Tannins as feed additives to modulate ruminal biohydrogenation: Effects on animal performance, milk fatty acid composition and ruminal fermentation in dairy ewes fed a diet containing sunflower oil

Potential modulating effects of Allium mongolicum regel ethanol extract on rumen fermentation and biohydrogenation bacteria of dairy cows in vitro

The objective of this study was to evaluate the potential modulating effects of Allium mongolicum regel ethanol extract (AME) on rumen fermentation and biohydrogenation (BH) bacteria in vitro. Four Holstein cows were used as donors for the rumen fluid used in this study. In experiment 1, five treatments (supplemented with 0 mg/g, 1 mg/g, 2 mg/g, 3 mg/g, and 4 mg/g of AME based on fermentation substrate, respectively) were conducted to evaluate the effects of different levels of AME on fermentation status in vitro. The results showed that after 24 h of fermentation, MCP was reduced with AME supplementation (p < 0.05), and the multiple combinations of different combinations index (MFAEI) value was the highest with 3 mg/g of AME. In experiment 2, six treatments were constructed which contained: control group (A1); the unsaturated fatty acid (UFA) mixture at 3% concentration (A2); the mixture of A2 and 3 mg/g of AME (A3); 3 mg/g of AME (A4); the UFA mixture at 1.5% concentration (A5); the mixture of A5 and 3 mg/g of AME (A6). The abundance of bacterial species involved in BH was measured to evaluate the potential modulating effect of AME on rumen BH in vitro. Compared with the A1 group, the A3, A4, and A6 groups both showed significant decreases in the abundance of rumen BH microbial flora including Butyrivibrio proteoclasticus, Butyrivibrio fibrisolvens, Ruminococcus albus and Clostridium aminophilum (p < 0.01). The A3 group was less inhibitory than A4 in the abundance of B. proteoclasticus, B. fibrisolvens, and R. albus, and the inhibitory effect of the A6 group was higher than that of A4. In conclusion, the supplementation with 3 mg/g of AME could modulate the rumen fermentation and affect BH key bacteria, which suggests that AME may have the potential to inhibit the rumen BH of dairy cows.

Valorization of Olive Mill Byproducts: Recovery of Biophenol Compounds and Application in Animal Feed

This study aimed to recover the phenols from olive oil mill wastewater, a major pollutant of the oil industry, by using spray-drying technology to produce a new feed with a nutraceutical value for animal feed supplementation and to evaluate its effect on the productivity and nutritional quality of ewe milk. Forty-five Sarda ewes in late lactation (150 ± 2 d) and with homogeneous live weight (52 ± 1.5 kg) were randomly allotted into three groups and fed with three dietary treatments containing increasing levels of polyphenols: 0% (C), 0.1% (T0.1), and 0.2% (T0.2) of dry matter. No effect of the dietary treatments was found on the milk yield and composition. Interestingly, milk urea content (p < 0.0001) and somatic cell counts (p < 0.001) decreased as the level of polyphenols inclusion in the diet increased. The inclusion of phenols (0.2% of dry matter) in the diet of sheep was effective in increasing the vaccenic (C18:1 trans-11) and rumenic acid (C18: cis-9 trans-11) levels, which are beneficial for human health. Finally, the recovery of polyphenols via spray-drying technology and their incorporation into a new fortified feed can be a valid strategy for naturally improving the nutritional value of milk while valorizing an oil industry byproduct, reducing environmental impact, and promoting waste reuse that is in line with circular economy principles.

Effects of Chestnut Hydrolysable Tannin on Intake, Digestibility, Rumen Fermentation, Milk Production and Somatic Cell Count in Crossbred Dairy Cows

This study was conducted to determine the effects of chestnut hydrolysable tannin (CHT) on intake, digestibility, rumen fermentation, milk yield and somatic cell count in crossbred dairy cows (>75% Holstein Friesian). Four crossbred dairy cows (467.6 ± 35.2 kg BW) were assigned to be supplemented with one of four levels of CHT according to a 4 × 4 Latin square design. Dietary treatments included the control (without CHT supplementation) and CHT treatments that consisted of supplementation with 3.15, 6.30 and 9.45 g CHT/day. Rice straw was given ad libitum. The results showed that increasing levels of CHT tended to quadratically decrease rice straw intake (p = 0.06). However, total dry matter intake (DMI) and other nutrients were not different (p > 0.05) among the dietary treatments. The apparent digestibility of DM, organic matter (OM) and crude protein (CP) in cows with CHT treatments were higher (p < 0.05) than those of control cows. Milk yield and milk composition were not different (p > 0.05) among treatments. Lactose yield tended to increase linearly (p = 0.09) as CHT supplementation increased. Ruminal pH and ammonia nitrogen (NH3-N) were not different (p > 0.05), but total volatile fatty acids (VFAs) increased linearly (p < 0.05) as CHT levels increased. The somatic cell count (SCC) and somatic cell score (SCS) in the CHT treatments were different (p < 0.01) than those in the control treatment. In conclusion, it appears that CHT supplementation improved feed utilization and influenced SCC in crossbred dairy cows. Long-term research is needed to confirm the benefit of CHT supplementation.

The Impact of Mineral and Energy Supplementation and Phytogenic Compounds on Rumen Microbial Diversity and Nitrogen Utilization in Grazing Beef Cattle

The objective of this study was to evaluate the effect of the addition of a phytogenic compound blend (PHA) containing hydrolyzable tannins, carvacrol, and cinnamaldehyde oil to mineral salt or energy supplementation on the rumen microbiota and nitrogen metabolism of grazing Nellore cattle. Eight castrated Nellore steers were distributed in a double-Latin-square 4 × 4 design, with a 2 × 2 factorial arrangement (two types of supplements with or without the addition of the PHA), as follows: energy supplement without the PHA addition (EW); energy supplement with the PHA addition (EPHA); mineral supplement without the addition of the PHA (MW); mineral supplement with the PHA addition (MPHA). Steers that received supplements with the PHA have a lower ruminal proportion of valerate (with the PHA, 1.06%; without the PHA, 1.15%), a lower ruminal abundance of Verrucomicrobia, and a tendency for lower DM digestibility (with the PHA, 62.8%; without the PHA, 64.8%). Energy supplements allowed for higher ammonia concentrations (+2.28 mg of NH₃-N/dL), increased the propionate proportion (+0.29% of total VFA), and had a higher ruminal abundance of Proteobacteria and Spirochaetae phyla in the rumen. The PHA addition in the supplement did not improve nitrogen retention, reduced the ruminal proportion of valerate, and had a negative impact on both the total dry-matter digestibility and the abundance of several ruminal bacterial groups belonging to the Firmicutes and Verrucomicrobia phyla.

