1.Kriss, M (1930) Quantitative relations of the dry matter of the food consumed, the heat production, the gaseous outgo, and the insensible loss in body weight of cattle. J Agric Res 40, 283–295.
2.Blaxter, K & Wainman, F (1961) The utilization of food by sheep and cattle. J Agric Sci 57, 419–425.
3.Lassey, KR, Ulyatt, MJ, Martin, RJ, et al. (1997) Methane emissions measured directly from grazing livestock in New Zealand. Atmos Environ 31, 2905–2914.
4.Münger, A & Kreuzer, M (2008) Absence of persistent methane emission differences in three breeds of dairy cows. Anim Prod Sci 48, 77–82.
5.Hammond, KJ, Pacheco, D, Burke, JL, et al. (2014) The effects of fresh forages and feed intake level on digesta kinetics and enteric methane emissions from sheep. Anim Feed Sci Technol 193, 32–43.
6.Warner, D, Bannink, A, Hatew, B, et al. (2017) Effects of grass silage quality and level of feed intake on enteric methane production in lactating dairy cows1. J Anim Sci 95, 3687–3699.
7.Blaxter, K & Clapperton, J (1965) Prediction of the amount of methane produced by ruminants. Br J Nutr 19, 511–522.
8.Charmley, E, Williams, SRO, Moate, PJ, et al. (2016) A universal equation to predict methane production of forage-fed cattle in Australia. Anim Prod Sci 56, 169–180.
9.Tubiello, F, Salvatore, M, Cóndor Golec, R, et al. (2014) Agriculture, forestry and other land use emissions by sources and removals by sinks. Rome: Statistics Division, Food and Agriculture Organization.
10.Goopy, JP, Onyango, AA, Dickhoefer, U, et al. (2018) A new approach for improving emission factors for enteric methane emissions of cattle in smallholder systems of East Africa – results for Nyando, Western Kenya. Agric Syst 161, 72–80.
11.Ndung’u, PW, Bebe, BO, Ondiek, JO, et al. (2019) Improved region-specific emission factors for enteric methane emissions from cattle in smallholder mixed crop: livestock systems of Nandi County, Kenya. Anim Prod Sci 59, 1136–1146.
12.Pinares-Patiño, CS, Ulyatt, MJ, Lassey, KR, et al. (2003) Rumen function and digestion parameters associated with differences between sheep in methane emissions when fed chaffed lucerne hay. J Agric Sci 140, 205–214.
13.Goopy, JP, Donaldson, A, Hegarty, R, et al. (2014) Low-methane yield sheep have smaller rumens and shorter rumen retention time. Br J Nutr 111, 578–585.
14.Shaver, RD, Nytes, AJ, Satter, LD, et al. (1986) Influence of amount of feed intake and forage physical form on digestion and passage of prebloom alfalfa hay in dairy cows. J Dairy Sci 69, 1545–1559.
15.Grimaud, P, Richard, D, Kanwé, A, et al. (1998) Effect of undernutrition and refeeding on digestion in Bos taurus and Bos indicus in a tropical environment. Anim Sci 67, 49–58.
16.Grimaud, P, Richard, D, Vergeron, MP, et al. (1999) Effect of drastic undernutrition on digestion in Zebu cattle receiving a diet based on rice straw. J Dairy Sci 82, 974–981.
17.Atti, N, Kayouli, C, Mahouachi, M, et al. (2002) Effect of a drastic and extended underfeeding on digestion in Barbary ewe. Anim Feed Sci Technol 100, 1–14.
18.Doreau, M, Michalet-Doreau, B, Grimaud, P, et al. (2003) Consequences of underfeeding on digestion and absorption in sheep. Small Ruminant Res 49, 289–301.
19.Rowe, JB, Loughnan, ML, Nolan, JV, et al. (1979) Secondary fermentation in the rumen of a sheep given a diet based on molasses. Br J Nutr 41, 393–397.
20.Goopy, JP, Nolan, JV & Pelaelo-Grand, T (2009) Does intra-ruminal recycling of fermentation products increase CH4 production? Recent Adv Anim Nutr 17, 174–174.
21.National Research Council (2001) Nutrient Requirements Of Dairy Cattle, 7th rev. ed. Washington, DC: National Academies Press.
22.Van Soest, P, Robertson, J & Lewis, B (1991) Carbohydrate methodology and nutritional implications in dairy cattle. Methods for dietary fiber, neutral detergent fiber and non-starch polysaccharides in relation to animal nutrition. J Dairy Sci 74, 3583–3597.
23.Helrich, K (1990) Official Methods of Analysis of the AOAC. Arlington, VA: Association of Official Analytical Chemists.
24.National Research Council (editors) (2001) Nutrient Requirements of Beef Cattle. Washington, DC: National Academies Press.
25.Udén, P, Colucci, PE & Van Soest, PJ (1980) Investigation of chromium, cerium and cobalt as markers in digesta. Rate of passage studies. J Sci Food Agric 31, 625–632.
26.Teeter, RG, Owens, FN & Mader, TL (1984) Ytterbium chloride as a marker for particulate matter in the rumen. J Anim Sci 58, 465–473.
27.Richter, H & Schlecht, E (2006) Accounting for marker disassociation when modelling time-dependent ruminal escape of particles based on the faecal excretion of ytterbium. Anim Feed Sci Technol 128, 135–154.
28.Anderson, DL & Henderson, LJ (1986) Sealed chamber digestion for plant nutrient analyses. Agron J 78, 937–939.
29.Bates, D, Mächler, M, Bolker, B, et al. (2015) Fitting linear mixed-effects models using lme4. J Stat Softw 67, 48.
30.Burnham, KP, Anderson, DR, Huyvaert, KPJBE, et al. (2011) AIC model selection and multimodel inference in behavioral ecology: some background, observations, and comparisons. Behav Ecol Sociobiol 65, 23–35.
31.Doreau, M, Michalet-Doreau, B & Béchet, G (2004) Effect of underfeeding on digestion in cows. Interaction with rumen degradable N supply. Livestock Prod Sci 88, 33–41.
32.Charan, J & Kantharia, ND (2013) How to calculate sample size in animal studies? J Pharmacol Pharmacother 4, 303–306.
33.Oliveira, AS (2015) Meta-analysis of feeding trials to estimate energy requirements of dairy cows under tropical condition. Anim Feed Sci Technol 210, 94–103.
34.Van Amburgh, M, Grant, R, Cotanch, K, et al. (2015) NDF – making something old, new again. Herd Health and Nutrition Conference, Syracuse, NY, Cornell University, Ithaca, NY. https://pdfs.semanticscholar.org/277b/0706160dde08e714e8d8e282b82954c17e55.pdf (accessed March 2020).
35.Kennedy, PM & Charmley, E (2012) Methane yields from Brahman cattle fed tropical grasses and legumes. Anim Prod Sci 52, 225–239.
36.Kaewpila, C & Sommart, K (2016) Development of methane conversion factor models for Zebu beef cattle fed low-quality crop residues and by-products in tropical regions. Ecol Evol 6, 7422–7432.