Document Type : Research Paper

Authors

• yaser feizdar barabadi ¹
• seyyed ehsan ghiasi ¹
• Rassoul Kadkhodaee ²
• Mohsen Mojtahedi ¹

¹ Department of Animal Science, Faculty of Agriculture, University of Birjand, Birjand, Iran.

² Department of Food Nanotechnology, Research Institute of Food Science and Technology, Mashhad, Iran

Abstract

Keywords

• protein nanofibrils
• Ruminal fermentation
• stabilized supplement
• trace minerals

Main Subjects

• Animal Nutrition and poultry

Extended Abstract

Introduction

    Zinc and copper are essential trace minerals that are crucial for maintaining the health and optimal production of animals. In animal feed, mineral supplements are commonly used, both in organic and inorganic forms. However, during the digestion process, these mineral forms can dissociate and interact with other molecules, resulting in reduced absorption and bioavailability, particularly for trace minerals. Thus, the objective of this research was to examine the effects of a chelate composed of whey protein isolate nanofibrils, as well as inorganic copper and zinc, on the production performance, blood indices, antioxidant enzyme activity, and rumen fermentation of fattening lambs, both in vivo and in vitro.

Materials and methods

    To facilitate the formation of stable chelates of copper and zinc in the rumen, whey protein was initially utilized to generate nanofibrils. During the nanofibril formation process, copper and zinc elements in the form of sulfate, along with 1% phenolic extract of pomegranate peel, were incorporated into the target solution. The resulting solution was subsequently subjected to centrifugation and freeze-drying to produce a stable chelate supplement. In a completely randomized design, eighteen male Kurdish lambs with an average initial weight of 30.60 ± 2.27 kg were assigned to one of three experimental diets. These diets consisted of: 1) control diet (containing zinc: 28.14 mg/kg of DM, copper: 4.164 mg/kg of DM), 2) control diet supplemented with copper and zinc in the form of sulfate (containing zinc: 58.33 mg/kg of DM, copper: 9 mg/kg of DM), and 3) control diet supplemented with stabilized copper and zinc chelate (chelate made from whey protein isolate nanofibrils with polyphenol of pomegranate peel extract, containing zinc: 58.33 mg/kg of DM, copper: 9 mg/kg of DM). These diets were administered to the lambs for a period of 12 weeks. Throughout the experimental period, the animals were weighed every two weeks, and measurements were taken for feed consumption, daily weight gain, food conversion ratio, and nutrient digestibility. Blood samples were collected on days 0, 28, 56, and 84, to assess blood parameters and liver enzymes. For the in vitro test, the semi-automatic gas production technique was employed, with 21 repetitions and 2 runs for each test. Measurements of pH, ammonia nitrogen concentration, and in vitro dry matter digestibility were recorded at 8, 12, 24, and 48 hours. Statistical analyses were conducted using the MIXED procedure for repeated data over time, and the GLM procedure of SAS software for data that were only repeated once over time. Averages were compared using the Tukey-Kramer test.

Results and discussion

   The results indicated that supplementing the diet with stabilized chelate in the rumen significantly increased the gas production potential and gas production rate constant (P<0.05). However, the lag phase, pH, ammonia nitrogen concentration, and in vitro digestibility of dry matter were not affected by the treatments. Additionally, zinc and copper supplementation led to an increase in daily feed intake, average daily weight gain, and final weight of lambs (P<0.05). However, the food conversion ratio was not influenced by the level and type of supplement in the diet. The use of zinc supplement resulted in improved apparent digestibility of dry matter, organic matter, and neutral detergent insoluble fiber (P<0.05). On the other hand, the digestibility of fat, crude protein, and acidic detergent insoluble fiber of the feed was influenced by the feeding surface, but not by the type of zinc supplement used. Furthermore, in this study, the addition of organic and mineral zinc supplements to the diet of fattening lambs increased the concentration of total protein, albumin, superoxide dismutase, and glutathione peroxidase (P<0.05). However, it had no significant effect on the concentration of glucose, triglyceride, cholesterol, and serum alkaline phosphatase enzyme activity.

Conclusion

Overall, this study's findings show that using zinc and copper supplements, regardless of where they come from, can increase gas production potential and enhance the growth performance of fattening lambs. These supplements also lead to increased liver and antioxidant enzyme activity associated with these elements. In contrast, the stable chelate supplement developed in this study had even better effects compared to the mineral form, indicating that it is more easily absorbed by the body.

Author Contributions

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All authors contributed equally to the conceptualization of the article and writing of the original and subsequent drafts.

Data Availability Statement

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Acknowledgements

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The authors would like to thank all participants of the present study.

Ethical considerations

The study was approved by the Ethics Committee of the University of ABCD (Ethical code: IR.UT.RES.2024.500). The authors avoided data fabrication, falsification, plagiarism, and misconduct.

Conflict of interest

The author declares no conflict of interest.

Conflict of interest

The author declares no conflict of interest.