Model of enteric methane emissions supports climate change mitigation in Colombia’s cattle sector

Key messages ◼ The RUMINANT model qualifies as an advanced or “Tier 3” method for estimating emissions from enteric fermentation in ruminant livestock. ◼ The RUMINANT model was validated for enteric methane emissions from cattle in the tropical lowlands (Cauca Valley) of Colombia using six different diets given to feeder steers in 2017. ◼ There was a good correlation between field measurements of enteric fermentation using the polytunnel technique and estimates made using the RUMINANT model. ◼ Based on findings from the validation process, RUMINANT has been used to improve Colombia’s National Greenhouse Gas Inventory to the United Nations Framework Convention on Climate Change (UNFCCC) and the preparation of the sustainable bovine livestock Nationally Appropriate Mitigation Actions (NAMA) information note. ◼ The RUMINANT model could support the measurement, reporting and verification (MRV) phase of the NDCs of Colombia and other countries

Enteric methane mitigation strategies for ruminant livestock systems in the Latin America and Caribbean region: a meta-analysis.

Latin America and Caribbean (LAC) is a developing region characterized for its importance for global food security, producing 23 and 11% of the global beef and milk production, respectively. The region?s ruminant livestock sector however, is under scrutiny on environmental grounds due to its large contribution to enteric methane (CH4) emissions and influence on global climate change. Thus, the identification of effective CH4 mitigation strategies which do not compromise animal performance is urgently needed, especially in context of the Sustainable Development Goals (SDG) defined in the Paris Agreement of the United Nations. Therefore, the objectives of the current study were to: 1) collate a database of individual sheep, beef and dairy cattle records from enteric CH4 emission studies conducted in the LAC region, and 2) perform a meta-analysis to identify feasible enteric CH4 mitigation strategies, which do not compromise animal performance. After outlier?s removal, 2745 animal records (65% of the original data) from 103 studies were retained (from 2011 to 2021) in the LAC database. Potential mitigation strategies were classified into three main categories (i.e., animal breeding, dietary, and rumen manipulation) and up to three subcategories, totaling 34 evaluated strategies. A random effects model weighted by inverse variance was used (Comprehensive Meta-Analysis V3.3.070). Six strategies decreased at least one enteric CH4 metric and simultaneously increased milk yield (MY; dairy cattle) or average daily gain (ADG; beef cattle and sheep). The breed composition F1 Holstein × Gyr decreased CH4 emission per MY (CH4IMilk) while increasing MY by 99%. Adequate strategies of grazing management under continuous and rotational stocking decreased CH4 emission per ADG (CH4IGain) by 22 and 35%, while increasing ADG by 22 and 71%, respectively. Increased dietary protein concentration, and increased concentrate level through cottonseed meal inclusion, decreased CH4IMilk and CH4IGain by 10 and 20% and increased MY and ADG by 12 and 31%, respectively. Lastly, increased feeding level decreased CH4IGain by 37%, while increasing ADG by 171%. The identified effective mitigation strategies can be adopted by livestock producers according to their specific needs and aid LAC countries in achieving SDG as defined in the Paris Agreement

Consumo y digestibilidad en novillos cebuínos en un sistema silvopastoril intensivo

