These studies were conducted to determine whether dietary homoarginine, derived from guanidination of synthetic lysine, affects the measurement of apparent and true ileal amino acid digestibility in the pig and to determine the optimal ratio of o-methylisourea (OMIU) to free synthetic lysine in the guanidination reaction that produces homoarginine. In two preliminary experiments, specific amounts of lysine were weighed and added to a solution of 0(.)6 mol/l OMIU to produce OMIU to free synthetic lysine ratios of 2:1, 1(.)5:1, 1(.)4:1, 1(.)3:1, 1(.)2:1, 1(.)1:1 and 1(.)0:1. The mixture was incubated at a pH of 10(.)5 and a temperature of 20 +/- 1 degrees C for 6 days. The highest yield of homoarginine (proportionately 0(.)995) was produced with an OMIU to free synthetic lysine ratio of 1(.)5:1. The serum concentrations of homoarginine and lysine were measured in two test pigs at various times after consuming a single meal containing either homoarginine or lysine. Blood samples were taken before and 0(.)5, 1(.)5, 2(.)5, 4(.)5, 6(.)0, 7(.)5, and 11(.)5 h after feeding. Thirty minutes after feeding the homoarginine-containing diet, the homoarginine concentration in serum was 0(.)013 mmol/dl, and increased to a maximum of 0(.)031 mmol/dl 1(.)5 h after feeding. Thirty minutes after feeding the lysine-containing diet, the serum lysine concentration was 0(.)011 mmol/dl and also reached its maximum concentration of 0(.)025 mmol/dl 1(.)5 h after feeding. The timing of the changes in concentration of homoarginine and lysine related to feeding were similar, which suggests that homoarginine is absorbed and metabolized in a similar manner to lysine. Six Large WhitexLandrace barrows, weighing 68(.)5 +/- 3(.)5 kg and fitted with a simple T-cannula at the distal ileum as well as a jugular vein catheter, were used to determine the effects of homoarginine on endogenous amino acid flows and apparent and true ileal amino acid digestibility. The experimental design was a doubly replicated 3x3 Latin-square design with the three treatments consisting of a lysine-free, zein-based diet and jugular infusion of a lysine solution; a lysine-free, zein-based diet supplemented with homoarginine; and a lysine-free, zein-based diet supplemented with l-lysine. There were no significant differences in endogenous ileal lysine flow for pigs receiving the different treatments (396(.)6, 407(.)6, and 360(.)4 mg/kg DMI, respectively, P=0(.)71). In addition, with the exception of phenylalanine (P=0(.)04), there were no significant differences (P > 0(.)10) in the apparent and true ileal digestibility of crude protein and amino acids among the three treatments. Therefore, it would appear that the presence of dietary homoarginine, derived from guanidination of synthetic lysine, does not affect endogenous amino acid losses or the digestibility of crude protein as well as most amino acids. These results are therefore supportive of the use of the homoarginine method as a means of measuring true ileal lysine digestibility.

Two experiments were conducted to determine if the performance of growing-finishing pigs fed corn-based diets is improved by enzyme supplementation. In experiment one, 72 crossbred pigs (32 castrates and 40 gilts) were fed one of the two corn-canola meal based diets, identical in composition except that one diet contained 0.12% of an enzyme cocktail (750 beta-glucanase units and 650 xylanase units per gram). In experiment two, 64 crossbred pigs (32 castrates and 32 gilts) were assigned to one of the four corn-soybean meal based diets including an unsupplemented control diet, a diet supplemented with xylanase (200 g/tonne containing 1250 units/g of xylanase and 385 units/g of beta-glucanase), a diet supplemented with protease (200 g/tonne containing 400 units/g ofprotease, 150 units/g of soybean meal hydrolytic activity, 360 units/g of xylanase and 165 units/g of beta-glucanase) or a diet supplemented with the two enzymes in combination (125 g/tonne xylanase and 75 g/tonne protease). The addition of the enzymes did not alter (P > 0.05) the digestibility of dry matter, crude protein or energy. There was no effect (P > 0.05) on weight gain, feed intake or carcass traits. However, during the growing period only, feeding xylanase significantly (P < 0.05) improved feed conversion. It is concluded that there is little justification for the routine inclusion of these enzymes in corn-based diets fed to swine.

