AFST: Influence of quebracho tannin extract fed at differing rates within a high-roughage diet on the apparent digestibility of dry matter and fiber, nitrogen balance, and fecal gas flux

Growth performance and carcass characteristics of bulls fed tannins associated or not with monensin

This study aimed to evaluate the effect of tannin (a mix of hydrolyzable and condensed) and its association with monensin on feed efficiency, growth performance, and carcass of bulls fed high-grain diets with 14% and 13% crude protein (CP). Bulls (64 Nellore and 96 crossbred Angus × Nellore; initial body weight (BW) = 342 ± 25 kg; 20 ± 1 months) were allocated into 20 pens (8 from the same breed per pen). The treatments were T14 - 1.5 g of tannin/kg of dry matter (DM) (Bypro; Silva Team Brasil, Estância Velha, Brazil) in a diet with 14% of CP; M14 - 25 ppm monensin (Rumensin; Elanco Saúde Animal, São Paulo, Brazil) in a diet with 14% of CP; TM14 - 1.5 g of tannin/kg of DM and 25 ppm monensin in a diet with 14% of CP; TM13 - 1.5 g of tannin/kg of DM and 25 ppm monensin in a diet with 13% of CP. Data were analyzed using a randomized block design with pens as experimental units. Supplementation with tannin resulted in greater final BW, average daily gain (ADG), and dry matter intake (DMI) compared with Monensin (P < 0.05). The association between Tannin and Monensin decreased (P < 0.05) DMI without affecting growth performance, consequently improving the gain-to-feed ratio compared to the Tannin-alone treatment. When Tannin was combined with Monensin, there was an increase (P < 0.05) in net energy for gain and net energy for maintenance compared with Tannin supplementation alone. Bulls supplemented with Tannin in their diet exhibited greater (P < 0.05) hot carcass weight, carcass gain, and gluteus medius area compared with those supplemented with Monensin alone. Final BW, ADG, and DMI were lower (P < 0.05) when the CP content of the diet was decreased from 14% to 13%. The optimal combination for achieving maximum growth and feed efficiency was observed when bulls were fed with tannin and monensin combined in a diet containing 14% CP.

Supplementing zebu cattle with crop co-products helps to reduce enteric emissions in West Africa

In Africa, a wide variety of diets (forage + crop co-products or other agricultural by-products) is being used by livestock farmers in different production systems to adapt to climate change. This study aimed to assess the performance of various local feeding strategies on Sudanese Fulani zebu cattle. Two experiments were carried out on 10 steers aged initially 33 months (142 kg body weight - BW). The animals were fed eight different diets at an intake level of 3.2% LW in dry matter (DM), including two control diets of 100% rangeland forage (100% RF) and six experimental diets made up of forage and crop co-products (75:25 DM ratio). In the first experiment, the control diet was made up of rangeland forage (RF) and supplements consisted of four cereal co-products (CC), i.e. maize, sorghum, millet, and rice straws. In the second experiment, the control diet consisted of Panicum maximum (Pmax) hay, and the supplements tested were two legume co-products (LC), i.e. cowpea and peanut haulms. Each experiment lasted 3 weeks, including 2 weeks of adaptation to the diet and 1 week of data collection on individual animals (intake, apparent digestibility, and enteric methane). The NDF content of the diets was different within each experiment (p < 0.05). Among diets containing CC, DM intake [g/kg BW] was significantly higher (+31%; p = 0.025) for the diet containing rice straw than for the other diets, which showed similar levels to the RF diet. Among diets containing LC, intake was significantly higher (p = 0.004) than for the Pmax diet. Intake was higher for the peanut haulm diet than for the cowpea haulm diet. The DM digestibility was similar between the different diets in each experiment. Enteric methane (eCH4) yield [g/kg DMI] from the CC and LC-containing diets were reduced by an average of 23% and 20% compared to the RF and Pmax control diets respectively. Raising awareness among agro-pastoralists about the use of crop co-products offers real prospects for eCH4 emissions mitigation in the Sahel region.

