The response of weaner pigs, grower/finisher pigs, and lactating sows to inclusion levels of solventextracted canola meal up to 250, 300, and 202 g/kg, respectively, was examined in 3 experiments. The average composition of the canola meal used in the experiments was 884 g DM/kg, 376 g CP/kg, 41 g fat/kg, 21.6 g lysine/kg, 12.4 MJ digestible energy (DE)/kg, and 4.5 mol glucosinolates/g. In all experiments, canola meal replaced other common protein sources in equal DE and equal lysine diets that were offered ad libitum to pigs. In Expt 1, 49 male pigs were weaned at 19.6 days of age and 6.27 kg liveweight and allocated to 7 diets containing 0–250 g/kg of canola meal for 42 days. Growth rate and voluntary feed intake were not significantly affected by level of canola meal up to 250 g/kg. However, there was a significant linear response in feed conversion ratio (FCR), indicating that as the level of canola meal increased, feed efficiency was improved. In Expt 2, pigs were randomly allocated at about 63 days of age and 24 kg liveweight to 16 group pens, each containing 12 pigs. Four pens were each allocated to one of 4 diets containing 0–300 g/kg canola meal up to slaughter at 140 days of age when pigs were approximately 97 kg liveweight. Canola meal level had no significant effect on growth performance, carcass quality, or weight of the thyroid gland. In Expt 3, 386 mixed parity sows were randomly allocated over a 70-day period to diets containing 0, 101, and 202 g/kg of canola meal that were offered during the lactation period of about 25 days. Average piglet growth between Day 3 and weaning was 244 g/day and was unaffected by inclusion level of canola meal in the sow diet. However, there was a significant positive linear response between sow feed intake and canola meal, which was particularly evident in the sows allocated during the initial period of the experiment when environmental temperatures were hotter. Average feed intake during lactation was 5.08, 5.50, and 5.67 for sows offered 0, 101, and 202 g/kg of canola meal, respectively. In conclusion, solvent-extracted canola meal can be included at levels up to 250, 300, and 202 g/kg in weaner pig, grower/finisher pig, and lactating sow diets, respectively, without adversely affecting the performance of these classes of pigs.

The present study was designed to determine the interrelationships between sex, weaning age, and weaning weight on subsequent growth performance. Ninety-six Large White × Landrace pigs were used in a 2 × 2 × 2 factorial experiment with the respective factors being: age at weaning (14 or 28 days), weight at weaning (heavy or light), and sex (boar or gilt). Eighty pigs were offered a high quality pelleted weaner diet ad libitum while the remaining 16 pigs (2 pigs from each treatment group) were removed from the sow and fasted for 24 h before being euthanased for determination of gut histology and enzymology. The remaining pigs were weaned into individual pens and given an ad libitum diet containing 15.5 MJ DE/kg and 0.95 g available lysine/MJ DE. On Day 6 and 13 after weaning, 2 pigs from each group at each time had their feed removed and, 24 h later, were euthanased. From 3 weeks post-weaning, the remaining pigs were group-penned with contemporary pigs and fed commercial rations until slaughter at 23 weeks of age. In the first week after weaning, the heavy pigs and those weaned at 28 days ate more feed and grew faster, and gilts ate more and grew faster than boars over the same time. Pigs that were heavier at weaning were also heavier at every subsequent age. At slaughter, heavy boars weighed more than heavy gilts (110.5 v. 103.7 kg, P = 0.027), whereas this was not the case for light boars and gilts (94.1 v. 94.4 kg, P = 0.96). Whereas there were no effects of sex or weight at weaning on P2 backfat depth, pigs weaned at 14 days had more backfat at 23 weeks than pigs weaned at 28 days (13.1 v. 10.9 mm, P = 0.009). In conclusion, these data clearly indicate that the greatest determinants of immediate post-weaning performance under the present conditions were the age and weight of the pigs at weaning. However, the key determinant of lifetime growth rate appeared to be weight of pigs at weaning or, by inference, birth. Although age at weaning had no effect on lifetime growth rate, early-weaned pigs were fatter at slaughter.