The mobile nylon bag technique was used to determine the potential of cannulated pigs to model intestinal dry matter (DM) and crude protein (CP) digestibility of ruminal undegradable residues (RUDR) of various feed samples in cattle. A total of 11 feeds (six protein supplements and five forages) varying in rumen degradability were utilized: canola meal (regular vs. heated); soybean meal (regular vs. heated); distillers’ grains (regular vs. heated ); alfalfa hay (regular vs. dehydrated alfalfa pellets); barley silage (regular vs. heated); and barley straw. Ruminal undegradable residues of each feedstuff were placed into eight polyester bags and inserted into the duodenum of two cannulated Hereford steers (644 ± 14 kg). Another eight bags for each RUDR sample were randomly allocated to six crossbred gilts (Camborough 15 line female × Canabred sire; 50 ± 1.2 kg body weight) and inserted into the pigs’ duodenum via duodenal cannulas. Bags were recovered in the feces from both the cattle and pigs. Regression analysis was used to relate intestinal DM and CP digestibility obtained in pigs with those obtained in steers. Intercepts not different from zero were forced through the zero intercept to obtain a measure of bias and loss of precision resulting from forcing the zero intercept. The non-zero regression equations relating steer estimates to those obtained from pigs were -3.17 + 0.95 X [r2 = 0.98, residual standard deviation (RSD) = 3.84] and 0.35 + 0.96 X (r2 = 0.98, RSD = 6.16) for DM and CP disappearance, respectively. Forcing the non-zero intercept resulted in pigs over predicting intestinal DM disappearance in cattle by 10.6% with a RSD of 4.30. Using the pig model, intestinal CP disappearance of cattle was over predicted by 3.1% with a RSD of 5.85. It was concluded that pigs can be used to model intestinal DM and CP disappearance of ruminal undegraded feed residues in cattle. Key words: Cattle, pigs, mobile nylon bag technique, intestinal nutrient availability

Eighty crossbred pigs (28.7 ± 3.9 kg BW) were assigned to one of five dietary treatments in a factorial design experiment (sex × treatment). The control diet was formulated using barley and soybean meal, while four experimental diets were formulated with either toasted or non-toasted canola meal replacing either half or all of the soybean meal in the test diets. The total glucosinolate content of the non-toasted meal was more than 15-fold higher than the to asted meal (1.01 vs. 15.58 µmol g-1). The principal glucosinolates in the non-toasted meal were 3-butenyl (3.05 µmol g-1), 2-OH-3-butenyl (5.47 µmol g-1) and 4-OH-3-methylindoyl (4.68 µmol g-1). Digestibility coefficients for dry matter, crude protein, and gross energy were significantly (P < 0.05) lower for the toasted and non-toasted canola meal diets compared with the soybean meal diet. There were no significant differences (P > 0.05) in digestibility coefficients between the two canola meals. Digestibility coefficients were higher (P < 0.05) for pigs fed the diets in which canola meal supplied only 50% of the supplementary protein compared with diets in which 100% of the supplementary protein was supplied by canola meal. Pigs fed toasted canola meal had similar weight gain, feed intake and feed conversion (P > 0.05) as pigs fed soybean meal while pigs fed non-toasted canola meal had lower weight gain and feed intake (P < 0.05) than pigs fed soybean meal. Feed conversion was unaffected by dietary treatment (P > 0.05). There were no significant effects (P < 0.05) due to diet on any carcass trait. The overall results of this experiment indicate that omitting the desolventization/toasting procedure from the process involved in the production of canola meal did not result in an improvement in the performance of pigs fed diets containing canola meal. Key words: Pigs, canola meal, performance, digestibility, carcass, toasting

The objective of this experiment was to compare corn and wheat in finishing pig diets in order to determine whether performance, carcass quality, fatty acid composition or fat colour is altered by choice of cereal grain. A total of 126 crossbred pigs were used in this experiment. At the start of the experiment, a portion of the experimental animals were assigned to receive a wheat-based diet formulated using soybean meal as the sole source of supplementary protein. The remainder of the pigs were assigned to a corn-based diet formulated to supply a similar level of lysine (0.65%) and energy (3,300 kcal/kg DE). At two week intervals, a portion of the pigs on the corn-based diet were switched to the wheat-based diet so that a gradient was produced with pigs being fed the corn and wheat-based diets for different proportions of the finishing period ranging from 100% on wheat to 100% on corn. There were no significant differences in the growth rate of pigs fed the two diets (p = 0.834). Pigs fed wheat tended to consume slightly less feed (p = 0.116) and had a significantly improved feed conversion (p = 0.048) compared with pigs fed corn. Choice of cereal did not affect dressing percentage (p = 0.691), carcass value index (p = 0.146), lean yield (p = 0.134), loin fat (p = 0.127) or loin lean (p = 0.217). Fatty acid composition of backfat was unaffected by the cereal grain fed (p > 0.05). Total saturated fatty acid content was 33.31% for both corn and wheat fed pigs (p = 0.997) while the polyunsaturated fatty acid content was 12.01% for corn fed pigs and 11.21% for wheat fed pigs (p = 0.257). The polyunsaturated/saturated ratio was 0.36 for pigs fed corn and 0.34 for pigs fed wheat (p = 0.751). Hunter Lab Colour Scores indicated no difference either in the whiteness or yellowness of the fat. In conclusion, wheat can substitute for corn in growing-finishing pig rations without detrimental effects on pig performance. There were no differences in either the fatty acid composition of backfat or in backfat colour indicating that the decision to use wheat vs. corn needs to be made on economic grounds rather than being based on their effects on fat quality.

