DL-Methionine (Met) has been conventionally used in swine diets with assumption of similar bioefficacy with L-Met. However, because L-Met is the form that is utilized by animals for protein synthesis, L-Met could, theoretically, be more available. Four experiments were conducted to evaluate L-Met bioavailability in nursery pigs with 21-day growth trials. A total of 105,105,112 and 84 crossbred pigs were used in Exp. 1, 2, 3 and 4, respectively. Each experiment had a low Met basal diet and 3 levels of the Met sources (DL-Met and L-Met). In addition to the basal diet, supplementation levels were 0.053%, 0.107% and 0.160% in Exp. 1, 0.040%, 0.080% and 0.120% in Exp. 2, 0.033%, 0.067% and 0.100% in Exp.3, 0.040%, 0.080% and 0.120% in Exp. 4. Body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), gain: feed (G:F) were measured and plasma urea nitrogen (PUN) was analyzed in blood samples weekly. In Exp. 3 and 4, preference studies were conducted with the basal diet and the second highest level of each Met source. When additional DL-Met or L-Met were supplemented to the basal diet, BW, ADG, ADFI, and G:F ratio increased (P < 0.05). In the comparison between the DL-Met and L-Met diets in Exp. 1, pigs in the L-Met group had greater ADG and G:F ratios in the d 0-7 (P < 0.05) period than those in the DL-Met group. However, there were no differences for the overall experimental period. In Exp. 2, pigs in the DL-Met group had greater BW (P < 0.05), ADG (P < 0.05) and ADFI (P < 0.05) than those in the L-Met group for the overall period whereas no differences were observed in G:F ratios and PUN concentrations. In Exp. 3 and 4, there were no differences in BW, ADG, ADFI, G:F ratios or PUN concentrations between L-Met and DL-Met groups for the overall period. There was no preference exhibited for either the DL-Met or L-Met diet. In the results of relative bioavailability of L-Met to DL-Met, the values was 111.1% for d 0-14 based on the estimation by ADG in Exp. 1; L-Met bioavailability was lower than DL-Met based on all response measures in Exp. 2. However, in Exp. 3, relative bioavailability of L-Met to DL-Met was 100.4, 147.3, and 104.1% for d 0-14 ADG, G:F ratio and PUN concentrations. In Exp 4, the relative bioavailability of L-Met was 92.9, 139.4 and 70.4% for d 0-14 ADG, G:F ratio and PUN concentrations. In conclusion, using L-Met in the nursery diet demonstrated no consistent beneficial effect on ADG, G:F ratio or relative bioavailability compared to conventional DL-Met.

published_or_final_version / abstract / toc / Zoology / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / toc / Anatomy / Doctoral / Doctor of Philosophy

No description available.

No description available.

Chronic subclinical levels of disease occur frequently in intensive swine production and compromise nutrient utilization efficiency. Sulfur amino acids (methionine plus cysteine; M+C) have been implicated in improving the animal’s response to immune system stimulation (ISS). Research objectives were to determine the effects of ISS on the optimal dietary methionine to methionine plus cysteine ratio (M:M+C) and on the fractional synthesis rate (FSR) of albumin, fibrinogen and total protein in plasma, liver, and small intestine (SI) of growing pigs. A nitrogen balance study showed that the optimal M:M+C was increased during ISS and greater than 0.62. In a flooding dose infusion study it was determined that total plasma protein FSR was increased during ISS and tended to decrease with reduced M+C intake. Plasma albumin FSR decreased with reduced M+C intake. The data implicates M+C as important nutrients involved in the immune response and careful dietary supplementation during ISS is necessary. / Funding sponsored by Evonik Degussa, Ontario Pork, the Ontario Ministry of Agriculture, Food and Rural Affairs and the Natural Sciences and Engineering Research Council of Canada.

There has been little research into the use of water cooling methods for pigs during transport to slaughter under conditions of high ambient temperature. The aim of this study was to examine the effects of water sprinkling pigs before departure from the farm and before unloading at the plant on behaviour during transport, unloading and lairage using live and remote observations, and on pig gastrointestinal tract temperature (GTT) and trailer micro-climate measured by data loggers. Above 23oC, the use of water sprinkling tended to decrease GTT upon arrival and significantly decreased drinking bouts during lairage. There were no detrimental effects of the water sprinkling on unloading behaviours (e.g. slips and falls) or on trailer micro-climate conditions in terms of temperature, humidity or ammonia. Water sprinkling to wet the skin of pigs can therefore be used to cool pigs during transport and lairage under high ambient temperatures.