Meat quality, metabolic profile and antioxidant status of lambs fed on seedless grape pomace (Vitis vinifera L.)

This study was aiming to research the effect of the seedless grape pomace (GP) added to feed mixture on meat quality, metabolic profile, and antioxidant status of Merinolandschaf lambs. The 90 days old lambs in the control group (C, n=10) were fed feed mixture without GP while in experimental groups were fed with 10% (GP10, n=10) or 20% (GP20, n=10) of GP in feed mixture for 30 days. There was a significant increase in L*, a* values and hue angle as well as a decrease in b* values of lamb carcasses in GP10 and GP20 compared to C group. When lambs were fed GP glucose concentrations decreased, while non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) increased on the 30th day in GP10 and GP20 compared with C group. A significant increase in SOD activity on day 30 and GPx activity on day 15 in lambs’ blood of GP10 and GP20 compared with C group was determined. Also, an increase in DPPH in lamb GP10 and GP20 compared with C was determined. The obtained results of the meat quality, metabolic profile and antioxidant status parameters of lamb meat showed that the use of 10% GP in the diet is justified, while 20% of GP was questionable.

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.

Condensed tannins to increase bioactive fatty acids in the milk from Canindé, Repartida, and Saanen goats

Bioactive fatty acids present in goat milk have the ability to reduce the risks of coronary heart disease in humans, and condensed tannins (CT) can modulate the polyunsaturated fatty acids (PUFA) biohydrogenation process in the rumen and consequently increase the levels of these fatty acids. Thus, the objective was to evaluate the inclusion of CT in the diet for Canindé, Repartida, and Saanen goats to increase the level of bioactive fatty acids in milk. Twenty-two lactating does of three genetic groups, six Canindé, eight Repartida, and eight Saanen, were randomly assigned in a 3 × 2 factorial arrangement of three genetic groups and two diets (control and with 50 g CT/kg DM). The inclusion of CT in the diet did not change (P > 0.05) nutrient intake and performance. However, the inclusion of CT promoted an increase (P < 0.05) in C14:1; cis-9; C18:2n6; C18:3n6; C18:3n3; PUFA; and long-chain fatty acids and reduction (P < 0.05) of C11; C12; C14; ω6/ω3; and atherogenicity index in milk fat. Thus, it is recommended to include CT in the diet for Canindé, Repartida, and Saanen goats to increase the level of bioactive fatty acids in milk. The inclusion of the tannins of Acacia mearnsii promoted an increase in C14:1; cis-9; C18:2n6; C18:3n6; C18:3n3; polyunsaturated fatty acid; and long-chain fatty acids and reduction of C11; C12; C14; ω6/ω3; and atherogenicity index in milk fat.

Amaranthus grain as a new ingredient in diets for dairy cows: productive, qualitative, and in vitro fermentation traits

BACKGROUND

In recent decades, grain amaranths have attracted attention due to their valuable combination of nutritional traits, with higher protein and oil content than conventional cereals. Before they can be proposed as an unconventional ingredient in animal feed, many aspects still need to be investigated from field production to nutritive value. The present research aimed to study the agronomic traits, proximate composition, and digestibility/degradability, fatty acid profile, antioxidant activity, and total phenolic content of two grain amaranth species, Amaranthus cruentus and Amaranthus hypochondriacus (for a total of six accessions), grown in a Mediterranean environment.

RESULTS

Both species showed seed yields comparable to or higher than the traditional cereal crops in the same environment. On the whole, A. cruentus resulted in a higher seed production than A. hypochondriacus. Mexico and Montana accessions, both belonging to A. cruentus, showed the highest yield (3.73 t ha^-1 , on average). Few differences emerged in nutritive value between species and accessions: the Illinois accession of A. cruentus showed the best performance in terms of in vitro degradability and gas production, but not for volatile fatty acid production; the fermentation kinetics was slowest in the Illinois accession and fastest in the Montana accession of A. cruentus and the India accession of A. hypochondriacus.

CONCLUSION

From a health perspective, the Nebraska accession of A. hypochondriacus represents the best accession, with the lowest saturated fatty acid content and the highest polyunsaturated fatty acid content. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The Utilisation of Tannin Extract as a Dietary Additive in Ruminant Nutrition: A Meta-Analysis

Simple Summary

Tannin has been extensively assessed for its potential and utilisation as a ruminant feed additive in recent years and is becoming important due to its beneficial effects on modulating ruminant performance and health and mitigating methane emissions. However, evidence concerning the effect of tannin in extracted forms on ruminants appears to be inconclusive on whether it can genuinely provide either beneficial or detrimental effects for ruminants. Moreover, the effects of various sources, types of tannin extract, or appropriate levels of supplementation on ruminants remain unclear. Therefore, there is a need for a systematic evaluation concerning the effects of tannin extract on rumen fermentation, digestibility, performance, methane emissions, and metabolism of ruminants.

Abstract

The objective of this meta-analysis was to elucidate whether there are general underlying effects of dietary tannin extract supplementation on rumen fermentation, digestibility, methane production, performance, as well as N utilisation in ruminants. A total of 70 papers comprised of 348 dietary treatments (from both in vivo and in situ studies) were included in the study. The database was then statistically analysed by the mixed model methodology, in which different experiments were considered as random effects and tannin-related factors were treated as fixed effects. The results revealed that an increased level of tannin extract inclusion in the diet lowered ruminant intake, digestibility, and production performance. Furthermore, the evidence also showed that an increased level of tannin extract decreased animal N utilisation where most of rumen by-pass protein was not absorbed well in the small intestine and directly excreted in the faeces. Due to the type of tannin extract, HT is more favourable to maintain nutrient intake, digestibility, and production performance and to mitigate methane production instead of CT, particularly when supplemented at low (<1%) to moderate (~3%) levels.