Soil greenhouse gas flux and nitrogen mineralization following manure application from tannin-fed dairy cows

Growing concerns about environmental impacts of dairy farms have driven producers to address greenhouse gas (GHG) emissions and nitrogen (N) losses from soil following land application of dairy manure. Tannin dietary additives have proved to be a successful intervention for mitigating GHG and ammonia (NH3 ) emissions at the barn scale. However, it is unknown how land application of dairy manure from cows fed tannin diets affects crop-soil nitrogen dynamics and soil GHG flux. To test this, cows were fed diets at three levels of tannins (0.0%, 0.4%, and 1.8% of dry matter intake) and their manure was field applied at two N rates (240 and 360 kg N ha-1 ). Soil NH4 + -N, NO3 - -N, corn silage yield, and soil GHG flux were then measured over a full growing season. Soils amended with tannin manure had lower initial NH4 + -N concentrations and lower total mineral N (NH4 + -N + NO3 - -N) concentrations 19 days after application, compared to soils amended with no tannin manures. Despite lower early season N availability in tannin-fertilized plots, there were no differences in corn silage yield. No differences in soil GHG and NH3 emissions were observed between manure-amended treatments. These results demonstrate that while tannin addition to dairy cow feed does not offer short-term GHG or NH3 emissions reductions after field manure application, it can promote slower soil N mineralization that may reduce reactive N loss after initial application.

Supplement Type Impact on the Performance and Nutrient Dynamics of Nursing Does and Kids Raised in Woodlands

The influence of different supplement types on the performance and nutrient dynamics of goats stocked in woodlands is not known. The objective of this study was to evaluate the effect of supplement type on the performance and the concentration of fecal nutrients of nursing does and the performance of kids raised in woodlands. One group of goats (SG, 9 does; 18 kids) was allowed supplemental grazing in adjacent silvopasture plots for 3-4 h daily and another group (SF, 8 does; 15 kids) was supplemented with corn (0.5% of metabolic weight) and ad libitum hay. Vegetation samples were collected and analyzed for productivity and quality (crude protein, CP; acid detergent fiber, ADF; neutral detergent fiber, NDF). The quality of the hay (N, ADF, NDF) and fecal samples (N, P, Ca) was analyzed. The animals' live weight, FAMACHA score, and body condition score were collected. The browsing height for does consuming woodland vegetation was measured. Data were analyzed using the GLM procedure, Mixed procedure, and MEANS procedure in SAS 9.4. SG does showed better FAMACHA scores vs. SF does (p < 0.05). Fecal N and ADF were greater (p < 0.0001) in SG does vs. SF does. The findings showed a better performance and greater concentration of fecal nutrients in SG does vs. SF does, suggesting grazing quality pastures is a better option than using feedstuffs to supplement nursing does in woodland.

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.

Tannin in Ruminant Nutrition: Review

Tannins are polyphenols characterized by different molecular weights that plants are able to synthetize during their secondary metabolism. Macromolecules (proteins, structural carbohydrates and starch) can link tannins and their digestion can decrease. Tannins can be classified into two groups: hydrolysable tannins and condensed tannins. Tannins are polyphenols, which can directly or indirectly affect intake and digestion. Their ability to bind molecules and form complexes depends on the structure of polyphenols and on the macromolecule involved. Tannins have long been known to be an "anti-nutritional agent" in monogastric and poultry animals. Using good tannins' proper application protocols helped the researchers observe positive effects on the intestinal microbial ecosystem, gut health, and animal production. Plant tannins are used as an alternative to in-feed antibiotics, and many factors have been described by researchers which contribute to the variability in their efficiencies. The objective of this study was to review the literature about tannins, their effects and use in ruminant nutrition.

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.

