Relationship between intake of tannin-containing tropical tree forage, PEG supplementation, and salivary haze development in hair sheep and goats

Effects of dietary supplementation of peanut skins (Arachis hypogaea) on performance, digestibility, and rumen fermentation of cattle: a meta-analysis

This study aimed to estimate the magnitude of the effects of dietary inclusion of peanut skins (PS) byproduct (Arachis hypogea L.) on intake, total-tract digestibility, and rumen fermentation of cattle via meta-analysis. Data were collected following the PRISMA methodology. Nine manuscripts and a graduate thesis met the inclusion criteria from 1983 to 2010. The effect size was estimated by calculating the weighted raw mean differences (RMD) between PS vs. control diets. The RMD was compared with a robust variance estimation method followed by a meta-regression and a dose-response analysis fitting the diet characteristics like crude protein content (CP), NDF content, ether extract content (EE), tannin content, and PS level in diet (0 to 40%) as covariates. Dietary PS decreased (P < 0.01) total-tract CP digestibility (52.0 vs. 64.3%), final body weight (371.5 vs. 397.9 kg), and average daily gain (1.14 vs. 1.44 kg/day) among treatment comparisons. Likewise, PS decreased total VFA (92.6 vs. 107.6 mmol/L) and NH3-N (8.22 vs. 12.1 mg/dL), but no effects were observed on rumen pH (6.47 vs. 6.14) and VFA molar proportions. Despite the between-cluster variance, dietary PS increased the ether extract digestibility (77.5 vs. 70.2%) among treatment comparisons. The subset and dose-response analysis revealed that PS should not exceed 8% (DM basis) in the diet to prevent negative effects on CP digestibility and animal performance. In conclusion, the results of this meta-analysis do not support the dietary inclusion of PS in cattle diets beyond 8%.

Tannins from Mimosa tenuiflora in the diet improves nutrient utilisation, animal performance, carcass traits and commercial cuts of lambs

Context Tannins are polyphenolic compounds found in legumes, trees and forage shrubs, such as Mimosa tenuiflora, and form hydrogen bonds with proteins. Aims The objective of the present study was to determine the optimal dietary concentration of natural tannins from M. tenuiflora for enhancing intake, digestibility, nitrogen (N) and tannin physiological balance, performance, carcass traits and commercial cuts of lambs. Methods Forty-eight uncastrated Santa Ines lambs were distributed between two experiments, each with four diets containing natural tannins (1.21 (control), 9.29, 17.4 and 25.4 g/kg dry matter (DM) total) from M. tenuiflora hay. Key results With increasing level of inclusion of natural tannins from M. tenuiflora hay in the diet, there were quadratic increases (P ≤ 0.05; up to 17.4 g/kg DM inclusion) in the daily nutrient intake, N faecal excretion, N urinary excretion, performance, carcass traits and rib and loin commercial cut weights of lambs. However, intake, faecal excretion, physiological balance of tannins and carcass leg circumference increased (P ≤ 0.05) linearly with an increasing inclusion of tannins from M. tenuiflora hay. Furthermore, there were linear decreases (P ≤ 0.05) in the digestibility of DM, crude protein, neutral detergent fibre corrected for ash and protein, acid detergent fibre, non-fibrous carbohydrate and total digestible nutrients and decreases in faecal excretion of total phenolic compounds and feeding efficiency in lambs with increasing dietary concentration of tannins. Conclusions It is recommended that M. tenuiflora hay replace Brachiaria decumbens hay at 250 g/kg of dietary roughage, corresponding to 17.4 g/kg DM of tannins, in the diet of Santa Ines finishing lambs because the resulting increased bioavailability of tannins improves nutrient intake, N retention, average daily gain, carcass weight and the weights of the most profitable cuts (leg, loin and rib). Implications The use of M. tenuiflora legume (which is common in the Caatinga biome) as hay roughage in the lamb diet increases tannin bioavailability and the efficiency of protein use, consequently improving performance and contributing to the economic viability of sheep production in the region.

Gymnopodium floribundum fodder as a model for the in vivo evaluation of nutraceutical value against Haemonchus contortus

This study validated a protocol to identify the nutraceutical value of Gymnopodium floribundum (GF) foliage based on its effects on sheep nutrition, production and health and its impact on adult Haemonchus contortus. Thirty animals (17.8 ± 3.44 kg BW) were distributed into five experimental groups (n = 6). Groups T1-T3 received feed including 20%, 30% and 40% GF content, respectively, and group T4 received feed with 0% GF. Groups T1-T4 were all infected with 6000 H. contortus infective larvae (L₃). Group T5 included six worm-free lambs fed a diet without GF. Feed intake, dry matter digestibility (DMD) and organic matter digestibility (OMD) were measured, in addition to the faecal excretion of eggs per gram (EPG) and total faecal egg count (TFEC) of H. contortus. On day 39 post-infection, lambs were humanely slaughtered to recover and count adult parasites and assess the length and fecundity of female worms. Higher levels of GF in the diet reduced DMD and OMD (P < 0.05), with the lowest values in T3 (40% GF) (P < 0.05). Body weight gain was similar for all groups (0.18 to 0.2 kg/day; P > 0.05). EPG and TFEC were lower in T1 and T3 than in T4 (P < 0.05), and the number of adult female worms was lowest in T3 (P < 0.05). In conclusion, GF leaf meal can be considered a nutraceutical when included at 40% (T3) in the diet of lambs, based on its ability to decrease the EPG and TFEC of H. contortus by reducing the female worm burden. A 40% inclusion level had no negative impact on lamb diet intake, production and health, although a reduction of digestibility was observed.

Salivary tannin-binding proteins are a pervasive strategy used by the folivorous/frugivorous black howler monkey

Dietary tannins can affect protein digestion and absorption, be toxic, and influence food selection by being astringent and bitter tasting. Animals that usually ingest tannins may regularly secrete tannin-binding salivary proteins (TBSPs) to counteract the negative effects of tannins or TBSPs production can be induced by a tannin-rich diet. In the wild, many primates regularly eat a diet that contains tannin-rich leaves and unripe fruit and it has been speculated that they have the physiological ability to cope with dietary tannins; however, details of their strategy remains unclear. Our research details the salivary protein composition of wild and zoo-living black howler monkeys (Alouatta pigra) feeding on natural versus manufactured low-tannin diets, and examines differences in TBSPs, mainly proline-rich proteins (PRPs), to determine whether production of these proteins is dependent on the tannin content of their food. We measured the pH, flow rate, and concentration of total protein and trichloroacetic acid soluble proteins (an index of PRPs) in saliva. Howler monkeys produced slightly alkaline saliva that may aid in the binding interaction between tannin and salivary proteins. We used gel electrophoresis to describe the salivary protein profile and this analysis along with a tannin-binding assay allowed us to detect several TBSPs in all individuals. We found no differences in the characteristics of saliva between wild and zoo-living monkeys. Our results suggest that black howler monkeys always secrete TBSPs even when fed on foods low in tannins. This strategy of constantly using this salivary anti-tannin defense enables them to obtain nutrients from plants that sometimes contain high levels of tannins and may help immediately to overcome the astringent sensation of their food allowing howler monkeys to eat tanniferous plants.