نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانش‌آموخته دوره دکتری تغذیه دام، دانشگاه آزاد اسلامی واحد ورامین پیشوا
2 استادیار ، گروه علوم دامی، دانشگاه آزاد اسلامی، واحد قائمشهر، ایران
3 استادیار ، ،تغذیه دام - عضو هئیت علمی ، ،دانشگاه آزاد اسلامی رودهن
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Lamb fattening is one of the important sources of red meat production in the country. Fattening is the management and proper feeding of livestock to obtain maximum extra weight with minimum cost in a certain period of time. The use of concentrate in the diet of fattening lambs in the country is normal and common, but what is important is the appropriate level of concentrate, or in other words, the appropriate ratio of forage to concentrate in the diet. The purpose of this study was to investigate the effect of increasing the ratio of concentrate to forage on feed intake traits, body weight, feed conversion ratio and carcass characteristics of Afshari fattening male lambs.
Materials and methods: The present study was conducted using 24 male lambs with a mean weight of 31.78 ± 1.3 kg and a mean age of 91 ± 3.13 days in four experimental groups (treatments) in a completely randomized experimental design with three treatments and 8 replications. The experimental treatments included diets with different ratios of forage to concentrate in the form of 30:70, 20:80 and 10:90. The experimental diet was set based on of NRC (2007) and the ingredients of the diet and their nutritional value were similar. Lambs were fed three times a day at 8, 14, and 20 until their appetite. The lambs were weighed at the end of the experiment after 16 hours of feed abstinence and six lambs from each treatment were killed. Study data was analyzed through Spss21, Excel.
Results: A significant difference was observed between different treatments in terms of weight gain. The third treatment produced the highest daily weight gain (296 g) and the first treatment produced the lowest daily weight gain (241 g) in lambs. With the increase of concentrate, the feed intake increased due to the higher content of energy and nutrients of the concentrate compared to the forage, and the lambs that consumed more concentrate had higher body weight and slaughter weight. So that the highest amount was related to 90% concentrate and 10% forage (1.830 g) and the lowest was related to 70% concentrate and 30% forage (1.573 g). The fourth treatment had a numerically lower feed conversion ratio (6.18) compared to the other two treatments. The mean final weight of lambs, hot and cold carcass weight showed a significant difference among experimental treatments.
Conclusion: According to the obtained results, the reduction of forage did not cause any production problems in these animals. Increasing the concentrate and reducing the forage in the diet increases the amount of feed intake and increases the daily weight and overall higher final weight in fattening lambs, and also improves the feed conversion ratio, growth performance and carcass percentage.
کلیدواژه‌ها [English]
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