Wondimagegne Bekele , Pekka Huhtanen , Abiy Zegeye , Addis Simachew , Abu Bakar Siddique , Benedicte Riber Albrectsen , Mohammad Ramin
{"title":"Methane production from locally available ruminant feedstuffs in Ethiopia – An in vitro study","authors":"Wondimagegne Bekele , Pekka Huhtanen , Abiy Zegeye , Addis Simachew , Abu Bakar Siddique , Benedicte Riber Albrectsen , Mohammad Ramin","doi":"10.1016/j.anifeedsci.2024.115977","DOIUrl":null,"url":null,"abstract":"<div><p>Achieving optimal nutrient composition in locally sourced ruminant feeds is important, but can be challenging in resource-limited production systems. For example, improving the composition of available local feed resources is a key obstacle to efficiently mitigating enteric methane (CH<sub>4</sub>) emissions in ruminants. This study characterized the nutritional content and <em>in vitro</em> methane (CH<sub>4</sub>) yield of ruminant feedstuffs accessible in Ethiopia. A survey of 60 experienced farmers in two representative districts in Amhara region, Ethiopia, provided 33 feed samples, which were classified into four ruminant feed categories: Grasses (n=10); indigenous plants (trees, shrubs, herbaceous plants) (n=13); crop residues (n=5); and agro-industrial by-products (n=5). Nutritional composition was assessed by proximate and detergent methods. Methane yield (g CH<sub>4</sub>/kg feed dry matter (DM)) and total gas yield (L/kg DM) were evaluated using a fully automated <em>in vitro</em> gas production system. A colorimetric assay was conducted to measure condensed tannin content (CT, mg/g) in relevant feeds. Lower crude protein (CP) values were observed for the grass (mean 65.2 g/kg DM) and crop residues (mean 54.5 g/kg DM) categories. Agro-industrial by-products had the highest CP (mean 260 g/kg DM), while indigenous plants exhibited intermediate levels (163 g/kg DM). There was significant variation in CH<sub>4</sub> yield (P<0.01) between grasses (12.4–24.7 g/kg DM) indigenous plants (1.8–19.3 g/kg DM), and agro-industrial by-products (8.1–26.9 g/kg DM). The indigenous plant <em>Trifolium acaule</em> gave the lowest <em>in vitro</em> CH<sub>4</sub> yield (1.8 g/kg DM). A positive relationship was observed between <em>in vitro</em> dry matter digestibility (IVDMD), CH<sub>4</sub>, and total gas yield. Percentage of CH<sub>4</sub> in total gas production varied with feed category (grasses 14.5–19.6%; indigenous plants 3.1–16.9%; crop residues 15.8–20.6%; agro-industrial by-products 12.8–18.7%), and within category, e.g., <em>Trifolium acaule</em> (3.1%), <em>Acacia nilotica L.</em> (7.1%), <em>Ziziphus spina-christi</em> (9.9%), brewer’s spent grains (BSG) (12.8%), local liquor (<em>areki</em>) residues (14.1%), and local beer (<em>tella</em>) residues (15.1%). A negative relationship was observed between CT content and <em>in vitro</em> CH<sub>4</sub> yield, with a stronger (P<0.05) correlation for soluble CTs (R<sup>2</sup> = 0.46) than cell-bound CTs (R<sup>2</sup> = 0.25) and total CTs (R<sup>2</sup> = 0.29). Based on methanogenic properties and effects of CTs on <em>in vitro</em> CH<sub>4</sub> yield, indigenous plants should be prioritized in ruminant rations in Ethiopia. Making nutritional composition and CH<sub>4</sub> data publicly available could help develop environmentally sound, cost-effective rations for ruminant livestock, benefiting local farmers and leading to more sustainable and efficient livestock production in Ethiopia.</p></div>","PeriodicalId":7861,"journal":{"name":"Animal Feed Science and Technology","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0377840124001056/pdfft?md5=9dd9c8c29dbf5d7cf5d2bf8e56e64bdc&pid=1-s2.0-S0377840124001056-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Animal Feed Science and Technology","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0377840124001056","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, DAIRY & ANIMAL SCIENCE","Score":null,"Total":0}
引用次数: 0
Abstract
Achieving optimal nutrient composition in locally sourced ruminant feeds is important, but can be challenging in resource-limited production systems. For example, improving the composition of available local feed resources is a key obstacle to efficiently mitigating enteric methane (CH4) emissions in ruminants. This study characterized the nutritional content and in vitro methane (CH4) yield of ruminant feedstuffs accessible in Ethiopia. A survey of 60 experienced farmers in two representative districts in Amhara region, Ethiopia, provided 33 feed samples, which were classified into four ruminant feed categories: Grasses (n=10); indigenous plants (trees, shrubs, herbaceous plants) (n=13); crop residues (n=5); and agro-industrial by-products (n=5). Nutritional composition was assessed by proximate and detergent methods. Methane yield (g CH4/kg feed dry matter (DM)) and total gas yield (L/kg DM) were evaluated using a fully automated in vitro gas production system. A colorimetric assay was conducted to measure condensed tannin content (CT, mg/g) in relevant feeds. Lower crude protein (CP) values were observed for the grass (mean 65.2 g/kg DM) and crop residues (mean 54.5 g/kg DM) categories. Agro-industrial by-products had the highest CP (mean 260 g/kg DM), while indigenous plants exhibited intermediate levels (163 g/kg DM). There was significant variation in CH4 yield (P<0.01) between grasses (12.4–24.7 g/kg DM) indigenous plants (1.8–19.3 g/kg DM), and agro-industrial by-products (8.1–26.9 g/kg DM). The indigenous plant Trifolium acaule gave the lowest in vitro CH4 yield (1.8 g/kg DM). A positive relationship was observed between in vitro dry matter digestibility (IVDMD), CH4, and total gas yield. Percentage of CH4 in total gas production varied with feed category (grasses 14.5–19.6%; indigenous plants 3.1–16.9%; crop residues 15.8–20.6%; agro-industrial by-products 12.8–18.7%), and within category, e.g., Trifolium acaule (3.1%), Acacia nilotica L. (7.1%), Ziziphus spina-christi (9.9%), brewer’s spent grains (BSG) (12.8%), local liquor (areki) residues (14.1%), and local beer (tella) residues (15.1%). A negative relationship was observed between CT content and in vitro CH4 yield, with a stronger (P<0.05) correlation for soluble CTs (R2 = 0.46) than cell-bound CTs (R2 = 0.25) and total CTs (R2 = 0.29). Based on methanogenic properties and effects of CTs on in vitro CH4 yield, indigenous plants should be prioritized in ruminant rations in Ethiopia. Making nutritional composition and CH4 data publicly available could help develop environmentally sound, cost-effective rations for ruminant livestock, benefiting local farmers and leading to more sustainable and efficient livestock production in Ethiopia.
期刊介绍:
Animal Feed Science and Technology is a unique journal publishing scientific papers of international interest focusing on animal feeds and their feeding.
Papers describing research on feed for ruminants and non-ruminants, including poultry, horses, companion animals and aquatic animals, are welcome.
The journal covers the following areas:
Nutritive value of feeds (e.g., assessment, improvement)
Methods of conserving and processing feeds that affect their nutritional value
Agronomic and climatic factors influencing the nutritive value of feeds
Utilization of feeds and the improvement of such
Metabolic, production, reproduction and health responses, as well as potential environmental impacts, of diet inputs and feed technologies (e.g., feeds, feed additives, feed components, mycotoxins)
Mathematical models relating directly to animal-feed interactions
Analytical and experimental methods for feed evaluation
Environmental impacts of feed technologies in animal production.