Graded replacement of maize grain with molassed sugar beet pulp modulated ruminal microbial community and fermentation profile in vitro.

BACKGROUND: Molassed sugar beet pulp (Bp) is a viable alternative to grains in cattle nutrition for reducing human edible energy input. Yet little is known about the effects of high inclusion rates of Bp on rumen microbiota. This study used an in vitro approach and the quantitative polymerase chain reaction technique to establish the effects of a graded replacement of maize grain (MG) by Bp on the ruminal microbial community, fermentation profile and nutrient degradation. RESULTS: Six different amounts of Bp (0-400 g kg-1 ), which replaced MG in the diet, were tested using the in vitro semi-continuous rumen simulation technique. The increased inclusion of Bp resulted in greater dietary content and degradation of neutral detergent fibre (P < 0.01). Further, Bp feeding enhanced (P < 0.01) the abundance of genus Prevotella and shifted (P < 0.01) the short-chain fatty acid patterns in favour of acetate and propionate and at the expense of butyrate. A total replacement of MG with Bp resulted in an increased daily methane production (P < 0.01). CONCLUSION: Results suggest positive effects of the replacement of MG by Bp especially in terms of stimulating ruminal acetate and propionate fermentation. However, high replacement rates of Bp resulted in lowered utilization of ammonia and higher ruminal methane production. © 2017 Society of Chemical Industry.

Long-term influence of feeding barley treated with lactic acid and heat on performance and energy balance in dairy cows.

The study evaluated the long-term influence of feeding ground barley treated with lactic acid (LA) alone or with LA and heat on performance, energy and protein balance in dairy cows. Thirty cows were fed three diets differing in the treatment of barley grain, either unprocessed ground barley (Control), ground barley steeped in 1% LA at room temperature (LA-treated barley) or ground barley steeped in 1% LA with an additional heating at 55°C (LAH-treated barley). Cows were studied from week 3 to 17 post-partum. Dry matter intake (DMI), milk yield and composition and body weight (BW) were measured daily. Estimated energy and protein balances were calculated and blood samples were collected three times during the experiment and analysed for common metabolites of energy and lipid metabolism. Digestibility of different treated barley and other dietary ingredients was investigated in vivo using four wethers. The treatment of barley with LA and LAH increased the digestibility of organic matter (OM) by approximately 5% and the content of metabolisable energy by 0.5-0.6 MJ/kg DM. Data showed no effect of feeding diets containing LA- or LAH-treated barley at 39% of DM on overall DMI, BW, BW change, milk production and composition and on the blood variables studied. Diet influenced the estimated balances of net energy of lactation (p < 0.01) and the content of utilisable protein at the duodenum (p = 0.07) with cows fed the diet with LA-treated barley showing improved balances. In conclusion, feeding diets containing LA- or LAH-treated barley had no influence on performance, milk composition and blood metabolites, but LA treatment without heat seems to improve the energy balance of cows.

Effects of feeding sunflower oil or seal blubber oil to horses with recurrent airway obstruction.

A crossover feeding trial was performed with 9 horses suffering from recurrent airway obstruction (RAO). The study aimed to determine whether ingestion of sunflower oil (SFO), rich in linoleic acid, or seal blubber oil (SBO), a source of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs), changes the fatty acid (FA) ratios in plasma and leukocyte membrane phospholipids (PLs) or the leukocyte numbers or proportions of cell types in the airways. We also investigated diet-related changes in respiratory rate, maximum change in pleural pressure (deltaPpl(max)), dynamic compliance (C(dyn)), and pulmonary resistance (RL). Each animal was fed hay and oats supplemented with 320 mg/kg body weight (BW) of either SFO or SBO for 10 wk. Before and after the feeding periods, we performed FA analyses, cytologic testing of the pulmonary epithelial lining fluid (PELF), clinical scoring, and pulmonary function testing. The results demonstrated that supplementary FAs were readily ingested and incorporated into leukocyte cell membranes. The n-6:n-3 FA ratios in plasma and leukocyte PLs were reduced after SBO supplementation, as were the PELF leukocyte counts (P < 0.05). On the other hand, pulmonary function and clinical signs were not markedly changed by the different dietary FAs. These results indicate a possible influence of dietary n-3 PUFAs on the pulmonary inflammation of horses with RAO. Further studies are warranted to address effects on inflammatory mediators and clinical outcome.

Alterations of the Lipid Metabolome in Dairy Cows Experiencing Excessive Lipolysis Early Postpartum.

