Ruminant-based food production faces currently multiple challenges such as environmental emissions, climate change and accelerating food–feed–fuel competition for arable land. Therefore, more sustainable feed production is needed together with the exploitation of novel resources. In addition to numerous food industry (milling, sugar, starch, alcohol or plant oil) side streams already in use, new ones such as vegetable and fruit residues are explored, but their conservation is challenging and production often seasonal. In the temperate zones, lipid-rich camelina (Camelina sativa) expeller as an example of oilseed by-products has potential to enrich ruminant milk and meat fat with bioactive trans-11 18:1 and cis-9,trans-11 18:2 fatty acids and mitigate methane emissions. Regardless of the lower methionine content of alternative grain legume protein relative to soya bean meal (Glycine max), the lactation performance or the growth of ruminants fed faba beans (Vicia faba), peas (Pisum sativum) and lupins (Lupinus sp.) are comparable. Wood is the most abundant carbohydrate worldwide, but agroforestry approaches in ruminant nutrition are not common in the temperate areas. Untreated wood is poorly utilised by ruminants because of linkages between cellulose and lignin, but the utilisability can be improved by various processing methods. In the tropics, the leaves of fodder trees and shrubs (e.g. cassava (Manihot esculenta), Leucaena sp., Flemingia sp.) are good protein supplements for ruminants. A food–feed production system integrates the leaves and the by-products of on-farm food production to grass production in ruminant feeding. It can improve animal performance sustainably at smallholder farms. For larger-scale animal production, detoxified jatropha (Jatropha sp.) meal is a noteworthy alternative protein source. Globally, the advantages of single-cell protein (bacteria, yeast, fungi, microalgae) and aquatic biomass (seaweed, duckweed) over land crops are the independence of production from arable land and weather. The chemical composition of these feeds varies widely depending on the species and growth conditions. Microalgae have shown good potential both as lipid (e.g. Schizochytrium sp.) and protein supplements (e.g. Spirulina platensis) for ruminants. To conclude, various novel or underexploited feeds have potential to replace or supplement the traditional crops in ruminant rations. In the short-term, N-fixing grain legumes, oilseeds such as camelina and increased use of food and/or fuel industry by-products have the greatest potential to replace or supplement the traditional crops especially in the temperate zones. In the long-term, microalgae and duckweed of high-yield potential as well as wood industry by-products may become economically competitive feed options worldwide.

An in vitro gas production system was conducted to investigate the effect of krabok (Irvingia malayana) seed oil (KSO) and Flemingia (Flemingia macrophylla) leaf powder (FLM) supplementation on gas production kinetics, volatile fatty acid (VFA) and methane production with different ratios of rice straw to cassava chip (RS : CC). The treatments were arranged according to a 4 × 2 × 2 factorial arrangement in a completely randomised design using four different ratios of RS : CC (100 : 0; 60 : 40; 20 : 80; and 0 : 100), two levels of KSO supplement (0% and 2.5% of total dietary substrate) and two levels of FLM supplement (0% and 2.5% of total dietary substrate). The gas production kinetics were affected by RS : CC, KSO and FLM supplementation (P < 0.05). However, there was no interaction between RS : CC*FLM, FLM*KSO, or RS : CC*FLM*KSO; with the exception of RS : CC*KSO (P < 0.05). Cumulative gas at 96 h post incubation was increased with increasing RS : CC especially at 0 : 100. However, KSO supplementation suppressed gas production whereas FLM could enhance gas production from feed fraction (P < 0.05). Increasing RS : CC ratio resulted in increasing total VFA, propionic acid and butyric acid whereas acetic acid concentration was reduced; therefore, ratio of acetic acid : propionic acid was reduced. However, KSO supplementation depressed VFA production whereas the FLM supplement had no effect. The methane production was reduced with increasing level of RS : CC especially with supplementation of KSO. Based on this study, it is concluded that KSO addition could reduce methane production whereas FLM could enhance the gas production and fermentation end products; hence, the combined use is potentially beneficial. However, further research under in vivo conditions should be conducted.