Nutritional Aspects of Ecologically Relevant Phytochemicals in Ruminant Production

This review provides an update of ecologically relevant phytochemicals for ruminant production, focusing on their contribution to advancing nutrition. Phytochemicals embody a broad spectrum of chemical components that influence resource competence and biological advantage in determining plant species' distribution and density in different ecosystems. These natural compounds also often act as plant defensive chemicals against predatorial microbes, insects, and herbivores. They may modulate or exacerbate microbial transactions in the gastrointestinal tract and physiological responses in ruminant microbiomes. To harness their production-enhancing characteristics, phytochemicals have been actively researched as feed additives to manipulate ruminal fermentation and establish other phytochemoprophylactic (prevent animal diseases) and phytochemotherapeutic (treat animal diseases) roles. However, phytochemical-host interactions, the exact mechanism of action, and their effects require more profound elucidation to provide definitive recommendations for ruminant production. The majority of phytochemicals of nutritional and pharmacological interest are typically classified as flavonoids (9%), terpenoids (55%), and alkaloids (36%). Within flavonoids, polyphenolics (e.g., hydrolyzable and condensed tannins) have many benefits to ruminants, including reducing methane (CH4) emission, gastrointestinal nematode parasitism, and ruminal proteolysis. Within terpenoids, saponins and essential oils also mitigate CH4 emission, but triterpenoid saponins have rich biochemical structures with many clinical benefits in humans. The anti-methanogenic property in ruminants is variable because of the simultaneous targeting of several physiological pathways. This may explain saponin-containing forages' relative safety for long-term use and describe associated molecular interactions on all ruminant metabolism phases. Alkaloids are N-containing compounds with vast pharmacological properties currently used to treat humans, but their phytochemical usage as feed additives in ruminants has yet to be exploited as they may act as ghost compounds alongside other phytochemicals of known importance. We discussed strategic recommendations for phytochemicals to support sustainable ruminant production, such as replacements for antibiotics and anthelmintics. Topics that merit further examination are discussed and include the role of fresh forages vis-à-vis processed feeds in confined ruminant operations. Applications and benefits of phytochemicals to humankind are yet to be fully understood or utilized. Scientific explorations have provided promising results, pending thorough vetting before primetime use, such that academic and commercial interests in the technology are fully adopted.

Effect of quebracho condensed tannin extract on fecal gas flux in steers

Naturally occurring gaseous by-products of ruminant production-carbon dioxide (CO₂ ), methane (CH₄ ), and nitrous oxide (N₂ O)-can negatively affect the environment. Along with enteric fermentation, manure on pasture is among the most significant contributors to non-CO₂ emissions. Condensed tannins, a group of naturally occurring phenolic compounds, can alter the route of nutrient excretion and interact with microbes, suggesting they are a plausible feed additive for reducing excreta gas emissions. We evaluated how quebracho (Schinopsis balansae) tannin extract fed at 0, 15, 30, and 45 g kg^-1 of dry matter (DM) within a roughage-based diet affected fecal gas emissions at multiple locations (College Station and Stephenville, TX) during two periods corresponding to winter and spring. During both periods, CO₂ , CH₄ , and N₂ O fluxes were determined using the vented-static chamber methodology over 39 d, and cumulative emissions were calculated. A random coefficients model with animal nested within dietary treatment and period as the random factor was analyzed by location due to the presence of collinearity with soil parameters within periods. Daily CO₂ flux was influenced by soil moisture and temperature (r = .34; P < .01), whereas CH₄ and N₂ O were associated with soil moisture. Cumulative gas production confirmed a dietary effect for CO₂ and gross CO₂ equivalent at the College Station site (P ≤ .001), demonstrating a linear reduction as quebracho inclusion increased. Variance partitioning indicated that dietary treatment and seasonal period likely influenced animal digestive and metabolic parameters. Within specific environments, quebracho supplementation may assist in reducing fecal gas emissions.