Effects of arginine supplementation during early gestation (day 1 to 30) on litter size and plasma metabolites in gilts and sows.

Two experiments were conducted, under typical commercial swine production conditions, to determine effects of dietary arginine supplementation during early gestation on the performance of gilts and sows. In Exp. 1, between d 1 and 30 of gestation, 62 Landrace gilts and 113 sows consumed a corn- and soybean meal-based diet supplemented with 1.3% -arginine HCl or 2.2% -alanine. Total numbers of piglets born ( < 0.05) and born alive ( < 0.01) per litter and litter birth weights of piglets born ( < 0.05) and born alive ( < 0.05) were increased in the arginine group compared with the control. In Exp. 2, 155 multiparous Landrace sows received 1.3% -arginine HCl supplementation between d 1 and 14 (T2; = 41), d 15 and 30 (T3; = 40), or d 1 and 30 (T4; = 37), whereas the control group received 2.2% -alanine supplementation between d 1 and 30 (T1; = 37). Blood samples were randomly obtained from 6 sows per group on d 1, 14, and 28 of gestation to determine plasma concentrations of AA and related metabolites. Total numbers of piglets born ( = 0.084) and born alive ( = 0.080) per litter tended to be higher for sows supplemented with arginine between d 1 and 14 of gestation (T2) than for control sows (T1). Concentrations of arginine and nitric oxide metabolites were greater ( < 0.05) in T4 compared with T1 and T3 on d 14 of gestation and were also greater in T4 compared with T1 and T2 on d 28 of gestation. Plasma concentrations of spermidine ( < 0.001) were increased in T3 and T4 compared with T1 and T2 on d 28. These results indicate that dietary arginine supplementation during early gestation improves the reproductive performance of gilts and sows, possibly via nitric oxide and polyamine-dependent mechanisms.

Estimation of the standardized ileal digestible valine to lysine ratio required for 25- to 120-kilogram pigs fed low crude protein diets supplemented with crystalline amino acids.

Four 28-d experiments were conducted to determine the standardized ileal digestible (SID) valine (Val) to lysine (Lys) ratio required for 26- to 46- (Exp. 1), 49- to 70- (Exp. 2), 71- to 92- (Exp. 3), and 94- to 119-kg (Exp. 4) pigs fed low CP diets supplemented with crystalline AA. The first 3 experiments utilized 150 pigs (Duroc × Landrace × Large White), while Exp. 4 utilized 90 finishing pigs. Pigs in all 4 experiments were randomly allocated to 1 of 5 diets with 6 pens per treatment (3 pens of barrows and 3 pens of gilts) and 5 pigs per pen for the first 3 experiments and 3 pigs per pen for Exp. 4. Diets for all experiments were formulated to contain SID Val to Lys ratios of 0.55, 0.60, 0.65, 0.70, or 0.75. In Exp. 1 (26 to 46 kg), ADG increased (linear, = 0.039; quadratic, = 0.042) with an increasing dietary Val:Lys ratio. The SID Val:Lys ratio to maximize ADG was 0.62 using a linear broken-line model and 0.71 using a quadratic model. In Exp. 2 (49 to 70 kg), ADG increased (linear, = 0.021; quadratic, = 0.042) as the SID Val:Lys ratio increased. G:F improved (linear, = 0.039) and serum urea nitrogen (SUN) decreased (linear, = 0.021; quadratic, = 0.024) with an increased SID Val:Lys ratio. The SID Val:Lys ratios to maximize ADG as well as to minimize SUN levels were 0.67 and 0.65, respectively, using a linear broken-line model and 0.72 and 0.71, respectively, using a quadratic model. In Exp. 3 (71 to 92 kg), ADG increased (linear, = 0.007; quadratic, = 0.022) and SUN decreased (linear, = 0.011; quadratic, = 0.034) as the dietary SID Val:Lys ratio increased. The SID Val:Lys ratios to maximize ADG as well as to minimize SUN levels were 0.67 and 0.67, respectively, using a linear broken-line model and 0.72 and 0.74, respectively, using a quadratic model. In Exp. 4 (94 to 119 kg), ADG increased (linear, = 0.041) and G:F was improved (linear, = 0.004; quadratic, = 0.005) as the dietary SID Val:Lys ratio increased. The SID Val:Lys ratio to maximize G:F was 0.68 using a linear broken-line model and 0.72 using a quadratic model. Carcass traits and muscle quality were not influenced by SID Val:Lys ratio. In conclusion, the dietary SID Val:Lys ratios required for 26- to 46-, 49- to 70-, 71- to 92-, and 94- to 119-kg pigs were estimated to be 0.62, 0.66, 0.67, and 0.68, respectively, using a linear broken-line model and 0.71, 0.72, 0.73, and 0.72, respectively, using a quadratic model.

