Effects of feed grade L-methionine on intestinal redox status, intestinal development, and growth performance of young chickens compared with conventional DL-methionine.

This study was conducted to test the effects of supplemental L-Met on redox status, gut development, and growth performance of young broiler chickens compared with DL-Met. A total of 888 (half male and half female) 1-d-old Ross 308 chickens were weighed and randomly allotted to 7 treatments in a randomized complete block design for 21 d, including a basal diet (BD), the BD + 0.095% L-Met or DL-Met, the BD + 0.190% L-Met or DL-Met, and the BD + 0.285% L-Met or DL-Met (representing 60, 70, 80, and 90% of the Met + Cys requirement). Feed disappearance and BW were recorded every 7 d. Liver and duodenum samples were collected on d 0, 7, and 21 to measure redox status and intestine morphology. On d 7, chicks fed a diet supplemented with either 0.285% L-Met or 0.285% DL-Met had increased (P < 0.05) concentrations of glutathione (GSH) and reduced (P < 0.05) protein carbonyl (PC) and malonedialdehyde contents in duodenum mucosa compared with chicks fed the BD. Chicks fed a diet supplemented with 0.285% L-Met had greater (P < 0.05) villus width compared with chicks fed a diet supplemented with 0.285% DL-Met. Chicks fed a diet supplemented with 0.285% L-Met had lower (P < 0.05) crypt depth and greater (P < 0.05) villus height:crypt depth ratio compared with chicks fed a diet supplemented with 0.285% DL-Met or the BD. On d 21, chicks fed a diet supplemented with 0.285% L-Met had increased (P < 0.01) concentrations of GSH and total antioxidant capacity (TAC) but reduced (P < 0.05) PC content in duodenum mucosa compared with chicks fed a diet supplemented with 0.285% DL-Met and the BD. Chicks fed a diet supplemented with 0.285% L-Met had greater (P < 0.05) villus height compared with chicks fed the BD. During the entire 21-d supplementation of either L-Met or DL-Met, ADG and G:F were enhanced (P < 0.01) compared with chicks fed the BD. Chicks fed diets supplemented with L-Met had greater (P < 0.05) ADG and G:F than chicks fed diets supplemented with DL-Met. The relative bioavailability of L-Met to DL-Met for ADG and G:F was 138.2 and 140.7%, respectively. Overall, supplementation of either L-Met or DL-Met has beneficial effects on villus development in association with increased GSH production and levels of TAC and reduced protein oxidation in duodenum. Supplementation of L-Met served a better function on redox status and development of the gut of chicks compared with DL-Met. Chicks fed diets with L-Met had better growth response than chicks fed diets with DL-Met.

Effect of feed grade L-methionine on growth performance and gut health in nursery pigs compared with conventional DL-methionine.

Two experiments were conducted to test if supplementation of LMET has beneficial effects on growth performance and gut health in nursery pigs compared with DL-Met. In Exp. 1, 168 pigs in 56 pens were randomly allotted to 7 dietary treatments for 20 d, including a basal diet (BD; 55% of the NRC requirement for Met), the BD+0.048% L-Met or DL-Met (70% of the NRC requirement), the BD+0.096% L-Met or DL-Met (85% of the NRC requirement), and the BD+0.144% L-Met or DL-Met (100% of the NRC requirement). Body weight and feed disappearance were recorded every 5 d for computation of growth performance. In Exp. 2, 20 individually housed nursery pigs were randomly allotted to 2 dietary treatments for 20 d: DML (0.16% Met from the BD+0.145% supplemental DL-Met) or LMET (0.16% Met from the BD+0.145% supplemental L-Met). Both diets had Met meeting 95% of the NRC requirement. Duodenum samples from all pigs were collected at the end of the trial to evaluate morphology and redox status. In Exp. 1, during the entire 20 d, pigs fed diets supplemented with L-Met tended to have greater (P=0.087) ADG and reduced (P<0.01) plasma urea nitrogen (PUN) than pigs fed diets supplemented with DL-Met. The relative bioavailability (RBA) of L-Met to DL-Met for ADG and G:F was 143.8 and 122.7%, respectively. In Exp. 2, pigs fed a diet supplemented with L-Met had duodenum tissue with greater (P<0.05) concentrations of glutathione (GSH) and greater villus height and width as well as lower (P<0.05) concentrations of protein carbonyl compared with pigs fed DL-Met. Overall, compared with DL-Met, the use of L-Met as a source of supplemental Met in nursery pig diets enhanced duodenum villus development in association with reduced oxidative stress and improved GSH. The beneficial effects of supplementing L-Met compared to DL-Met in gut of nursery pigs resulted in a potential enhancement of ADG and reduction of PUN.

Effects of increasing tryptophan intake on growth and physiological changes in nursery pigs.

