein, Low-density lipoprotein and very low-density lipoprotein) were not affected by the treatments (P>0.05). However, superoxide dismutase activity of Zn supplemented groups showed Numerical increase compared to control group (P=0.08).
Conclusion: The results showed that adding 20 mg Zn/kg DM as Zn sulfate, Zn hydroxychloride and organic Zn caused increased serum Zn and Alkaline phosphatase concentrations and finally, led to the improvement of dry matter intake and daily weight gain. But there was no significant difference between the Zn supplemented groups for serum Zn and Alkaline phosphatase concentrations and dry matter intake and daily weight gain.
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| نویسندگان مقاله |
لیلا چراغی مشعوف | Leyla Cheraghi Mashoof
Department of Animal Sciences, Faculty of Agriculture, Bu Ali Sina University, Hamedan, Iran
گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران
حسن علی عربی | Hassan Aliarabi
Department of Animal Sciences, Faculty of Agriculture, Bu - Ali Sina University, Hamedan, Iran
گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا همدان، ایران
داریوش علیپور | Daryoush Alipour
Department of Animal Sciences, Faculty of Agriculture, Bu - Ali Sina University, Hamedan, Iran
گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران
پویا زمانی | Pouya Zamani
Department of Animal Sciences, Faculty of Agriculture, Bu - Ali Sina University, Hamedan, Iran
گروه علوم دامی، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران
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