Potential of 2 Northern European brown seaweeds (Fucus serratus and Fucus vesiculosus) as enteric methane inhibitors in dairy cows.

The 2 brown seaweeds, Fucus serratus and Fucus vesiculosus, have demonstrated anti-methanogenic properties in vitro with reductions in CH4 production ranging from 53 to 63%. This study aimed to investigate the effects of the 2 Fucus seaweeds on enteric CH4 emissions, DMI, ECM, and nutrient digestibility when fed to dairy cows. The experiment was conducted using 4 multi-cannulated lactating Danish Holstein dairy cows, which over 3 experimental periods received either: 1) basal diet (CON; diet without any seaweed), 2) basal diet diluted with 4% (DM basis) Fucus serratus (SER), or 3) basal diet diluted with 4% (DM basis) Fucus vesiculosus (VES); resulting in one complete 3 × 3 Latin square and one incomplete 3 × 3 Latin square. Each period lasted 21 d and consisted of 14 d of adaptation, followed by 3 d of digesta sampling, and 4 d of gas exchange measurements using respiration chambers. Milk yield and feed intake were recorded daily. Blood samples were collected on d 15 and 17. All parameters were statistically analyzed using a mixed procedure of R. Opposite to what we had expected, neither of the 2 Fucus seaweeds reduced CH4 emissions from the dairy cows as daily CH4 production was significantly higher for both Fucus treatments compared with CON. Additionally, CH4 yield (g CH4/kg DMI) and intensity (g CH4/kg ECM) were significantly higher for SER compared with CON. Milk yield, DMI, and total-tract digestibility were unaffected by the treatments; however, SER resulted in lower milk protein yield (kg/d) and lower milk and blood plasma urea concentrations compared with CON. In conclusion, neither Fucus serratus (SER) nor Fucus vesiculosus (VES) showed potential as methane-mitigating feed additives when fed to dairy cows at an inclusion level of 4% of DM. The inclusion of the 2 brown seaweeds had no effects on DMI, milk yield, or total-tract digestibility.

Non-targeted metabolomics of saliva to explore potential biomarkers for gastric ulceration in pigs fed hemp.

Gastric ulceration is a common disease in pig production worldwide and is associated with economic losses as well as animal health and welfare issues. The aim of this study was to explore potential salivary biomarkers for gastric ulceration in pigs. In addition, the aim was to study the effect of hemp on the incidence of gastric ulcers. Approximately 440 growing-finishing pigs in the period from 30 to 110 kg BW were allocated to four different diets: meal feed (Meal); pelleted feed (Pellets); pelleted feed added 4% hempseed cake (Hemp Cake); pelleted feed added 4% hempseed hulls (Hemp Hulls). The day before slaughter, saliva samples from each pig were collected. After slaughter, the stomachs were emptied to assess the consistency of the stomach content and examined for gastric ulceration using an index scale (0-10). Noticeable changes of the gastric mucosa (total index score ≥ 6) were observed in 291 pigs. The odds of having index scores 0-5 relative to index scores 6-8 and 9-10, respectively, were higher (P < 0.001) for pigs fed Meal compared to pigs fed Pellets. The odds of suffering from severe gastric ulcers tended (P = 0.08) to be lower in pigs fed Hemp Hulls compared to pigs fed Pellets. A non-targeted liquid chromatography mass spectrometry based metabolomics analysis was performed on saliva samples to determine any separation between pigs with healthy stomachs and those with gastric ulcers and to examine a possible correlation between gastric ulcer index and potential biomarkers. Partial least-squares discriminant analysis showed a separation between pigs with ulcers and those with healthy stomachs/hyperkeratosis (HK). Metabolites contributing to the separation between groups were identified. Levels of oxylipins deriving from linoleic acid were lower (P < 0.001) in pigs with ulcers compared to healthy/HK pigs. This may indicate a shift in the metabolic pathways towards more pro-inflammatory arachidonic acid-derived eicosanoids, which might reflect an increased inflammatory response. Thus, reduced levels of oxylipins derived from linoleic acid seemed to be associated with active gastric ulcers, and thereby they might function as biomarkers for gastric ulceration in pigs. In addition, supplementation of hempseed hulls had a beneficial effect on severe gastric ulcers, as hempseed hulls changed the consistency of the gastric content by conferring more solidness. However, it was not possible to observe any reliable separation between pigs fed pellets supplemented with hemp products and pigs fed non-supplemented pellets according to the identified salivary metabolites.