Sammanfattning

Measurements of energy balance (EB) require the use of respiration chambers, which are quite expensive and laborious. The GreenFeed (GF) system (C-Lock Inc.) has been developed to offer a less expensive, user friendly alternative. In this study, we used the GF system to estimate the EB of cows in early lactation and compared it with EB predicted from energy requirements for dairy cows in the Finnish feeding standards. We also evaluated the association between milk fatty acids and the GF estimated EB. The cows were fed the same grass silage but supplemented with either cereal grain or fibrous by-product concentrate. Cows were followed from 1 to 18 wk of lactation, and measurements of energy metabolism variables were taken. Data were subjected to ANOVA using the mixed model procedure of SAS (SAS Institute Inc.). The repeatability estimates of the gaseous exchanges from the GF were moderate to high, presenting an opportunity to use it for indirect calorimetry in EB estimates. Energy metabolism variables were not different between cows fed different concentrates. However, cows fed the grain concentrate produced more methane (24.0 MJ/d or 62.9 kJ/MJ of gross energy) from increased digestibility than cows fed the by-product concentrate (21.3 MJ/d or 56.5 kJ/MJ of gross energy). Nitrogen metabolism was also not different between the diets. Milk long-chain fatty acids displayed an inverse time course with EB and de novo fatty acids. There was good concordance (0.85) between EB predicted using energy requirements derived from the Finnish feed table and EB estimated by the GF system. In conclusion, the GF can accurately estimate EB in early-lactating dairy cows. However, more data are needed to further validate the system for a wide range of dietary conditions.

Nyckelord

dairy cow; energy balance; GreenFeed; milk fatty acids; nitrogen metabolism

Publicerad i

Journal of Dairy Science
2021, Volym: 104, nummer: 6, sidor: 6701-6714

SLU författare

• Guinguina, Abdulai

  • Institutionen för norrländsk jordbruksvetenskap, Sveriges lantbruksuniversitet
    

• Huhtanen, Pekka

  • Institutionen för norrländsk jordbruksvetenskap, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Husdjursvetenskap


Publikationens identifierare

DOI: https://doi.org/10.3168/jds.2020-19591

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/111466