Supplementation of Aloe vera extract in lactating goats' diet: effects on rumen fermentation efficiency, nutrient utilization, lactation performance, and antioxidant status

The present work was conducted to investigate the effects of supplementing Aloe vera extract on rumen fermentation efficiency, nutrient utilization, lactation performance, and antioxidant status of goats. Twenty-four crossbreed lactating goats (Alpine × Beetal) were divided into three experimental groups (AV0, AV2, and AV4). AV0 had no supplementation, groups AV2 and AV4 received ready to feed aqueous extract of Aloe vera at 20 and 40 g/kg dry matter intake, respectively, along with basal diet and experiment lasted for 100 days. Average DMI did not vary (P > 0.05) among treatment groups; however, the metabolic bodyweight of AV4 was significantly lower (P < 0.05) than the AV0 and AV2 groups (AV0 = AV2 > AV4). Intake and digestibility of DM, OM, CP, NDF, ADF, and EE were unaffected (P > 0.05) by Aloe vera supplementation. The milk production, yield of milk fat, protein, lactose, and solid not fat (SNF) of goats in the AV4 group were significantly higher (P < 0.05) than other groups (AV4 > AV2 = AV0). The activity of superoxide dismutase and catalase enzymes and levels of plasma ferric reducing total antioxidant power were high (P < 0.01) in the Aloe vera supplemented group (AV4 = AV2 > AV0). There was no significant difference (P = 0.979) in the pH, acetic acid (P = 0.449), and butyric acid (P = 0.864) concentration of the rumen liquor among the treatment groups. The propionic acid concentration was similar between AV2 and AV4 and significantly higher (P = 0.024) than the AV0 group (AV4 = AV2 > AV0). Moreover, C2:C3 values were significantly lower (P = 0.037) in the AV4 group compared to the control (AV0). Thus, Aloe vera supplementation enhanced milk yield, propionic acid production, and antioxidant status without affecting nutrient utilization; however, results were better in the AV4 group. The inclusion of Aloe vera at 40 g/kg of DMI would improve the rumen fermentation efficiency, lactation performance, and overall health status of the dairy goats.

Effects of ground, steam-flaked, and super-conditioned corn grain on production performance and total-tract digestibility in dairy cows

This study aimed to evaluate the effects of feeding ground, steam-flaked, or super-conditioned corn on production performance, rumen fermentation, nutrient digestibility, and milk fatty acid (FA) profile of lactating dairy cows. Twenty-four lactating Holstein cows (130 ± 12 d in milk) in a completely randomized block design experiment were assigned to 1 of 3 treatments that contained 31% of one of the following corn types: (1) ground corn; (2) steam-flaked corn; and (3) super-conditioned corn. Actual milk yield was greater in the super-conditioned corn diet than in the steam-flaked and ground corn diets. Dry matter intake, 3.5% fat-corrected milk and energy-corrected milk remained unaffected by treatments; however, milk fat concentration decreased in the super-conditioned corn diet compared with the ground and steam-flaked corn diets. The molar proportion of ruminal acetate decreased in the super-conditioned corn diet compared with the ground and steam-flaked corn diets, whereas the molar proportion of propionate spiked in the super-conditioned corn diet. Ruminal pH dropped in cows fed super-conditioned corn compared with the other 2 diets. A similar pattern was observed for ruminal NH₃-N and acetate-to-propionate ratio. Total-tract starch digestibility increased the most in the super-conditioned corn diet followed by the steam-flaked and ground corn diets (96.8, 95.1, and 92.5%, respectively). The neutral detergent fiber digestibility declined in cows fed the super-conditioned corn diet as opposed to other diets (~3.9%). The concentrations of 16:0 and mixed-FA in milk fat dropped in the super-conditioned corn-based diet compared with the ground corn diet. Milk trans-10 18:1 FA increased, whereas trans-11 18:1 FA decreased in cows fed the super-conditioned diet. We concluded that super-conditioned corn has the potential to increase milk yield and starch digestibility in lactating dairy cows; however, reduced milk fat output caused by altering ruminal pH and ruminal FA biohydrogenation pathways may not be desirable in certain markets. Future research is warranted to investigate how super-conditioned corn affects feed efficiency.

Sainfoin (Onobrychis viciifolia) silage in dairy cow rations reduces ruminal biohydrogenation and increases transfer efficiencies of unsaturated fatty acids from feed to milk

The effects of replacing grass silage by sainfoin silage in a total mixed ration (TMR) based diet on fatty acid (FA) reticular inflow and milk FA profile of dairy cows was investigated. The experiment followed a crossover design with 2 dietary treatments. The control diet consisted of grass silage, corn silage, concentrate and linseed. In the sainfoin diet, half of the grass silage was replaced by a sainfoin silage. Six rumen cannulated lactating multiparous dairy cows with a metabolic body weight of 132.5 ± 3.6 kg BW^0.75, 214 ± 72 d in milk and an average milk production of 23.1 ± 2.8 kg/d were used in the experiment. Cows were paired based on parity and milk production. Within pairs, cows were randomly assigned to either the control diet or the sainfoin diet for 2 experimental periods (29 d per period). In each period, the first 21 d, cows were housed individually in tie-stalls for adaptation, then next 4 d cows were housed individually in climate-controlled respiration chambers to measure CH₄. During the last 4 d, cows were housed individually in tie stalls to measure milk FA profile and determine FA reticular inflow using the reticular sampling technique with Cr-ethylenediaminetetraacetic acid disodium salt dihydrate (EDTA) and Yb-acetate used as digesta flow markers. Although the dietary C18:3n-3 intake was lower (P = 0.025) in the sainfoin diet group, the mono-unsaturated FA reticular inflow was greater (P = 0.042) in cows fed the sainfoin diet. The reticular inflow of trans-9, trans-12-C18:2 and cis-12, trans-10 C18:2 was greater (P ≤ 0.024) in the sainfoin diet group. The cows fed sainfoin diet had a lower (P ≤ 0.038) apparent ruminal biohydrogenation of cis-9-C18:1 and C18:3n-3, compared to the cows fed the control diet. The sainfoin diet group had greater (P ≤ 0.018) C18:3n-3 and cis-9, cis-12-C18:2 proportions in the milk FA profile compared to the control diet group. Transfer efficiencies from feed to milk of C18:2, C18:3n-3 and unsaturated FA were greater (P ≤ 0.0179) for the sainfoin diet. Based on the results, it could be concluded that replacing grass silage by sainfoin silage in dairy cow rations reduces ruminal C18:3n-3 biohydrogenation and improves milk FA profile.

