The principle of animal wellbeing, which states that animals should be free from pain, injury, and disease, is difficult to maintain, because microorganisms are most frequently found to be resistant or multi-resistant to drugs. The secondary metabolites of plants are an alternative for the treatment of these microorganisms. The aim of this work was to determine the antibacterial effect of Salix babylonica L. hydroalcoholic extract (SBHE) against Escherichia coli, Staphylococcus aureus and Listeria monocytogenes, and identify the compounds associated with the activity. The SBHE showed activity against the three strains, and was subjected to a bipartition, obtaining aqueous fraction (ASB) with moderate activity and organic fraction (ACSB) with good activity against the three strains. The chromatographic separation of ACSB, allowed us to obtain ten fractions (F1AC to F10AC), and only three showed activity (F7AC, F8AC and F10AC). In F7AC, five compounds were identified preliminary by GC-MS, in F8AC and F10AC were identified luteolin (1) and luteolin 7-O-glucoside (2) by HPLC, respectively. The best antibacterial activity was obtained with F7AC (Listeria monocytogenes; MIC: 0.78 mg/mL, MBC: 0.78 mg/mL) and F8AC (Staphylococcus aureus; MIC: 0.39 mg/mL; MBC: 0.78 mg/mL). The results indicated that the compounds obtained from SBHE can be used as an alternative treatment against these microorganisms and, by this mechanism, contribute to animal and human health.

We tested whether the milk yield capacity of mixed-breed goats on a Chihuahuan desert rangeland in northern Mexico during the dry season affects milk composition, body weight gain, and weaning weight of their progeny. Milk yield and composition, and progeny postnatal growth performance, were recorded weekly. One week after kidding, mixed-breed goats (a mixture of Criollo × dairy breeds; n = 40) were allotted into medium (MP) or low (LP) milk yielding groups (20 goats per group). Mean 105-d total milk yield for MP and LP goats was 45.2 ± 12.5 and 20.7 ± 5.2 L, respectively. Milk lactose (4.3 vs. 4.2%) and solids-non-fat (SNF; 8.2 vs. 8.0) differed (p < 0.05) between MP and LP goats; milk protein content tended to differ (p = 0.08) between MP and LP goats with no difference for milk fat content (p > 0.05). Maternal body weight was positively associated with milk yield, milk lactose, and SNF content (p < 0.05 to p < 0.001). Goats giving birth to males produce more milk than goats giving birth to females, but milk fat percentage was higher in goats bearing females (p < 0.001). Milk yield and composition throughout lactation did not influence body weight gain (47.8 vs. 48.7 g/day for kids from MP and LP goats) and weaning weight (6.7 vs. 6.7 kg from MP and LP goats) of the offspring (p > 0.05). Birth weight and weaning weight of the progeny were positively related to maternal body weight (p ≤ 0.05). The postnatal growth of the kids was reduced, extending the time to reach market weight. Nevertheless, non-supplemented mixed-breed goats reared on semi-arid rangeland of northern Mexico have the potential for moderate milk production. Therefore, due to the limited nutrients ingested by grazing goats during the dry season, a nutritional supplement is necessary to keep up milk production and adequate growth of kids.

The objective of this experiment was to evaluate the impact of maize co-ensiling with increasing percentages of MOL forage on the kinetics of biogas, methane (CH₄), carbon monoxide (CO) and hydrogen sulfide (H₂S) production, as well as the characteristics of ruminal fermentation and CH₄ conversion efficiency, using steers (STI) and sheep (SHI) as inoculum sources. With the STI, the inclusion of MOL reduced (linear: p ≤ 0.0199; quadratic: p ≤ 0.0267) biogas production (mL g⁻¹ DM incubated and degraded), CH₄ (mL g⁻¹ DM degraded), CO (mL g⁻¹ DM degraded), and H₂S (mL g⁻¹ DM incubated and degraded), without affecting (p > 0.05) the parameters (b = asymptotic gas, c = rate of gas production and Lag = initial delay time before gas production) of CH₄ and H₂S, and the proportion and production of CH₄ per kg of dry matter (DM). In addition, with this inoculum, pH, and dry matter degradation (DMD) increased (linear: p ≤ 0.0060), and although short-chain fatty acids (SCFA) and metabolizable energy (ME) decreased (linear: p < 0.0001; quadratic: p ≤ 0.0015), this did not affect (p > 0.05) the CH₄ conversion efficiency. Meanwhile, with the SHI, the inclusion of MOL only decreased (linear: p ≤ 0.0206; quadratic: p ≤ 0.0003) biogas per dry matter (DM) degraded and increased (linear: p ≤ 0.0293; quadratic: p ≤ 0.0325) biogas per DM incubated, as well as the production (mL g⁻¹ DM incubated and degraded and g⁻¹ kg DM) and proportion of CH₄, and CO per DM incubated and degraded. In addition, it did not impact (p > 0.05) on the CH₄ and H₂S parameters, and in the H₂S by DM incubated and degraded, and although it increased (linear: p ≤ 0.0292; quadratic: p ≤ 0.0325) the DMD, SCFA, and ME, it was inefficient (quadratic: p ≤ 0.0041) in CH₄ conversion. It is concluded that regardless of the percentage of MOL, the STI presented the highest values in the production of biogas, CH₄, H₂S, DMD, SCFA, and ME, and the lowest pH, so it turned out to be the most efficient in CH₄ conversion, while with the SHI only the highest production of CO and pH was obtained, and the lowest DMD, SCFA, and ME, so it was less efficient compared to STI.

