Document Type : Research Paper

Authors

• Hasan Rouhanipour ¹
• Omid Ashayerizadeh ²
• Seyed Davood Sharifi ³
• Behrouz Dastar ⁴

¹ Corresponding Author, Department of Animal and Poultry Nutrition, Faculty of Animal Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. E-mail: hassan.rouhanipour_s99@gau.ac.ir

² Department of Animal and Poultry Nutrition, Faculty of Animal Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. E-mail: o.ashayeri@gau.ac.ir

³ Faculty of Agricultural Technology, University of Tehran, Pakdasht, Iran. E-mail: sdsharifi@ut.ac.ir

⁴ Faculty of Animal Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. E-mail: dastar@gau.ac.ir

Abstract

Objective: Young laying hens produce eggs with inferior eggshell quality, which is commonly reported as a problem in laying hens farms as it limits the productive life of hens and decreases table egg quality, which has a great negative impact on the poultry industry. In recent years, poultry research has often focused attention on the potent effects of dietary arginine (Arg) on poultry performance. Also, the use of amino acid supplements with an essential trace element (Copper sulfate; CuSO4) in the diets of laying hens has become essential as a result of their lack of access to fresh feed, storage in cages, and processing of feed.
Methods: The effects of dietary copper and L-Arginine supplementation on production performance, egg quality parameters, and serum biochemical metabolites during 22 to 30 weeks of age with a total of 288 Hy-Line W-80 white laying hens were used in 2×3 factorial arrangements with two levels of supplemental Cu (8 and 16 mg/kg in the layer diet denoted as Cu8, Cu16) and three levels of LA [include the recommended level according to Hy-line (RHL), as well as 20% higher (LA20) and 40% higher (LA40) than the recommended level] in the diet, 6 replicates with 8 birds per cage, for 8 weeks. The eggs produced were collected daily and after weighing, the percentage of laying, feed intake, conversion factor, average egg weight and egg shape index were calculated weekly. On the last two days of each week, the eggs produced by each experimental unit were collected and tested for qualitative traits such as shell thickness, haugh unit, and etc. Feed intake of experimental units was calculated from the fraction of feed consumed at the end of the period from the feed allocated at the beginning of the period, based on hen days. At the end of 30 weeks, two birds with close to average weight were selected from each replicate and 5 ml of blood was collected from them with a syringe through the wing vein and transported to the laboratory using regular (non-heparin) blood tubes to measure serum biochemical parameters (LDL, HDL, glucose, triglycerides, cholesterol) and estradiol hormone.
Results: Egg production of birds in response to Cu16+LA20 and Cu16+RHL diets increased, compared to birds fed with Cu8+RHL (P<0.05). Feed conversion ratio of birds in response to Cu16+RHL diet decreased, compared to birds fed with Cu8+LA40 (P<0.05). The egg Shape index in birds fed Cu16+LA20 increased, compared to Cu8+RHL, Cu8+LA20, and Cu16+RHL diets (P<0.05). Cholesterol was decreased in the groups supplemented with Cu16+LA40, compared to those fed with Cu16+RHL and Cu8+LA20 treatments (P<0.05). The serum superoxide dismutase level in birds fed Cu16+LA40 increased compared to birds fed Cu8+LA20 (P<0.05).
Conclusion: Adding 16 mg/kg copper with 20% and 40% higher of L-arginine than the recommended level can improve production, egg quality and serum biochemical parameters of laying hens at 22 to 30 weeks of age.

Keywords

• Blood serum metabolites
• Copper
• L-arginine
• Laying hen
• Production performance