مقايسه عملكرد اقتصادي گوسفند و بز متكي به مرتع در استان تهران و اصفهان

Comparison of the economic function of the sleep and goat depending on rangelands in Tehran and Isfahan provinces

سيستم سنتي بهره برداري از مراتع بيشترين سهم را در بهره برداري از مراتع كشور براي توليدات دامي دارد. جمعيت دام مازاد بر ظرفيت مراتع در اين روش بهره برداري، علاوه بر تغيير در تركيب پوشش گياهي و تخريب مراتع، باعث كاهش بازدهي دام نيز مي شود. شناخت دامهاي با عملكرد اقتصادي بيشتر زمينه كاهش دام با حفظ درآمد را در بهره-برداري پايدار از مراتع فراهم مي نمايد. در اين تحقيق در استانهاي تهران و اصفهان دو نوع دام در سه طبقه سني در گله هايي با دو تركيب گوسفند زندي، بز بومي در استان تهران و گوسفند ناييني و بز بومي در استان اصفهان بررسي گرديد. هزينه دام براساس سرانه هزينه هر راس دام در استفاده از هريك از منابع علوفه اي (مرتع، پس‌چر مزارع و علوفه دستي) به تفكيك نوع دام و بر مبناي مدت استفاده محاسبه و درآمد بدست آمده براساس وزن دام مورد فروش در زمان عرضه به بازار محاسبه گرديد. درآمد ساير محصولات دامي نظير شير و فراورده هاي مرتبط با آن، پشم، مو و كرك حاصل از گله و نيز بره زايي در درآمد دام منظور گرديد. طرح براساس پايه آماري اسپليت پلات كه در آن تيمار اصلي نوع دام (گوسفند و بز) و تيمار فرعي سن دام (در طبقات سني تا سه سال، 4 تا 6 سال و بيش از 6 سال) انجام شد. نتايج نشان داد كه تفاوتهاي آشكاري بين ميزان توليدات در گله هاي دو استان وجود دارد. از سوي ديگر در بين وزن بره ها و بزغاله‌هاي بدست آمده از گله نيز تفاوت معني دار وجود دارد. براساس نتايج آماري سن دام بر وزن بره ها و بزغاله ها موثر بوده است، به نحوي كه بهترين سن بره زايي براي هر دو نژاد گوسفند ناييني و زندي و هم در بزهاي بومي 3 تا 6 سال تعيين گرديد. البته در هر دو استان اصلي ترين منبع درآمد گوسفند بوده و بز عمدتاً تامين كننده نياز خانوارهاي دامدار مي‌باشد.

This research was performed in Isfahan and Tehran Provinces. The races considered in Tehran province were Zandi Sheep and native goat. Naeini Sheep and native goat were also studied in Isfahan province. To feed livestock, rangelands (winter range and summer range), aftermath of farms and handy hay were used. Using of aftermath and handy hay was done in all flocks. The usage duration of hay, aftermath and rangelands in Tehran province was different among the flocks considered in this study due to different flocks and different years as they differed from 65 to 120, 100 to 180 and 90 to 245 days respectively. The usage duration of hay, aftermath and rangelands in Isfahan province also differed from 85 to 100, 30 to 240 and 90 to 245 days respectively. In both provinces, the forage of rangelands and hay were used simultaneously to compensate the shortage of forage in rangelands. Livestock products in the flocks were milk, cheese, curd, butter, wool and fuzz. The amount of Per capita production was different per head. In Tehran province, sheep suck differed from 25 to 120 days in the flocks considered here. In Isfahan province the milk of sheep was used by lambs hence there was no sheep suck. Curd production was just done in one flock which approximately produced 0.5kg curd per a head of sheep annually. Wool harvest was performed in all flocks. Per capita production of wool differed from 800 to 900gr per a head of sheep. Cheese production was done through the milk of sheep and goat and its amount for sheep and goat differed from 2 to 7.7 and 4.5 to 12kg respectively. The average of wool and fuzz production in Isfahan province differed from 500 to 800 and 200 to 250gr in different flocks respectively. In this province, cheese produced from the milk of goat and differed from 90 to 1200gr related to the duration of suck in different flocks. The amount of curd production also differed from 150 to 1500gr per a head of goat. The amount of milk production in goat differed from 3 to 10kg related to the duration of suck. The sale of lamb and goat was the main source of ranchersʹ income. The sale weight of lamb and goat differed in various ages. Average weight of lamb and goat were different as below: The average weight in 3, 3 to 6 and more than 6-year-old lambs of Naeini and Zandi races was 28.8, 34.8 and 32.6kg respectively. Average weight in less than 3, 3 to 6 and more than 6-year-old goats of native races in Isfahan and Tehran was 23.8, 23.8 and 24.7 kg respectively. There was a significant difference between the weight of lambs and goats. There was a significant difference between the weight of Naeini and Zandi sheep. The results showed that the most economic age of livestock in both Naeini and Zandi races were 3 to 6- year-old. Weights of 3 to 6-year-old lambs in Naeini and Zandi races were 29.6 and 39.8 kg respectively. The weight of 3 to 6-year-old goats in native races of Isfahan and Varamin were 20.8 and 30.4 kg, respectively.