Research in the last years has resulted in a better understanding of factors influencing methane (CH4) emissions, the main greenhouse gas produced by ruminants. A large proportion of the variation in enteric CH4 emissions from animals can be explained by diet composition and feed intake. Nevertheless, differences in CH4 release might be ascribed to each individual cow. Aim of the study was to screen the CH4 production in individual dairy cows using the Gas Endeavour® in vitro system (GE, Bioprocess Control, Svezia). For this purpose, 58 Italian Friesian dairy cows from the University of Bologna dairy research farm were enrolled. Animals had, on average, 3.5 years of age (±1.36), 176.5 DIM (±110.52), 40l/day milk yield (±11.79), 3.92% fat (±0.43), 3.45% protein (±0.23). Diet fed to all animals was mainly composed by alfalfa hay (35.1%DM), wheat hay (11.16%DM), and cereal mix (48%DM). Rumen fluid was sampled with an esophageal probe at 9.0 am after feeding. After collection, the rumen fluid was filtered with a sieve (1mm diameter pores) to eliminate gross material, and then measured for its pH using a pH meter (PH20er, VWR). The rumen fluid was thus used as inoculum for in vitro TMR fermentation, according to the Tilley and Terry (1963) modified technique. CH4 production was measured in vitro using the GE. CH4 production was evaluated at 3 different time points: 8 (T1), 12 (T2) and 24 (T3) hours of incubation. Data distributions were different per time point, as expected (170mL in T1, 204.4mL in T2, 228.8mL in T3, on average). In addition, we observed a significant correlation between CH4 production at T2 and T3 (r2=0.99, p <0.01). Rumen fluid pH was 6.13 (±0.38) on average, and positively correlated with CH4 production (r2=0.3, p=0.28). On the opposite, age (r2=−0.33, p=0.83) and milk yield (r2=−0.12, p=0.79) were negatively correlated. The result showed that cows with the same diet had different CH4 productions also in vitro. Differences between the groups remained constant for all fermentation time points evaluated. Interestingly, a high correlation of CH4 production was achieved between T2 and T3. In conclusion, these results indicated that 12h of fermentation are sufficient to have reliable data on CH4 production in vitro.
Assessment of individual dairy cows in vitro rumen methane emissions / Francesca Ghiaccio, Alessia Federiconi, Riccardo Colleluori, Giorgia Canestrari, Alberto Palmonari. - In: ITALIAN JOURNAL OF ANIMAL SCIENCE. - ISSN 1828-051X. - ELETTRONICO. - (2023), pp. O306.156-O306.156. (Intervento presentato al convegno 25th Congress of the Animal Science and Production Association tenutosi a Monopoli (BA) nel 13-16 Giugno 2023).
Assessment of individual dairy cows in vitro rumen methane emissions
Francesca Ghiaccio;Alessia Federiconi;Riccardo Colleluori;Giorgia Canestrari;Alberto Palmonari
2023
Abstract
Research in the last years has resulted in a better understanding of factors influencing methane (CH4) emissions, the main greenhouse gas produced by ruminants. A large proportion of the variation in enteric CH4 emissions from animals can be explained by diet composition and feed intake. Nevertheless, differences in CH4 release might be ascribed to each individual cow. Aim of the study was to screen the CH4 production in individual dairy cows using the Gas Endeavour® in vitro system (GE, Bioprocess Control, Svezia). For this purpose, 58 Italian Friesian dairy cows from the University of Bologna dairy research farm were enrolled. Animals had, on average, 3.5 years of age (±1.36), 176.5 DIM (±110.52), 40l/day milk yield (±11.79), 3.92% fat (±0.43), 3.45% protein (±0.23). Diet fed to all animals was mainly composed by alfalfa hay (35.1%DM), wheat hay (11.16%DM), and cereal mix (48%DM). Rumen fluid was sampled with an esophageal probe at 9.0 am after feeding. After collection, the rumen fluid was filtered with a sieve (1mm diameter pores) to eliminate gross material, and then measured for its pH using a pH meter (PH20er, VWR). The rumen fluid was thus used as inoculum for in vitro TMR fermentation, according to the Tilley and Terry (1963) modified technique. CH4 production was measured in vitro using the GE. CH4 production was evaluated at 3 different time points: 8 (T1), 12 (T2) and 24 (T3) hours of incubation. Data distributions were different per time point, as expected (170mL in T1, 204.4mL in T2, 228.8mL in T3, on average). In addition, we observed a significant correlation between CH4 production at T2 and T3 (r2=0.99, p <0.01). Rumen fluid pH was 6.13 (±0.38) on average, and positively correlated with CH4 production (r2=0.3, p=0.28). On the opposite, age (r2=−0.33, p=0.83) and milk yield (r2=−0.12, p=0.79) were negatively correlated. The result showed that cows with the same diet had different CH4 productions also in vitro. Differences between the groups remained constant for all fermentation time points evaluated. Interestingly, a high correlation of CH4 production was achieved between T2 and T3. In conclusion, these results indicated that 12h of fermentation are sufficient to have reliable data on CH4 production in vitro.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
