Changes in rumen protozoal community by condensed tannin fractions of different molecular weights from a Leucaena leucocephala hybrid in vitro

Effects of Increasing Levels of Total Tannins on Intake, Digestibility, and Balance of Nitrogen, Water, and Energy in Hair Lambs

This study aims to evaluate the effects of increasing tannin levels from Mimosa tenuiflora hay on the intake, digestibility, and balance of nitrogen (N), water, and energy in hair lambs. Thirty-two Santa Ines lambs, at an average age of 150 days and body weight of 26.75 ± 2.29 kg, were randomly assigned to four treatments in a completely randomized design. The treatments consisted of four diets: a control diet, tannin-free, and three diets with increasing levels of total tannin, 26.2, 52.4, and 78.6 g tannin/kg dry matter (DM). Including the total tannins in the lambs' diet led to a quadratic increase in the intake of nutrients, N-retention (g/day), water intake, water absorption and retention, energy intake, and energy excretion in feces and gases. However, the digestibility of crude protein, neutral and acid detergent fibers, and total carbohydrates decreased. It was observed that there is a correlation between the variable nutrient digestibility and N-ingested and the N-absorbed, N-urinary, and N-retained. However, the N-excreted in feces did not correlate with any of the variables studied. It is recommended to include 33 g/kg DM of total natural tannins from Mimosa tenuiflora hay in the diet of hair lambs, as it improves intake, energy balance, dietary N, and body water composition while reducing the excretion of N-urinary and gas emissions to the environment.

Effects of Dietary Tannins’ Supplementation on Growth Performance, Rumen Fermentation, and Enteric Methane Emissions in Beef Cattle: A Meta-Analysis

The environmental sustainability of beef production is a significant concern within the food production system. Tannins (TANs) can be used to minimize the environmental impact of ruminant production because they can improve ruminal fermentation and ruminants’ lifetime performances and mitigate methane (CH4) emissions. The objective of this study was to evaluate the effects of dietary supplementation with TANs as sustainable natural alternative to reduce the environmental impact on growth performance, rumen fermentation, enteric CH4 emissions, and nitrogen (N) use efficiency of beef cattle through a meta-analysis. A comprehensive search of studies published in scientific journals that investigated the effects of TANs’ supplementation on the variables of interest was performed using the Scopus, Web of Science, and PubMed databases. The data analyzed were extracted from 32 peer-reviewed publications. The effects of TANs were assessed using random-effects statistical models to examine the standardized mean difference (SMD) between TANs’ treatments and control (non-TANs). The heterogeneity was explored by meta-regression and subgroup analysis was performed for the covariates that were significant. TANs’ supplementation did not affect weight gain, feed consumption, feed efficiency, or N use efficiency (p > 0.05). However, it reduced the concentration of ammonia nitrogen in rumen (SMD = −0.508, p < 0.001), CH4 emissions per day (SMD = −0.474, p < 0.01) and per unit dry matter intake (SMD = −0.408, p < 0.01), urinary N excretion (SMD = −0.338, p < 0.05), and dry matter digestibility (SMD = −0.589, p < 0.001). Ruminal propionate (SMD = 0.250) and butyrate (SMD = 0.198) concentrations and fecal N excretion (SMD = 0.860) improved in response to TANs’ supplementation (p < 0.05). In conclusion, it is possible to use TANs as a CH4 mitigation strategy without affecting cattle growth rate. In addition, the shift from urinary to fecal N may be beneficial for environment preservation, as urinary N induces more harmful emissions than fecal N. Therefore, the addition of tannins in the diet of beef cattle could be used as a sustainable natural alternative to reduce the environmental impact of beef production.

Effect of Leucaena leucocephala and corn oil on ruminal fermentation, methane production and fatty acid profile: an in vitro study

