Influence of medium chain fatty acids on selected microbes and on in vitro ruminal fermentation of air-exposed corn silage.

Several medium chain fatty acids and different chemical forms of these acids were evaluated in vitro as treatments of aerobically-exposed corn silage against spoilage and pathogenic microbes and for effects on rumen fermentation. Treatments were control (no additive), myristate (MY), laurate (LA), monolaurin (MLA), methyl ester laurate (MELA), a blend of mono-, di- and triglycerides of laurate (BLA), and monocaprylate (MC). After 24 h of aerobic incubation (37°C), yeast and mold growth were not influenced (P > 0.05) by treatments, while the net growth of lactic acid bacteria was decreased, albeit slightly, compared to that by untreated controls (P < 0.01) by all treatments of the air-exposed corn silage. Compared with controls, wild-type enterococci were decreased (P < 0.01) in MLA, MELA, and BLA. Staphylococcus aureus was reduced (P < 0.01) with MLA, MELA, BLA, and MC. Total aerobes showed reductions (P < 0.01) with MLA, BLA, and MC. Listeria monocytogenes numbers were reduced (P < 0.01) with MELA. Anaerobic incubation (24 h; 39°C) of ruminal fluid (10 mL) with 0.2 g air-exposed and MCFA-treated corn silage revealed higher hydrogen accumulations (P < 0.01) with MLA and MC over the control treatment. Methane was decreased (P < 0.01) solely by MLA. There was an increase (P < 0.01) of acetate with MELA and MC; of propionate with MELA or by BLA; and of butyrate with MLA, MELA, BLA, and MC. Total VFA, hexose fermented, and ammonia were increased (P < 0.01) with MELA, BLA, and MC. The acetate:propionate ratio was increased (P < 0.01) with MC. The results showed that treatment of air-exposed corn silage with esterified MCFA had no effect on yeasts and molds but prevented propagation or reduced populations of some unwanted and potentially desirable bacteria. Modest methane reduction was seen during in vitro incubation of rumen fluid suspensions with MLA-treated silage and ammonia accumulations were increased in esterified MCFA-treated silage. Little, if any, other detrimental effects on beneficial ruminal fermentation characteristics were observed.

Assessment of Gastrointestinal Parasites and Productive Parameters on Sheep Fed on a Ration Supplemented with Guazuma ulmifolia Leaves in Southern Mexico.

This study aimed at evaluating the impact of a diet supplemented with Guazuma ulmifolia leaves on the productive performance and gastrointestinal parasites (GI) eggs/oocysts shedding of sheep (Pelibuey breed). Twenty-two non-lactating ewes were used. They were randomly allocated to two similar groups in terms of age, weight, body condition score (BCS), and GI parasites status. For 30 days, while the control group (G0) was given basic forage hay of Cynodon nlemfuensis, the test group (G1) received a blend of G. ulmifolia fresh foliage and C. nlemfuensis hay (respectively 30 and 70% of the diet on a DM basis). Animals were housed in separate covered pens. Quantitative coprological analysis was performed. Weight and BCS were evaluated. The daily feed amounts given and refused were measured in order to assess nutrient components intake (minerals, energy, and nitrogen). The results showed no significant differences between G1 and G0 regarding the anthelmintic and anticoccidial effects (p = 0.57, p = 0.91, respectively). Similarly, no significant overall impact on weight and BCS during the experiment (p = 0.77, p = 0.32, respectively) was observed. Nevertheless, concerning the bromatological analysis of G. ulmifolia, its use as a diet supplement to address protein and mineral deficits due to a poor-quality diet is fully justified.