Determine more productivity livestock for maximum economic output of rangelands.

Current uses of forage in rangelands (pastures) are performed through traditional patterns. The pressure of overgrazing on vegetation composition and nutrition of livestock using rangelands (pastures) affects their economic output. The present study was done to determine the maximum economic output of rangelands (pastures) and to clarify the kind of animal and the period in which it may have more productivity in order to convert the forage of rangeland into the livestock products. 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. Flock composition was sheep and goat in both provinces. The average of flock population in Tehran and Isfahan was 308 heads (83% sheep and 17% goat) and 1553 heads (73% sheep and 27% goat) respectively. 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 Percapita 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 0.5 kg curd per a head of sheep annually. Wool harvest was performed in all flocks. Percapita production of wool differed from 800 to 900 gr 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 12 kg respectively. The average of wool and fuzz production in Isfahan province differed from 500 to 800 and 200 to 250 gr in different flocks respectively. In this province, cheese produced from the milk of goat and differed from 90 to 1200 gr related to the duration of suck in different flocks. The amount of curd production also differed from 150 to 1500 gr per a head of goat. The amount of milk production in goat differed from 3 to 10 kg related to the duration of suck. The sale of lamb and goat was the main source of ranchers' income. The sale weight of lamb and goat differed in various ages. The average weight of lamb and goat are 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 32.6 kg respectively. The 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 had been 3 to 6- year-old. The weight of 3 to 6-year-old lambs in Naeini and Zandi races was 29.6 and 39.8 kg respectively. The weight of 3 to 6-year-old goats in native races of Isfahan and Varamin was 20.8 and 30.4 kg respectively.