Less feed but as much weight gain

Press, Volume CXI, Issue 32612, 21 May 1971, Page 13

Less feed but as much weight gain

In the beef house on the research farm at Lincoln College young cattle have put on almost as much weight per day on very much less than the amount of fodder beet and Tama ryegrass that they can eat if it is fed to them without restriction. The investigations have been part of studies into the wintering of young cattle for 18 to 20 months old beef production. Mr A. M. Nicol, lecturer in animal science at the college, told fanners who attended a field afternoon at the college this week, that fodder beet and Tama ryegrass were two feeds that they felt offered possibilities for wintering nine-month-old cattle. He warned, however, that their results were from only one year’s work and consequently needed to be treated with some reservation, but if confirmed they could have important implications. Where a 4501 b weaner was fed as much fodder

beet as it would take it would eat 501 b of fresh material per day. he said, and likewise 1001 b of fresh Tama ryegrass, which contained only about, 10 per cent of dry matter.

At these ad lib levels of feeding live-weight gains were about 1.3 or 1.41 b per day.

Where only 251 b of Tama and 151 b at fodder beet were fed a day, together with barley straw, liveweight gains fell to 0.4 or 0.51 b per day, which was too low for this type of production-

But on a medium restricted diet of 601 b of Tama or 351 b of fodder beet, with in each case barley straw, the gains were 1.2 to 1.31 b per day, and no further responses were obtained to additional amounts of fodder beet or Tama. These were the optimum levels for 4501 b weaners.

The reason why these cattle did not do better on a higher level of Tama was perhaps that because it contained 90 per cent of water these relatively small animals were taking in nine gallons' of cold water per day, which they had to heat up and then urinate out again a very inefficient process. However, straw, which had a low digestibility, gave off heat as it was digested and where it was fed with Tama this would tend to counteract the heat required to heat up the water coming from the grass.

On the medium restricted diet that is regarded as the optimum, Mr Nicol said that three animals would be carried on the Tama that would be eaten by two eating without restrictions, and four animals would be supported on the same quantity of fodder beet that would be eaten by three on ad lib feeding.

Taking this a stage further with crops of beet producing 18,0001 b of dry matter or Tama 35001 b, Mr Nicol calculated assuming 100 per cent utilisation, beet would carry 25 steers to the acre and Tama 6.5, and on the basis ,of the time that the crop was in the ground up to the end of the winter, he further estimated that fodder beet would carry the equivalent of 1.6 steers per acre per month and Tama 0.8 steers per month, but it was noted that with Tama there would be a lot of. extra production outside this period in September and October.