The objective of this experiment was to determine the effects of feeding graded levels of Linpro (a 50:50 combination of extruded full-fat flax seed and peas) on pig performance and carcass traits, particularly the fatty acid composition of backfat. Eighty crossbred pigs (Camborough 15 Line female × Canabred sire, Pig Improvement Canada Ltd., Airdrie, AB) weighing an average of 22.7 ± 2.2 kg were assigned on the basis of sex, weight and litter to one of five dietary treatments in a 5 × 2 factorial arrangement (treatment × sex). The experimental diets were based on barley and soybean meal and contained 0, 7.5, 15, 22.5 or 30% Linpro during the growing period (22.7–69.7 kg) and 0, 6, 12, 18 or 24% Linpro during the finishing period (69.7–111.1 kg). Digestibility coefficients for dry matter were not significantly affected by incorporation of Linpro in the diet. Digestibility coefficients for crude protein (P = 0.01) and gross energy (P = 0.04) exhibited a cubic effect due to Linpro incorporation with the highest digestibility coefficients observed for pigs fed 7.5% Linpro. Over the entire experimental period (22.7–111.1 kg), daily gain was affected both linearly (P = 0.02) and quadratically (P = 0.04) by Linpro inclusion. The most rapid gains were obtained by pigs fed 7.5% Linpro (6% in finisher), while pigs fed 30% Linpro (24% in finisher) gained weight the slowest. Feed intake was not significantly affected by Linpro inclusion, while feed conversion exhibited a quadratic effect (P = 0.02) with pigs fed the highest and lowest levels o f Linpro showing the poorest feed conversion. Linpro inclusion, had no significant effects on carcass traits including slaughter weight, carcass weight, dressing percent, carcass value index, lean yield, loin fat or loin lean. Inclusion of 30% Linpro (24% in finisher) significantly (P < 0.05) increased the levels of linolenic acid in backfat and this increase could provide significant health benefits for consumers of pork. Linpro would appear to be an acceptable alternative to soybean meal as a protein supplement for use in growing-finishing swine diets and can be incorporated at levels as high as 22.5% in the grower period and 18% in the finisher period without detrimental affects on pig performance. Key words: Swine, extrusion, flax, peas, digestibility, growth, backfat

The following experiment was conducted using the mobile nylon bag technique (MNBT) to determine dry matter and energy digestibility in traditional feeds as well as non-traditional feeds in order to calculate digestible energy (DE) values for use in ration formulation programmes. A total of 22 ingredients were tested in this experiment including the traditional cereal grains barley, corn, oats and wheat, as well as secondary cereal grains such as normal and low viscosity rye, low lignin and high fat oat groats, wheat heavies and #1 wheat screenings and a new bread wheat designated as CDC Teal. Three legumes (lupines, peas and dehydrated alfalfa), three varieties of canary seed (CDC Maria, dehulled CDC Maria and Keet), and raw and micronized canola seed were tested as protein sources. Finally, three oilseed meals obtained from the Chinese feed industry (Chinese rapeseed meal, Chinese cottonseed meal and extruded full-fat soybean meal) were also included. After simulating gastric digestion the nylon bags were inserted into the duodenum of five barrows through simple duodenal T-cannulae. Eight bags were administered to each pig daily. Ten nylon bags were prepared for each feed with two bags being inserted into each of the five barrows. A total of 220 bags were inserted over a 7-day period. The overall results of this experiment indicate that the MNBT has great potential for use in determining the digestible energy content of swine feeds. For the most part, values obtained in the present experiment compared favourably with previously published values. Four feedstuffs produced digestible energy values that differed by greater than 5% from previously reported values. However, variation in chemical content provided a reasonable explanation for these discrepancies. The MNBT has several advantages compared with conventional digestibility methods in that many feeds can be tested in a relatively short duration of time with significantly fewer animals being used, only small amounts of feed are required and the test allows for energy measurements in feedstuffs that would not normally be fed to pigs as a single ingredient. Additional research on a wider variety of feedstuffs should be conducted to confirm the potential of the MNBT as a tool to accurately determine DE values for swine.

