Effects of two commercial diets and technical feed treatment on stomach lesions and immune system of fattening pigs

Effects of rumen cannulation combined with different pre-weaning feeding intensities on the intestinal, splenic and thymic immune system in heifer calves several month after surgery

Fistulation is a helpful procedure in animal nutritional research and also common practise in human medicine. However, there are indications that alterations in the upper gastrointestinal tract contribute to intestinal immune modulations. The present study aimed to investigate effects of a rumen cannulation in week 3 of life on the intestinal and tissue specific immune system of 34-week old heifers. Nutrition influences the development of the neonatal intestinal immune system to a high extent. Therefore, rumen cannulation was investigated in combination with different pre-weaning milk feeding intensities (20% (20MR) vs. 10% milk replacer feeding (10MR). Heifers of 20MR without rumen cannula (NRC) showed higher cluster of differentiation (CD)8⁺ T cell subsets in mesenteric lymph nodes (MSL) compared to heifers with rumen cannula (RC) and 10MRNRC heifers. CD4⁺ T cell subsets in jejunal intraepithelial lymphocytes (IELs) were higher in 10MRNRC heifers compared to 10MRRC heifers. CD4⁺ T cell subsets in ileal IELs were lower and CD21⁺ B cell subsets were higher in NRC heifers compared to RC heifers. CD8⁺ T cell subsets in spleen tended to be lower in 20MRNRC heifers compared to all other groups. Splenic CD21⁺ B cell subsets were higher in 20MRNRC heifers compared to RC heifers. Splenic toll like receptor (TLR) 6 expression was increased and IL4 expression tended to be increased in RC heifers than NRC heifers. Splenic TLR2, 3 and 10 gene expression was higher in 20MR compared to 10MR heifers. Jejunal prostaglandin endoperoxide synthase 2 expression was higher in RC heifers than NRC heifers, and MUC2 expression tended to increase in 20MR heifers compared to 10MR heifers. In conclusion, rumen cannulation modulated T and B cell subsets in the down streaming gastrointestinal tract and spleen. Pre-weaning feeding intensity seemed to affect intestinal mucin secretion and T and B cell subsets in MSL, spleen and thymus until several month later. Interestingly, in MSL, spleen and thymus the 10MR feeding regime evoked similar modulations of T and B cell subsets like rumen cannulation.

Supplementing oat hulls to the diet of suckling piglets altered their intestinal tract and colonic microbiota development

Current study evaluated the effect of a fine and coarsely ground insoluble dietary fibre source on the gastrointestinal development of suckling pigs. Oat hulls (OH) were selected as a model feedstuff, rich in cellulose, lignin, and insoluble dietary fibre. Three experimental supplemental diets were formulated: a finely ground, low fibre and nutrient dense diet served as control (CON). For the 2 high fibre diets, 15% heat-treated starch in CON was exchanged with OH, either finely (OH-f) or coarsely ground (OH-c). Litters of 10 primi- and multiparous sows (mean litter size 14.6 ± 0.84) were used. Within a litter, experimental diets were allotted to triplets of 4 piglets. From approximately 12 d of age, piglets' individual feed intakes were recorded 2 times per day when separated from their dam for 70 min. Piglets could suckle with their dam for the remainder of the day. On d 24 and 25, from the total pool of 120 piglets, seven healthy well-eating piglets per treatment were selected for post-mortem evaluation, resulting in 14 replicates per treatment. Consumption of OH-c and OH-f did not impede clinical health and production performance of piglets. The full stomach weights tended to be greater for OH-c compared to OH-f whereas CON was intermediate (P = 0.083). Supplementing OH significantly increased ileal villus height and caecal dry matter concentration (P < 0.05). For the colon, OH increased its length, contents weight, short-chain fatty acid concentration and reduced total bacterial count as well as γ-proteobacteria count and proportion (P < 0.05). The OH-c treatment specifically increased full gastrointestinal tract weight and caecum contents weight compared to piglets fed CON and OH-f. Furthermore, OH-c reduced colonic crypt depth when compared to OH-f (P = 0.018). In conclusion, supplementing OH to a diet for suckling piglets exerted subtle developmental effects on gastrointestinal morphology and colonic microbial community. These effects were largely independent from the particle size of the OH.

