PMID- 33934856
OWN - NLM
STAT- MEDLINE
DCOM- 20210713
LR  - 20210713
IS  - 1525-3198 (Electronic)
IS  - 0022-0302 (Linking)
VI  - 104
IP  - 8
DP  - 2021 Aug
TI  - Differences in net fat oxidation, heat production, and liver mitochondrial DNA 
      copy numbers between high and low feed-efficient dairy cows.
PG  - 9287-9303
LID - S0022-0302(21)00571-3 [pii]
LID - 10.3168/jds.2020-20031 [doi]
AB  - Improving feed utilization efficiency in dairy cattle could have positive 
      economic and environmental effects that would support the sustainability of the 
      dairy industry. Identifying key differences in metabolism between high and low 
      feed-efficient animals is vital to enhancing feed conversion efficiency. 
      Therefore, our objectives were (1) to determine whether cows grouped by either 
      high or low feed efficiency have measurable differences in net fat and 
      carbohydrate metabolism that account for differences in heat production (HP), and 
      if so, whether these differences also exists under conditions of feed withdrawal 
      when the effect of feeding on HP is minimized, and (2) to determine whether the 
      abundance of mitochondria in the liver can be related to the high or low 
      feed-efficient groups. Ten dairy cows from a herd of 15 (parity = 2) were 
      retrospectively grouped into either a high (H) or a low (L) feed-efficient group 
      (n = 5 per group) based on weekly energy-corrected milk (ECM) divided by dry 
      mater intake (DMI) from wk 4 through 30 of lactation. Livers were biopsied at wk 
      -4, 2, and 12, and blood was sampled weekly from wk -3 to 12 relative to 
      parturition. Blood was subset to be analyzed for the transition period (wk -3 to 
      3) and from wk 4 to 12. In wk 5.70 +/- 0.82 (mean +/- SD) postpartum (PP), cows spent 
      2 d in respiration chambers (RC), in which CO(2), O(2), and CH(4) gases were 
      measured every 6 min for 24 h. Fatty acid oxidation (FOX), carbohydrate oxidation 
      (COX), metabolic respiratory quotient (RQ), and HP were calculated from gas 
      measurements for 23 h. Cows were fed ad libitum (AD-LIB) on d 1 and had feed 
      withdrawn (RES, restricted diet) on d 2. Additional blood samples were taken at 
      the end of the AD-LIB and RES feeding periods in the RC. During wk 4 to 30 PP, H 
      had greater DMI/kg of metabolic body weight (BW(0.75)), ECM per kilogram of 
      BW(0.75) yield, and ECM/DMI ratio, compared with L, but a lower body condition 
      score between wk 4 and 12 PP. In the RC period, we detected no differences in BW, 
      DMI, or milk yield between groups. We also detected no significant group or group 
      by feeding period interactions for plasma metabolites except for Revised 
      Quantitative Insulin Sensitivity Check Index, which tended to have a group by 
      feeding period interaction. The H group had lower HP and HP per kilogram of 
      BW(0.75) compared with L. Additionally, H had lower FOX and FOX per kilogram of 
      BW(0.75) compared with L during the AD-LIB period. Methane, CH(4) per kilogram of 
      BW(0.75), and CH(4) per kilogram of milk yield were lower in H compared with L, 
      but, when adjusted for DMI, CH(4)/DMI did not differ between groups, nor did 
      HP/DMI. Relative mitochondrial DNA copy numbers in the liver were lower in the L 
      than in the H group. These results suggest that lower feed efficiency in dairy 
      cows may result from fewer mitochondria per liver cell as well as a greater 
      whole-body HP, which likely partially results from higher net fat oxidation.
CI  - The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American 
      Dairy Science Association(R). This is an open access article under the CC BY-NC-ND 
      license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
FAU - Kennedy, K M
AU  - Kennedy KM
AD  - Institute for Farm Animal Biology (FBN), Institute of Nutritional Physiology 
      "Oskar Kellner," Dummerstorf 18196, Germany.
FAU - Becker, F
AU  - Becker F
AD  - Institute for Farm Animal Biology (FBN), Institute of Reproductive Biology, 
      Dummerstorf 18196, Germany.
FAU - Hammon, H M
AU  - Hammon HM
AD  - Institute for Farm Animal Biology (FBN), Institute of Reproductive Biology, 
      Dummerstorf 18196, Germany.
FAU - Kuhla, B
AU  - Kuhla B
AD  - Institute for Farm Animal Biology (FBN), Institute of Nutritional Physiology 
      "Oskar Kellner," Dummerstorf 18196, Germany. Electronic address: 
      b.kuhla@fbn-dummerstorf.de.
LA  - eng
PT  - Journal Article
DEP - 20210430
PL  - United States
TA  - J Dairy Sci
JT  - Journal of dairy science
JID - 2985126R
RN  - 0 (DNA, Mitochondrial)
SB  - IM
MH  - *Animal Feed
MH  - Animals
MH  - Cattle
MH  - DNA Copy Number Variations
MH  - *DNA, Mitochondrial
MH  - Diet/veterinary
MH  - Energy Metabolism
MH  - Female
MH  - Lactation
MH  - Liver
MH  - Milk/metabolism
MH  - Mitochondria
MH  - Pregnancy
MH  - Retrospective Studies
MH  - Thermogenesis
OTO - NOTNLM
OT  - dairy cows
OT  - efficiency
OT  - heat production
EDAT- 2021/05/04 06:00
MHDA- 2021/07/14 06:00
CRDT- 2021/05/03 05:48
PHST- 2020/12/11 00:00 [received]
PHST- 2021/03/18 00:00 [accepted]
PHST- 2021/05/04 06:00 [pubmed]
PHST- 2021/07/14 06:00 [medline]
PHST- 2021/05/03 05:48 [entrez]
AID - S0022-0302(21)00571-3 [pii]
AID - 10.3168/jds.2020-20031 [doi]
PST - ppublish
SO  - J Dairy Sci. 2021 Aug;104(8):9287-9303. doi: 10.3168/jds.2020-20031. Epub 2021 
      Apr 30.