Seasonal variation on phytosociology and carrying capacity of sheep in different pasture systems

The field experiments were conducted at the Livestock Farm Complex, Tamil Nadu
Veterinary and Animal Sciences University, Chennai, Tamil Nadu, India. Five years old
Silvipasture and hortipasture systems established in an acre at livestock farm complex were
taken for the study. The species under the storey of the trees were identified, and counted for
calculation of phytosociology indices and palatability. Based on the biomass collected seasonally
were used for calculation of carrying capacity and water use efficiency of pastures. The results
showed that 20 and 6 species were identified under the storey of the trees in the pasture systems.
The phytosociological indices revealed that the major species belonged to graminacea family
followed by cyperaceae and amaranthaceae in silvipasture system and graminaceae and fabaceae
in hortipasture system. Irrespective of the pasture system, higher biomass was produced during
kharif season followed by rabi season. The higher biomass production of 1959.5± 41.4 kg ha -1
was recorded with hortipasture system followed by 1876.2± 39.7 kg ha -1 during rabi season under
hortipasture system. Under silvipasture system, during rabi season, the biomass produced was
1318.2± 15.2 kg ha -1 and during kharif season, the biomass production was 1122.4± 13.0 kg ha -1 .
The carrying capacity of 10.74 sheep ha -1 was calculated for kharif season under hortipasture
system and 7.3 sheep ha -1 for silvipasture system. The lowest carrying capacity was during the
winter season (5.40±0.0012 sheep ha -1 and 4.1± 0.0063 sheep ha -1 ) during hortipasture and
silvipasture system respectively. Water use efficiency obtained during summer season was
highest during the summer season (2.06 kg mm -1 ) under the hortipasture system, whereas
silvipasture system recorded 1.525 2.06 kg mm -1 . The lowest water use efficiency of 0.171 kg
mm -1 was recorded under hortipasture system and 0.103 kg mm -1 was recorded under silvipasture
system during rabi season.