Drop in intake and milk production of cows fed with Lolium perenne infected with Acremonium lolii
1994
Butendieck B, Norberto (Instituto de Investigaciones Agropecuarias, Temuco (Chile). Estacion Experimental Carillanca) | Romero Y, Oriella | Hazard T, Sergio | Mardones M, Pablo | Galdames G, Rafael
Milk production in southern Chile is based on mixed swards of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). Recently new ryegrass cultivars infected with endophyte have been introduced to improve persistency through enhanced resistance to insects. In a trial designed to measure intake, two groups of eight Holstein cows were randomly assigned to treatments T1: grazing group and T2: soiling group. Perennial ryegrass cultivars Santa Elvira and Embassy were the only feed supplied. The two cow groups grazed both cultivars during 4 days since 01.15.93. From 01.19.93, cows in group T2 were individually fed indoors with cultivar Santa Elvira until 24.01.93. The average initial milk production in T1 was 21.3 kg and 21.2 kg in T2, with intakes in T2 of 13.7 kg D.M. at day 1 and 15.9 kg on day six. On day 7, cultivar Embassy was offered to cows in both groups. In group T2 the intake declined to 12.3 kg D.M. and the milk production dropped to 17.1 kg. In the grazing group the milk reduction was lower, 18.4 kg. On day 8, the clinical symptoms of ryegrass staggers became evident in both groups. In T2 the intake declined to 8.6 kg D.M. and the milk production to 13 kg. In T1 milk production dropped to 17 kg. The clinical symptoms were more severe in the indoor fed group, with two downer cows. After changing the forage supply to a mixture of ryegrass cv. Nui and white clover cv. Huia, the intake and production returned within 12 days to former levels. The experience described points out to the need to test with animals every new cultivar before it is released to be marketed
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