Effect of a High Proportion of Rye in Compound Feed for Reduction of Salmonella Typhimurium in Experimentally Infected Young Pigs

Rye Bran as a Component in the Diets of Lactating Sows-Effects on Sow and Piglet Performance

From a cost and sustainability perspective, the use of by-products such as rye bran in sow diets is of particular interest. Rye bran has valuable ingredients that have potential benefits for the gut health of sows. The aim of this study was to investigate the effects of including 15% rye bran in the sows' feed on the performance of sows and piglets. The feeding started one week before the farrowing date and ended at weaning. Performance was evaluated by measuring sow (n = 175) and piglet body weight (n = 1372) and sows' backfat thickness (n = 80). These data were additionally used to calculate the colostrum intake of the suckling piglets and the sows' milk production. It was found that there were no differences in the performance parameters between the experimental and control groups. However, this study showed that the piglets with light birth weight (LBW (<1000 g)) and medium birth weight (MBW (1000-1500 g) consumed more colostrum when the sows were fed rye bran (LBW: C/R 203.0 ± 39.2 g/214.3 ± 35.9 g; MBW: 291.3 ± 39.0 g/298.5 ± 36.4 g). It can be concluded that including 15% rye bran in the feed of lactating sows has no obvious negative effects on the performance of sows and piglets. Further studies are needed to evaluate the possible positive effects of rye bran.

Rye and Rye Bran as Components of Diets in Piglet Production-Effects on Salmonella Prevalence

The nutritional benefits of rye (and therefore rye bran) are mainly due to its high content of fermentable dietary fiber, the non-starch polysaccharides (NSP). Microorganisms in the large intestine are able to convert these into short-chain fatty acids (SCFA), including butyrate. Butyrate strengthens the epithelial barrier function in the colon by nourishing the enterocytes and inhibiting the spread of Salmonella in the intestinal tract. Therefore, the aim of this study was to test under field conditions whether a diet with rye or rye bran as the main ingredient for gilts, sows, and weaned piglets is associated with a lower Salmonella prevalence. Depending on the age groups, between 20-30% rye or between 15-20% rye bran was used in the experimental group. A total of n = 1983 boot swabs, n = 356 fecal samples, and n = 1909 serum samples were examined. The results of this study show that rye or rye bran at the levels used had no apparent effect on the number of positive Salmonella samples. However, the Salmonella OD values in the experimental groups were significantly lower than in the control group. This suggests that the use of rye leads to a lower incidence of infection, but this effect could not be proven from swabs.

Effects of substituting wheat by rye in diets for young fattening pigs on nutrient digestibility, performance, products of intestinal fermentation, and fecal characteristics

Climate change and increasing demands to reduce the environmental impact of feed production are major challenges for animal nutritionists. Compared to wheat, which is commonly used in high levels in European piglet diets, rye is more efficient in using limited resources, most importantly, water and phosphorus. As a result, its cultivation has a relatively low carbon footprint. The high amounts of non-starch polysaccharides of rye might lead to an increased intestinal fermentation with potential beneficial effects on gut health. However, the high levels of non-starch polysaccharides in rye, which have a major impact on the physico-chemical conditions of the digesta, might affect digestibility and performance especially in young animals. It was therefore of interest to compare the effects of isoenergetic diets with increasing levels of rye as a replacement for wheat fed to young fattening pigs (bodyweight: 16-40 kg). The control diet contained 69% of wheat, while in the other three experimental diets, the amount of wheat was gradually replaced (by a third in each case) with rye. Thus, the experimental diets contained 23, 46, and 69% of rye. A total of 40 young pigs were housed individually in four dietary treatment groups. During a 4 week trial, effects on performance, digestibility, products of intestinal fermentation, and fecal characteristics were evaluated. There were no negative effects on feed intake and gains, even though the feed conversion ratio increased with the highest dietary rye level (69%). Digestibility rates of organic matter and crude protein did not differ significantly. Without affecting the characteristics of the feces, numerically higher amounts of intestinal fermentation products and higher colonic digesta mass were observed.