Simple SummaryFermentation in ruminants can influence greenhouse gas production, especially methane (CH4) production. Phytonutrients (PTN) and secondary metabolites (tannins, saponins) have antimicrobial activity which can be used for the inhibition of rumen methanogens and the reduction of methane emissions in ruminants. The aim of the present study was to investigate the influence of PTN containing both mangosteen peel powder and banana flower powder on feed consumption, nutrient digestibility, and rumen microorganisms in swamp buffaloes. The results suggest that supplementation of PTN can improve fiber digestibility, increase the proteolytic and cellulolytic bacteria, and alter rumen volatile fatty acids (VFAs), especially increased C3 and reduced methane production. This study shows that PTN containing either mangosteen peel powder (MSP) or banana flower powder (BFP) could be used as a rumen modifier. AbstractThis experiment aimed to use dietary sources containing phytonutrients (PTN) such as mangosteen peel powder (MSP) and banana flower powder (BFP) as sources of phytonutrients. Four swamp buffalo bulls fitted with rumen fistulae were used as experimental animals. A digestion trial covering four periods was used according to a 4 × 4 Latin square design with four treatments: Treatment 1 (T1) = control (Cont), T2 = supplementation of PTN1 fed at 100 g/d, T3 = supplementation of PTN2 fed at 100 g/d, and T4 = supplementation of PTN3 fed at 100 g/d. The experiment was conducted for four periods; each period lasted for 21 days. All animals were fed a concentrate mixture at 0.5% body weight, while rice straw, water, and mineral blocks were fed ad libitum. The findings revealed significant increases in the digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF), while no changes in dry matter feed consumption occurred due to PTN supplementation. Rumen fermentation end-products, such as total volatile fatty acids (TVFA), propionic acid (C3), and butyric acid (C4), were notably enhanced (p < 0.05) and there were the highest in PTN2 and PTN3, whilst acetic acid (C2) was significantly decreased with PTN supplementation groups. Furthermore, the rumen protozoal population was suppressed (p < 0.05), which resulted in decreased rumen methane production (p < 0.05), while the bacterial population was enhanced. Using PTN sources can improve rumen fermentation as well as mitigating rumen methane production.

Four rumen-fistulated dairy steers, 3 years old with 180 ± 15 kg body weight (BW), were randomly assigned according to a 4 × 4 Latin square design to investigate on the effect of Flemingia macrophylla hay meal (FMH) and cassava hay meal (CH) supplementation on rumen fermentation efficiency and estimated methane production. The treatments were as follows: T1 = non-supplement, T2 = CH supplementation at 150 g/head/day, T3 = FMH supplementation at 150 g/head/day, and T4 = CH + FMH supplementation at 75 and 75 g/head/day. All steers were fed rice straw ad libitum and concentrate was offered at 0.5 % of BW. Results revealed that supplementation of CH and/or FMH did not affect on feed intake (P > 0.05) while digestibility of crude protein and neutral detergent fiber were increased especially in steers receiving FMH and CH+FMH (P < 0.05). Ruminal pH, temperature, and blood urea nitrogen were similar among treatments while ammonia nitrogen was increased in all supplemented groups (P < 0.05). Furthermore, propionic acid (C3) was increased while acetic acid (C2), C2:C3 ratio, and estimated methane production were decreased by dietary treatments. Protozoa and fungi population were not affected by dietary supplement while viable bacteria count increased in steers receiving FMH. Supplementation of FMH and/or FMH+CH increased microbial crude protein and efficiency of microbial nitrogen supply. This study concluded FMH (150 g/head/day) and/or CH+FMH (75 and 75 g/head/day) supplementation could be used as a rumen enhancer for increasing nutrient digestibility, rumen fermentation efficiency, and microbial protein synthesis while decreasing estimated methane production without adverse effect on voluntary feed intake of dairy steers fed rice straw.

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BACKGROUND Phytonutrient pellet, a new rumen enhancer, was formulated from various tropical fruit peels containing phytonutrients (condensed tannins and saponins) and named MARABAC. To substantiate the MARABAC supplementation effect, it was supplemented with low and high levels of concentrate supplementation in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement using beef cattle. Based on this investigation, interesting findings were highlighted and are reported herein. RESULTS The high level of concentrate supplementation (HCS) reduced rumen pH remarkably, but was buffered and enhanced by MARABAC supplementation. Rumen pH was reduced to 5.74 at 8 h, post feeding upon receiving HCS, and was buffered back to 6.19 with MARABAC supplementation. The supplementation exhibited an additional pronounced (P < 0.01) effect on improving nutrient digestibility and efficiency of microbial nitrogen supply, mitigating rumen methane production and reducing protozoal population. Rumen and fermentation end‐products, especially propionate production, were enhanced (P < 0.05), while rumen methane production was subsequently mitigated (P < 0.01). CONCLUSION MARABAC is a new promising dietary rumen enhancer for future replacement of chemicals and antibiotics used to enhance the rumen fermentation. Nevertheless, more in vivo feeding trials should be further conducted to elucidate the insight impacts. © 2021 Society of Chemical Industry

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Fodder shrub, Flemingia macrophylla silage (FMS), was nutritionally evaluated for rumen fermentation characteristics using an in vitro gas production technique. Dietary treatments were imposed in a 2 × 7 factorial arrangement in a completely randomised design. The first factor was two ratios of roughage:concentrate (R:C at 60:40 and 40:60), and the second factor was seven levels of FMS supplementation at 0, 20, 40, 60, 80, 100 and 120 g/kg of dietary substrate. The results revealed that a R:C ratio at 40:60 increased the kinetics of gas production (P &lt; 0.001). Moreover, supplementation of FMS increased in vitro degradability and the concentration of propionic acid (P &lt; 0.001), whereas acetic acid concentration, protozoal population and methane production were reduced (P &lt; 0.001). In conclusion, supplementation of FMS at 120 g/kg of dietary substrate improved rumen fermentation and subsequently reduced methane production. However, in vivo feeding trials using FMS should be conducted to gain more information for further implementations.