Influences of Maternal Conjugated Linoleic Acid and Essential Fatty Acid Supply During Late Pregnancy and Early Lactation on T and B Cell Subsets in Mesenteric Lymph Nodes and the Small Intestine of Neonatal Calves

Conjugated linoleic acid (CLA) isomers are known for their health-promoting effects in mammals and metabolic functions in dairy cows and are synthesized in the forestomach depending on essential fatty acid (EFA) intake. The current preliminary study investigated effects of a maternal fatty acid supplementation (MFAS) during late pregnancy and early lactation with coconut oil (CON, control), CLA (Lutalin®), or CLA + EFA (Lutalin® linseed oil; safflower oil) on plasma fatty acid composition and T and B cell subsets in mesenteric lymph nodes (MLN) and the small intestine of 5-day-old calves. MFAS of CLA + EFA increased α-linolenic, eicosapentaenoic, docosapentaenoic, and n-3 fatty acid proportions in calf plasma fat on days 1 and 5 after birth (P < 0.05). On day 5, CLA and CLA + EFA calves showed higher plasma fat trans-10, cis-12 CLA proportions, and CLA calves had higher plasma cis-9, trans-11 CLA proportions compared with CON calves (P < 0.1). MFAS of CLA tended to increase CD4⁺ T cell subsets in MLN and increased CD21⁺ B cell subsets in ileal lamina propria compared with CON but decreased CD2⁺ T cell subsets in jejunal lamina propria (P < 0.05). CLA + EFA decreased CD4⁺ T cell subsets in MLN compared with CLA (P < 0.05). MFAS of CLA seemed to affect the intestinal adaptive immune system of calves, but additional EFA supplementations reversed CLA effects. Possible direct CLA and EFA effects or whether changes in milk composition affected this immune modulation must be clarified in further studies.

Fine Grinding or Expanding as Pre-treatment for Pelleting in Processing Diets Varying in Dietary Rapeseed Expeller Proportions: Investigations on Performance, Visceral Organs, and Immunological Traits of Broilers

Pelleted feed is associated with improved broiler performance but also with a higher incidence of proventricular dilatation and ascites. The present study aimed to investigate influences of expanded and pelleted (ExP) or finely ground and pelleted feeds (FgP) containing either 6% rapeseed expeller (RSE) or 12% RSE on these adverse effects by studying performance, visceral organ, and immunological traits in 36 broilers. ExP reduced daily feed intake compared to FgP when feeding a 6% RSE diet (P < 0.05) but did not affect the daily feed intake when feeding a 12% RSE diet, which was also reflected in the body weight gain. There were no significant differences in the size of proventriculus and gizzard between feeding groups but significant diet-by-technical feed treatment interactions in case of proventricular and gizzard weights and the proventricular length (P < 0.05). Proventriculi and gizzards were heavier in birds fed 6%ExP than proventriculi or gizzards of animals from all other groups except for birds of the group 12%FgP. A total of three animals (1 from 6%ExP, 1 from 6%FgP, and 1 from 12%ExP) developed ascites during the study. Pooled LsMeans of peripheral blood leucocyte proportions of CD3⁺/CD4^-/CD8^- cells were increased in birds fed FgP compared to birds fed ExP (P = 0.048). Pooled LsMeans of CD3⁺/CD4⁺/CD8⁺ T cell subsets in jejunal lamina propria were higher in birds fed 12% RSE compared to birds fed 6% RSE (P = 0.024). Concluding, technical feed treatment or diet did not inhibit adverse effects of pelleting on gizzard and proventricular development. Morphometric alterations of proventriculus and gizzard might modify the local immune system of the distal digestive tract and promote the development of ascites; however, further studies are required to confirm this hypothesis since in the present study only three birds developed ascites.