Abstract #T177

# T177
Performance of crossbred cows on Tanzania grass pastures subjected to two pasture-management strategies.
Alberto Magno Fernandes*1, Ricardo Augusto Mendonça Vieira1, Tadeu Silva de Oliveira1, Fermino Deresz2, 1Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, Rio de Janeiro, Brazil, 2EMBRAPA-Gado de Leite, Juiz de Fora, Minas Gerais, Brazil.

The objective of this study was to evaluate nutrient intake and yield and components of milk from Holstein × Zebu cows on Tanzania grass using a fixed resting period (FR) or according to 95% light interception (LI, by accuparLP-80) for managing Tanzania-grass pastures. As the LI of the herbage mass reached 95%, the animals were allowed to graze each paddock for 3 d; and (2) 30 d defoliation interval with a 3-d grazing period (FR). Experimental unit consisted of 11 paddocks grazed by 5 Holstein-Gir cows allowing for 2 replicates per defoliation treatment in the first year with the same areas assigned to the same treatment the following year grazed by 4 Holstein-Gir cows per experimental unit. Intake and digestibility were estimated using the external marker chromic oxide (Cr2O3). Each grazing animal received 5 g of Cr2O3 administered orally in paper cartridges twice daily at 12-h intervals for 12 d. The cows were milked twice daily, at 06.00 and 15.00 h. Milk samples were analyzed every 14 d to determine protein, fat, lactose, energy, and total solids (TS) contents. The management strategies imposed on the Tanzania-grass pasture did not affect (P > 0.05) the intake or digestibility of nutrients. Milk yield and milk components were not affected (P > 0.05) by the management strategies, but treatment LI95 yielded 2,067 ± 288 kg milk/ha while FR was less at 1,861 ± 288 kg milk/ha (P < 0.05). In conclusion, adopting forage management utilizing a 95% light interception defoliation interval improves milk production per land unit and efficiency of land resources.

Key Words: grass, intake, milk