The determination of the dry matter intake (DMI) of animals is essential to determine the productive ability and nutritional status of domestic animals. Many techniques exist for esti- mating DMI and that of n-alkanes has shown special appeal, since it also allows the determi- nation of the selectivity of the fodder consumed. The present study aimed to estimate voluntary feed intake and fecal nutrient excretion in Zebu steers fed in an intensive silvopastoral system (ISS). The study was conducted at the Cotové Research Center of the National University of Colombia in Santa Fe, Antioquia. Six steers with an average weight of 381.16±12.1 kg were evaluated and the n-alkane technique was used to determine DMI. The average for- age DMI intake was 9.54 kg day -1 of which, 75.24 % corresponded to intake of grasses and 24.76 % to legume intake. Nutrient intake (kg) was 1.33, 5.8, 4.02, 1.13, 0.058 and 0.021 for CP, NDF, ADF, ashes, Ca and P, respectively. These intakes were adequate for the type of animals evaluated and provided a diet of good nutritional quality. The digestibility was 53 % for the diet without supplementation and 58 % for the diet with supplementation, which together with the DMI data, suggests that animals met their requirements of key nutri- ents. In turn, nutrient excretion (kg) was 4.15, 0.44, 2.56, 1.78, 0.8, 0.054 y 0.02 for DN, CP, NDF, ADF, ashes, Ca and P, respectively. Faecal N excretion was calculated at 29,9 kg per animal per year, and this contributes to the biomass production of the ISS grasses.La determinación del consumo voluntario de materia seca (CMS) por los animales, es indispensable para determinar su capacidad productiva y su estado nutricional. Existen muchas técnicas para la estimación del CMS, siendo una de ellas la técnica de n-alcanos la cual permite además estimar la selectividad de los forrajes consumidos. El presente trabajo tuvo como objetivo estimar el consumo voluntario y la excreción fecal de nutrientes por no- villos cebuínos alimentados en un sistema silvopastoril intensivo (SSPi). El estudio se realizó en el Centro Experimental Cotové, propiedad de la Universidad Nacional de Colombia. Se evaluaron seis novillos castrados con un peso promedio de 381±12 kg y se utilizó la técnica de alcanos para determinar CMS. El CMS promedio de forraje fue de 9,54 kg dia -1 , del cual, el 75,24 % correspondió a consumo de gramíneas y el 24,76 % a consumo de leguminosa. En promedio, el consumo de nutrientes (kg) fue de 1,33; 5,8; 4,02; 1,13; 0,058 y 0,021 para PC, FDN, FDA, Cenizas, Ca y P respectivamente. Estos consumos fueron adecuados para el tipo de animales del estudio aportando una dieta de buena calidad nutricional. La digestibilidad fue del 53 % para el tratamiento sin inclusión del suplemento y del 58 % para el tratamiento con suplemento, lo que junto con el CMS, permite afirmar que los animales satisficieron sus requerimientos de los principales nutrientes. Las cantidades excretadas (kg) fueron 4,15; 0,44; 2,56; 1,78; 0,8; 0,054 y 0,02 para MS, PC, FDN, FDA, Cenizas, Ca y P, respectivamente. La excreción fecal de N por animal al año se calculó en 29,9 kg, contribuyendo a la producción de biomasa de las gramíneas acompañantes en el SSPi

Enteric methane mitigation strategies for ruminant livestock systems in the Latin America and Caribbean region: a meta-analysis.

Abstract: Latin America and Caribbean (LAC) is a developing region characterized for its importance for global food security,producing 23 and 11% of the global beef and milk production, respectively. The region?s ruminant livestock sector however, is under scrutiny on environmental grounds due to its large contribution to enteric methane (CH4) emissions and influence on global climate change. Thus, the identification of effective CH4 mitigation strategies which do not compromise animal performance is urgently needed, especially in context of the Sustainable Development Goals (SDG) defined in the Paris Agreement of the United Nations. Therefore, the objectives of the current study were to: 1) collate a database of individual sheep, beef and dairy cattle records from enteric CH4 emission studies conducted in the LAC region, and 2) perform a meta-analysis to identify feasible enteric CH4 mitigation strategies, which do not compromise animal performance. After outlier?s removal, 2745 animal records (65% of the original data) from 103 studies were retained (from 2011 to 2021) in the LAC database. Potential mitigation strategies were classified into three main categories (i.e., animal breeding, dietary, and rumen manipulation) and up to three subcategories, totaling 34 evaluated strategies. A random effects model weighted by inverse variance was used (Comprehensive Meta-Analysis V3.3.070). Six strategies decreased at least one enteric CH4 metric and simultaneously increased milk yield (MY; dairy cattle) or average daily gain (ADG; beef cattle and sheep). The breed composition F1 Holstein ×Gyr decreased CH4 emission per MY (CH4IMilk) while increasing MY by 99%. Adequate strategies of grazing management under continuous and rotational stocking decreased CH4 emission per ADG (CH4IGain) by 22 and 35%, while increasing ADG by 22 and 71%, respectively. Increased dietary protein concentration, and increased concentrate level through cottonseed meal inclusion, decreased CH4IMilk and CH4IGain by 10 and 20% and increased MY and ADG by 12 and 31%, respectively. Lastly, increased feeding level decreased CH4IGain by 37%, while increasing ADG by 171%. The identified effective mitigation strategies can be adopted by livestock producers according to their specific needs and aid LAC countries in achieving SDG as defined in the Paris Agreement