PMID- 36339499
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20221108
IS  - 2666-9102 (Electronic)
IS  - 2666-9102 (Linking)
VI  - 2
IP  - 3
DP  - 2021 May
TI  - Evaluation of relationship between ruminal pH and the proportion of de novo fatty 
      acids in milk.
PG  - 123-126
LID - 10.3168/jdsc.2020-0042 [doi]
AB  - The objective of this study was to evaluate the relationship between ruminal pH 
      and milk de novo fatty acid (DNFA) concentrations determined by Fourier-transform 
      infrared spectroscopy. Data were collected from 18 multiparous Holstein cows 
      fitted with a rumen cannula and fed 1 of the experimental diets differing in 
      starch content (22.1 vs. 28.3%) with or without supplementation of a 
      Saccharomyces cerevisiae fermentation product in a previous study. Milk was 
      sampled on d 7 and 21 after calving, and concentrations of milk fat, DNFA (C6 to 
      C14), mixed-origin fatty acids (FA; C16:0 and C16:1), and preformed FA (>/=C18) 
      were estimated using Fourier-transform infrared spectrometry. Ruminal pH was 
      recorded in the ventral sac every 30 s continuously for 72 h on d 7 to 9 and 21 
      to 23 after calving. Daily maximum, nadir, and mean ruminal pH as well as 
      duration and area below pH 5.8 were determined for each period. Milk DNFA (g/100 
      g of FA) was positively related to nadir (r = 0.428) and mean (r = 0.471) ruminal 
      pH and negatively related to duration (r = -0.511) and area (r = -0.520) below pH 
      5.8. Milk fat content did not have a relationship with ruminal pH variables in 
      this study. The regression lines for d 7 and 21 were similar, likely because 
      plasma free FA concentrations were not different between d 7 and 21 (513 vs. 534 
      microEq/L) for the current data set. The coefficients of determination between DNFA 
      and ruminal pH were greater for DNFA in total milk FA (g/100 g of FA) than in 
      milk (g/100 g of milk), suggesting that DNFA in milk fat (g/100 g of FA) is an 
      appropriate measurement variable that relates to ruminal pH even for cows in 
      early lactation.
CI  - (c) 2021.
FAU - Fukumori, R
AU  - Fukumori R
AD  - Department of Veterinary Medicine, School of Veterinary Medicine, Rakuno Gakuen 
      University, Ebetsu, Japan 069-8501.
FAU - Shi, W
AU  - Shi W
AD  - Department of Agricultural, Food and Nutritional Science, University of Alberta, 
      Edmonton, AB, Canada T6G 2P5.
FAU - Oikawa, S
AU  - Oikawa S
AD  - Department of Veterinary Medicine, School of Veterinary Medicine, Rakuno Gakuen 
      University, Ebetsu, Japan 069-8501.
FAU - Oba, M
AU  - Oba M
AD  - Department of Agricultural, Food and Nutritional Science, University of Alberta, 
      Edmonton, AB, Canada T6G 2P5.
LA  - eng
PT  - Journal Article
DEP - 20210405
PL  - United States
TA  - JDS Commun
JT  - JDS communications
JID - 9918300983806676
PMC - PMC9623763
EDAT- 2021/04/05 00:00
MHDA- 2021/04/05 00:01
PMCR- 2021/04/05
CRDT- 2022/11/07 04:46
PHST- 2020/10/21 00:00 [received]
PHST- 2021/02/13 00:00 [accepted]
PHST- 2022/11/07 04:46 [entrez]
PHST- 2021/04/05 00:00 [pubmed]
PHST- 2021/04/05 00:01 [medline]
PHST- 2021/04/05 00:00 [pmc-release]
AID - S2666-9102(21)00044-2 [pii]
AID - 10.3168/jdsc.2020-0042 [doi]
PST - epublish
SO  - JDS Commun. 2021 Apr 5;2(3):123-126. doi: 10.3168/jdsc.2020-0042. eCollection 
      2021 May.