Final answer:
Exogenous growth hormone (GH) was used in the dairy industry to increase milk production via its direct and indirect effects on tissue metabolism and protein synthesis. GH promotes the breakdown of lipids and glycogen, facilitating an increase in energy availability.
Step-by-step explanation:
Exogenous growth hormone was used extensively in the dairy industry to increase milk production. Growth Hormone (GH), which is naturally produced by the anterior portion of the pituitary gland, has both direct and indirect effects on various tissues. One direct action of GH is to stimulate triglyceride breakdown, which leads to an increase in blood fatty acid levels, a glucose-sparing effect.
The indirect actions of GH are mediated by insulin-like growth factors (IGFs), which promote the uptake of amino acids for protein synthesis in muscle and other tissues. These mechanisms enhance the overall production capability of the animal, including the mammary glands. Hence, the use of exogenous GH aimed to amplify these beneficial effects on milk production in dairy cattle.