Forty crossbred barrows (Camborough 15 Line female x Canabred sire) weighing an average of 79.6 +/- 8.0 kg were used in a factorial design experiment (5 barleys x 2 enzyme levels) conducted to determine the effects of phytase supplementation on nutrient digestibility in low-phytate barleys fed to finishing pigs. The pigs were assigned to one of 10 dietary treatments comprised of a normal 2-rowed, hulled variety of barley (CDC Fleet, 0.26% phytate) or 2 low-phytate hulled genotypes designated as LP422 (0.14% phytate) and LP635 (0.09% phytate). A normal, hulless barley (CDC Dawn, 0.26% phytate) and a hulless genotype designated as LP422H (0.14% phytate) were also included. All barleys were fed with and without phytase (Natuphos 5000 FTU/kg). The diets fed contained 98% barley, 0.5% vitamin premix, 0.5% trace mineral premix, 0.5% NaCl and 0.5% chromic oxide but no supplemental phosphorus. The marked feed was provided for a 7-day acclimatization period, followed by a 3-day faecal collection. In the absence of phytase, phosphorus digestibility increased substantially (P < 0.05) as the level of phytate in the barley declined. For the hulled varieties, phosphorus digestibility increased from 12.9% for the normal barley (0.26% phytate) to 35.3 and 39.8% for the two low-phytate genotypes (0.14 and 0.09% phytate respectively). For the hulless varieties, phosphorus digestibility increased from 9.2% for the normal barley (0.26% phytate) to 34.7% for the hulless variety with 54% of the normal level of phytate (0.14% phytate). In contrast, when phytase was added to the diet, there was little difference in phosphorus digestibility between pigs fed normal barley and those fed the low-phytate genotypes (significant barley x enzyme interaction, P = 0.01). For the hulled varieties, phosphorus digestibility was 50.1% for the barley with the normal level of phytate (0.26% phytate) compared with 51.1 and 52.4% for the varieties with 54 and 35% of the normal level of phytate (0.14 and 0.09% phytate respectively). For the hulless varieties, phosphorus digestibility increased from 47.1% for the normal barley (0.26% phytate) to 54.4% for the hulless variety with 54% of the normal level of phytate (0.14% phytate). In conclusion, both supplementation with phytase and selection for low-phytate genotypes of barley were successful in increasing the digestibility of phosphorus for pigs. Unfortunately, the effects did not appear to be additive. Whether or not swine producers will choose low-phytate barley or supplementation with phytase as a means to improve phosphorus utilization, will likely depend on the yield potential of low-phytate barley and the additional costs associated with supplementation with phytase.

The objective of this study was to compare a high-fat oat recently developed at the University of Saskatchewan with regular oat as energy sources for use in diets fed to growing-finishing pigs. Seventy crossbred pigs (Pig Improvement Canada Ltd, Acme, AB) weighing an average of 27.5 ± 2.6 kg were assigned on the basis of sex, weight and litter to one of five dietary treatments in a factorial design experiment. The main effects tested included oat type (normal and high fat), level of oat inclusion (0, 25 and 50%) and sex of pig (barrows and gilts). Digestibility coefficients for dry matter (P = 0.002), crude protein (P = 0.001) and gross energy (P = 0.004) were significantly higher for pigs fed high-fat oat compared with normal oat. Pigs fed the high-fat oat also gained weight significantly faster (P = 0.01) and with increased efficiency (P = 0.01) compared with pigs fed diets containing normal oat. Oat level did not affect pig performance (P > 0.05). Neither type of oat nor level of inclusion had any significant (P > 0.05) effects on any carcass trait including dressing percent, carcass value index, lean yield, loin fat or loin lean. In conclusion, feeding diets containing a recently developed high-fat oat to pigs improved growth rate and efficiency of feed conversion compared with feeding diets containing normal-fat oat. Nutrient digestibility also improved with no negative effects on carcass quality. High-fat oat is an attractive alternative to normal oat as an energy source for growing-finishing pigs and can be fed at higher levels than are currently recommended for normal oat without hindering pig performance. Key words: Swine, high-fat oat, digestibility, growth, carcass composition

