Accuracy of methane emissions predicted from milk mid-infrared spectra and measured by laser methane detectors in Brown Swiss dairy cows

Abstract

Characteristics of low methane emitting cows as categorized by midinfrared spectra and respiration chamber measurements. Denninger et al. Mid-infrared spectra (MIR) were used to identify low and high methane emitting dairy cows within the Swiss, Brown Swiss population. Thirty individuals were selected for methane measurements using respiration chambers and laser methane detectors. The MIR predictions were fairly persistent across different environments and differently developed equations. However, correlations with methane measurements were too weak to use MIR as a tool to select low emitting cows. Cows categorized as low emitters by respiration chamber data expressed distinct characteristics in digestion and efficiency.

Measuring Livestock CH4 Emissions with the Laser Methane Detector: A Review

“…When deciding on the appropriate number of replicates per animal, there is a trade-off between workload and invasiveness on the one hand and the quality of the data on the other. Studies with a small number of animals often use many replicates per animal, e.g., [17,26,30]. On the other hand, a study with a large number of animals (622 dairy cows) used one to three repeats per animal to calculate estimates of heritability (h 2 ) for CH 4 phenotypes [14].…”

“…LMD measurements were performed at different locations inside buildings: in RC, e.g., [18,36]; in free-stalls, e.g., [12,14]; in a tie-stall [17]; in the milking parlour (according to the author's experience); a weighing facility for sheep [15]; and in individual pens, e.g., [38,42]. A few studies have been conducted on pasture [31,32,43] or in other half or full outdoor locations [19].…”

“…So far, there is no consensus on the best phenotype. The mean of the peak values seems to be the most studied phenotype [12,13,17,26,38], but other measures that summarise all values [28,30,42,46], peak values [19,38,42], respiration or eructation values [18], respiration or eructation peak values and eructation events [14,15,19,35,38,46] have also been analysed (Table 3). So far, different phenotypes based on total, respiration, and eructation values have performed inconsistently and differently across studies in terms of CH 4 prediction accuracy [18] and usability for genetic [14,15] and nutritional analyses [38].…”

“…In recent years, it has also been used to detect CH 4 concentrations in exhaled air from animals. Since the first known application for this purpose in 2009 by Chagunda et al [12], researchers have further developed and evaluated the measurement, refined the analysis of data obtained with the LMD, and applied the LMD in studies on genetic analyses [13][14][15], on nutrition and feed efficiency [16][17][18], on the physiological status of animals [15], and to characterize different husbandry systems [19]. So far, measurements with the LMD have been carried out mostly on dairy cows, but also on sheep, beef cattle, and goats.…”

In Vitro and In Vivo Evaluation of the Effects of a Compound Based on Plants, Yeast and Trace Elements on the Ruminal Function of Dairy Cows

“…The predictions of emitted methane were performed using the equation developed on milk Fourier transform MIR spectra by Vanlierde et al, 2016 [20]. This equation was validated using data from respiratory chambers [20,21], was regularly updated and its limits, defined in several publications [22,23], were strictly observed in this paper. The results were reported per cow (methane (g)/cow/d) and kg of milk and/kg energy corrected milk (ECM) produced by each animal.…”