The antimicrobial peptide sublancin ameliorates necrotic enteritis induced by Clostridium perfringens in broilers.

Sublancin is an antimicrobial peptide produced by 168 containing 37 amino acids. The objective of this study was to investigate its inhibitory efficacy against both in vitro and in vivo. In the in vitro study, we determined that sublancin had a minimum inhibitory concentration of 8 µM against , which was much higher than the antibiotic lincomycin (0.281 µM). Scanning electron microscopy showed that sublancin damaged the morphology of . The in vivo study was conducted on broilers for a 28-d period using a completely randomized design. A total of 252 chickens at 1 d of age were randomly assigned to 1 of 6 treatments including an uninfected control; an infected control; 3 infected groups supplemented with sublancin at 2.88, 5.76, or 11.52 mg activity/L of water; and an infected group supplemented with lincomycin at 75 mg activity/L of water (positive control). Necrotic enteritis was induced in the broilers by oral inoculation of on d 15 through 21. Thereafter, the sublancin or lincomycin were administered fresh daily for a period of 7 days. The challenge resulted in a significant decrease in ADG ( < 0.05) and a remarkable deterioration in G:F ( < 0.05) during d 15 to 21 of the experiment. There was a sharp increase of numbers in the cecum ( < 0.05). The addition of sublancin or lincomycin reduced caecal counts ( < 0.05). The counts had a tendency to decrease in the lincomycin treatment ( = 0.051) but were the highest in the sublancin treatment (5.76 mg activity/L of water). A higher villus height to crypt depth ratio in the duodenum and jejunum as well as a higher villus height in the duodenum were observed in broilers treated with sublancin or lincomycin ( < 0.05) compared with infected control broilers. It was observed that sublancin and lincomycin decreased IL-1ß, IL-6, and tumor necrosis factor-α levels ( < 0.05) in the ileum compared with the infected control. In conclusion, although sublancin's minimum inhibitory concentration is much higher than lincomycin in vitro, less sublancin is needed to control necrotic enteritis induced by in vivo than lincomycin. These novel findings indicate that sublancin could be used as a potential antimicrobial agent to control necrotic enteritis.

Dietary supplementation with Lactobacillus fermentum I5007 improves the anti-oxidative activity of weanling piglets challenged with diquat.

AIMS: To determine the effects of Lactobacillus fermentum I5007 on the redox state of piglets oxidatively stressed with diquat. METHODS AND RESULTS: Twenty-four, 28-day-old barrows were used in a 2 × 2 factorial design experiment with the main effects being Lact. fermentum supplementation and diquat challenge. Half of the pigs (n = 12) were orally administered with 20 ml of a solution containing 10(8 ) CFU ml(-1) of Lact. fermentum each morning of the 21-day trial, while the remainder received saline. On day 8, these two groups were further subdivided so that half of the pigs in each group (n = 6) were intraperitoneally injected with 10 mg kg(-1) BW diquat, while the remainder received saline. The diquat-injected pigs had significantly poorer performance and increased levels of plasma cortisol, adrenaline, carbonyl and malondialdehyde. Lactobacillus fermentum supplementation significantly increased superoxide dismutase and glutathione and increased the ability to inhibit superoxide anion production in liver and muscle. CONCLUSIONS: Lactobacillus fermentum improved the anti-oxidative defence system and alleviated damage caused by diquat. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus fermentum has the potential to alleviate oxidative stress and improve weaning pig performance.

Phosphorus utilization and characterization of excreta from swine fed diets containing a variety of cereal grains balanced for total phosphorus.

Intrinsic phytase in swine feeds may increase phytate utilization and alter the solubility of the excreted P. The objective of this experiment was to quantify changes in fecal P composition from swine fed a variety of cereal grains containing a range of phytate concentrations and endogenous phytase activities. Twenty-five crossbred barrows (89.3 +/- 6.8 kg) were fed 1 of 5 dietary treatments that were based on wheat, corn, barley, low-phytate barley, or high-fat-low-lignin oats. Experimental diets were formulated to contain 75% of the test grain and were fed for a 7-d acclimation period followed by a 3-d fecal collection period. Total-tract apparent digestibility coefficients were determined for DM, P, and phytate using an indicator method. Fecal P was characterized using solution-state (31)P nuclear magnetic resonance spectroscopy. Water-soluble P (WSP) and WSP-to-total P (TP) ratio were determined in the feces. Apparent total-tract digestibility coefficients for P and phytate ranged from 0.33 (barley) to 0.45 (low-phytate barley) and from 0.20 (corn) to 0.79 (oats), respectively. The majority of P excreted in the feces was in the form of phosphate (>47% of TP), and phytate degradation was not related to the endogenous phytase activity in the diet. There was a positive linear relationship between dietary NDF and apparent total-tract phytate digestibility (r(2) = 0.82; P = 0.03), indicating that greater dietary fiber content may enhance microbial breakdown of phytate in the hindgut. There was a negative relationship between the fecal WSP-to-TP ratio and the percentage of TP that was in the form of phytate in the feces. In summary, our results indicate that the majority of P in the feces of pigs fed diets based on cereal grains is present in the form of phosphate and relatively small amounts of phytate were contained in the excreta. The exception to this was the corn diet, for which 45% of the total fecal P was in the form of phytate. Hydrolysis of phytate in the gut did not appear to be related to the content of either phytate or phytase in the grain, but was related to dietary fiber concentration.

