Authors
1
Master's degree graduate in Animal Nutrition, Department of Animal Sciences, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
2
Dep, Animal Sci Mohaghegh Ardabili
3
Professor, Department of Animal Sciences, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
4
Professor, Department of Animal Sciences, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
5
Associate professor, Department of Animal Sciences, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
6
Doctoral student in Animal Nutrition, Department of Animal Sciences, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
Abstract
Background and Objectives: Alfalfa is one of the plants that requires a lot of water among crops. Iran has an arid climate and with the increasing need for water, the problem of water shortage will become more acute in the coming years. Therefore, diversifying animal feeds can reduce the negative effects of water shortage on the livestock industry. Forage corn is one of the most nutritious non-legume green forages and does not contain any anti-nutritional factors. Corn silage is a very palatable food and an economical and energy-rich source for ruminants. Therefore, the aim of the present study was to investigate the effect of different ratios of alfalfa to silage corn on fattening performance, blood parameters, nutrient digestibility and carcass characteristics of male Moghani lambs.
Materials and Methods: This study was conducted using 20 male Moghani lambs with an average age of about 6 months and an average body weight of 25±2 kg in a completely randomized design with 4 experimental groups and 5 replications (lambs) per diet. The duration of the experiment was 75 days and 15 days of the adaptation period. The experimental diets in this study included: 1) diet with 100% dry alfalfa, 2) diet with a ratio of 75% dry alfalfa to 25% corn silage, 3) diet with a ratio of 50% dry alfalfa to corn silage, and 4) diet with a ratio of 25% dry alfalfa to 75% corn silage. The lambs were randomly grouped between different treatments based on body weight, and each group was fed one of four diets. Before the start of the rearing period, lambs were vaccinated against enterotoxaemia and received antiparasitic medication to control internal and external parasites. Lambs were fed two meals a day at 9 am and 5 pm in individual pens. Lambs had free access to water. The basal diet was based on the nutritional requirements recommended by the National Research Council (2007 NRC) using sheep software (SRNS, version 1.9.4468) and based on the nutritional requirements of lambs weighing approximately 30 kg and gaining 220 g daily. Blood samples were taken monthly from all lambs 3 hours after feeding from the jugular vein. Apparent digestibility was measured at the end of the period by collecting feces from the anus for 5 consecutive days during the last week using bags prepared for this purpose.
Results: Feeding diets with 25 and 50% corn silage in the forage portion improved feed intake and average daily weight gain throughout the fattening period (P<0.05). Feeding diets with a forage portion consisting entirely of alfalfa or 75% alfalfa and 25% corn silage improved the apparent digestibility of dry matter and organic matter in fattening lambs (P<0.01). Blood metabolites were not affected by the experimental diets. Feeding different levels of alfalfa and corn silage did not affect any of the carcass traits of fattening lambs.
Conclusion: Considering the improvement in feed consumption, daily weight gain throughout the entire period, and the lack of negative effects on other rearing parameters and the digestibility of dry matter and organic matter, it is recommended to use forage corn at a rate of 25% of the forage portion in the diet of fattening lambs.
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