Apparent Amino Acid Availability and Apparent Metabolizable Energy Values of Tower and Candle Rapeseeds and Rapeseed Meals

Abstract

An experiment was conducted to measure the amino acid (AA) availability and metabolizable energy of whole and ground Tower and Candle rapeseeds (RS). This was done by the apparent metabolizable energy (AME) method of total excreta collection using mature White Leghorn cockerels. Since the AA availability values were not corrected for metabolic plus endogenous AA losses they were called apparent AA availability (AAAA) values. A sample of soybean meal (SBM) and Tower and Candle rapeseed meals (RSM) were also included in the experiment. The AAAA values for the whole and ground RS of any particular cultivar did not differ significantly. The values for Tower RS were higher than those for the Candle RS or the two RSM. However, compared with those of the RS and RSM, the SBM showed somewhat higher AAAA values. The AME values of whole Tower and Candle RS were much lower than the corresponding values obtained with ground seed. Furthermore, Candle RS, whole or ground, was lower in AME content than the corresponding values for Tower rapeseed. The Tower and Candle RSM were similar in their AME contents but lower than the SBM. The AAAA and AME results with RS showed that while grinding increased the AME values of the seeds, it did not enhance their AA availabilities.