Tryptophan (Trp) as a precursor of serotonin (5-hydroxytryptamine, 5-HT) has long been used to extenuate aggressive behavior and control stress of humans as well as several farm animals. This study was conducted to determine the effect of supplemental L-Tryptophan (L-Trp) on growth, cerebral 5-HT concentration, stress hormone concentration, oxidative stress status, and behavior response of pigs under social stress, and also to determine an optimal daily total Trp intake that would benefit nursery pigs under social stress. Seventy two individually housed barrows at 6 wk of age were randomly allotted to 6 treatments with supplementation of 0, 2, 4, 6, 8, or 10 g L-Trp/kg to corn and soybean meal-based feedstuffs. Pigs were fed assigned feedstuffs for 15 d. Body weight was measured on d 0, 5, 10, and 15. Saliva and blood were collected on d 5, 10, and 15. On d 5 and 10, all 12 pigs in each treatment were paired in 6 new pens to record behavior for a 2-d period and returned to original individual pens. On d 15, pigs were euthanized to obtain hypothalamus. During the first 5 d, ADG and G:F increased (linear, P < 0.01) with increasing supplemental L-Trp. During the entire 15 d, ADG and G:F increased (linear, P = 0.01 and P < 0.01, respectively) with increasing supplemental L-Trp. Estimates of the daily total Trp intake based on ADG on d 15 were 10.8 g/d (P < 0.01; R(2) = 0.16) using a 1-slope broken-line analysis. Hypothalamic 5-HT and 5-hydroxyindoleacetic acid increased (linear, P < 0.01 and P = 0.03, respectively) with increasing supplemental L-Trp. Malonedialdehyde in plasma and hypothalamus, as well as salivary cortisol, on d 15 decreased (linear, P = 0.01, P < 0.01, and P < 0.01, respectively) with increasing supplemental L-Trp. Plasma urea nitrogen decreased (linear, P < 0.01) with increasing supplemental L-Trp. Increasing supplemental L-Trp affected pig behaviors during the first 2-d observation period by decreasing (quadratic, P = 0.04) lying, decreasing (linear, P = 0.04) sitting, and increasing (linear, P = 0.02) drinking. Overall, supplementation of L-Trp improved growth performance of 6 wk-old nursery pigs under social stress in association with increasing hypothalamic 5-HT production, reducing stress hormone concentrations, decreasing lipid peroxidation, increasing drinking, and reducing sitting and lying. Increase in BW gain of nursery pigs under social stress was maximal when daily total Trp intake was 10.8 g.

Effects of supplementing Saccharomyces cerevisiae fermentation product in sow diets on performance of sows and nursing piglets.

Forty-two sows were used to determine the effects of adding a Saccharomyces cerevisiae fermentation product (SCFP) to the gestation and lactation diets on the performance of sows and their progeny. At 5 d before breeding, sows were allotted to 2 dietary treatments representing 1) sows fed a diet with 12.0 g of fermentation product/d through gestation and 15.0 g of fermentation product/d through lactation (SCFP treatment, n=22), and 2) sows fed a diet with equal amounts of a mixture of corn and soybean meal instead of the SCFP (CON treatment, n=20). Sow BW and backfat thickness were recorded. Blood was collected from sows, as well as piglets, for the measurement of cell numbers, plasma urea nitrogen (PUN), and IgG. Fecal samples from d 7 to 9 of lactation were collected to determine apparent total tract nutrient digestibility. The composition of colostrum and milk was also measured. No difference (P > 0.10) in reproductive performance was observed between treatments. However, sows in the SCFP treatment tended to have increased total litter weaning weight (P=0.068) and litter BW gain (P=0.084) compared with sows in the CON treatment. Neutrophil count was decreased (P < 0.05) by adding the fermentation product on d 110 of gestation and d 17 of lactation, whereas a decreased (P < 0.05) white blood cell count was observed only on d 110 of gestation. Concentration of PUN tended to be greater (P=0.069) for sows in the CON treatment compared with sows in the SCFP treatment on d 110 of gestation. Apparent total tract nutrient digestibility values of ash, CP, DM, and ether extract were not affected (P > 0.10) by adding the fermentation product. Protein and fat contents in colostrum and milk did not differ (P > 0.10) between treatments. Colostrum from sows in the SCFP treatment contained a greater (P < 0.05) amount of ash than colostrum from sows in the CON treatment. Immunoglobulin G measured in the colostrum, milk, and plasma of piglets did not differ (P > 0.10) between sows in the CON and SCFP treatments. This study indicates that adding the SCFP in the gestation and lactation diets has the potential to 1) improve litter BW gain during lactation, possibly by improving maternal protein utilization, as shown in a tendency to reduce PUN; 2) improve the maternal health status, as shown by the reduced neutrophil cell count; and 3) increase milk production, as shown in a tendency to improve litter BW gain without affecting nutrient composition of the colostrum and milk.