Phosphorus utilization and characterization of ileal digesta and excreta from broiler chickens fed diets varying in cereal grain, phosphorus level, and phytase addition.

Both intrinsic and exogenous phytase in poultry feeds can alter phytate utilization and the solubility of P excreted. This experiment determined the effects of feeding diets varying in cereal grain, P concentration and phytase addition on phytate and P utilization and P characterization of ileal digesta and excreta. Twelve treatments, consisting of diets based on corn, wheat, barley, or high fat-low lignin oat and 3 P treatments (low P with 0.30% nonphytate P; low P + 1,000 phytase units of phytase; high P with 0.45% nonphytate P), were fed to 300 broilers using a factorial design. Fresh excreta were collected at 20 and 21 d and ileal digesta was collected at 21 d. Ileal digesta and excreta were analyzed for total P, phytate P and Ca, with P composition determined by solution (31)P nuclear magnetic resonance spectroscopy. Excreta samples were also analyzed for water soluble P (WSP). Apparent ileal digestibility coefficients for phytate P and total P ranged from 0.03 to 0.42 and 0.56 to 0.71, respectively. Diets supplemented with phytase had greater phytate P hydrolysis than unsupplemented diets. Apparent total tract digestibility coefficients for phytate P and total P ranged from 0.10 to 0.73 and 0.43 to 0.61, respectively. Across cereal grains, there was almost a 3-fold increase in total tract phytate P hydrolysis with phytase supplementation. The P composition of ileal digesta was predominantly phytate P (70 to 88% of total P), whereas excreta phytate P ranged from 26 to 76% of total P. Excreta WSP ranged from 3.2 to 7.5 g kg(-1) and was least for the barley diets. There was a 25% reduction in excreta WSP from the high P to the low P + phytase diets and a 37% reduction from the high P to the low P diets. As cereal grain had little influence on phytate digestibility, it is unlikely that intrinsic phytase in grain has much influence on phytate utilization by poultry. Both total P and WSP in excreta were reduced by the low P diet and the low P + phytase diet, irrespective of cereal grain, which reduces the risk of P transfer to water bodies when excreta are applied to land as fertilizer.

Nutrient excretion, phosphorus characterization, and phosphorus solubility in excreta from broiler chicks fed diets containing graded levels of wheat distillers grains with solubles.

Increased interest in ethanol production in North America has led to increased production of distillers dried grains with solubles (DDGS), the majority of which are fed to livestock. To determine the impact of including wheat DDGS in broiler diets on nutrient excretion and P characterization and solubility, 125 one-day-old male broiler chicks were fed wheat- and soybean meal-based diets containing 0, 5, 10, 15, or 20% wheat DDGS. There were 5 replicate pens per treatment, with 5 birds per pen arranged in a randomized block design. Apparent retention of both N and P were determined by using the indicator method. Nutrients excreted per kilogram of DM intake were also calculated. Characterization of excreta P was determined by (31)P-solution nuclear magnetic resonance spectroscopy, and water-soluble P (WSP) was determined by extraction of excreta with deionized water. The apparent retention of both N (P < 0.001) and P (P < 0.008) decreased linearly with increasing inclusion rates of DDGS from 0 to 20%. The nutrient output per kilogram of DM intake increased linearly with increased DDGS inclusion rate for N (P < 0.04), P (P < 0.0001), and WSP (P < 0.0003). As the inclusion rate of DDGS increased, the P concentration in excreta increased (P < 0.008), whereas excreta phytate P concentrations decreased (P < 0.01), which led to an increase in WSP and the fraction of total P that was soluble. Because the inclusion of DDGS in poultry diets increased N and P output, as well as the solubility of P excreted, care should be taken when including high levels of DDGS in poultry diets, because increases in N and P excretion are a concern from an environmental standpoint.