The objective of this study was to evaluate the impact of the genotype on the chemical composition, feeding value and in vitro rumen degradability of fresh and ensiled forage of four native maize varieties (Amarillo, Olotillo, Tampiqueño and Tuxpeño) from Tamaulipas, Mexico, and a commercial hybrid, as well as the stability and aerobic deterioration of the silage. In all genotypes, fresh forage consisted of whole plants of maize that were harvested when the grain reached a milky-mass state, and silage was fresh forage chopped and ensiled in plastic bags, where it fermented for 120 days. The hybrid presented the highest content (p < 0.05) of dry matter (DM), organic matter (OM), ether extract, non-fibrous carbohydrates (NFCs) and starch, as well as the lowest content (p < 0.05) of fibers (NDF and ADF), acid detergent lignin and water-soluble carbohydrates (WSCs). Furthermore, the hybrid and Amarillo genotypes obtained the lowest pH and ammoniacal nitrogen content (p < 0.05), intermediate values (p < 0.05) of lactic and butyric acid, and the lowest and highest acetic acid content (p < 0.05), respectively. Although OM did not differ (p > 0.05) between states of the forage, the fresh forage presented a higher (p < 0.05) content of DM, crude protein, NDF, ADF, WSCs, pH and butyric acid in all genotypes, while the rest of the parameters were higher (p < 0.05) in the silage. However, Amarillo obtained the highest feeding value (p < 0.05) in terms of DM intake, relative forage value, digestible energy, metabolizable energy and rumen degradability (DM, NDF and ADF), and between states of the forage, ensiled obtained the highest feeding value (p < 0.05). During the aerobic exposure, the Amarillo and hybrid silage showed greater (p < 0.05) stability (>38 h), and less (p < 0.05) deterioration, pH increase and loss of DM and OM, while Tuxpeño obtained less stability and greater deterioration. In conclusion, the genotype did influence the chemical composition of fresh and ensiled forage, which affected the feeding value and in vitro rumen degradability, and the Amarillo and hybrid genotypes presented the best values in the evaluated parameters.

Efecto antibacteriano del extracto metanólico de Salix babylonica sobre bacterias de importancia en salud pública

Tillandsia recurvata is an epiphyte that grows on the canopy of many trees in tropical and subtropical areas of America. The objective of this study was to evaluate the effect of partial or complete substitution of sorghum stubble with T. recurvata on liveweight change, metabolic profile, and complete blood count of goats fed increasing levels (0, 30, and 60%, dry matter basis) of T. recurvata. Thirty non-pregnant three-year-old, non-lactating, healthy mixed-breed goats, ten animals per treatment (T0, T30, and T60), were adapted to diets and facilities for 14 days (d-14). Blood samples were collected at d-15, 28, and 56. At the last phase of the trial (from days 67 on), control goats tended to gain more (p = 0.09) weight than their counterparts consuming T. recurvata. Plasma protein, glucose, triglycerides, calcium, and phosphorus concentrations did not differ among dietary treatments (p > 0.05). Dietary treatment influenced red blood cells (higher for T60; p < 0.01), white blood cells (higher for T30; p < 0.05), mean corpuscular volume (higher for T0; p < 0.001), and mean corpuscular hemoglobin concentration (higher for T0; p < 0.01), although not the rest of the blood variables (p > 0.05). The hematocrit percentage tended to be higher (p = 0.06) in T30 than T0 and T60. It was concluded that replacing sorghum stubble with T. recurvata did not modify the metabolic status and maintained live weight of goats. Nevertheless, the use of T. recurvata as feed for goats would improve the nutrition of these animals in the dry season compared to the current diet obtained from an arid rangeland, reducing production costs, and would alleviate the damage caused by this aggressive epiphyte to host trees.