Development Of Suckling Research Articles

Correlation between age and levels of heavy metals in mares mammary gland secretions

The content of heavy metals in the secretions of the mare's mammary gland should be tested not only because of the possibility of human consumption of mare's milk but also because of the influence of these elements on the development of suckling in the neonatal period and later in adolescence. The aim of the research was to assess the dependence of heavy metals concentration in the secretions of the mammary gland on the mare. Studies were carried out on 16 English Thoroughbred mares. Mares aged 4 to 19 years were divided into 2 research groups: Group Y - young mares 10 years of age (n = 8) Group O - mares older then10 years of age (n = 8) The experimental material, colostrum were collected before 12 hours after delivery and milk were collected on the 3rd day after foaling. The concentration of metals (Zn, Cu, Ni, Mn, Fe, Pb, Cd) was determined by the atomic absorption spectrometry (AAS apparatus Unicam 929 spectrometer). All elements (Ni, Zn, Cu, Mn, Fe, Cd) analysed in colostrum showed higher concentration in young mares. For Ni and Zn differences were significantly higher in young mares while for Mn and Cd those differences were highly significant. In analysed samples of milk Ni, Zn, Mn, Fe and Cd content were higher in young mares, while Cu content were higher in older mares. We reported highly statistical differences for Ni, Mn, and Fe.

Purification and Properties of Parathyroid Hormone- Related Peptide Isolated from Milk*

The occurrence and properties of PTH-related peptide (PTH-RP) in milk was investigated. PTH-RP was purified to homogeneity from human and bovine milk using heat and acid to precipitate milk proteins followed by ion exchange chromatography and reverse-phase HPLC. The peak of PTH-RP from HPLC was detected using a sensitive bone cell bioassay. A single band of peptide was detected on silver-stained polyacrylamide gels, which migrated as a 20-21-kDa macromolecule. PTH-RP isolated from either human or bovine milk had similar electrophoretic mobilities on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The partially purified bovine PTH-RP stimulated cAMP production in UMR106-01 and OK cell lines and elicited a concentration-dependent inhibition of sodium-dependent phosphate transport in OK cells. Incubation of milk extracts with an anti-PTH antiserum did not affect their bioactivity, whereas an antihuman PTH-RP 1-34 antiserum markedly reduced the cAMP response of UMR106-01 cells to the immunoabsorbed milk extracts. A PTH antagonist, norleu PTH 3-34, blocked the stimulation of cAMP production in UMR106-01 cells treated with milk extracts. PTH-RP immunoreactivity and bioactivity occurred in milk extracts of diverse animals from both eutherian and metatherian (marsupial) species. Porcine colostrum also had immunoreactive PTH-RP, although the levels were lower than the immunoreactive PTH-RP concentrations observed in milk samples collected at 7 and 14 days of lactation. Thus, a 20-21-KDa PTH-RP is secreted into milk where it could play a role in the development of suckling, newborn animals.

Malnutrition in utero and during lactation in the rat: Relationhship of dams weight gain and development of suckling

The objective of this study was to determine the physiological weight changes seen in rat dams and their offspring as sequelae of malnutrition during pregnancy and lactation. The dams were killed during lactation period (15th and 30th days postpartum) and the absolute and relative weights of the brain, liver, kidneys, adrenal, glands, hypophysis, and ovaries were recorded. The number and weight of the pups were noted at birth. at 15 days and 30 days, and the absolute and relative weights of the brain, liver, kidneys, hypophysis, adrenals, ovaries, testes and seminal vesicles were measured. Our results indicate a highly significant decrease in body and organ weights in experimental dams, which may be an important determinant of growth retardation in pups whose body and organ weights were significantly smaller than the controls.