Effect of Prickly Pear Cactus Peel Supplementation on Milk Production, Nutrient Digestibility and Rumen Fermentation of Sheep and the Maternal Effects on Growth and Physiological Performance of Suckling Offspring

Simple Summary

The agricultural byproducts commonly used as a feedstuff depend on their high abundance and the nutritional composition. Moreover, several agricultural byproducts are a valuable source of active ingredients, which could be used as feed supplements to improve the quality of formulated diets and animal performance. The present study evaluated the use of prickly pear cactus peels (Opuntia ficus-indica, PPCP) as an agricultural byproduct rich with phytochemicals in the diet of lactating Barki ewes at two doses (5 and 10 g/head/day). Supplementation with 5 g PPCP improves the milk production and composition of ewes. The maternal effect of supplementation of both doses of PPCP in the diets of lactating Barki ewes has been successful to improve the serum lipid profile, kidney function, hormonal and antioxidant status of their suckling lambs. Moreover, supplementation with 5 g PPCP improves the nutrient digestibility and rumen fermentation parameters in the sheep.

Abstract

Prickly pear cactus peels (Opuntia ficus-indica, PPCP) are sustainable byproducts available in arid regions and a rich source of antioxidants. Fifteen multiparous Barki ewes (2–3 years old, 46.94 ± 0.59 kg body weight, BW) at postpartum were individually distributed in three equal groups and fed diets supplemented with PPCP at doses of 0, 5 and 10 g/head/day. Lambs were individually distributed into three equal groups according to their mothers’ groups to investigate the maternal effect on lambs’ growth performance, hematology and serum metabolites. This trial lasted for 56 days from birth to weaning. Moreover, nine adult male Barki sheep with a live BW of 65.76 ± 0.54 kg were randomly allocated into three equal groups to determine the effect of PPCP on the nutrient digestibility of the experimental diets. The results indicate that supplementing PPCP at low levels (5 g/head/day) increased milk yield (p = 0.050), fat-corrected milk (p = 0.022), energy-corrected milk (p = 0.015) and the yield of milk constituents compared to 10 g PPCP and the control group. In addition, lambs suckling from ewes fed the diet supplemented with 5 g PPCP had a higher (p = 0.001) weaning BW compared to other groups. Serum total protein, globulin, superoxide dismutase, glutathione peroxidase enzyme activities and the triiodothyronine hormone improved significantly in lambs suckling from ewes fed diets supplemented with 5 g PPCP compared to the control group. Serum cholesterol profile and kidney activities were enhanced significantly in lambs suckling from ewes fed diets supplemented with 5 and 10 g of PPCP compared to the control group. The dietary supplementation of 5 g PPCP improved the crude protein digestibility, digestible crude protein value, nitrogen balance and rumen fermentation characteristics of male sheep compared to the control group. In conclusion, supplementation with 5 g PPCP improved ewes’ milk production, offspring growth and physiological status. Furthermore, it improved the crude protein digestibility and rumen fermentation characteristics of Barki sheep.

Sheep and Goats Respond Differently to Feeding Strategies Directed to Improve the Fatty Acid Profile of Milk Fat

Simple Summary

Sheep and goat milk, as well as dairy products, are considered good sources of high-quality nutrients, particularly proteins and fats. Many positive effects on human health have been attributed to the consumption of dairy containing specific fatty acids, including some compounds originating from the polyunsaturated FA (PUFA) biohydrogenation operated by rumen microbes. In this bibliographic review, several nutritional strategies able to improve the milk fatty acids (FA) profile, in terms of an increase in the concentration of fatty acids considered beneficial to human health, are presented and discussed, with special attention to the differences between the two species.

Abstract

This bibliographic review presents and discusses the nutritional strategies able to increase the concentration of beneficial fatty acids (FA) in sheep and goat milk, and dairy products, with a particular focus on the polyunsaturated FA (PUFA), and highlights differences between the two species. In fact, by adopting appropriate feeding strategies, it is possible to markedly vary the concentration of fat in milk and improve its FA composition. These strategies are based mostly on the utilization of herbage rich in PUFA, or on the inclusion of vegetable, marine, or essential oils in the diet of lactating animals. Sheep respond more effectively than goats to the utilization of fresh herbage and to nutritional approaches that improve the milk concentration of c9,t11-conjugated linoleic acid (c9,t11-CLA) and α-linolenic acid. Dietary polyphenols can influence milk FA profile, reducing or inhibiting the activity and growth of some strains of rumen microbes involved in the biohydrogenation of PUFA. Although the effectiveness of plant secondary compounds in improving milk FA composition is still controversial, an overall positive effect has been observed on the concentration of PUFA and RA, without marked differences between sheep and goats. On the other hand, the positive effect of dietary polyphenols on the oxidative stability of milk fat appears to be more consistent.