A decrease in insulin sensitivity enhances adipose tissue lipolysis helping early lactation cows counteracting their energy deficit. However, excessive lipolysis poses serious health risks for cows, and its underlying mechanisms are not clearly understood. The present study used targeted ESI-LC-MS/MS-based metabolomics and indirect insulin sensitivity measurements to evaluate metabolic alterations in the serum of dairy cows of various parities experiencing variable lipolysis early postpartum. Thirty (12 primiparous and 18 multiparous) cows of Holstein Friesian and Simmental breeds, fed the same diet and kept under the same management conditions, were sampled at d 21 postpartum and classified as low (n = 10), medium (n = 8), and high (n = 12) lipolysis groups, based on serum concentration of nonesterified fatty acids. Overall, excessive lipolysis in the high group came along with impaired estimated insulin sensitivity and characteristic shifts in acylcarnitine, sphingomyelin, phosphatidylcholine and lysophospholipid metabolome profiles compared to the low group. From the detected phosphatidylcholines mainly those with diacyl-residues showed differences among lipolysis groups. Furthermore, more than half of the detected sphingomyelins were increased in cows experiencing high lipomobilization. Additionally, strong differences in serum acylcarnitines were noticed among lipolysis groups. The study suggests an altered serum phospholipidome in dairy cows associated with an increase in certain long-chain sphingomyelins and the progression of disturbed insulin function. In conclusion, the present study revealed 37 key metabolites as part of alterations in the synthesis or breakdown of sphingolipids and phospholipids associated with lowered estimated insulin sensitivity and excessive lipolysis in early-lactating cows.

Peculiarities of enhancing resistant starch in ruminants using chemical methods: opportunities and challenges.

High-producing ruminants are fed high amounts of cereal grains, at the expense of dietary fiber, to meet their high energy demands. Grains consist mainly of starch, which is easily degraded in the rumen by microbial glycosidases, providing energy for rapid growth of rumen microbes and short-chain fatty acids (SCFA) as the main energy source for the host. Yet, low dietary fiber contents and the rapid accumulation of SCFA lead to rumen disorders in cattle. The chemical processing of grains has become increasingly important to confer their starch resistances against rumen microbial glycosidases, hence generating ruminally resistant starch (RRS). In ruminants, unlike monogastric species, the strategy of enhancing resistant starch is useful, not only in lowering the amount of carbohydrate substrates available for digestion in the upper gut sections, but also in enhancing the net hepatic glucose supply, which can be utilized by the host more efficiently than the hepatic gluconeogenesis of SCFA. The use of chemical methods to enhance the RRS of grains and the feeding of RRS face challenges in the practice; therefore, the present article attempts to summarize the most important achievements in the chemical processing methods used to generate RRS, and review advantages and challenges of feeding RRS to ruminants.

Colostrum and milk selenium, antioxidative capacity and immune status of dairy cows fed sodium selenite or selenium yeast.

Dietary selenium (Se) can be supplemented from organic or inorganic sources and this may affect Se metabolism and functional outcome such as antioxidative status and immune functions in dairy cows. A feeding trial was performed with 16 Holstein-Friesian dairy cows fed with a total mixed ration (0.18 mg Se/kg dry matter (DM)) either without Se supplement (Control, n = 5), or with Se from sodium selenite (Group SeS, n = 5) or Se yeast (Group SeY, n = 6). In Groups SeS and SeY, the Se supplementation amounted to an additional intake of 4 mg Se and 6 mg Se/d during gestation and lactation, respectively. The effect of both Se sources was characterised by milk Se and antioxidant levels, and the phenotyping and functional assessment of phagocytic activity of milk immune cells. Se yeast has been found to increase (p ≤ 0.001) the milk Se and antioxidant levels markedly compared to the control group. The experimental treatment did not affect the immune parameters of the cows. Lymphocyte subpopulations and phagocytosis activity of neutrophilic granulocytes were affected neither by the Se intake nor by the two different dietary supplements. It can be concluded that sodium selenite and Se yeast differ considerably in their effects on antioxidant status in dairy cows. However, the basal dietary Se concentration of 0.18 mg/kg DM seemed to be high enough for the measured immune variables.

Highly deoxynivalenol contaminated oats and immune function in horses.

The aim of the present study was to investigate the impact of deoxynivalenol (DON) on cellular and humoral immune parameters in horses. A feeding trial using naturally contaminated oats with high (20.2 mg/kg) and low (0.49 mg/kg) levels of DON was conducted. Two groups of five mares were fed 2 kg oats daily with high or low DON levels for two weeks, using a crossover design with a three-week wash-out period. No adverse effects on general health were observed. Only minor diet-related changes in differential blood counts and serum biochemistry were noted. Serum haptoglobin concentration was significantly elevated after feeding DON (p = 0.04). Lymphocyte subsets (CD4+ CD8+, CD2+, CD21+, MHCII+) and lymphocyte proliferation data (concanavalin A, phytohemagglutinin, pokeweed mitogen) were not different between feeding-groups. It can be concluded that daily DON intakes as high as 6.9 to 9.5 mg/100 kg BW appear to have no major impact on the measured immune response of horses, indicating that this species has a high tolerance for DON.