Barley, Triticale, or Rye? The Type of Grain Can Affect the Growth Performance and Meat Quality of Sustainable Raised Pigs

The effect of high level of barley, triticale, or rye as base of complete mixtures for growing-finishing pigs on growth performance, carcass traits, meat quality, and fatty acid profile in meat and backfat was investigated. The 100-day experiment involved 72 pigs, assigned into three groups (24 animals each). Pigs of each group were kept in six pens (two gilts and two barrows per pen). Diets offered to pigs differed in the proportion of cereals as the leading ingredients in the mixture formulation: I-barley, II-triticale, III-rye. The results showed diversified grain influence on the production results and meat quality. Triticale- and barley-based diets ensured better weight gain and lower carcass fatness than rye (p ≤ 0.05). The basic nutrients digestibility of mixtures containing triticale was comparable to that containing barley and higher than that of rye (p ≤ 0.05). The meat and backfat of pigs receiving diet with triticale or barley was characterized by more favorable fatty acids profile in respect to the health-promoting indicators (atherogenicity and thrombogenicity indexes; hypocholesterolemic/hypercholesterolemic ratio). The cholesterol level in various tissues was the lowest in pigs fed with rye diet, and their meat characterized by better water holding capacity and more SFA. Higher fat saturation indicate better resistance to oxidation during storage and longer meat shelf life. It seems that the supplementation of triticale to diet may improve the growth efficiency of pigs and the health-promoting value of meat, while the supplementation of rye may be better for the production of traditional or long-matured meat products.

Weanling pigs consume more feed if hybrid rye replaces corn in diets, but average daily gain and fecal scores are not impacted by hybrid rye

An experiment was conducted to test the hypothesis that growth performance and health status of pigs will not be reduced if hybrid rye is included in diets at the expense of corn during the initial 5 wk post-weaning. A total of 128 weanling pigs (5.6 ± 0.5 kg) were randomly allotted to 32 pens and 4 dietary treatments. Pigs were fed experimental diets for 35 d in three phases with days 1 to 7 being phase 1, days 8 to 21 being phase 2, and days 22 to 35 being phase 3. Within each phase, a control diet primarily based on corn and soybean meal was formulated, and three additional diets were formulated by including 8.0, 16.0, or 24.0% (phase 1), 16.0, 32.0, or 48.0% (phase 2), and 20.0, 40.0, or 60.3% (phase 3) hybrid rye in the diet at the expense of corn. Pig weights were recorded at the start and conclusion of each phase, fecal scores were visually assessed every other day on a pen basis, and blood samples were obtained from 1 pig per pen on days 21 and 35. Results indicated that average daily gain (ADG) in phase 1 increased (linear, P < 0.05) as the inclusion of hybrid rye increased, but no other differences in ADG were observed. Average daily feed intake linearly increased in phase 1, phase 3, and overall (P < 0.05) as hybrid rye inclusion increased in the diets, and gain:feed was negatively impacted by the inclusion of hybrid rye in the diet (phase 1, linear, P < 0.05; phases 2, 3, and overall, quadratic, P < 0.05). No differences in average fecal scores or diarrhea incidence were observed. On days 21 and 35, blood urea N increased (linear, P < 0.05) as hybrid rye increased in the diets; and on day 21, serum total protein also increased (linear, P < 0.05) with increasing hybrid rye inclusion in the diet. Mean blood hemoglobin concentration on day 35 increased and then decreased as hybrid rye inclusion increased (quadratic, P < 0.05). On day 21, interleukin (IL) 2 and IL 10 decreased and then increased (quadratic, P < 0.05) as hybrid rye inclusion increased. On day 35, IL 8 and IL 12 increased and then decreased (quadratic, P < 0.05) and interferon-gamma decreased and then increased (quadratic, P < 0.01) as hybrid rye inclusion increased. In conclusion, the ADG of pigs was not different among treatments, but at the highest hybrid rye inclusion level, pigs consumed more feed than if corn was fed and gain:feed was reduced with increasing hybrid rye in diets. Differences in blood serum cytokines indicate the immune system was affected differently when hybrid rye instead of corn was fed.

High Dietary Intake of Rye Affects Porcine Gut Microbiota in a Salmonella Typhimurium Infection Study

Bacterial fermentation of undigested carbohydrates in the hindgut has considerable potential for the stimulation or inhibition of the growth of distinct bacteria within microbiota. The aim of the present study was to evaluate whether high levels of rye affect porcine gut microbiota composition with subsequent effects on the load of Salmonella Typhimurium, an intestinal pathogen with zoonotic relevance. Therefore, forty-two 25-day-old piglets were allocated to two groups and fed a diet containing either 69% wheat or 69% rye for 35 days. One week after introducing the two different diets, the piglets were experimentally infected with Salmonella Typhimurium. The microbiota composition of cecal and fecal samples of the piglets were evaluated 28 days after infection. In the cecum, promoted growth of Bifidobacterium, several lactic acid bacteria and Faecalibacterium prausnitzii were seen in pigs fed the diet containing 69% rye. Bacterial species belonging to the genera Bifidobacterium and Catenisphaera were associated with differing bacterial counts of Salmonella Typhimurium detected in the cecal contents of all piglets in both feeding groups via cultural cultivation. The high intake of rye instead of wheat seems to promote the growth of beneficial intestinal bacteria accompanied by impaired growth conditions for the foodborne pathogen Salmonella Typhimurium.