Phosphorus composition of manure from swine fed low-phytate grains: evidence for hydrolysis in the animal.

Including low-phytic-acid grains in swine diets can reduce P concentrations in manure, but the influence on manure P composition is relatively unknown. To address this we analyzed manure from swine fed one of four barley (Hordeum vulgare L.) varieties. The barley types consisted of wild-type barley (CDC bold, normal barley diet) and three low-phytic-acid mutant barleys that contained similar amounts of total P but less phytic acid. The phytic acid concentrations in the mutant barleys were reduced by 32% (M422), 59% (M635), and 97% (M955) compared with that in the wild-type barley, respectively. Phosphorus concentrations were approximately one-third less in manures from animals fed low-phytic-acid barleys compared with those fed the wild-type variety. Phytic acid constituted up to 55% of the P in feed, but only trace concentrations were detected in NaOH-EDTA extracts of all manures by solution (31)P nuclear magnetic resonance (NMR) spectroscopy. Phosphate was the major P fraction in the manures (86-94% extracted P), with small concentrations of pyrophosphate and simple phosphate monoesters also present. The latter originated mainly from the hydrolysis of phospholipids during extraction and analysis. These results suggest that phytic acid is hydrolyzed in swine, possibly in the hind gut by intestinal microflora before being excreted in feces, even though the animals have little phytase activity in the gut and derive little nutritional benefit from phytate P. We conclude that feeding low-phytic-acid grains reduces total manure P concentrations and the manure P is no more soluble than P generated from normal barley diets.

Effect of phytase supplementation on phosphorus digestibility in low-phytate barley fed to finishing pigs.

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.

Performance of growing-finishing pigs fed diets based on normal or low viscosity rye fed with and without enzyme supplementation.

One hundred and forty crossbred pigs (Pig Improvement Canada Ltd, Acme Alberta), weighing an average of 21.5 + 3.6 kg, 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 100.7 kg), 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.

Increasing the calcium content of mealworms (Tenebrio molitor) to improve their nutritional value for bone mineralization of growing chicks.

The purpose of these studies was to determine the husbandry variables that optimize the Ca content of mealworms (Tenebrio molitor) and to determine the bioavailability of this Ca for bone mineralization in chicks that consume the mealworms. To determine the optimal level of Ca in the substrates used in short-term (< 14 days) holding of mealworms and to determine the length of time that mealworms should be exposed to high-Ca substrates, mealworms were placed in either a wheat bran or a chicken starter substrate supplemented with 0, 4, 8, or 12% Ca from CaCO3. The mealworms were harvested after 0.5, 1, 2, 3, 4, 7, or 14 days. The Ca content of the mealworms was greatest with the use of chicken starter and increased linearly with the Ca content of the substrate. In general, the Ca content of the mealworms increased during the first 24 hr and decreased after > or = 1 wk, especially at the higher levels of Ca supplementation. The chicken starter also resulted in higher levels of vitamin D in mealworms. Mealworms held in wheat bran with 8% Ca were fed to growing chicks. Ca bioavailability was calculated from the chicks' bone ash. The Ca in these mealworms was 76% as bioavailable as the Ca in oyster shell.

Growth hormone as an amplifier of insulin-like growth factor-I action: potentiated oestradiol accumulation.

The interaction between GH and IGF-I in modulating oestradiol biosynthetic capacity was examined in cultured porcine granulosa cells. Granulosa cells (2 x 10(6) viable cells/culture) were initially cultured for 96 h (treatment period) in an androstenedione-free medium in the absence or presence of IGF-I (0 or 50 ng/ml), with or without GH at 100 ng/ml. At the conclusion of this period, culture media were discarded and the cells were washed twice with the androstenedione-free medium and reincubated for an additional 24 h (test interval) in an androstenedione (10(-7) M)-supplemented medium for oestradiol accumulation. GH alone induced no stimulation (P > 0.05) of basal oestradiol accumulation. In contrast, concurrent treatment with IGF-I produced a 4.3-fold increase (26 vs 112 ng/ 2 x 10(6) cells per 24 h, P < 0.001) in oestradiol accumulation. GH amplified IGF-I-induced oestradiol production in a dose (minimal dose requirement of 0.3 ng/ml)- and time (minimal time requirement of 24-48 h)-dependent manner. Studies on the site(s) of action indicated that GH exerts its amplifying effects on IGF-I-induced oestradiol production both proximal and distal to cAMP generation. As the specificity study and the inhibitory study indicated, GH amplification of IGF-I-induced oestradiol production is a process involving gene transcription and/or translation and the synergism is not solely specific to IGF-I as IGF-II-induced oestradiol production was also amplified in the presence of GH.