This experiment was conducted to determine the effect of graded levels of number 1 wheat screenings on performance, nutrient digestibility and carcass traits when fed to growing-finishing pigs. Forty crossbred pigs (Camborough 15 Line female × Canabred sire) weighing an average of 19.7 ± 2.8 kg were assigned to one of five dietary treatments in a 5 × 2 factorial design experiment. The main effects tested included level of wheat screenings and sex of pig (barrows and gilts). The levels of inclusion were 0, 18, 36, 54 and 72% in the grower diet and 0, 20.5, 41, 61.5 and 82% in the finisher diet. Screenings were added largely at the expense of barley. A botanical analysis was preformed and it indicated that the screenings contained approximately 88.5% whole or cracked wheat with the most prevalent weed seeds being wild buckwheat (6.7%), canola seed (2.8%) and cleavers (0.96%). There was a linear (P = 0.001) increase in the digestibility of dry matter, crude protein and gross energy with increased incorporation of wheat screenings in the diet. Over the entire experimental period (19.7–105.1 kg), there was no change in growth rate due to feeding wheat screenings, but feed intake declined in a linear (P = 0.044) fashion while feed conversion improved linearly (P = 0.014) as the inclusion level of screenings increased. There were no sex effects on pig performance. Dietary inclusion of wheat screenings had no significant effects on any carcass traits including dressing percent, carcass value index, lean yield, loin fat or loin lean. The carcass value index for gilts was higher than that of barrows (P = 0.038). The overall results of this experiment indicate that number 1 wheat screenings can be successfully uti lized as an energy source for use in growing-finishing diets and can be fed at levels as high as 72% for growing pigs and 82% for finishing pigs with no negative effects on pig performance or carcass quality. However, should the level of weed seeds increase or the type of weed seeds contaminating the screenings change appreciably from those reported here, then it may be necessary to reduce the incorporation level of screenings in the diet. Key words: Pigs, wheat screenings, performance, digestibility, carcass

This experiment was conducted to measure nutrient digestibility and performance in broiler chicks fed diets based on normal and low viscosity rye or barley fed with and without enzyme (pentosanase and beta-glucanase) during a 17 day growth trial. A total of 150 one-day old, male broiler chicks (5 birds per pen and 5 pens per treatment) were randomly assigned to one of six dietary treatments in a 3x2 factorial design experiment (3 cerealsx2 enzyme levels). Digestibility coefficients were determined using chromic oxide. Digestibility coefficients for dry matter and crude protein were significantly (p=0.0001) higher for the barley-based diets than for any of the rye-based diets. Digestibility coefficients for gross energy did not differ (p>0.05) due to cereal grain. There were no differences in the digestibility coefficients for dry matter and gross energy between chicks fed normal and low viscosity rye. However, the digestibility coefficient for crude protein was higher (p=0.01) for the low viscosity rye compared with the normal viscosity rye. Addition of enzyme to the diet significantly (p=0.0001) increased digestibility coefficients for dry matter, crude protein and energy. There were no significant differences in weight gain, feed intake or feed conversion between birds fed barley or rye or between birds fed normal or low viscosity rye. Enzyme supplementation significantly improved (p=0.0001) weight gain, intake and feed conversion. The overall results of this experiment indicate that unsupplemented barley and rye do not support adequate growth rates in poultry. Enzyme supplementation dramatically improved broiler performance. In addition, genetic selection to reduce the viscosity of rye had only a modest effect on the nutritive value of rye for broilers.

