TITLE:
Productivity and Grazing Behavior of Ewes with Single or Twin Lambs Raised in Mixed Italian Ryegrass/White Clover Pasture in Southern Brazil
AUTHORS:
Felipe Jochims, Cleber Cassol Pires, Malcolm J. Gibb, Eduardo Bohrer de Azevedo, Diego Bitencourt de David, Émerson Mendes Soares
KEYWORDS:
Area Weight Gain; Birth Type; Herbage Allowance; Lambs Daily Weight Gain; Sheep
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.7,
March
26,
2014
ABSTRACT: The aim of this
study was to compare the area production and grazing behavior of single- and
twin-rearing ewes kept on a mixed Italian ryegrass/white clover pasture. The herbage
allowance was maintained at 12 kg DM/100kg live
weight during the experiment, by continuous variable stocking management for
112 days (4 periods of 28 days). We measure the live
weight gains, the area production and the body condition score of ewes and
lambs. Animal behavior was observed on four occasions during which we evaluated
whether the lambs were grazing near to or far from their mother. Live-weight
output from the ewes and lambs, and net output (ewes and lambs) were
calculated. Results showed that being irrespective of
birth type, ewes had similar mean daily weight gains, although ewes with twin
lambs presented a mean lower body condition score. Ewes live weight output/ha
did not differ significantly among birth types, but
twin lambs produced 98.2 kg (45%) more live weight gain/ha. Total net
live-weight output (ewes + lambs) was 121.5 kg greater for twins than for
singles. Ewes with twin lambs spent more time grazing and ruminating. Lambs
increased the time they spent grazing in each successive period. Single lambs
spent significantly longer time grazing within 12 m of their dams (near
grazing). Analysis of far grazing times by the broken line method showed that
growing lambs rapidly increase the time spent far grazing up to a live weight
of 20.3 kg in both birth types, which occurs at 95.3 and 115.9 days of age for
single and twins, respectively. The results indicate that twin lambs are more productive than singles, when evaluated per area unit of pasture.