Better Laying After Less Feed

Press, Volume CI, Issue 29820, 12 May 1962, Page 6

Better Laying After Less Feed

IT has been found that laying stock will lay more and bigger eggs and will withstand stresses better if during the period from about six weeks to 22 weeks of age their feed intake is restricted. Mr R. B. Cumming, lecturer in poultry science in the faculty of rural science at the University of New England in New South Wales, Australia, told the South Island poultryfarmers' refresher course at Lincoln this week that an old idea of poultry farmers that they should not force pullets had been proved correct.

This phenomenon was associated with research on cancer with rats and mice, Mr Cumming said. It had been found in America and Great Britain that if the growing mouse from weaning to sexual maturity was restricted to 70 per cent of its normal food intake it had far less trouble with cancer and heart ailments. This also undoubtedly applied to human beings, he said. Discussing work along these lines carried out at Armidale, Mr Cumming said that the figure of 70 per cent was selected because work with mice and poultry in the United States had shown that a ration below this level resulted in animals that were stunted and did not subsequently recover The saving in feed in this growing period where birds were restricted was about 20 to 25 per cent., but there was at most only

a slight saving tn feed over a year as when restriction ceased the birds did not stop eating for two or three days. It was usually not possible to notice any difference between full fed and bird* on restricted feed up to 18 weeks, but at 20 to 22 weeks, although having a similar frame they were about %lb lighter and sexual maturity was delayed by two or three weeks

The outcome wa» that pul

lets which had been on the restricted routine started laying two or three weeks later but they then began laying eggs of bigger size and fewer small eggs and they also produced eggs at a slightly faster rate. Over a year they outlayed their full-fed sisters by the order of 1 to 2 per cent and on average produced fractionally larger eggs. The tendency was tor these birds to outperform their full-fed sisters the longer they went on laying. It had also been noticed that among birds subject to cancer adult mortality was often reduced where birds had been subject to restricted feeding It was also observed that these birds, which under restricted feeding had been through a period of prolonged mild stress, later stood up better to such stresses as lights failing in an artificially lighted house or the water supply freezing up The gains from all this were not terrific —only 2 to 3 per cent.—said Mr Cumming, but as poultry farming became more scientific these small profit margins could mean quite a lot Mr Cumming said it was important that birds on restricted feeding should have sufficient hopper space—about four inches a bird—so that it did not end up with a few birds being full fed and others so underfed as to be stunted Because birds were not eating a full ration and therefore not getting the full amount of coccidiostat they might be subject to coccidiosis but the coccidiostat in the ration could be increased slightly. Where disease did strike birds under restricted feeding it was essential that they should immediately be returned to full feeding. To avoid any chance of cannibalism under the routine all birds were debeaked at Armidale

In one experiment Mr Cumming said that cockerels were divided into four groups One group was on full feed, another had access to the feed troughs for four hours a day, a further group was starved on alternate days, and a fourth group was starved one day tn three. The birds that were on the fourhour dally feeding and one in three days’ starvation received exactly the 70 per cent of a full ration, according to measurements made by a Colombo Plan student, but the birds that were fed no alternate days obtained too little feed. The birds on the four-hour routine also gave the best food conversion.

In another experiment with pullets being reared for this year’s laying one group was full fed, another w» on a TO per cent ration, still another group had a full ration to

18 weeks when it went for a further month on to a low protein ration of 8 per cent, protein milo (a grain sorghum) and a fourth group were again full fed for 18 weeks with the ration then being reduced to 50 per cent, to reduce the weight of the birds to the level of those on the 70 per cent ration.

The objective of the last two treatments was to see if a more severe restriction over a short period would give the same result

Results available so far for Australorps hatched in June showed that the full-fed birds began laying in December with a large number of small eggs. The group on a straight 70 per cent, ration started laying two weeks later with slightly higher eggs and soon overtook and passed their full-fed sisters' production. The group on the milo ceased taking this feed after two weeks and had been trailing the production of the other groups. The other group, which had a 50 per cent ration over the last four weeks of restricted feeding, weighed the same at the end of the restricted treatment as those on the straight 70 per cent ration., but had not matched their egg production though their egg size was a little better.

Where birds were moved from the cage to the floor, Mr Cumming said birds which had been on the straight 70 per cent ration had been quickest to show a recovery in egg production following the decline associated with the change of environment

To Mr F. C. Bobby, chief advisory officer (poultry) of the Department of Agriculture. Mr Cumming said that no study had been made of egg qaulity at Armidale and he agreed that it might be interesting.