Aims This in vitro study aimed to examine the effect of proportions of Leucaena (Leucaena leucocephala (Lam.) de Wit) to Napier grass (Pennisetum purpureum Schumach) or levels of corn oil (CO) and their interaction on ruminal fermentation, methane (CH4) production and fatty acid profile. Methods The experiment was conducted as a 4 × 3 factorial arrangement following a completely randomised design with two factors. The treatments were according to the proportion of Leucaena and Napier grass (in g/kg DM, Treatment (T)1 = 0:750 (control), T2 = 250:500, T3 = 500:250, T4 = 750:0). Three levels of CO (in mg rumen fluid, CO1 = 0, CO2 = 10, CO3 = 20 respectively) were added to each of the diet, giving a total 12 dietary treatments. Key results Replacing Napier grass with Leucaena at 500 g/kg (T3) and 750 g/kg (T4) levels increased the molar volatile fatty acid concentration, microbial protein synthesis (P &lt; 0.001) and ammonia nitrogen concentration (P = 0.003), whereas ruminal protozoa concomitantly decreased (P &lt; 0.05). The addition of CO at 10 mg also reduced the number of ruminal protozoa compared with the control (P &lt; 0.001). A significant Leucaena × CO interaction was observed on the increase of ammonia nitrogen and microbial protein synthesis, and CH4 production was simultaneously suppressed (P &lt; 0.001). There was also a significant Leucaena × CO interaction on increasing concentration of C18:1 cis-9, C18:2 cis-10 cis-12 and α-linolenic acid, which thus contributed to the increase of n-3 polyunsaturated fatty acids accumulation in the culture (P &lt; 0.001). However, the concentration of C18:0 was not influenced by the treatments (P &gt; 0.05). Conclusion This study demonstrated that the inclusion of Leucaena into a Napier grass-based diet at 500 g/kg and 750 g/kg DM positively affected rumen fermentation, reduced CH4 formation and increased beneficial fatty acids in the rumen. Although CO had similar positive effects on CH4 production and targeted beneficial fatty acids, it reduced the microbial protein synthesis at inclusion of 20 mg/mL DM. Overall, there were synergistic interactions between Leucaena and CO in reducing CH4 production and improving the fatty acid profile in the rumen. Implications It is possible to improve animal productivity while reducing the environmental impact of livestock production through inclusion of tannin-containing Leucaena and CO in ruminant diets in tropical regions where C4 grasses typically have low nutritive value.

Extending Burk Dehority's Perspectives on the Role of Ciliate Protozoa in the Rumen

Dr. Burk Dehority was an international expert on the classification and monoculture of ruminal ciliated protozoa. We have summarized many of the advancements in knowledge from his work but also in his scientific way of thinking about interactions of ruminal ciliates with the entire rumen microbial community and animal host. As a dedication to his legacy, an electronic library of high-resolution images and video footage catalogs numerous species and techniques involved in taxonomy, isolation, culture, and ecological assessment of ruminal ciliate species and communities. Considerable promise remains to adapt these landmark approaches to harness eukaryotic cell signaling technology with genomics and transcriptomics to assess cellular mechanisms regulating growth and responsiveness to ruminal environmental conditions. These technologies can be adapted to study how protozoa interact (both antagonism and mutualism) within the entire ruminal microbiota. Thus, advancements and limitations in approaches used are highlighted such that future research questions can be posed to study rumen protozoal contribution to ruminant nutrition and productivity.

Effect of Dried Leaves of Leucaena leucocephala on Rumen Fermentation, Rumen Microbial Population, and Enteric Methane Production in Crossbred Heifers

The effects of dietary inclusion of dried Leucaena leucocephala leaves (DLL) on nutrient digestibility, fermentation parameters, microbial rumen population, and production of enteric methane (CH₄) in crossbred heifers were evaluated. Four heifers were used in a 4 × 4 Latin square design consisting of four periods and four levels of inclusion of DLL: 0%, 12%, 24%, and 36% of dry matter (DM) intake. Results showed that DM intake (DMI), organic matter intake, and gross energy intake (GEI) were similar (p > 0.05) among treatments. Apparent digestibility of organic matter, neutral detergent fiber, and energy decreased with increasing levels of DLL in the ration (p < 0.05). In contrast, digestible crude protein (CP) was higher (p < 0.05) in treatments with 12% and 24% DM of DLL. The inclusion of DLL did not affect (p > 0.05) rumen pH and total volatile fatty acids. Rumen microbial community was not affected (p > 0.05) by treatment. There was a linear reduction (p < 0.05) in CH₄ emissions as the levels of DLL in the ration were increased. Results of this study suggest that an inclusion of 12% DM of ration as DLL enhances digestible CP and reduces daily production of enteric CH₄ without adversely affecting DMI, rumen microbial population, and fermentation parameters.