Effects of yeast culture supplementation on growth performance, intestinal health, and immune response of nursery pigs.

A total of 216 weaning pigs were used in 2 experiments to determine the effects of dietary supplementation of yeast culture (YC) at different dose levels on the growth performance, nutrient digestibility, intestinal morphology, intestinal microflora, and immune response in weanling pigs and to determine whether YC can be a candidate to replace antibiotic growth promoters (AGP). In Exp. 1, 192 pigs (7.5 +/- 0.2 kg of BW) weaned at 28 d of age were randomly allotted to 6 treatments: 1) control (without AGP or YC); 2) AGP (chlortetracycline, 80 mg/kg); 3) 2.5 g/kg of YC (Diamond V XP Yeast Culture); 4) 5 g/kg of YC; 5) 10 g/kg of YC; and 6) 20 g/kg of YC. Each treatment had 8 replicated pens with 4 pigs per pen. Pigs were fed the experimental diets for 21 d. Average daily gain of pigs fed 5 g/kg of YC was greater (P < 0.05) than that of pigs in the control and other YC groups. However, there was no difference between the YC and AGP group. Pigs supplemented with 5 g/kg of YC, 10 g/kg of YC, and AGP had a greater (P < 0.01) ADFI than the control; however, G:F was not affected by treatment. Thus, 5 g/kg of YC supplementation level was chosen for Exp. 2. In Exp. 2, to elucidate the mode of action of YC, 24 nursery pigs (5.8 +/- 0.1 kg of BW; 21 d of age) were randomly allotted into 3 treatments for a 21-d trial. Treatments consisted of 1) control (without AGP or YC), 2) AGP, and 3) 5 g/kg of YC. Blood samples were collected weekly to measure CD4(+), CD8(+) percentage, and blood cytokine content. All pigs were harvested to determine treatment effects on gut microbiota, morphology, and immune function. Dietary supplementation of 5 g/kg of YC improved (P < 0.05) ADG of pigs compared with the control group, but performance of pigs fed YC was similar to those fed AGP. Pigs receiving 5 g/kg of YC had greater (P < 0.05) digestibility of DM, CP, GE, and jejunal villus height and villus height:crypt depth ratio (P < 0.05) compared with pigs fed the control diet. However, no differences in performance, digestibility, or gut morphology were observed between pigs fed YC and AGP. Gut interferon (IFN)-gamma concentrations were greater (P < 0.01) for pigs supplemented with YC compared with control pigs and pigs supplemented with AGP on d 21. However, plasma IFN-gamma concentrations were decreased (P < 0.01) in pigs supplemented with YC and AGP compared with control pigs on d 7, and CD4(+) was decreased (P < 0.01) in pigs supplemented with YC and AGP on d 14. Results indicate that dietary YC supplementation at 5 g/kg had a positive effect on growth performance of nursery pigs by improving jejunal villus height and villus height:crypt depth ratio and by modulating gut immune response. The comparable effect of 5 g/kg of YC supplementation and AGP on the growth performance of nursery pigs indicates that YC may be a good candidate as an antibiotic alternative.

Effects of Forsythia suspensa extract on growth performance, nutrient digestibility, and antioxidant activities in broiler chickens under high ambient temperature.

A 42-d trial was conducted with 252 broiler chickens (d 1 of age, 38.8 +/- 1.3 g of BW) to determine the effects of Forsythia suspensa extract on growth performance, nutrient digestibility, and antioxidant activities under high ambient temperature (32 +/- 1 degrees C). The feeding program consisted of a starter diet from d 1 to 21 of age and a finisher diet from d 22 to 42 of age. Dietary treatments included a negative control group (NC) fed a cornsoybean meal based diet without vitamin C or Forsythia suspensa extract, a positive control group fed a diet with 200 mg of vitamin C/kg, and a test group (FS) fed with 100 mg of Forsythia suspensa extract/kg. There were 14 cages per treatment and 6 birds per cage during the study. Birds had free access to diets and water during the entire period. Body weight and feed intake were measured at d 21 and 42. Blood and tissue samples were collected at d 21 and 42 for assay of antioxidant indices. Growth performance did not differ among treatment groups during the starter period. In the finisher phase, birds in FS had greater (P < 0.05) average daily gain, feed conversion, and apparent digestibility of energy, CP, calcium, and phosphorus than birds in NC. Furthermore, birds in FS had greater (P < 0.05) total antioxidant capacity and superoxide dismutase activity and lower (P < 0.05) malondialdehyde activity in the serum than birds in NC. The FS birds had greater (P < 0.05) muscle superoxide dismutase activity and lower (P < 0.05) malondialdehyde than NC birds. During the entire period, hepatic superoxide dismutase activity of FS birds was greater (P < 0.05) than that of NC birds. Dietary supplementation with Forsythia suspensa extract can enhance nutrient digestibility and growth performance possibly by reducing oxidative stress of broiler chickens under high ambient temperatures.