The links between supplementary tannin levels and conjugated linoleic acid (CLA) formation in ruminants: A systematic review and meta-analysis

A systematic review and meta-analysis were conducted to predict and identify ways to increase conjugated linoleic acid (CLA) formation in ruminant-derived products to treat human health issues with dietary tannins. The objective was to compare and confirm the effects of dietary tannins on CLA formation by analyzing in vitro and/or in vivo studies. We reported the results of the meta-analysis based on numerical data from 38 selected publications consisting of 3712 treatments. Generally, via multiple pathways, the CLA formation increased when dietary tannins increased. Concurrently, dietary tannins increased Δ⁹ desaturation and the CLA indices in milk and meat (P < 0.05 and P < 0.001, with average R² values of 0.23 and 0.44, respectively), but they did not change the rumen fermentation characteristics, including total volatile fatty acids (mmol/L) and their acid components. In vitro observations may accurately predict in vivo results. Unfortunately, there was no relationship between in vitro observations and in vivo results (R² < 0.10), indicating that it is difficult to predict CLA formation in vivo considering in vitro observations. According to the statistical meta-analysis results regarding animal aspects, the ranges of tannin levels required for CLA formation in vitro and in vivo were approximately 0.1–20 g/kg dry matter (DM) (P < 0.001) and 2.1–80 g/kg DM (P < 0.001), respectively. In conclusion, the in vivo method was more suitable for the direct observation of fatty acid transformation than the in vitro method.

Can Agro-Industrial By-Products Rich in Polyphenols be Advantageously Used in the Feeding and Nutrition of Dairy Small Ruminants?

Simple Summary

In the Mediterranean area, where dairy sheep and goats are widespread, the use of by-products in the diet of small ruminants is an ancient practice. Today the great availability of industrial by-products produced at the local level (e.g., grape, olive, tomato and myrtle residues), appears to be a promising strategy for reducing competition with human edible foods and the cost of off-farm produced feeds since they are imported worldwide. Moreover, these co-feeds can contribute to reducing the ecological and water footprint associated with crop cultivation. The presence of bioactive compounds, such as polyphenols, confers added value to these materials. Several positive aspects are apparent when such by-products are included in the diets of small dairy ruminants, in particular on ruminal metabolism, animal health, and the quality of derived products.

Abstract

Recently, the interest in industrial by-products produced at the local level in Mediterranean areas, resulting from fruit and vegetable processes, has increased because of their considerable amounts of bioactive compounds, including polyphenols. In this review, we analyze the most recent scientific results concerning the use of agro-industrial by-products, naturally rich in polyphenols (BPRP), in the diets of small dairy ruminants. Effects on milk production, milk and rumen liquor fatty acid profile, metabolic parameters, and methane production are reviewed. The feed intake and digestibility coefficients were generally depressed by BPRP, even though they were not always reflected in the milk yield. The main observed positive effects of BPRP were on quality of the milk’s FA profile, antioxidant activity in milk and blood, a reduction of rumen ammonia, and, consequently, a reduction of milk and blood urea. The expected beneficial effects of dietary polyphenols in small ruminants were not always observed because of their complex and variable matrices. However, owing to the large quantities of these products available at low prices, the use of BPRB in small ruminant nutrition offers a convenient solution to the valorization of residues arising from agricultural activities, reducing feed costs for farmers and conferring added value to dairy products at the local level, in a sustainable way.

Long-term oral administration of sweet chestnut (Castanea sativa Mill.) extract does not affect the contraction ability of isolated ileum

Extracts of sweet chestnut (Castanea sativa Mill.) which contain hydrolysable tannins are used to prevent diarrhoea in farm animals due to the astringent effect of tannins. The aim of this study was to establish whether long-term treatment with the chestnut extract as a feed additive affects the acetylcholine (ACh)-triggered contractions of isolated rat ileum. Wistar rats of both sexes were divided into 4 male and 4 female groups with 6 animals in each group. The first, second and third groups of both sexes received feed with 3, 15 and 30 g of chestnut extract per kg, respectively. The fourth group of both sexes received feed without the added chestnut extract and served as the control group. After the 90-day trial, the animals were euthanized, and ilea were isolated and placed in an organ bath filled with Tyrode’s solution. Ilea were connected to an isometric transducer. Ileal contractions were triggered by 0.005, 0.01, 0.05, 0.1, 0.5, 1.0, 5.0 and 10.0 mg of ACh, and contractions were recorded. The groups exhibited dose responsiveness to the ACh treatment steps; however, no significant differences in the contraction intensity were observed among the groups at the same ACh dose level. These results suggest that long-term treatment with chestnut extract as an astringent does not influence the intensity of ileal contractions triggered by ACh. Thus, no adverse effect on intestinal motility can be expected during a long-term use of chestnut extract as a feed additive in livestock production; however, further studies in target animal species are needed to confirm the findings.

Invited review: Plant polyphenols and rumen microbiota responsible for fatty acid biohydrogenation, fiber digestion, and methane emission: Experimental evidence and methodological approaches

The interest of the scientific community in the effects of plant polyphenols on animal nutrition is increasing. These compounds, in fact, are ubiquitous in the plant kingdom, especially in some spontaneous plants exploited as feeding resources alternative to cultivated crops and in several agro-industry by-products. Polyphenols interact with rumen microbiota, affecting carbohydrate fermentation, protein degradation, and lipid metabolism. Some of these aspects have been largely reviewed, especially for tannins; however, less information is available about the direct effect of polyphenols on the composition of rumen microbiota. In the present paper, we review the most recent literature about the effect of plant polyphenols on rumen microbiota responsible for unsaturated fatty acid biohydrogenation, fiber digestion, and methane production, taking into consideration the advances in microbiota analysis achieved in the last 10 yr. Key aspects, such as sample collection, sample storage, DNA extraction, and the main phylogenetic markers used in the reconstruction of microbial community structure, are examined. Furthermore, a summary of the new high-throughput methods based on next generation sequencing is reviewed. Several effects can be associated with dietary polyphenols. Polyphenols are able to depress or modulate the biohydrogenation of unsaturated fatty acids by a perturbation of ruminal microbiota composition. In particular, condensed tannins have an inhibitory effect on biohydrogenation, whereas hydrolyzable tannins seem to have a modulatory effect on biohydrogenation. With regard to fiber digestion, data from literature are quite consistent about a general depressive effect of polyphenols on gram-positive fibrolytic bacteria and ciliate protozoa, resulting in a reduction of volatile fatty acid production (mostly acetate molar production). Methane production is also usually reduced when tannins are included in the diet of ruminants, probably as a consequence of the inhibition of fiber digestion. However, some evidence suggests that hydrolyzable tannins may reduce methane emission by directly interacting with rumen microbiota without affecting fiber digestion.

