PERFORMANCE OF EGG-STRAIN BIRDS DURING THEIR COMMERCIAL LIFE CYCLE WHEN CONTINUOUSLY FED DIETS CONTAINING TOWER RAPESEED GUMS

In response to queries regarding the long-term effect of utilizing rapeseed gums in poultry diets, an experiment was initiated in which this product was continuously fed throughout the life cycle of the laying hen. Treatments consisted of: (1) soybean meal control, (2) 15% Tower rapeseed meal (3) 15% Tower rapeseed containing 1.5% of rape gums (4) soybean meal containing 1.5% of rape gums, and (5) soybean meal containing 1.5% of soy gums. The meals containing gums were manufactured in Western Canada. The diets were offered to one commercial White Leghorn and University strains of White Leghorns and Rhode Island Red, with conventional dietary specifications used in relation to age of bird. Gums had no persistent effect on feed intake or body weight of pullets from day of age to 20 wk. During this period mortality was low and not influenced by diet. In a subsequent laying period of 308 days, these same dietary treatments had no significant effect on egg production, while breed differences influenced all parameters measured. The addition of gums to rapeseed meal caused a reduction in egg size for a commercial strain of White Leghorns while the converse was true for a Guelph strain of White Leghorns. This apparent dichotomy may have been related to differences in feed intake. Diet had no influence on fertility or hatchability or on the performance of subsequent offspring when these were fed diets comparable to those of their dams. It is concluded that no toxic effects in terms of productive performance accrue from the use of up to 15% Tower rapeseed meal which contains 1.5% rapeseed gums, when fed throughout the commercial life cycle of egg strain birds and their offspring. Performance data also indicate that the addition of such gums to soybean meal offers an alternative means of their disposal.