GROWTH, FEED UTILIZATION AND CARCASS QUALITY RESPONSES OF PIGS FED FROST-DAMAGED CANOLA SEED (LOW-GLUCOSINOLATE RAPESEED) AS AFFECTED BY GRINDING, PELLETING AND AMMONIATION

Abstract

Canola seed (CS) having 20, 45 and 65% frost damage was fed at dietary levels up to 30% to 144 pigs of 23 ± 1 kg initial weight to determine the effects of processing on feeding value. In exp. 1, 10, 20 and 30% levels of each lot of CS were fed to barrows (M) and gilts (F) up to 100 kg liveweight. Average daily gain (ADG) increased with increasing frost damage (0.75, 0.77, 0.78 kg). Similarly, feed intake (FI) increased (2.19, 2.27 and 2.35 kg day−1). Feed-adjusted ADG were equal. ADG and FI were reduced at the 30% level in diet compared with 10%. A palatability effect is postulated. Glucosinolate levels declined with increasing frost damage. In exp. 2, 45% frost-damaged CS was fed at 30% of the diet to M and F pigs up to 57 kg liveweight to compare whole vs. ground CS, fed as meal or pellets. Grinding depressed FI but not ADG. Pelleting improved ADG but not FI. Both processes improved feed:gain ratio. In exp. 3, diets containing 45% frost-damaged, ground CS, with and without ammoniation (0.5% NH3), were compared with a control diet supplemented with soybean and canola meals by feeding to M and F pigs up to 100 kg liveweight. ADG and FI of pigs fed CS were below both the controls and pigs fed the ammoniated CS. Ammoniation had minor effects on amino acid and available lysine content but improved FI and ADG. Carcass index values were unaffected by either level or treatment of CS. Key words: Rapeseed, canola, processing, feeding trials, pigs, freezing