Biomaterial Database

Developmental and nutritional regulation of the prepubertal heifer mammary gland: I. Parenchyma and fat pad mass and composition. 2006

M J Meyer, and A V Capuco, and D A Ross, and L M Lintault, and M E Van Amburgh

Department of Animal Science, Cornell University, Ithaca, NY 14850, USA. mev1@cornell.edu

Prior to puberty, elevated nutrient intake has been shown to negatively affect prepubertal mammary development in the heifer. The objective of this study was to evaluate the effects of increased nutrient intake on mammary development in Holstein heifers at multiple body weights from birth through puberty. Specifically, this study evaluated the effects of nutrient intake and body weight at harvest on 1) total weight and DNA content of the parenchyma (PAR) and mammary fat pad (MFP) and 2) PAR and MFP composition. Starting at 45 kg of body weight, heifers (n = 78) were assigned to either a restricted (R) or elevated (E) level of nutrient intake supporting 650 (R) or 950 (E) g/d of body weight gain. Heifers were harvested at 50-kg increments from 100 to 350 kg of body weight. Mammary fat pad weight and DNA content were greater in E- than in R-heifers. Additionally, E-heifers had a greater fraction of lipids and a smaller fraction of protein in their MFP than did R-heifers. Parenchyma weight and DNA were lower in E- than in R-heifers; however, when analyzed with age as a covariate term, treatment was no longer a significant term in the model. Level of nutrient intake had no effect on the lipid, protein, or hydroxyproline composition of the PAR. Collectively, these data demonstrate that PAR is refractory to the level of nutrient intake whereas MFP is not. Furthermore, the covariate analysis demonstrated that age at harvest, not the level of nutrient intake, was the single greatest determinant of total PAR DNA content.

UI	MeSH Term	Description	Entries
D008321	Mammary Glands, Animal	MAMMARY GLANDS in the non-human MAMMALS.	Mammae,Udder,Animal Mammary Glands,Animal Mammary Gland,Mammary Gland, Animal,Udders
D010060	Ovulation	The discharge of an OVUM from a rupturing follicle in the OVARY.	Ovulations
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D004032	Diet	Regular course of eating and drinking adopted by a person or animal.	Diets
D005260	Female		Females
D000273	Adipose Tissue	Specialized connective tissue composed of fat cells (ADIPOCYTES). It is the site of stored FATS, usually in the form of TRIGLYCERIDES. In mammals, there are two types of adipose tissue, the WHITE FAT and the BROWN FAT. Their relative distributions vary in different species with most adipose tissue being white.	Fatty Tissue,Body Fat,Fat Pad,Fat Pads,Pad, Fat,Pads, Fat,Tissue, Adipose,Tissue, Fatty
D000367	Age Factors	Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.	Age Reporting,Age Factor,Factor, Age,Factors, Age
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000821	Animal Feed	Foodstuff used especially for domestic and laboratory animals, or livestock.	Fodder,Animal Feeds,Feed, Animal,Feeds, Animal,Fodders