Asian-Australasian Journal of Animal Sciences

Asian Australasian Association of Animal Production Societies (아세아태평양축산학회)
권호 표지
DOI QR코드

DOI QR Code

Diurnal Variations in Milk and Blood Urea Nitrogen and Whole Blood Ammonia Nitrogen in Dairy Cows

  • Received : 2001.03.23
  • Accepted : 2001.06.08
  • Published : 2001.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

The levels of urea nitrogen both in blood (BUN) and milk (MUN), and milk protein (MP) reflect protein and energy intake in dairy herd feeding. Blood and milk constituents may be changes rhythmically and influence by different sampling time within a day and after feeding. Trials were conducted using five dietary treatments in both lactating and dry cows to study the effects of sampling time on concentrations of BUN, MUN and whole blood ammonia nitrogen (BAN) in practical dairy cow feeding in Taiwan. The conventional feed ingredients and forages including corn silage, alfalfa hay, timothy or pangola hay and corn grain were used as major source of the diet to follow practical dairy cow feeding. Five different diets were varying in amounts (low=L; standard=S; high=H) of crude protein (P) and energy (E) according to the NRC (1989). The energy to protein ratios in kcal/kg for the PSES, PLES, PHES, PSEH and PSEL were 10.82, 12.54, 9.41, 12.53 and 9.13 in lactating cows, and 11.38, 13.33, 9.78, 13.28 and 9.74 in dry cows, respectively. Results showed that after feeding at 9:30, BUN reached peak at 13:30 and was significantly higher than those to that sampled at 14:30 to 18:30 (p<0.05) in dry cows. Therefore the best blood sampling time for urea nitrogen assay in dry cows is 4 hours after morning feeding. In lactating cows, BUN of 13:30 was significantly higher than those of 8:30 to 11:30 (p<0.05), but there were no significant difference between the BUN values of other sampling time. Hence the suitable blood sampling time for BUN value in lactating cows was located on 3 to 8 hours after morning feeding, but the best time was 4 hours after morning feeding. MUN content is significantly higher in the afternoon collected bulk milk than the fore-strip morning milk (p<0.05), therefore the best sampling time for MUN is from afternoon collected bulk milk. Diurnal BAN changed without traceable rhythmic pattern and was negatively correlated to the BUN (r = -0.78). It is suggested that BAN may not be a good indicator for monitoring dairy cow feeding.

Keywords

Cited by

  1. Milk, plasma, and blood urea nitrogen concentrations, dietary protein, and fertility in dairy cattle vol.223, pp.5, 2003, https://doi.org/10.2460/javma.2003.223.628
  2. Tropical legume supplementation influences microbial protein synthesis and rumen ecology vol.101, pp.3, 2016, https://doi.org/10.1111/jpn.12458
  3. Evaluation of blood metabolites in dairy cows grazing under two pasture allowances and supplemented with corn silage under restricted grazing conditions vol.45, pp.11, 2016, https://doi.org/10.1590/s1806-92902016001100007
  4. Short communication: Urea induces T helper 2 (Th2) type environment at transcriptional level and prostaglandin E 2 secretion in bovine oviduct epithelial cells in culture vol.99, pp.7, 2016, https://doi.org/10.3168/jds.2016-10874
  5. Urea influences amino acid turnover in bovine cumulus-oocyte complexes, cumulus cells and denuded oocytes, and affects in vitro fertilization outcome vol.8, pp.1, 2018, https://doi.org/10.1038/s41598-018-30774-2
  6. Biochanin A (an Isoflavone Produced by Red Clover) Promotes Weight Gain of Steers Grazed in Mixed Grass Pastures and Fed Dried-Distillers’ Grains vol.57, pp.1, 2001, https://doi.org/10.2135/cropsci2016.07.0590
  7. Seasonal changes in serum oxidative stress biomarkers in dairy and beef cows in a daytime grazing system vol.80, pp.1, 2001, https://doi.org/10.1292/jvms.17-0321
  8. Plasma proteins δ15N vs plasma urea as candidate biomarkers of between-animal variations of feed efficiency in beef cattle: Phenotypic and genetic evaluation vol.15, pp.8, 2001, https://doi.org/10.1016/j.animal.2021.100318
  9. Effects of Milk Urea Nitrogen (MUN) and Climatological Factors on Reproduction Efficiency of Holstein Friesian and Jersey Cows in the Subtropics vol.11, pp.11, 2001, https://doi.org/10.3390/ani11113068
  10. Epidermal growth factor alleviates the negative impact of urea on frozen-thawed bovine sperm, but the subsequent developmental competence is compromised vol.11, pp.1, 2001, https://doi.org/10.1038/s41598-021-83929-z