caa a22 4500 386320055 CHVBK 20200709103300.0 cr unu---uuuuu 161130e198810 xx s 000 0 eng 10.1017/S000335610000324X doi S000335610000324X pii (NATIONALLICENCE)cambridge-10.1017/S000335610000324X Somatomedin C in dairy cows related to energy and protein supply and to milk production [Elektronische Daten] Somatomedin C and other hormones, as well as blood metabolites, were measured during the dry period and during lactation in dairy cows, given different amounts of energy and protein, to study metabolic and endocrine adaptations. Somatomedin C, specifically measured by radioimmunoassay after separation from its binding protein, did not exhibit typical diurnal variations, in contrast to somatotropin and insulin, which increased particularly after concentrate intake. Somatomedin C markedly decreased at parturition and reached lowest values around the peak of lactation, while levels of somatotropin, nonesterified fatty acids and ketone bodies were high and those of glucose, insulin, thyroxine and triiodothyronine were low. Thereafter somatomedin C values slowly increased up to the 12th week of lactation and remained elevated. Low energy and protein balances were characterized by particularly low somatomedin C concentrations. An additional protein deficit at peak lactation, when cows were already provided with low amounts of energy, did not further decrease somatomedin C levels. However, when high amounts of energy were given in the form of starch or crystalline fat, somatomedin C increased. Overall, there was a positive correlation of somatomedin C primarily with energy, but also with protein balances and a negative correlation with milk yield. Conversely, somatotropin increased markedly after parturition and was positively correlated with milk production and negatively with protein and energy balances. Thus, somatomedin C levels were paradoxically low in the presence of high circulating somatotropin. Insulin most closely paralleled somatomedin C levels. Therefore the anabolic state of metabolism at the end of pregnancy was characterized by high somatomedin C and insulin and relatively low somatotropin, whereas the catabolic state of early lactation was characterized by high somatotropin, low somatomedin C, insulin and thyroid hormones. Copyright © British Society of Animal Science 1988 Ronge H. Department of Nutrition Pathology, Institute of Animal Breeding, University of Berne, School of Veterinary Medicine, 3012 Berne, Switzerland Blum J. Department of Nutrition Pathology, Institute of Animal Breeding, University of Berne, School of Veterinary Medicine, 3012 Berne, Switzerland Clement C. Department of Nutrition Pathology, Institute of Animal Breeding, University of Berne, School of Veterinary Medicine, 3012 Berne, Switzerland Jans F. Federal Research Station for Animal Production, Grangeneuve, 1725 Posieux, Switzerland Leuenberger H. Institute of Animal Science, Federal Institute of Technology, 8092 Zurich, Switzerland Binder H. Institute of Animal Breeding, University of Zurich, School of Veterinary Medicine, 8057 Zurich, Switzerland Animal Production Cambridge University Press 47/2(1988-10), 165-183 0003-3561 47:2<165 1988 47 ASC https://doi.org/10.1017/S000335610000324X text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-cambridge NATIONALLICENCE 856 40 https://doi.org/10.1017/S000335610000324X text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ronge H. Department of Nutrition Pathology, Institute of Animal Breeding, University of Berne, School of Veterinary Medicine, 3012 Berne, Switzerland NATIONALLICENCE 700 1- Blum J. Department of Nutrition Pathology, Institute of Animal Breeding, University of Berne, School of Veterinary Medicine, 3012 Berne, Switzerland NATIONALLICENCE 700 1- Clement C. Department of Nutrition Pathology, Institute of Animal Breeding, University of Berne, School of Veterinary Medicine, 3012 Berne, Switzerland NATIONALLICENCE 700 1- Jans F. Federal Research Station for Animal Production, Grangeneuve, 1725 Posieux, Switzerland NATIONALLICENCE 700 1- Leuenberger H. Institute of Animal Science, Federal Institute of Technology, 8092 Zurich, Switzerland NATIONALLICENCE 700 1- Binder H. Institute of Animal Breeding, University of Zurich, School of Veterinary Medicine, 8057 Zurich, Switzerland NATIONALLICENCE 773 0- Animal Production Cambridge University Press 47/2(1988-10), 165-183 0003-3561 47:2<165 1988 47 ASC SWISSBIB 386320055