Concerns about global warming and greenhouse gases have increased the interest of governments and the public sector to find solutions. To reduce the effects of global warming caused by greenhouse gases, especially methane, it is necessary to change animal production systems and adopt new strategic approaches. The reduction of enteric methane in livestock is a long-standing problem regarding the energy efficiency of consumed feed. In this review, the sources of production, dissemination, and introduction of accepted scientific and practical solutions in order to reduce methane gas in breeding and production units of dairy cows have been investigated. To carry out this research, a thorough search was conducted in articles published in valid databases between 1967 and 2022. A total of 213 articles were reviewed, and after screening, 159 were included in the study and analyzed using a PRISMA flow diagram. In general, low livestock efficiency, low-quality feed, a shortage of knowledge, and inadequate investment are the main causes of emission of these gases in poor or developing countries. On the other hand, developing countries may not always have access to the same methods that are utilized in industrialized countries to minimize the production of methane and other greenhouse gases like nitrous oxide. According to their conditions, developing countries should use the available tools to reduce methane production and emission, considering the costs, local knowledge, feasibility, and local laws. In future, there will be a greater need for interdisciplinary research to look for sustainable and acceptable methods for reducing methane emissions and other greenhouse gases from animal husbandry units, especially dairy cows. To change the population of rumen methanogens, as the main producers of methane, strategies such as feeding management, addition of inhibitors and vaccination are suggested. Also, there is a need for more applied research for reducing methane emissions.

Background: Undoubtedly, global warming has caused a decrease in the production of agricultural commodities. This problem has increased the price of animal feed due to competition with human consumption. Meanwhile, the physiology of ruminants gives them the ability to use by‐products and agricultural waste and supply their requirements for growth, maintenance and even production.Berberis vulgarisis a plant native to Iran, and after separating the fruit, its waste (mainly leaf) is unused and causes environmental pollution. The leaves of this plant contain significant amounts of phenolic compounds, alkaloids and anthocyanins that have antioxidant properties.Objectives: This experiment was conducted with the aim of determining the chemical properties of barberry leaves, such as crude protein, phenolic compounds, tannins and alkaloids. The effects of substituting ofB. vulgarisleaf (BVL) in the diet on performance characteristics of fattening Baluchi lambs were evaluated. The quality and antioxidant status of meat and blood parameters such as glucose, cholesterol, blood urea nitrogen and liver enzymes were investigated.Material and methods: A total of 21 male of 5–6 months old lambs with a mean body weight of 30.60 ± 1.28 kg were randomly assigned to one of three dietary treatments with different levels of BVL: 1–diet without BVL (control), 2–diet containing 7.5% BVL (BVL7.5), and 3–diet containing 15% BVL (BVL15; dry matter [DM] basis). Blood samples were harvested after overnight fasting from the jugular vein at 0, 28, 56 and 84 days. The lambs were slaughtered after 84 days of feeding trial and longissimus dorsi (LD) muscle was dissected. Meat quality and antioxidant stability status were measured.Results: 15% substitution of alfalfa hay by BVL (BVL15) increased DM intake) and decreased average daily gain (p ≤ 0.05). The LD muscle (p ≤ 0.05), liver (p ≤ 0.01) and plasma (p ≤ 0.05) samples of lambs fed either BVL7.5 or BVL15 displayed a greater total antioxidant capacity than that of lambs fed the control diet. Also, malondialdehyde concentration was decreased in plasma (p ≤ 0.01) and LD muscle of lambs (p ≤ 0.05) fed both BVL7.5 and BVL15. In addition, higher a* and C* values (p ≤ 0.05) were observed in the meat of lambs fed BVL15 than those fed with the control, while the lightness (L*) in BVL15 was lower, compared to other experimental dietsConclusions: Overall, our results indicated that 7.5% substitution of alfalfa hay by BVL may positively modulate the antioxidant status of fattening lambs and improve the colour stability of meat without negative effects on performance characteristics.