The fatty acid composition of ewe milk or suckling lamb meat can be used to discriminate between ewes fed different diets

Thirty-nine ewe-lamb pairs were used to evaluate the effects of the diet of lactating ewes, the type of forage (pasture vs hay) and the inclusion of 10% quebracho in the concentrate on the fatty acid (FA) profile of their milk and the meat of their suckling lambs. The estimated forage–concentrate ratio was 80:20. Milk from pasture ewes had a higher percentage of saturated FAs (SFAs; 62.3 vs 56.5), lower percentages of monounsaturated FAs (MUFAs; 30.4 vs 36.6) and n-6 polyunsaturated FAs, and a lower n-6:n-3 ratio (1.9 vs 2.3) than did that of hay ewes (P &lt; 0.001). Meat of pasture lambs had higher percentages of total polyunsaturated FAs (PUFAs; 23.0 vs 20.4; P &lt; 0.05) and n-3 (7.0 vs 5.0; P &lt; 0.001) and lower percentages of MUFAs (37.9 vs 41.8; P &lt; 0.001) and n-6:n-3 (2.0 vs 2.8; P &lt; 0.001) than did that of hay lambs. The inclusion of quebracho increased MUFAs in milk (P &lt; 0.05) and decreased SFAs in meat (P &lt; 0.05). Ewes were correctly classified to the different treatments by using the FA profile of milk (100% score outcome), and to a lesser extend by using the FA profile of lamb (82–100% score outcome); de novo synthesis of FAs in lamb muscle might have reduced the classification accuracy. In conclusion, forage type had a greater effect on the FA profiles of ewe milk and the meat of suckling lambs than did the inclusion of quebracho in the concentrate. To improve the classification of meat of suckling lamb, other biomarkers should be examined. These results are relevant for ewes farmed for the production of milk as well as lambs.

Composição de ácidos graxos do queijo e leite de vacas alimentadas com casca de banana

RESUMO Objetivou-se avaliar os níveis de casca de banana seca ao sol na dieta de vacas F1 Holandês x Zebu sobre o perfil de ácidos graxos do leite e do queijo minas frescal. Os tratamentos foram constituídos de 0, 15, 30, 45 e 60% de substituição da silagem de sorgo pela casca de banana. O delineamento experimental foi em dois quadrados latinos 5 x 5 simultâneos. As amostras de leite e queijo foram analisadas quanto ao perfil de ácidos graxos por cromatografia gasosa. Observou-se efeito quadrático para o somatório de ácidos graxos poli-insaturados do leite, com valor máximo no nível de 23,54% de substituição. Houve efeito linear decrescente para os ácidos graxos C15:0 iso e C16:0 iso. Os ácidos graxos heneicosanoico, linoleico, linoleico conjugado e araquidônico apresentaram efeito quadrático. Não houve efeito das dietas sobre os ácidos graxos no queijo. A substituição de até 60% da silagem de sorgo por casca de banana na dieta de vacas em lactação pode ser alternativa para produção e processamento do leite, quando se considera a melhora no valor nutricional da fração lipídica do leite e o aumento dos teores de ácido linoleico conjugado.

Effect of dietary inclusion of date seed (Phoenix dactylifera L.) on intake, digestibility, milk production, and milk fatty acid profile of Holstein dairy cows

The objective of this experiment was to investigate the influence of ground date seed (GDS) on intake, digestibility, and milk yield and milk fatty acid (FA) composition of lactating Holstein cows. The experimental design was a 4 × 4 replicated Latin square with eight lactating dairy cows with an average milk production of 35.5 ± 1.5 kg and 75 ± 5 days in milk (DIM). Dairy cows were fed one of the four treatments contained 0, 2, 4, and 6% of diet dry matter (DM) GDS in replacement of wheat bran. All diets contained the same amount of forages (alfalfa hay and corn silage). Dietary treatments had no effect on DM intake (DMI), total tract apparent digestibility, milk yield, and milk composition. Increasing GDS linearly decreased concentration of C13:0 and increased cis-9 C14:1 and trans-11 C18:1 (vaccenic acid) (P < 0.05). A linear tendency for more C16:1 content in milk fat was observed with increasing GDS (P = 0.06). Feeding GDS resulted in a linear decrease (P < 0.01) in saturated FA (SFA) but increased milk fat monounsaturated FA (MUFA) and trans FA (TFA) (P < 0.05). Therefore, low levels of GDS (up to 6%) in the diet of Holstein dairy cows can beneficially modify milk FA composition without any adverse effects on intake, digestibility, and milk yield.

Potency of cashew nut shell liquid in rumen modulation under different dietary conditions and indication of its surfactant action against rumen bacteria

Background

Cashew nut shell liquid (CNSL) is an agricultural byproduct containing alkylphenols that has been shown to favorably change the rumen fermentation pattern only under experimentally fixed feeding conditions. Investigation of CNSL potency in rumen modulation under a variety of feeding regimens, and evidence leading to the understanding of CNSL action are obviously necessary for further CNSL applications. The objective of this study was to evaluate the potency of CNSL for rumen modulation under different dietary conditions, and to visually demonstrate its surfactant action against selected rumen bacteria.

Methods

Batch culture studies were carried out using various diets with 5 different forage to concentrate (F:C) ratios (9:1, 7:3, 5:5. 3:7 and 1:9). Strained rumen fluid was diluted with a buffer and incubated with each diet. Gas and short chain fatty acid (SCFA) profiles were characterized after 18 h incubation at 39 °C. Monensin was also evaluated as a reference additive under the same conditions. Four species of rumen bacteria were grown in pure culture and exposed to CNSL to determine their morphological sensitivity to the surfactant action of CNSL.

