Year: 1942
Type: article
Abstract: Evidence was presented in previous publications (31,33) that sufficient blood fat is taken up by the active mammary gland of the cow to account for most of the milk fat.More recent publications (24, 28) from this laboratory demonstrated for the first time the utilization of reiatively large quantities of the intermediate product of fat metabolism, ~-hydroxybutyric acid, by the mammary gland of the cow.In ketosis it was observed that this utilization was increased by over 100 per cent and would account for the total oxygen consumption of the gland if oxidized for energy purposes.The acetoacetic acid and acetone fraction was not used in measurable quantities by the gland of either the normal cow or the cow with ketosis.As it is generally assumed that most of the tissues of the body utilize both 13-hydroxybutyric acid and acetoacetic acid for energy purposes it was considered possible that ~3-hydroxybutyric acid was used in direct synthesis, and the suggestion was made that some of the short chain fatty acids peculiar to milk fat were derived from this source (27).In this paper data are presented on the effect of ketosis and glucose therapy in ketosis upon the character of the fatty acids synthesized by the mammary gland.Data are also presented on the source of energy for the mammary gland and on the cause of the low respiratory quotient during fasting.The volume of blood per unit of volume of milk was calculated by a method less open to criticism than methods used previously. METHODSThe following methods of analysis were used : blood glucose, the Somogyi (23) modification of the Shaffer-ttartmann method; blood lactic acid, the method of Miller and Muntz (19), as modified by Koenemann (16) and Barker and Summerson (2) ; blood acetone bodies, the method of Barnes and Wick (3); blood calcium, the Clark-Collip modification (5) of the Kralner-Tisdall method ; blood acid-soluble phosphorus, the method of Fiske
Source: Journal of Dairy Science
Authors: J.C. Shaw, Ross C. Powell, C.B. Knodt
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W2018368185