This study was aimed to first, determine the nutritional value of Berberis vulgaris leaf (BVL), using in vitro gas production technique and second, determine the effect of replacing alfalfa hay (AH) with BVL in lamb diets on nutrient intake, performance, and carcass traits. In vitro rumen gas kinetics and fermentation profile were assessed using three fistulated lambs and 96 h incubation of samples. For the in vivo trial, 21 Baluchi male lambs of 5–6 mo of age and 30.6 ± 1.28 kg body weight (BW) were randomly assigned to three treatment diets containing BVL at 0% (CTRL), 7.5% (BVL7.5), and 15% (BVL15) of the total dry matter (DM) inclusion. The study lasted 84 d, which included 14 d for adaption and 70 d for sample collection. In vitro results showed that BVL had lower gas yield (GY24, P ≤ 0.05) than AH. In vivo trial revealed that DM intake increased with BVL15 followed by BVL7.5 (P ≤ 0.05). Digestibility of DM, organic matter, NDF, and acid detergent lignin decreased (P ≤ 0.05) with BVL15. Total weight gain, average daily gain, hot carcass weight, and cold carcass weight were decreased (P ≤ 0.05) with BVL15, however, no differences were observed between the BVL7.5 and CTRL groups. Feed cost per kilogram BW gain decrease (P ≤ 0.05) by increasing the inclusion levels of BVL. In conclusion, BVL (up to 7.5% DM of diet) have positive consequences on performance, nutrient intake, rumen fermentation without deleterious effects on fattening performance. Barberry (Berberis vulgaris) leaf (BVL) is an agricultural by-product rich in plant secondary compounds such as alkaloids, flavonoids, anthocyanins, and tannin. The present study was aimed to first, evaluate in vitro nutritional value of BVL and second, explore the effects of BVL inclusion in finishing lambs diet (at levels of 0%, 7.5%, and 15% dry matter [DM] of diet), in partial replacement of alfalfa hay, on performance, carcass characteristics, and ruminal fermentation. BVL had less crude protein, ash, and natural detergent fiber than alfalfa hay, but more phenolic compounds and total tannin. The dietary inclusion of BVL at 7.5% and 15% DM of diet enhanced dry matter intake in fattening lambs and affected apparent digestibility. The relationship between nutrient intake and digestibility (DM, organic matter, neutral detergent fiber, and acid detergent fiber) was optimal with 7.5% BVL inclusion. The highest levels of dietary BVL were associated with lower weight gain; however, the production costs were reduced by BVL inclusion, and return per kilogram body weight gain was improved. However, additional trials are needed to refine the potential effects BVL on ruminal fermentation, methane emission and quality of products.

The objective of this study was to determine the effects of dietary agro-industrial by-products (AIBP) with different amounts of metabolizable energy (ME) and crude protein (CP) on fermentation (96 h) and gas production (GP) kinetics in vitro, as well as acceptability, animal performance, digestibility, and blood parameters in lambs. The gas production technique (GPT) and fermentation characteristics were used in an in vitro trial. This experiment used diets with ME contents of 6.28, 7.53, and 9.62 MJ/kg, as well as levels 120, 140, and 160 g/kg CP. Principal component analysis (PCA) was used to select the most important dietary ingredient ruminal fermentation parameters. The in vitro results showed that increasing ME and CP content increased and decreased GP (P < 0.05), respectively. An increase in CP content caused an increase in ruminal ammonia nitrogen (NH3-N) concentration (P < 0.05) and an increase in ME caused a decrease in pH (P < 0.05). PCA, by reducing the dimensions of the variables, shows that neutral detergent fiber (NDF), synchronization index (SI), and lignin as dietary parameters and pH and NH3 as fermentation quality parameters were the main variables in predicting LWG (P < 0.05). Next, to prove the ineffectiveness of dietary protein content on LWG, the highest ME content (ME = 9.62 MJ/kg) was selected for in vivo experiment. For the in vivo trial, eighteen male lambs of 6-7 months of age and 30.6 ± 2.27 kg body weight were randomly fed on three diets containing 120, 140, and 160 g/kg CP and ME 9.62 MJ/kg. There was no effect of the experimental diets on acceptability, performance characteristics, or apparent digestibility in an in vivo trial (P > 0.05). NH3-N concentration was affected by the varying content of CP (P < 0.05). The results of this study indicate that Khorasan Kurdish lambs have a high potential for using AIBP in their diet. Additionally, lamb producers can prevent N wastage without worrying about the loss of animal performance by using 120 g/kg CP, which meets the animals’ needs and has beneficial environmental consequences.