Ten barrows, weaned at 28 days (7.2 +/- 0.1 kg BW), were used to evaluate the effects of feeding extruded full-fat soybeans on intestinal morphology and mucosal cell turnover time. All pigs were fed corn-based diets with half of the pigs receiving diets supplemented with 15.5% soybean meal and 3% soybean oil and the remaining pigs fed a diet in which the soybean meal and oil were replaced by 18.5% extruded full-fat soybeans. The pigs were individually placed in 80 x 150 cm metabolic cages and fed twice daily an amount approximately equal to their ad libitum intake for a period of 14 days. On day 14, pigs were weighed and then injected intraperitoneally with [H-3]thymidine (100 muCi/kg of BW, specific activity 20 Ci/mmol) 6 h after the morning meal. A pig from each treatment was killed 1, 4, 8, 16, or 24 h post-injection and intestinal tissues were collected. Daily gains for pigs fed the soybean diet and extruded full-fat soybean diet were 0.24 and 0.31 kg/day (p = 0.05) with feed conversions of 1.58 and 1.39 (p = 0.05), respectively. In comparison with pigs fed soybean meal, pigs fed moist extruded full-fat soybeans had a decreased crypt depth in their duodenum and cecum (p < 0. 1), while the villus height in the mid jejunum and ileum and the total height (villus height plus crypt depth) of the ileum and mid jejunum increased (p < 0.05). The villus width in the duodenum and mid jejunum decreased (p < 0.05). The number of crypt epithelial cells in the upper jejunum increased but decreased in the ileum, colon and cecum (p < 0.05). The number of villus epithelial cells in the ileum and the upper and mid jejunum increased (p < 0.05). The time for migration of epithelial cells in the crypt-villus column decreased (p < 0.05) in all sites except the upper jejunum, ileum and cecum. The mucosal turnover rate for all intestinal sites except the upper jejunum, colon and cecum decreased (p < 0.05). From these data, we conclude that inclusion of moist extruded full-fat soybeans in weanling pig diets can improve the intestinal morphology and slow the migration rate and turnover time of epithelial cells of the small intestine, especially in the mid jejunum compared with soybean meal.

A three-week trial was conducted to evaluate the effects of the oligosaccharide stachyose on performance, diarrhoea incidence and intestinal bacterial populations in weaned pigs (7.96±0.2kg). A total of 144 crossbred (Landrace × Large White × Duroc) pigs weaned at 28 days were allotted to one of four treatments with six pens per treatment and six pigs per pen. The experimental diets were based on maize, dried whey and whole-fat milk and were supplemented with 0, 1 or 2% stachyose. A fourth diet contained no milk but instead contained 20% soybean meal to provide 0.78% stachyose and 0.21% raffinose. Inclusion of 1 or 2% stachyose in the diet depressed growth compared with pigs fed the control diet. Pigs fed the soybean meal diet gained weight at a rate similar to pigs fed the diet containing 1% added stachyose. Diarrhoea incidence was highest for pigs fed the soybean meal diet and lowest for pigs fed the control diet, with pigs fed the diets containing stachyose being intermediate. Pigs fed 1% stachyose had more lactobacilli in the ileum as well as more bifidobacteria in the caecum and colon than control pigs. They also had fewer enterobacteria in the colon. In contrast, pigs fed the diet containing 2% stachyose had fewer lactobacilli and bifidobacteria in the jejunum, ileum and caecum than did control pigs. Volatile fatty acids in the ileum, caecum and colon were highest for pigs fed 1% stachyose and lowest for pigs fed 2% stachyose. Volatile fatty acid concentrations were not significantly different between pigs fed the soybean meal diet and those fed the control. The overall results of this experiment indicate that the oligosaccharide stachyose had a negative effect on pig performance and its presence may partially explain the poorer performance observed when soybean meal is used as the sole source of supplemental protein in cereal-based diets fed to weaned pigs.

Twenty-four crossbred barrows (Camborough 15 Line female × Canabred sire) weighing an average of 51.3 ± 5.1 kg were used in a trial conducted during two periods according to a completely randomized block design. The pigs were assigned to one of six dietary treatments comprised of a normal two-rowed, hulled variety of barley (CDC Bold) or three low-phytate genotypes selected to contain approximately 68, 41 or 3% of the normal level of phytate. A normal hulless barley (CDC Dawn) and a hulless genotype selected to contain 54% of the normal phytate content were also included. The diets fed contained 99.5% barley and 0.5% chromic oxide. The marked feed was provided for a 7-d acclimatization period, followed by a 3-d fecal collection. At the conclusion of the first replicate, the pigs were assigned to different treatments and the procedure was repeated resulting in eight observations per treatment. Selection for phytate content had no effects on the apparent fecal digestibility of dry matter, crude protein or gross energy (P > 0.05). The digestibility coefficients for dry matter and energy were significantly higher for the hulless varieties of barley than the hulled genotypes. Phosphorus digestibility increased as the level of phytate in the barley declined. The linear relationship relating phosphorus digestibility (y) to phytate content (x) was: y = 67.7 − 12.54x (r2= 0.64; P < 0.0001).