Effects of chito-oligosaccharide supplementation on the growth performance, nutrient digestibility, intestinal morphology, and fecal shedding of Escherichia coli and Lactobacillus in weaning pigs.

A total of 50 weaning pigs (16 d of age; 4.72 +/- 0.23 kg of BW) were selected to investigate the effect of dietary chito-oligosaccharide (COS) supplementation on growth performance, fecal shedding of Escherichia coli and Lactobacillus, apparent digestibility, and small intestinal morphology. Pigs housed in individual metabolic cages were assigned randomly to 5 treatments (n = 10), including 1 basal diet (control), 3 diets with COS supplementation (100, 200, and 400 mg/kg), and 1 diet with chlortetracycline (CTC) supplementation (80 mg/kg). Fresh fecal samples were collected to evaluate shedding of E. coli and Lactobacillus on d 0, 7, 14, and 21 postweaning. Fresh fecal samples collected from each cage from d 19 to 21 were stored frozen for determination of apparent total tract digestibility. On d 21, all pigs were killed to collect the middle sections of the duodenum, jejunum, and ileum for determination of mucosa morphology. Supplementation of COS at 100 and 200 mg/kg and supplementation of CTC improved (P < 0.05) overall ADG, ADFI, and G:F in comparison with the control. Supplementation of COS at 200 mg/kg as well as supplementation of CTC increased (P < 0.05) apparent total tract digestibility of DM, GE, CP, crude fat, Ca, and P, whereas COS at 100 mg/kg increased (P < 0.05) the digestibility of DM, Ca, and P in comparison with the control diet. Pigs receiving diets supplemented with COS or CTC had a decreased (P < 0.05) incidence of diarrhea and decreased diarrhea scores compared with control pigs. Fecal samples from pigs receiving diets supplemented with COS had greater (P < 0.05) Lactobacillus counts than those from control pigs and pigs receiving diets supplemented with CTC on d 14 and 21. However, supplementation of COS at 200 mg/kg and supplementation of CTC decreased (P < 0.05) E. coli counts in the feces on d 21 compared with the control diet. Dietary supplementation of COS at 200 mg/kg and of CTC increased (P < 0.05) the villus height and villus:crypt ratio at the ileum and jejunum, and COS at 100 mg/kg also increased (P < 0.05) the villus height in the ileum compared with the control diet. The current results indicated that dietary supplementation of COS at 100 and 200 mg/kg enhanced growth performance by increasing apparent digestibility, decreasing the incidence of diarrhea, and improving small intestinal morphology.

Effects of chito-oligosaccharide supplementation on performance, nutrient digestibility, and serum composition in broiler chickens.

A total of 196 day-old male broiler chicks were randomly allocated to 1 of 4 treatments in a study conducted to determine the effects of dietary supplementation of chito-oligosaccharide (COS) on growth, nutrient digestibility, and serum composition. The experimental diets consisted of an unsupplemented control diet based on corn, soybean meal, and fish meal or similar diets supplemented with either chlortetracycline, 50 mg/kg of COS, or 100 mg/kg of COS. Each treatment was fed to 7 replicate pens of birds, with 7 birds per pen. Broiler performance, nutrient digestibility, cecal microbial concentrations, and serum indices were measured at the end of the starter (d 21) and grower phases (d 42). During the starter period and overall, broilers fed 50 or 100 mg/kg of COS had better (P<0.05) average daily gain, average daily feed intake, and feed conversion than the control birds. The performance of birds fed chlortetracycline was generally intermediate between that of the control and the 2 COS treatments. Compared with the birds in the control or chlortetracycline treatments, the birds receiving 100 mg/kg of COS had better nutrient digestibility of DM, energy, calcium, and phosphorus; higher (P<0.05) concentrations of cecal Lactobacillus; and lower (P<0.05) serum triglyceride and total cholesterol during the starter phase. During the grower phase, the birds fed 100 mg/kg of COS had higher (P<0.05) calcium digestibility and CP retention than those fed the chlortetracycline treatment, and lower concentrations of cecal Escherichia coli than birds in the control treatment. The serum growth hormone level in birds fed 50 mg/kg of COS was higher (P<0.05) than in the other treatments. The birds fed 100 mg/kg of COS had lower (P<0.05) serum triglyceride, higher (P<0.05) serum high-density lipoprotein cholesterol, and higher serum total protein content than birds in the other treatments. In conclusion, dietary supplementation with COS appeared to improve the average daily gain of broilers by increasing the average daily feed intake and nutrient digestibility and modulating the concentrations of cecal microbial flora. Additionally, COS increased serum protein and high-density lipoprotein cholesterol and decreased serum triglyceride.