Results

CNSL supplementation decreased total gas production in diets with 5:5 and 3:7 F:C ratios, whereas the F:C ratio alone did not affect any gas production. Methane decrease by CNSL addition was more apparent in diets with 5:5, 3:7, and 1:9 F:C ratios. An interactive effect of CNSL and the F:C ratio was also observed for methane production. CNSL supplementation enhanced propionate production, while total SCFA production was not affected. Monensin decreased methane production but only in a diet with a 1:9 F:C ratio with increased propionate. Studies of pure cultures indicated that CNSL damaged the cell surface of hydrogen- and formate-producing bacteria, but did not change that of propionate-producing bacteria.

Conclusion

CNSL can selectively inhibit rumen bacteria through its surfactant action to lead fermentation toward less methane and more propionate production. As CNSL is effective over a wider range of dietary conditions for such modulation of rumen fermentation in comparison with monensin, this new additive candidate might be applied to ruminant animals for various production purposes and at various stages.

Effects of Leymus chinensis replacement with whole-crop wheat hay on blood parameters, fatty acid composition, and microbiomes of Holstein bulls

This study investigated the replacement of Leymus chinensis (LC) with whole-crop wheat hay (WCWH) in the diets of Holstein bulls in the fattening stage and examined the potential effects on blood parameters, fatty acids in rumen fluid and serum, and the rumen microbiomes. In this study, 12 Holstein bulls in the fattening period (body weight = 485.0 ± 40.8 kg) were assigned to 1 of 4 dietary treatments using a 4 × 4 Latin square design. Each experimental period consisted of a 17-d adaptation period and a 5-d collection period. The dietary treatments consisted of 4 proportions of WCWH (0, 33, 67, and 100%) as a substitute for LC (designated as WCWH0, WCWH33, WCWH67, and WCWH100, respectively). On d 18 and 22 of each experiment period, blood and rumen content samples were collected for analysis, respectively. Real-time quantitative PCR was used to analyze the rumen microbiomes. The results from this study revealed no differences in the saturated, monounsaturated, and polyunsaturated long-chain fatty acid proportions of rumen liquid among the treatments. It was observed in the present trial that rumen microbiotal flora were not significantly different in the bulls fed LC compared with the bulls fed WCWH. Additionally, blood sample analysis demonstrated that the concentration of urea nitrogen in the WCWH100 group was higher than that observed in the other groups. Meanwhile, no differences were detected for other serum parameters. There were no differences in the proportions of serum saturated, monounsaturated, and polyunsaturated long-chain fatty acids among the treatments. In conclusion, our data revealed that LC can be replaced with WCWH in the diet of Holstein bulls in the fattening stage with no negative effects on the blood indicators, fatty acids, and microbiomes.

Modulation of in vitro rumen biohydrogenation by Cistus ladanifer tannins compared with other tannin sources

BACKGROUND

Tannins are polyphenolic compounds able to modify the ruminal biohydrogenation (BH) of unsaturated fatty acids, but their activity may vary among different tannin sources. The effect of rockrose (Cistus ladanifer) on BH has never been compared with other more common tannin sources. Tannin extracts (100 g kg^-1 substrate dry matter) from chestnut (CH), quebracho (QB), grape seed (GS) and rockrose (CL) were incubated in vitro for 6 h with ruminal fluid using as substrate a feed containing 60 g kg^-1 of sunflower oil. A control treatment with no added tannins was also included.

RESULTS

Compared with the control, GS and CL, but not CH and QB, increased (P < 0.05) the disappearance of c9,c12-18:2 with a consequent larger production of c9,t11-18:2 and t11-18:1. However, no differences among treatments (P > 0.05) were observed for the disappearance of c9-18:1 and c9,c12,c15-18:3. The production of 18:0 was not different (P > 0.05) among treatments, although its proportion in the total BH products was lower (P < 0.05) for GS than for the other treatments.

CONCLUSION

Condensed tannins from GS and, to a lesser extent, from CL stimulate the first steps of BH, without a clear inhibition of 18:0 production. © 2016 Society of Chemical Industry.

Effects of various dietary lipid additives on lamb performance, carcass characteristics, adipose tissue fatty acid composition, and wool characteristics

Tasco (Ascophyllum nodosum; TA) was compared to canola (CO), flax (FO), and safflower oils (SO) for effects on performance, carcass characteristics, and fatty acid profiles of adipose tissue in skirt muscle (SM), subcutaneous and perirenal adipose tissues, and wool production and quality characteristics of Canadian Arcott lambs. Fifty-six lambs were randomly assigned to dietary treatments (n = 14 per treatment). Diets consisted of a pelleted, barley-based finishing diet containing either TA, CO, FO, or SO (2% of dietary DM). Feed deliveries and orts were recorded daily. Lambs were weighed weekly and slaughtered once they reached ≥ 45 kg BW. Carcass characteristics, rumen pH, and liver weights were determined at slaughter. Wool yield was determined on mid-side patches of 100 cm2 shorn at d 0 and on the day before slaughter (d 105 or 140). Dye-bands were used to determine wool growth, micrometer and staple length. Adipose tissues and SM samples were taken at slaughter and analyzed for FA profiles. No effects were observed on intake, growth, or carcass characteristics. A greater (P = 0.02) staple strength of lambs fed CO was the only effect observed in wool. Flax oil increased total n-3 and decreased the n-6/n-3 ratio in tissue FA profiles (P < 0.001) in comparison to other diets. Tasco increased (P ≤ 0.001) SFA/PUFA in all tissues, whereas concentrations of CLA c-9, t-11 were greatest with SO in all tissues (P ≤ 0.02), compared to other diets. These results suggest Tasco supplementation did not improve the n-3/n-6 or SFA/PUFA ratios of lamb adipose tissues compared to other dietary lipid additives.