Thirty gilts were assigned to receive no hormone injection (Group 1), an injection of 400 IU eCG plus 200 IU hCG (Group 2), or 750 IU eCG followed 78 h later by 500 IU hCG (Group 3). The average inter-estrus intervals were 21, 26, and 32 d for groups 1, 2 and 3, respectively. Cystic-like follicles (>15 mm) were observed in two group 2 gilts, and five group 3 gilts. One group 1gilt had a follicle of 18 mm. All other control gilt ovaries were grossly normal. The induction of cystic-like follicles would appear to preclude the commercial application of gonadotrophins during the luteal phase for extending the inter-estrus interval in gilts. Key words: Gonadotrophins, inter-estrus interval, gilts

One hundred and forty crossbred pigs (Pig Improvement Canada Ltd, Acme Alberta), weighing an average of 21.5 + 3.6kg, were assigned on the basis of sex, weight and litter to one of five dietary treatments. The control diet was barley-based, while in the remaining four treatments, the grain component consisted of either normal or low viscosity rye fed with or without pentosanase. Digestibility coefficients for dry matter, crude protein and gross energy were significantly ( P = 0.0001) higher for the rye-based diets than the barley based diet. There were no differences in digestibility coefficients between normal and low viscosity diets or between diets supplemented or unsupplemented with pentosanase. Over the entire experimental period (21.5 to 100.7kg), pigs fed the normal viscosity rye gained better ( P = 0.001) and had a higher daily intake ( P = 0.001) than pigs fed the low viscosity rye. Pigs fed the low viscosity rye tended to gain slower than pigs fed barley and with lower intake while pigs fed the normal viscosity rye had similar gains and intake to the pigs fed barley. Enzyme supplementation failed to improve pig performance. Males had higher gains and intake than females ( P < 0.05). Enzyme supplementation, rye viscosity or choice of cereal grain had no effect on any of the carcass traits measured. In conclusion, the results of the present experiment indicate that rye is a good alternative to barley for use in growing-finishing rations and becomes increasing attractive as the age of the pig increases. Breeding efforts directed towards reducing the viscosity of rye are unlikely to be successful in improving the nutritive value of rye for swine.

Seventy-two crossbred pigs weighing an average of 41.5 kg were assigned on the basis of sex, weight and litter to one of four dietary treatments in a factorial (4 treatments x 2 sexes) arrangement. The control diet was based on barley and soybean meal while the experimental treatments consisted of diets in which a portion of the dietary protein was supplied by 20% of a 50:50 blend of extruded (130 degreesC for 20 to 25 sec) peas and full-fat canola seed, 20% of a 50:50 blend of unextruded peas and full-fat canola seed or a diet containing 10% peas, 6% canola meal and 4% canola oil (to equal the level of canola oil provided by 10% whole canola seed). Digestibility coefficients for dry matter, crude protein and gross energy were significantly higher (p <0.05) for the control diet than for the other three diets. Extrusion produced no beneficial effects (p >0.05) on nutrient digestibility and there were no differences in digestibility between the diet ba-sed on intact canola seed compared with the diet containing canola meal and oil. Choice of protein supplement had no significant effects on gain, feed intake or feed conversion during the grower or finisher phases and over the entire experimental period. Extrusion of the pea-canola blend produced no beneficial effects on pig performance as the performance of pigs fed either the extruded or unextruded blend of peas and canola seed was similar, In addition, the performance of pigs fed diets containing intact canola seed was similar to that of pips fed canola meal and oil. Castrates gained faster and consumed more feed than gilts (P <0.05). However, their feed conversion was poorer than that of the gilts during the finisher period, There were no significant differences in carcass traits between pigs fed the control and any of the experimental treatments, Extrusion had no effect on carcass traits and the carcasses of pigs fed canola meal and oil did not differ from those of pigs fed whole canola seed. Castrates had a significantly lower dressing percentage, lower estimated lean yield but greater loin fat depth than gilts (p <0.05), The results of this experiment indicate that peas in combination with canola seed or canola meal are an acceptable alternative to soybean meal as a protein supplement for use in growing-finishing swine diets. Extrusion did not appear to have any beneficial effects on the nutritional value of the canola seed-pca blend as nutrient digestibility, growth performance and carcass traits were similar for pigs fed the unextruded blend of peas and canola seed compared with the extruded product. Since the process adds to the cost of the raw products, its use is unlikely to be economical.

