Objective:

To evaluate the effect of the offer level of silage from Avena sativa L., Altoandina variety, on the total dry matter intake of the diet and the productivity of lactating cows under grazing conditions in the Pasto municipality, Colombia.

Materials and Methods:

Twelve F1 cows (Kiwi cross x Holstein) were used, of 450 kg of average live weight, in a crossover design. Two treatments were established, which corresponded to two silage inclusion levels: 20 (T1) and 35 % (T2) of the total dry matter intake. Periods of 12 days were evaluated, seven of adaptation and five for measurement. Dry matter intake, milk quality and production, as well as the indicators of the metabolic profile (glucose, cholesterol and blood ureic nitrogen) were estimated. The information was processed through a variance analysis and Tukey’s mean comparison test.

Results:

There was significant effect (p < 0,05) for the variables total dry matter intake of the silage (2,8 vs. 1,4 kg/DM/cow/day for 35 and 20 % of inclusion of oat silage, respectively). The milk production was 14,9 vs. 14,3 kg/cow/day, for 35 and 20 % of inclusion of oat silage, respectively. The milk ureic nitrogen and blood ureic nitrogen were higher in T1 with regards to T2 (15,8 and 3,1 vs. 14,5 and 2,8, respectively).

Conclusions:

The introduction in the diet of silage of A. sativa, Altoandina variety (20 and 35 %), affected the total dry matter intake. In addition, the inclusion of 35 % of the silage influenced positively milk production, increasing by 4 %.

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