In vitro evaluation of sodium butyrate on the growth of three Salmonella serovars derived from pigs at a mild acidic pH value

Foodborne zoonotic diseases can be transferred into the food chain at the stage of livestock farming. As an emerging public health challenge, practicable reduction measures in porcine health management for Salmonella are constantly being investigated. This in vitro study aimed to determine the influence of six different sodium butyrate (SB) concentrations (0, 5, 10, 20, 40, and 80 mM) on the growth of three different Salmonella enterica serovars at a constant pH value of 6.0, corresponding to conditions in the pig's hindgut. S. Derby and S. Typhimurium, isolated from a pig farm, and S. Typhimurium DSM 19587, which served as control, were used. Broth microdilution assay was applied to record Salmonella growth in the presence of different SB-concentrations over six different incubation periods (0, 1, 2, 4, 6, and 24 h). Results were quantified in the log colony-forming units (log10 CFU/mL). For 1 h incubation, the addition of SB showed no significant differences in the range of initial Salmonella dose of about 5.7 log10 between concentrations (0-80 mM, 5.26 ± 0.10-5.60 ± 0.07 log10, p > 0.05). After 6 h, for SB addition, the range of Salmonella counts was significantly lower compared to no addition of SB (5-80 mM, p < 0.05), 6.78 ± 0.84-7.90 ± 0.10 log10 for 5 mM, and 7.53 ± 0.04-8.71 ± 0.22 log10 for 0 mM. Moreover, for SB concentrations of 40 and 80 mM, no difference in the range of Salmonella counts over 6 h was obtained (5.23 ± 0.11-5.38 ± 0.05 log10, p > 0.05), and minor Salmonella growth was recorded at the earliest after 24 h incubation. Growth rates for varying SB concentrations and incubation times were confirmed in a similar manner for the three serovars. Obtained results suggest that increasing SB concentrations suppress Salmonella growth for concentrations of 5-20 mM over a 6 h incubation period and for 40 and 80 mM over a 24 h incubation period. When transferring these in vitro findings to the porcine organism, it may be assumed that Salmonella reduction can be achieved by increased butyrate content in the chyme of the large intestine.

Effects of Dietary Cereal and Protein Source on Fiber Digestibility, Composition, and Metabolic Activity of the Intestinal Microbiota in Weaner Piglets

Simple Summary

Rye and rapeseed meal can be alternative feed components for weaner piglets instead of wheat and soybean meal. Both components can help to meet current challenges in pig nutrition, such as increasingly dry weather conditions and the high amount of imported soybean. Since they contain more and differently composed fiber, effects on digestive physiology and intestinal microbiota might help to maintain gut health and prevent post-weaning diarrhea. This study shows that despite a similar composition of the large intestinal microbiota, the higher amount and solubility of complex carbohydrates from rye lead to a higher fermentative activity compared to wheat, which is considered a beneficial effect. The high amount of insoluble dietary fiber in rapeseed-based diets lowered bacterial metabolic activity and caused a shift toward insoluble fiber degrading bacteria.

