Predicting enteric methane production from cattle in the tropics

Animal

R.S. Ribeiro¹  R.M. Maurício¹  R. Guimarães Júnior²  F.S. Machado³  T.R. Tomich³  L.G.R. Pereira³  M.M. Campos³  A.L. Ferreira³  R.D. Santos⁴  A.L.C.C. Borges⁵  R. Reis e Silva⁵  J.P.P. Rodrigues⁶  S.C. Valadares Filho⁷  J.A.G. Azevêdo⁸  T.T. Berchielli⁹ 

[1] Bio-Engineering Department, Federal University of São João Del Rei, 36307-352 São João Del Rei, Minas Gerais, Brazil;Brazilian Agricultural Research Corporation (EMBRAPA Cerrados), 73310-970 Brasília, Distrito Federal, Brazil;Brazilian Agricultural Research Corporation (EMBRAPA Dairy Cattle), 36038-330 Juiz de Fora, Minas Gerais, Brazil;Brazilian Agricultural Research Corporation (EMBRAPA Semiárido), 56302-970 Petrolina, Pernambuco, Brazil;Federal University of Minas Gerais State (UFMG), 31270-901 Belo Horizonte, Minas Gerais, Brazil;Federal University of Southern and Southeastern Pará (UNIFESSPA), 68557-335 Xinguara, Pará, Brazil;Federal University of Viçosa (UFV), 36570-900 Viçosa, Minas Gerais, Brazil;State University of Santa Cruz, 45662-900 Ilhéus, Bahia, Brazil;São Paulo State University (UNESP), 14884-900 Jaboticabal, São Paulo, Brazil;

关键词: beef;    dairy;    digestibility;    emissions;    greenhouse gas;   

DOI  :  

来源: DOAJ

【 摘 要 】

Accurate estimates of methane (CH4) production by cattle in different contexts are essential to developing mitigation strategies in different regions. We aimed to: (i) compile a database of CH4 emissions from Brazilian cattle studies, (ii) evaluate prediction precision and accuracy of extant proposed equations for cattle and (iii) develop specialized equations for predicting CH4 emissions from cattle in tropical conditions. Data of nutrient intake, diet composition and CH4 emissions were compiled from in vivo studies using open-circuit respiratory chambers, SF6 technique or the GreenFeed® system. A final dataset containing intake, diet composition, digestibility and CH4 emissions (677 individual animal observations, 40 treatment means) obtained from 38 studies conducted in Brazil was used. The dataset was divided into three groups: all animals (GEN), lactating dairy cows (LAC) and growing cattle and non-lactating dairy cows (GCNL). A total of 54 prediction equations available in the literature were evaluated. A total of 96 multiple linear models were developed for predicting CH4 production (MJ/day). The predictor variables were DM intake (DMI), gross energy (GE) intake, BW, DMI as proportion of BW, NDF concentration, ether extract (EE) concentration, dietary proportion of concentrate and GE digestibility. Model selection criteria were significance (P < 0.05) and variance inflation factor lower than three for all predictors. Each model performance was evaluated by leave-one-out cross-validation. The Intergovernmental Panel on Climate Change (2006) Tier 2 method performed better for GEN and GCNL than LAC and overpredicted CH4 production for all datasets. Increasing complexity of the newly developed models resulted in greater performance. The GCNL had a greater number of equations with expanded possibilities to correct for diet characteristics such as EE and NDF concentrations and dietary proportion of concentrate. For the LAC dataset, equations based on intake and animal characteristics were developed. The equations developed in the present study can be useful for accurate and precise estimation of CH4 emissions from cattle in tropical conditions. These equations could improve accuracy of greenhouse gas inventories for tropical countries. The results provide a better understanding of the dietary and animal characteristics that influence the production of enteric CH4 in tropical production systems.

【 授权许可】

Unknown