Background: Annually, a massive amount of broiler litter (BL) is produced in the world, which causes soil and surface water pollution due to its high nitrogen content and microbial count. While ruminants can use this non‐protein nitrogen (NPN) source for microbial protein synthesis. This issue becomes more critical when protein sources are unavailable or very expensive. One of the sources of NPN is BL which is produced at a considerable amount in the world yearly.Objectives: This aim of this research was to conduct a survey of non‐thermal technologies such as electrocoagulation (EC), ultraviolet (UV) radiation, and ultrasound (US) waves on the microbial safety and nutritional value of BL samples as a protein source in ruminant diets.Materials and methods: The methodology of this study was based on the use of an EC device with 24 V for 60 min, UV‐C light radiation (249 nm) for 1 and 10 min, and US waves with a frequency of 28 kHz for 5, 10 and 15 min to process BL samples compared with shade‐dried samples. Chemical composition and nutritional values of processed samples were determined by gas production technique and measurement of fermentation parameters in vitro.Results: Based on the results, microbial safety increased in the samples processed with the US (15 min). The EC method had the best performance in reducing the number of fungi and mould. However, none of the methods could remove total bacteria and fungi. Digestibility of BL was similar in shade‐dried, EC, and US (10 min) treatments. In general, the use of EC and US15 without having adverse effects on gas production caused a decrease in the concentration of ammonia nitrogen. In contrast, it caused a decrease in neutral detergent fibre (NDF) in the investigated substrate.Conclusions: In general, it can be concluded that the use of US5 and EC methods without having a negative effect on the parameters of gas production and fermentation in vitro, while reducing NDF, causes a significant reduction in the microbial load, pathogens, yeast, and mould. Therefore, it is suggested to use these two methods to improve feed digestibility for other protein and feed sources.

This study evaluates the effects of plant part (leaves vs. stems), harvest season (spring vs. autumn), and irrigation on the chemical composition, in vitro ruminal fermentation kinetics, and digestibility of three Mediterranean leguminous shrubs: Acacia fimbriata, Medicago arborea and Anthyllis barba-jovis. Samples were collected under field conditions, analysed for chemical composition, and assessed for in vitro ruminal fermentation, including incubations with and without polyethylene glycol (PEG) to assess the biological activity of phenolic compounds. Crude protein and fibre fractions did not differ significantly among species; ash was highest (p < 0.05) in Ac. fimbriata. In vitro fermentation kinetics were similar among species; however, the response to PEG was higher (p < 0.05) for Ac. fimbriata than for M. arborea and An. barba-jovis. In vitro digestibility was superior (p < 0.05) in M. arborea and An. barba-jovis. Leaves contained higher ash and protein contents and less fibre than stems, resulting in greater gas production, fermentation rate, and digestibility (p < 0.05). Spring-harvested fodder showed higher digestibility than autumn samples. Irrigation had negligible effects, except for a marginal numerical but nonsignificant (p = 0.05) greater extent of degradation observed in browse prior to irrigation. Overall, M. arborea showed a better nutritional quality, whereas Ac. fimbriata was the species with the lowest nutritive value. Forage quality was strongly influenced by plant part and harvest season, with leaves and fodder in spring showing superior potential as a feedstuff for ruminants.