The effect of introducing timothy, cocksfoot and red fescue into a perennial ryegrass sward and the application of sodium fertilizer on the behaviourof male and female cattle

The effects on cattle grazing behaviour of introducing the three novel spec ies into a perennial ryegrass pasture were examined in a Latin Square desig n. Castrated male and entire female cattle of similar age were grazed on pl ots of perennial ryegrass only (treatment I), perennial ryegrass and timoth y (treatment 2), perennial ryegrass, timothy and cocksfoot (treatment 3) an d perennial ryegrass, timothy, cocksfoot and red fescue (treatment 4). Pere nnial ryegrass had the greatest nutritional value, with a high crude protei n and low MADF content, whereas cocksfoot and red fescue had high MADF cont ents. The introduction of timothy had no effects on grazing behaviour. When cocksfoot was additionally included, the cattle grazed for longest on the cocksfoot plots and total grazing time and the time spent ruminating both i ncreased. When red fescue was additionally included with the other three sp ecies it was mostly avoided. When they did graze the red fescue, the cattle had slow biting and walking rates and reduced lateral head movement, sugge sting greater selectivity. Mean treatment herbage height was increased in t reatments three and four because cocksfoot and red fescue were taller than the other two species. Sodium fertilizer increased the sodium concentration of all species but particularly perennial ryegrass and cocksfoot. The graz ing time was only increased by sodium for these two species, and the rates of biting and walking during grazing were also increased, suggesting that s odium reduced selectivity. Male cattle had faster biting and walking rates than female cattle and extended lateral head movement during grazing. It is concluded that perennial ryegrass, timothy and cocksfoot were more accepta ble to cattle than red fescue. There was an increase in acceptability of th e natrophilic species, perennial ryegrass and cocksfoot, when sodium fertil izer was applied, suggesting that sodium content partly determines herbage acceptability. (C) 1999 Elsevier Science B.V. All rights reserved.