Abstract

This study aimed to investigate the effect of fiber-rich rye and rapeseed meal (RSM) compared to wheat and soybean meal (SBM) on fiber digestibility and the composition and metabolic activity of intestinal microbiota. At weaning, 88 piglets were allocated to four feeding groups: wheat/SBM, wheat/RSM, rye/SBM, and rye/RSM. Dietary inclusion level was 48% for rye and wheat, 25% for SBM, and 30% for RSM. Piglets were euthanized after 33 days for collection of digesta and feces. Samples were analyzed for dry matter and non-starch-polysaccharide (NSP) digestibility, bacterial metabolites, and relative abundance of microbiota. Rye-based diets had higher concentrations of soluble NSP than wheat-based diets. RSM-diets were higher in insoluble NSP compared to SBM. Rye-fed piglets showed a higher colonic and fecal digestibility of NSP (p < 0.001, p = 0.001, respectively). RSM-fed piglets showed a lower colonic and fecal digestibility of NSP than SBM-fed piglets (p < 0.001). Rye increased jejunal and colonic concentration of short-chain fatty acids (SCFA) compared to wheat (p < 0.001, p = 0.016, respectively). RSM-fed pigs showed a lower jejunal concentration of SCFA (p = 0.001) than SBM-fed pigs. Relative abundance of Firmicutes was higher (p = 0.039) and of Proteobacteria lower (p = 0.002) in rye-fed pigs compared to wheat. RSM reduced Firmicutes and increased Actinobacteria (jejunum, colon, feces: p < 0.050), jejunal Proteobacteria (p = 0.019) and colonic Bacteroidetes (p = 0.014). Despite a similar composition of the colonic microbiota, the higher amount and solubility of NSP from rye resulted in an increased fermentative activity compared to wheat. The high amount of insoluble dietary fiber in RSM-based diets reduced bacterial metabolic activity and caused a shift toward insoluble fiber degrading bacteria. Further research should focus on host–microbiota interaction to improve feeding concepts with a targeted use of dietary fiber.

Effects of increasing dietary rye levels on physicochemical characteristics of digesta and its impact on stomach emptying as well as the formation of 'doughballs' in stomachs of young pigs

Despite quite similar contents of starch and crude fibre of wheat and rye, the unique non-starch-polysaccharide fraction of rye (e.g. high levels of arabinoxylans and fructans) might have an impact on physicochemical properties of the digesta in pigs. Forty pigs (age: 46.8 ± 5.28 days; bodyweight: 16.1 ± 4.13 kg) were divided into four treatment groups. During four weeks, the pigs received diets consisting of wheat and/or rye, barley, soy, potato protein and a mineral supplement. The sum of wheat and rye was 69% in all diets, whereby the compound feed of each group was characterized by a different ratio (%) of wheat/rye (69/0; 46/23; 23/46; 0/69, respectively). In the stomach, 'doughballs' occurred more frequently with increasing dietary rye levels (9/10; 69% rye). With higher DM content and extract-viscosity of gastric digesta, the stomach emptying tended to be retarded in rye groups. Compared to the control group (69% wheat), maximum dietary rye levels (69%) resulted in significantly higher concentrations of lactic acid in digesta of the stomach and small intestine. With increasing lactic acid concentrations, the pH tended to be lower in small intestinal digesta. With an intensified formation of lactic acid, effects against Gram-negative bacteria, for example Salmonella, can be expected. Moreover, because of higher viscosity and the retarded stomach emptying, there could be advantages of including rye in compound feeds when a longer lasting satiety is intended, for example when feeding pregnant sows (regularly fed restrictively).

Effects of cereal and protein source on performance, apparent ileal protein digestibility and intestinal characteristics in weaner piglets

Rye and rapeseed meal (RSM) are alternatives to wheat and soybean meal (SBM) in pig nutrition. The inclusion of rye and RSM instead of wheat and SBM may increase dietary fibre content in the feed, which may affect digestive physiology and intestinal function. However, research on the combined feeding of rye and RSM in piglets is still scarce. The aim of this study was to investigate the effects of rye and RSM containing feed on growth performance, protein and amino acid digestibility, physical characteristics of the digesta and the intestinal morphology in weaner piglets. A total of 88 piglets aged 28 d were randomly allotted to four different feeding groups at weaning: wheat/SBM, wheat/RSM, rye/SBM, rye/RSM. Cereals were included at 48%, SBM at 25% and RSM at 30%. Body weight gain and feed intake were recorded weekly. After 33 d, piglets were euthanised for assessment of digesta and intestinal morphology. Rye did not affect performance, whilst RSM resulted in reduced weight gain (p = 0.024) and feed intake (p = 0.037). Apparent ileal digestibility of crude protein and amino acids was decreased by rye and RSM (p < 0.05). Rye caused an acidification (p = 0.045) and increased viscosity (p = 0.013) of small intestinal digesta, a lower dry matter content of jejunal and colonic digesta (p < 0.05) and an increased relative weight of the colon tissue (p < 0.001). In conclusion, performance was not reduced when rye was used as an alternative to wheat in diets for weaner piglets. The inclusion of RSM instead of SBM to piglets' diet lowered animal performance under our conditions. Further investigations are warranted to characterise the quality of rapeseed meal and the optimum inclusion level in the diet for young pigs.