Digestive capacity of early-weaned pigs may be insufficient to fully digest many ingredients currently used in weaner diets. The aim of this experiment was to determine whether an exogenous enzyme preparation with broad carbohydrase activity could benefit pigs that developmentally might be immature at weaning, especially with regard to gastrointestinal development. Eighty Large White × Landrace pigs were used in a 2 × 2 × 2 × 2 factorial experiment with the factors being: weaning age (14 or 24 days), weaning weight (heavy or light), sex (boar or gilt), and dietary Biofeed Plus CT (0 or 500 μg/g) which contained fungal xylanases, pentosanases and β-glucanases. Pigs were housed individually and given a wheat-based (550 g/kg) diet containing 15.0 MJ DE and 15.9 g lysine/kg on an ad libitum basis for 21 days. The diet also contained 50 g/kg of soybean meal and 50 g/kg of lupin (Lupinus�angustifolius) kernels. The liveweights of heavy (H) pigs weaned at 24 or 14 days and light pigs (L) weaned at 24 or 14 days were 7.9 and 5.3 and 5.2 and 3.9 kg, respectively. Pigs weaned at 14 days grew slower (157 v. 345 g/day) than those weaned at 24 days, although there was a suggestion of an interaction between age and weight at weaning (P = 0.081). Thus, H and L pigs weaned at 14 days grew at 148 and 166 g/day, whereas H and L pigs weaned at 24 days grew at 374 and 315 g/day, respectively. Although there was no main effect of enzymes on daily gain (248 v. 254 g/day, P = 0.80), feed intake (278 v. 284 g/day, P = 0.79), or feed conversion ratio (1.19 v. 1.25, P�=�0.35), there were interactions with weaning age on daily gain (P = 0.050) and feed intake (P = 0.060). Pigs weaned at 14 days grew slower (176 v. 138 g/day) and ate less (206 v. 174 g/day), whereas pigs weaned at 24 days grew faster (321 v. 369 g/day) and ate more (351 v. 394 g/day), when supplemented with enzymes. During the third week after weaning there were interactions between dietary enzymes and sex (P = 0.060) and dietary enzymes and age (P = 0.023) on daily gain. Thus, pigs weaned at 24 days and supplemented with Biofeed Plus CT grew more quickly during the third week (559 v. 460 g/day), whereas the converse was true for pigs weaned at 14 days (286 v. 334 g/day). Also, enzyme-supplemented boars grew better over this period (457 v. 371 g/day), whereas the converse was true for gilts (388 v. 423 g/day). In conclusion, these data clearly indicate that the greatest determinant of post-weaning performance under the present conditions was the age of the pigs at weaning. Dietary enzyme supplementation appeared most efficacious in boars weaned at an older age, although benefits did not become apparent until 2 weeks after weaning.

A production experiment was conducted with 96 fourteen-day-old weaned male piglets to compare diets containing preparations of freeze-dried porcine plasma (P) and freeze-dried bovine colostrum (C) for 35 days after weaning. These diets were compared with a diet consisting of soybean meal (SP) and a diet with animal protein sources (AP). All diets contained varying proportions of bloodmeal, fishmeal, meat and bone meal, and skim milk powder. The levels of colostrum and porcine plasma were reduced from 60 g/kg to 25 g/kg after the first week of weaning. There were no effects of diet on performance in the first 4 days after weaning. However, between 18 and 21 days of age, pigs fed the SP diet ate less (P < 0.001) and grew slower (P = 0.002) than pigs fed diets containing AP, C, or P. In the second week after weaning, pigs fed diets with C and P showed a tendency to perform better (P�=�0.11) than those fed AP or SP. By 35 days of age, pigs fed diets containing colostrum and plasma were, on average, 6% heavier (P = 0.037) than pigs fed the AP and SP diets. The effects of dietary protein on voluntary feed intake were most pronounced up to 28 days of age in pigs fed the SP diet. There appeared little benefit of feeding C and P to early-weaned pigs over feeding a predominantly animal protein diet, although daily gain was 6% less (P�= 0.47). There were no differences (P > 0.05) in feed intake and growth rate between 28 and 35 days of age, and feed conversion efficiency was not altered by dietary protein source. Under these experimental conditions the use of bovine colostrum and a combination of animal protein sources was comparable with using freeze-dried porcine plasma in diets for early-weaned pigs. Inclusion of soybean meal in diets, however, resulted in inferior performance.

Seventy 14-day-old male pigs that were either heavy (6.0 kg) or light (3.6 kg) for age were weaned into individual pens and fed 1 of 7 diets containing 9.2–21.0 g lysine/kg feed in a study designed to determine the effect of dietary lysine and weight on lysine requirements of pigs. Five pigs from each weight group were used to determine initial body composition. When pigs reached 10 kg they were slaughtered and empty body composition was analysed to determine protein tissue accretion rates. Protein deposition rate was not affected by weight at weaning but increased with dietary lysine content before reaching a plateau. The relationship between protein deposition (PD, g/day) and dietary lysine (L, g/kg) was described by 3 models. The rectilinear model, which had a linear ascending phase (PD = 4.84 + 1.948L, R2 = 0.935, P = 0.002) and a horizontal component representing maximum protein deposition rate of 32.3 g/day, revealed that maximum protein deposition occurred at 14.1 g lysine/kg. The quadratic function (PD = – 2.74 + 3.74L – 0.099L2 , R2 = 0.916, P = 0.003) provided an estimate of the lysine requirement of 14.9 g lysine/kg occurring at a point where PD reached 95% of the maximum protein deposition rate (32.5 g/day). Use of an asymptotic model (PD = 32.60 – 186 0.727L, R2 = 0.919, P = 0.003) provided an estimate of 14.9 g lysine/kg occurring at a point where PD reached 95% of the maximum protein deposition rate (32.6 g/day). These data indicate that early weaned pigs should be fed a highly digestible diet containing 14–15 g lysine/kg to maximise protein deposition.