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Grazing behaviour, intake and performance of dairy ewes with restricted access time to berseem clover ( Trifolium alexandrinum L.) pasture
Author(s) -
Molle G.,
Decandia M.,
Giovanetti V.,
Manca C.,
Acciaro M.,
Epifani G.,
Salis L.,
Cabiddu A.,
Sitzia M.,
Cannas A.
Publication year - 2017
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/gfs.12228
Subject(s) - grazing , pasture , trifolium alexandrinum , hay , biology , randomized block design , agronomy , zoology , dry matter , trifolium repens , forage , factorial experiment , mathematics , statistics
The effects of restricted access time to pasture (2, 4 or 6 h d −1 ; 2H, 4H or 6H) on ingestive behaviour and performance were assessed on four occasions per target grazing day (D1, initial day; D4, intermediate day; and D7, final day) in dairy ewes rotationally grazing berseem clover with a 7‐day grazing period and a 21‐day recovery period. A randomized block design with two replicates per treatment was used. All ewes were supplemented daily with 700 g per head of concentrates and 700 g per head of ryegrass‐based hay. Pasture subplot and animal group data were analysed by a factorial model including access time ( AT ), grazing day (D) and their interaction as fixed factors. Sward height decreased from D1 ( P < 0·001) and green leaf mass from D4 ( P < 0·001) onwards during the grazing period. Grazing time as a proportion of AT was higher in 2H than in 4H and 6H ewes on D1 and D4 but not on D7 ( P < 0·05 for AT × D). Herbage intake rate was higher in 2H than in 4H and 6H ewes ( P < 0·001). Herbage and total intakes were higher in 4H and 6H than in 2H ewes ( P < 0·001), with herbage intake varying non‐linearly during the grazing period ( P < 0·05). Milk yield was higher in 4H and 6H than in 2H ewes ( P < 0·01). To conclude, despite the evidence of compensatory behaviour, restricting access time to 2 h d −1 constrained intake and performance of dairy ewes rotationally grazing berseem clover.