Body fat mobilization in early lactation influences methane production of dairy cows

Abstract

Long-chain fatty acids mobilized during early lactation of dairy cows are increasingly used as energy substrate at the expense of acetate. As the synthesis of acetate in the rumen is closely linked to methane (CH4) production, we hypothesized that decreased acetate utilization would result in lower ruminal acetate levels and thus CH4 production. Twenty heifers were sampled for blood, rumen fluid and milk, and CH4 production was measured in respiration chambers in week −4, +5, +13 and +42 relative to first parturition. Based on plasma non-esterified fatty acid (NEFA) concentration determined in week +5, animals were grouped to the ten highest (HM; NEFA > 580 μmol) and ten lowest (LM; NEFA < 580 μmol) mobilizing cows. Dry matter intake (DMI), milk yield and ruminal short-chain fatty acids did not differ between groups, but CH4/DMI was lower in HM cows in week +5. There was a negative regression between plasma NEFA and plasma acetate, between plasma NEFA and CH4/DMI and between plasma cholecystokinin and CH4/DMI in week +5. Our data show for the first time that fat mobilization of the host in early lactation is inversely related with ruminal CH4 production and that this effect is not attributed to different DMI.

Variations in methane yield and microbial community profiles in the rumen of dairy cows as they pass through stages of first lactation

“…Cows calved between October 2014 and April 2015. In wk 5, 13, and 42 (±0.2 wk; SE) of lactation animals were transferred from the freestall into open-circuit respiration chambers as described previously (Bielak et al, 2016). Before the actual gas exchange measure-ments, the animals were adapted several times to the rubber mat-floored chambers to ensure normal feeding and lying behavior.…”

“…It has been suggested that early life may represent a window during which the establishing rumen microbiome can be manipulated with long-term effects (Yáñez-Ruiz et al, 2015;Abecia et al, 2014). However, CH 4 emissions vary during different periods of an animal's lifetime; for example, CH 4 levels have been reported to increase by up to 35% from early to late lactation (Bielak et al, 2016;Garnsworthy et al, 2012), but this increase is primarily due to an increase in DMI, the main driver of the CH 4 production. Targeting specific periods of increased CH 4 production may facilitate the development of short-term interventions that can contribute to an overall strategy for the mitigation of CH 4 levels from agriculture.…”

Assessment of methane emission traits in ewes using a laser methane detector: genetic parameters and impact on lamb weaning performance

“…Kandel et al (2017) and Chagunda et al (2009a) confirmed such unfavorable associations between CH 4 emissions and milk yield in cattle. Interestingly, the CH 4 eructation traits represent larger CH 4 emissions than the respiration traits (Blaxter and Joyce, 1963), but only the respiration CH 4 traits CH 4 r and CH 4 rmax significantly influenced LBW and EBW. An explanation for the significant impact of "low-level CH 4 " (CH 4 r , CH 4 rmax ) on LBW and EBW might be due to the short recording interval of only 3 min.…”

“…Consequently, we suggest selection strategies on low CH 4 emissions, in order to avoid further energy losses. Bielak et al (2016) suggested plasma levels of nonesterified fatty acids (NEFAs) as indicators for body fat mobilization. In lactating dairy cows, Bielak et al (2016) identified a negative relationship between CH 4 production per DMI and NEFA plasma levels.…”

“…Bielak et al (2016) suggested plasma levels of nonesterified fatty acids (NEFAs) as indicators for body fat mobilization. In lactating dairy cows, Bielak et al (2016) identified a negative relationship between CH 4 production per DMI and NEFA plasma levels. Nevertheless, intensified body fat mobilization with decreasing CH 4 emissions in cows is in contradiction with the identified associations in the present study for sheep.…”