Effect of maternally supplied n-3 and n-6 oils on the fatty acid composition and mononuclear immune cell distribution of lymphatic tissue from the gastrointestinal tract of suckling piglets.

Fatty acids are essential for immune cell function. Maternal dietary fatty acid supply influences body fat composition of their offspring. As a first step to study immunonutritional interactions at an early age of pigs, four sows were fed a diet containing sunflower oil or oil from seal blubber during pregnancy and lactation. Corresponding piglets were sacrificed at three consecutive time points in the suckling period and their mesenteric lymph nodes and spleen were analysed by gas chromatography for levels of fatty acid. At the same time mononuclear cells of these organs and of the intestinal lymphoid tissue from the jejunum were isolated and subpopulations characterised by flow cytometry. Levels of fatty acids from the lymphatic organs of the piglets were significantly influenced by the maternal diet. The concentration of the fatty acids 20:5n-3, 22:5n-3 and 22:6n-3 were higher in the spleen and mesenteric lymph node of piglets suckled to sows of the test diet. Additionally, suckling time affected the levels of some long chain polyunsaturated fatty acids. Dietary effects were seen on some subpopulations including CD4-CD8alpha+ lymphocytes of the mesenteric lymph nodes and CD4+CD8alpha+ lymphocytes of the lamina propria, which were higher in the group fed seal blubber oil. The levels of CD21+ B-cells were higher in the group fed sunflower oil. The results indicate that the maternal diet and suckling time affect the fatty acid status of the investigated lymphatic tissues of piglets, but may have minor effects on the investigated lymphocyte subpopulations.

Effects of a probiotic Lactobacillus acidophilus strain on feed tolerance in dogs with non-specific dietary sensitivity.

This study investigated the effects of the probiotic Lactobacillus acidophilus strain DSM 13241 in dogs with non-specific dietary sensitivity (NSS). Six adult German Shorthair Pointers with NSS consecutively received a control dry diet and the same diet supplemented with the probiotic (6 x 10(6) cfu/g) for 12 weeks each, followed by another control period of four weeks. Frequency of defecations, faecal quality and nutrient digestibility were determined. Faeces were cultured for Clostridium perfringens, Escherichia spp., lactobacilli and bifidobacteria and quantitative fluorescence in situ hybridisation (FISH) was performed. Feeding the probiotic improved faecal consistency, faecal dry matter and defecation frequency (p < 0.05). Faecal concentrations of culturable lactobacilli and bifidobacteria increased numerically, but not significantly, also the decrease of the numbers of C. perfringens and Escherichia spp. did not reach the level of significance. Results from FISH showed more constant bacterial populations. It can be concluded that L. acidophilus DSM 13241 can stabilise the digestive processes in dogs with NSS.

Phenotypic and functional aspects of the neonatal immune system as related to the maternal dietary fatty acid supply of sows.

The maternal-fetal transfer and subsequent uptake of sow milk enriched with n-6- or n-3-polyunsaturated fatty acids may not only influence neonatal body fat but may also have an impact on the immune function of newborn piglets. Sows were fed a diet containing sunflower oil as n-6-source or oil from seal blubber with long chain polyunsaturated n-3-fatty acids during pregnancy and lactation. Sow serum was investigated during pregnancy and serum and milk during lactation; piglet serum and liver were investigated in the suckling period until day 19. Piglet leukocyte subpopulations were characterised by flow cytometry and leukocyte proliferation was tested after stimulation with mitogens. No differences were noted in performance. The serum and milk fatty acid status of the sows was markedly influenced by the diet. Eicosapentaenoic acid (20:5n-3), 22:5n-3 and 22:6n-3 were higher (p < 0.001) in serum and liver of piglets delivered from sows fed the seal blubber oil. Piglets at birth had lower lymphocyte counts (p < 0.01) than piglets 19 days after birth. However, no influence of feeding the different oil sources was noted on lymphocyte phenotyping and leukocyte proliferation test. The results of the present study show that the maternal diet affected the fatty acid status of neonates, but much more in the sucking period. Immunological traits were not affected, probably as the mononuclear cell lineage is too immature around birth. Effects of PUFA n-3 might only be seen at a later time point or in the polymorphonuclear cell lineage as they were dominating right after birth.