An experiment was conducted to compare the nutritional composition of 16 varieties of chickpeas (Kabuli and Desi) and to determine their nutrient digestibility for swine using the mobile nylon bag technique. The average crude protein content of the Kabuli chickpeas (226 g kg(-1)) was lower than that of the Desi chickpeas (235 g kg(-1)). Desi chickpeas were higher in acid detergent fibre (145 versus 50 g kg(-1)) and neutral detergent fibre (264 versus 181 g kg(-1)) than Kabuli chickpeas. Digestibility coefficients for dry matter (83.1 versus 72.5%), gross energy (83.5 versus 74.8%) and crude protein (83.7 versus 79.4%) were higher for Kabuli chickpeas than for Desi chickpeas. Based on chemical analysis and nutrient digestibility, Kabuli chickpeas would appear to have greater potential as a protein and energy source for use in swine rations than Desi chickpeas. (C) 2002 Society of Chemical Industry.

Previous studies conducted with swine have reported that the mobile nylon bag technique (MNBT) does not always accurately predict in vivo nutrient digestibilities. Therefore. in this study: the MNBT was modified so that nutrient digestibilities would more closely resemble those from conventional (Con) digestibility studies obtained using the indicator method. A total of 19 feeds were tested including five cereal grains. five legumes, three: high protein sources and sis mixed diets. The principle changes to the MNBT included the use of a fecal collection harness which minimized the number of bags lost. In addition, previous protocols involved pooling of bags within pig while in the present experiment all bags were analyzed separately to increase the precision of the test. Finally, chemical analyses were done using the entire nylon bag plus residue rather than opening the bags and scraping out the contents. With the exception of the barley sample (p=0.01), dry matter digestibility (DMD) coefficients obtained with the: MNBT were not significantly different from those obtained with the indicator method. The linear regression equation relating the MNBT to the indicator method was Con DMD=-0.77+1.02 MNBT DMD (r(2) =0.93. p <0.0001). There was no significant (p >0.05) difference in gross energy digestibility (GED) coefficients determined using the MNBT or the indicator method for any of the 19 feeds. The regression line equation relating the MNBT to the indicator method was Con GED=-5.68+1.06 MNBT GED (r(2)=0.94: p <0.0001). The MNBT was less effective in predicting in vivo crude protein digestibility (CPD) than it was in predicting dry matter and energy digestibility. Differences greater than five percentage units were observed for two of the legumes, Kabuli chickpeas (p=0.02) and the extruded pea-canola seed mixture (p=0.01) as well as for three of the mixed diets including the unheated hulled barley-based diet (p=0.01), the unheated hulless-barley based diet (p=0.08) and the barley-soybean meal based diet (p=0.008). The regression equation relating the MNBT to the indicator method was Con CPD=5.75 + 0.90 MNBT CPD (r(2)=0.76: p <0.0001). This study indicates that the modified MNBT can be used for the rapid determination of dry matter and energy digestibility in a wide variety of ingredients. For the measurement of crude protein digestibility, the technique produces results similar to conventional digestibility studies for cereal grains and high protein feeds but tends to overestimate protein digestibility for legumes and mixed diets.

Five feeds and five castrates were used to study the effects of washing rather than scrapping feces fr om bags on nutrient digestibility obtained with the mobile nylon bag technique (MNBT). Using unwashed bags, the MNBT and the conventional indicator method (CON) produced similar dry matter digestibility (DMD) with barley being the only ingredient where a difference (P < 0.05) was obtained between the two techniques. The linear regression equation was CON DMD = 5.39 + 0.92 MNBT DMD (r2 = 0.95). The MNBT overestimated DMD with a bias of less than 0.1%. When washed bags were used, differences (P < 0.05) were obtained between the two techniques for barley, corn and oats and the MNBT overestimated DMD with a bias of 6.6%. There were no differences in gross energy digestibility (GED) when obtained with the indicator method or the MNBT using unwashed bags. The regression line equation was CON GED = 3.85 + 0.94 MNBT GED (r2 = 0.95) and the MNBT overestimated GED with a bias of 1.4%. When washed bags were used, significant (P < 0.05) differences were obtained between techniques for GED with barley, corn, and oats. The MNBT overestimated GED with a bias of 7.3%. With unwashed bags, there were no differences in crude protein digestibility (CPD) obtained with the indicator method or the MNBT, with the exception of the mixed diet. The regression line equation was CON CPD = 28.16 + 0.60 MNBT CPD (r2 = 0.53) and the MNBT overestimated CPD with a bias of 3%. When washed bags were used, significant (P < 0.05) differences were obtained between techniques for barley, corn, oats, wheat and the mixed diet, and the MNBT overestimated CPD with a bias of 12.8%. The overall results of this experiment indicate that washing bags greatly overestimates nutrient digestibility coefficients obtained with the MNBT. Key words: Nylon bag, pigs, digestibility, protein, energy, cannula