Comparison of growth hormone-releasing factor and somatotropin: thyroid status of lactating, primiparous cows

Journal of Dairy Science
S KahlW M Moseley

Abstract

Effects of recombinant bovine growth hormone-releasing factor and recombinant bST on thyroxine 5'-deiodinase activities of liver and mammary gland were studied for lactating cows. Beginning on d 118 of lactation, 30 primiparous Holsteins received continuous infusions of 12 mg/d of releasing factor or 29 mg/d of bST or served as uninfused controls for 63 d. Blood samples were collected on d 1, 29, and 57, and samples of whole milk were collected at the early afternoon milking on d -5, 30, and 58. Liver and mammary tissue samples were obtained at slaughter on d 63. Infusion of releasing factor and bST decreased serum concentration of triiodothyronine by 10% and the ratio of triiodothyronine to thyroxine in serum by 20%. Concentrations of circulating triiodothyronine reflected a 30% decrease in hepatic 5'-deiodinase activity in response to infusion with releasing factor and bST. In contrast, treatment with releasing factor and bST did not affect 5'-deiodinase activity in the mammary gland and did not alter triiodothyronine concentration in milk. Data suggest that releasing factor and bST increase the hypothyroid status of the lactating cow and maintain an euthyroid condition in the mammary gland, thus enhancing the metabolic prior...Continue Reading

References

Jun 1, 1989·Endocrinology·C Aceves, C Valverde
Mar 1, 1989·Endocrinology·C Valverde, C Aceves
Oct 1, 1987·Hormone and Metabolic Research = Hormon- Und Stoffwechselforschung = Hormones Et Métabolisme·M GiraltT Mampel
Feb 1, 1987·Proceedings of the Society for Experimental Biology and Medicine·S KahlJ Bitman
Oct 1, 1985·Analytical Biochemistry·P K SmithD C Klenk
Jun 1, 1981·Journal of Dairy Science·H A Tucker
Aug 1, 1994·The Journal of Endocrinology·L J JackA V Capuco
Jun 1, 1993·The Journal of Clinical Investigation·J P ChanoineJ L Leonard

❮ Previous
Next ❯

Citations

Mar 26, 2003·Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine·J A NikolićGy Huszenicza

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.