Three studies were conducted. In the first study, 12 Yorkshire barrows (initial BW of 23.2 ± 2.0 kg) were allotted to 2 dietary treatments with 6 replications per treatment using a completely randomized design to determine apparent Ca and P digestibility (AD), true digestibility (TD) and endogenous output (EO) in a corn/SBM-based diet. All pigs were placed in individual feeder pens that allowed for easy collection of individual feces. The AD of Ca and P were 28.4% and 23.9%, respectively. Their TD of 42% and 40% for Ca and P respectively were significantly (P < 0.05) higher than the corresponding AD. EO was 0.8g for Ca and 1.3g for P per kg of dry matter intake (DMI). In the second study, the optimal dietary ratio of true digestible Ca and P was determined in terms of its effect on growing pig performance, excretion of Ca and P in feces and urine in a corn/SBM-based diet using a randomized complete block design. Thirty six growing barrows (initial BW: 24.2 ± 1.9 kg) were allotted to 6 dietary treatments with 6 replications per block. Six corn/SBM-based diets with very similar nutrient contents were formulated but differed in their dietary ratio of Ca to P. The balances of Ca and P and their true digestibility/retention were calculated for each diet. Animal performance and true retention of both Ca and P was optimal (P < 0.05) with diet 2 with a true digestible Ca to P ratio of 0.82: 1 compared to other experimental diets. The third study was conducted with a similar protocol to that used in experiment 1 involving 12 barrows (initial BW: 23.9 ± 1.1 kg) to determine Mg, Cu, Fe, Mn, Se and Zn TD values for the growing pig. Se and Zn AD of 73.9% and 9.5% significantly (P < 0.05) underestimated their TD of 82.1% and 15%, respectively. Se and Zn EO were 0.00004mg and 0.01 mg/kg of DMI, respectively. The TD and EO for Mg, Cu, Fe and Mn could not be estimated because of their negative AD.

The aim of this study was to determine growth responses and apparent total tract nutrient digestibility in growing pigs fed diets containing graded levels of distillers dried grains with solubles (DDGS) and to determine the effect of a multicarbohydrase enzyme (MC) supplementation on visceral organ mass and fasting whole-body oxygen consumption (FWBOC). In Experiment 1, 48 pigs (25.5 ± 0.14 kg BW) were assigned on the basis of sex and BW (2 pigs per pen) to 4 diets (6 pens per diet) based on corn-barley-soybean meal with 0, 10, 20 and 30% DDGS in a 42-d trial. Apparent total tract digestibilities (ATTD) of energy and other nutrients were determined using acid insoluble ash (AIA) as the indigestible marker. Inclusion of DDGS in the diets decreased (linear, P < 0.05) average daily gain (ADG) and tended to decrease gain to feed ratio (G:F) (linear, P = 0.067) but not average daily feed intake (ADFI) (P > 0.10); however, pigs fed the 20% DDGS diet had similar ADG as pigs fed the 0% DDGS diet. Increasing DDGS content in the diet linearly decreased (P < 0.01) the ATTD of DM, energy and CP (cubic, P < 0.05) but not (P > 0.10) P and Ca; however, ATTD of neutral detergent fiber (NDF) increased (linear, P < 0.01) when DDGS was included in the diet. In Experiment 2, 24 pigs (19.9 ± 0.46 kg BW) were randomly assigned to 3 corn-soybean meal-basal diets (8 pigs per diet): Control (C, 0% DDGS); basal diet with 30% DDGS (C+30% DDGS) or C+30% DDGS supplemented with MC (C+30% DDGS+MC). On d 15, WBOC during the 24- to 30-h postprandial period was determined using an open-circuit indirect calorimeter on 4 pigs per diet. On d 28, pigs were killed to determine visceral organ mass and intestinal morphology. There was no diet effect (P > 0.10) on final BW, FWBOC, and liver, spleen, pancreas, heart, stomach and caecum weights relative to empty BW. However, pigs fed the C and C+30% DDGS+MC had heavier (P = 0.05) empty BW compared with those fed unsupplemented 30% DDGS-containing diet. Small intestine, colon plus rectum and the portal-drained viscera (PDV) were heavier (P < 0.05) in DDGS-fed pigs compared with C; supplementing with MC substantially decreased the effect of DDGS on the weight of these visceral organs. Feeding pigs DDGS tended to decrease (P < 0.10) villous height (VH) and VH:CD in the ileum. Results show that including DDGS in grower pig diets up to 20% has no effect on performance although ATTD of energy, DM, and N may be reduced. Inclusion of DDGS at 30% increased PDV mass and reduced dressing percentage but these effects were overcome by a multicarbohydrase enzyme supplementation.

Two experiments were conducted to determine the effects of phosphorus (P) in growing pigs. In experiment 1, fifty-four pigs were randomly allotted to three diets with available phosphorus (aP) concentrations of 0.23%, 0.17% and 0.11%. In experiment 2, twenty-eight pigs were assigned to four treatments including T1 (diet with 0.23% aP for three wks), T2 (diet with 0.11% aP for wk1 replaced by diet with 0.23% aP for wk2 and wk3), T3 (diet with 0.11% aP for wk1 and wk2 replaced by diet with 0.23% aP for wk3) and T4 (diet with 0.11% aP for all three wks). The 0.11% aP diet proved to be very low with negative effects on performance and bone quality. Reduced dietary P resulted in reduced P intake and reduced P excretion. In conclusion, growing pigs are sensitive to P and environmental pollution because of dietary P can be reduced by dietary manipulation of P.