Influence of dietary oils rich in omega-6 or omega-3 fatty acids on rumen microbiome of dairy cows.

The objective of this study was to compare the effect of supplementing dairy cow diets with contrasting sources of omega-6 (soybean oil) and omega-3 (fish oil) PUFA on rumen microbiome. For 63 d, 15 mid-lactating cows were fed a control diet (n = 5 cows; no fat supplement) or control diet supplemented with 2.9% dry matter (DM) of either soybean oil (SO; n = 5 cows) or fish oil (FO; n = 5 cows). Ruminal contents were collected on days 0, 21, 42, and 63 for 16S rRNA gene sequencing. Beta diversity and Shannon, Simpson and Chao1 diversity indices were not affected by dietary treatments. In terms of core microbiome, Succiniclasticum, Prevotella, Rikenellaceae_RC9_gut_group, and NK4A214_group were the most prevalent taxa regardless of treatments. Bifidobacterium was absent in SO diet, Acetitomaculum was absent in FO, and Sharpea was only detected in SO. Overall, results showed that at 2.9% DM supplementation of either SO or FO over 63 days in dairy cow diets does not cause major impact on bacterial community composition and thus is recommended as feeding practice.

Chemical Composition, Antioxidant, and Antimicrobial Activities of Leaves of Ajuga Iva.

The main objective of this research was to study the biological characteristics in terms of antioxidant and antimicrobial activities of Ajuga iva and determine the best analytical and extraction methods applicable to this specie and studied compounds. A short screening of its nutritional value in terms of chemical composition is also included. A. iva leaves were analyzed for crude protein (CP), cell wall [neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL)], minerals, fatty acids, essential oils, and phenolic compounds. Mature aerial parts of A. iva were randomly collected during the Spring season from Mograne-Zaghouan, Tunisia. Leaves of A. iva contained 13.4 ± 0.4% CP, 26.3 ± 0.35% NDF, 20.2 ± 0.42% ADF, and 5.13 ± 0.21% ADL. Mineral content (13.0 ± 0.45%) was mainly composed of potassium (4.5% g DM) and magnesium (4.25% DM). Leaves of A. iva had linolenic (26.29 ± 0.760%) and linoleic (37.66 ± 2.35%) acids as the main components of the acid profile. Thymol was found to be the most dominant (23.43%) essential oil, followed by 4-vinylguaiacol (14.27%) and linalool (13.66%). HPLC-PDA-ESI-MS/MS analysis pointed out the presence of phytoecdysteroids. Phenolic acids and flavonoids, such as glycosylated derivatives of naringenin, eriodyctiol, and apigenin, were detected in the methanol extract of A. iva leaves. Our results underline the importance of choosing proper extraction methods and solvents to extract and characterize the described compounds profile of A. iva leaves. Results also show A. iva leaves as a potential source of functional ingredients with beneficial health-promoting properties. Overall, leaves of A. iva have low biological activities (antioxidant and antimicrobial activities) with a chemical composition suitable as a feed for ruminants in rangeland pasture. It also has low-grade antibacterial or medicinal characteristics when fed to ruminants.

Diet inclusion of devil fish (Plecostomus spp.) silage and its impacts on ruminal fermentation and growth performance of growing lambs in hot regions of Mexico.

The aim of this study was to evaluate the inclusion of devil fish (Plecostomus spp.-DF) silage in Criollo × Blackbelly lamb diets in hot region of Guerrero state of Mexico. Rumen fermentation including pH, volatile fatty acids (VFA) and ammonia-N (NH3-N) and productive variables including feed intake (FI), average daily gain (ADG), and feed conversion were determined. Twenty lambs with 18 ± 1.2 kg body weight in a completely randomized design were fed a total mixed ration (TMR) of concentrate (based on soybean meal, whole oat hay, ground corn cob, vitamins-minerals supplement) with DF silage at 0 % (DF0), 9 % (DF9), 18 % (DF18), and 27 % (DF27) of the TMR for 75 days. The ruminal pH showed no difference (P > 0.05) between treatments: ranging between 6.21 and 6.36. Propionic acid molar proportions showed an irregular pattern between experimental groups, which only differed (P < 0.05) between DF9 and DF27, without differences between the other treatments. A greater molar proportion of butyric acid was noted (P < 0.05) in DF27 when compared to the other treatments. The ruminal concentration of NH3-N showed some insignificant differences (P > 0.05) among treatments. The daily FI was increased (P < 0.01) in DF27 (1.131 g) when compared with DF0, while DF9 and DF18 showed intermediate consumption with no differences (P > 0.05) among them. The ADG showed only difference (cubic effect, P = 0.02) between DF9 and DF18. The highest feed conversion was observed (cubic effect, P < 0.01) with DF18, with a value of 4.7 kg of feed to gain 1 kg of body weight. It could be concluded that the inclusion of up to 18 % of DF silage in the TMR of growing lamb diets, in hot regions of Mexico, may improve productive performance and ruminal fermentation kinetics, without any negative effects.