The Influence of Several factors on the Protein and Solids-Not-Fat Content in the Milk of Jersey Cows
Year: 1956
Type: article
Abstract: The effects of milking time, herd differences, season, and stage of lactation on the protein and solids-not-fat production of an individual cow were studied.Milk samples were taken biweekly for a 15-month period from two herds of purebred Jersey cattle.Equations are presented for predicting solids-not-fat content from protein or fat content.Editor.The increased emphasis now being placed on the solids-not-fat portions of milk makes it desirable to know more about factors that affect these constituents in the milk of individual cows.Several workers (1,8,11) have indicated that composition may be altered by breeding and/or feeding practices.Other workers (2, 3, 4, 5, 10, 13, 1~) have suggested that various environmental factors have an influence on the composition of milk.The relations between solids-not-fat, fat, and protein contents of milk have been reported (6,7,9,12).This investigation was instituted to study the effects of milking time, herd differences, season, and stage of lactation on the protein and solids-not-fat production of the individual cow and the relationships among fat, protein, and solids-not-fat values.EXPERIMENTAL PROCEDURE Two herds of purebred Jersey cattle, owned by the Michigan Agricultural Experiment Station, were sampled biweekly for a 15-month period.Protein values were determined for the last 12 months of this period.Samples from cows showing visible signs of mastitis were excluded.The following determinations were made on milk samples from individual cows: fat content by the Babcock method; protein by the Pyne modification of the formol titration method, as outlined by Richardson et al. (12); total solids by the 1V[ojonnier nlethod; and solids-not-fat as the difference between total solids and fat content. RESULTS AND DISCUSSIONVariations in morning and evening milk.Samples of morning and evening milk from a herd of ]2 animals (Herd A) were analyzed.The results presented
Source: Journal of Dairy Science
Institution: Michigan State University
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W1990704848