Milk fatty acid composition, rumen microbial population, and animal performances in response to diets rich in linoleic acid supplemented with chestnut or quebracho tannins in dairy ewes

The aim of the study was to evaluate milk fatty acid (FA) profile, animal performance, and rumen microbial population in response to diets containing soybean oil supplemented or not with chestnut and quebracho tannins in dairy ewes. Eighteen Comisana ewes at 122±6 d in milking were allotted into 3 experimental groups. Diets were characterized by chopped grass hay administered ad libitum and by 800 g/head and day of 3 experimental concentrates containing 84.5 g of soybean oil/kg of dry matter (DM) and 52.8 g/kg of DM of bentonite (control diet), chestnut tannin extract (CHT diet), or quebracho tannin extract (QUE diet). The trial lasted 4 wk. Milk yield was recorded daily, and milk composition and blood parameters were analyzed weekly. At the end of the experiment, samples of rumen fluid were collected to analyze pH, volatile fatty acid profile, and the relative proportions of Butyrivibrio fibrisolvens and Butyrivibrio proteoclasticus in the rumen microbial population. Hepatic functionality, milk yield, and gross composition were not affected by tannin extracts, whereas milk FA composition was characterized by significant changes in the concentration of linoleic acid (CHT +2.77% and QUE +9.23%), vaccenic acid (CHT +7.07% and QUE +13.88%), rumenic acid (CHT -1.88% and QUE +24.24%), stearic acid (CHT + 8.71% and QUE -11.45%), and saturated fatty acids (CHT -0.47% and QUE -3.38%). These differences were probably due to the ability of condensed versus hydrolyzable tannins to interfere with rumen microbial metabolism, as indirectly confirmed by changes in the relative proportions of B. fibrisolvens and B. proteoclasticus populations and by changes in the molar proportions of volatile fatty acids. The effect of the CHT diet on the milk FA profile and microbial species considered in this trial was intermediate between that of QUE and the control diet, suggesting a differential effect of condensed and hydrolyzable tannins on rumen microbes. Compared with control animals, the presence of B. fibrisolvens increased about 3 times in ewes fed CHT and about 5 times in animals fed QUE. In contrast, the abundance of B. proteoclasticus decreased about 5- and 15-fold in rumen liquor of ewes fed CHT and QUE diets, respectively. The use of soybean oil and a practical dose of QUE or CHT extract in the diet of dairy ewes can be an efficient strategy to improve the nutritional quality of milk.

Effects of dietary cottonseed oil and tannin supplements on protein and fatty acid composition of bovine milk

This experiment was conducted to determine the effects of diets supplemented with cottonseed oil,Acacia mearnsii-condensed tannin extract, and a combination of both on composition of bovine milk. Treatment diets included addition of cottonseed oil (800 g/d; CSO), condensed tannin fromAcacia mearnsii(400 g/d; TAN) or a combination of cottonseed oil (800 g/d) and condensed tannin (400 g/d; CPT) with a diet consisting of 6·0 kg dry matter (DM) of concentrates and alfalfa hay ad libitum, which also served as the control diet (CON). Relative to the CON diet, feeding CSO and CPT diets had a minor impact on feed intake and yield of lactose in milk. These diets increased yields of milk and protein in milk. In contrast to the TAN diet, the CSO and CPT diets significantly decreased milk fat concentration and altered milk fatty acid composition by decreasing the proportion of saturated fatty acids but increasing proportions of monounsaturated and polyunsaturated fatty acids. The CPT diet had a similar effect to the CSO diet in modifying fatty acid profile. Overall, reduction in milk fat concentration and changes in milk fatty acid profile were probably due to supplementation of linoleic acid-rich cottonseed oil. The TAN diet had no effect on feed intake, milk yield and milk protein concentration. However, a reduction in the yields of protein and lactose occurred when cows were fed this diet. Supplemented tannin had no significant effect on fat concentration and changes in fatty acid profile in milk. All supplemented diets did not affect protein concentration or composition, nitrogen concentration, or casein to total protein ratio of the resulting milk.

Oral administration of cobalt acetate alters milk fatty acid composition, consistent with an inhibition of stearoyl-coenzyme A desaturase in lactating ewes

Previous investigations have shown that cobalt (Co) modifies milk fat composition in cattle, consistent with an inhibition of stearoyl-coenzyme A desaturase (SCD) activity, but it remains unclear whether other ruminant species are also affected. The present study examined the effects of oral administration of Co acetate on intake, rumen function, and milk production and fatty acid (FA) composition in sheep. Twenty lactating Assaf ewes were allocated into 1 of 4 groups and used in a continuous randomized block design that involved a 15-d adaptation, a 6-d treatment, and a 10-d posttreatment period. During the treatment period, animals received an oral drench supplying 0 (control), 3 (Co3), 6 (Co6), and 9 (Co9) mg of Co/kg of BW per day, administered in 3 equal doses at 8-h intervals. Cobalt acetate had no influence on intake or milk fat and protein concentrations, whereas treatments Co6 and Co9 tended to lower milk yield. Results on rumen parameters showed no effects on rumen fermentation, FA composition, or bacterial community structure. Administration of Co acetate decreased milk concentrations of FA containing a cis-9 double bond and SCD product:substrate ratios, consistent with an inhibition of SCD activity in the ovine mammary gland. Temporal changes in milk fat composition indicated that the effects of treatments were evident within 3d of dosing, with further changes being apparent after 6d and reverting to pretreatment values by d 6 after administration. Effect on milk FA composition did not differ substantially in response to incremental doses of Co acetate. On average, Co decreased milk cis-9 10:1/10:0, cis-9 12:1/12:0, cis-9 14:1/14:0, cis-9 16:1/16:0, cis-9 17:1/17:0, cis-9 18:1/18:0, and cis-9,trans-11 18:2/trans-11 18:1 concentration ratios by 30, 32, 38, 33, 21, 24, and 25%, respectively. Changes in milk fat cis-9 10:1, cis-9 12:1, and cis-9 14:1 concentrations to Co treatment indicated that 51% of cis-9 18:1 and cis-9,trans-11 18:2 secreted in milk originated from Δ(9)-desaturation. In conclusion, results demonstrated the potential of oral Co administration for the estimation of endogenous synthesis of FA containing a cis-9 double bond in the mammary gland of lactating ruminants. Indirect comparisons suggest that the effects of Co differ between sheep and cattle.