Responses of dairy cows supplemented with somatotropin during weeks 5 through 43 of lactation

• Published in: Journal of dairy science 1996-05, Vol.79 (5), p.800-812
• Main Authors: Chalupa, W. (University of Pennsylvania, Kennett Square.), Vecchiarelli, B, Galligan, D.T, Ferguson, J.D, Baird, L.S, Hemken, R.W, Harmon, R.J, Soderholm, C.G, Otterby, D.E, Annexstad, R.J
• Format: Article
• Language: English
• Subjects: Animal Nutritional Physiological Phenomena; Animals; Biological and medical sciences; Body Weight; Cattle - physiology; CICLO ESTRAL; CONDICION CORPORAL; CONTENIDO DE LIPIDOS; CONTENIDO PROTEICO; CONTEO DE CELULAS SOMATICAS; CYCLE OESTRAL; DIFERENCIAS BIOLOGICAS; DIFFERENCE BIOLOGIQUE; Eating; EFFICACITE ALIMENTAIRE; EFICIENCIA DE CONVERSION DEL PIENSO; ETAT CORPOREL; Female; Food industries; Fundamental and applied biological sciences. Psychology; GLANDE MAMMAIRE; GLANDULAS MAMARIAS; GRASA DE LA LECHE; Growth Hormone - administration & dosage; Health Status; INGESTION DE PIENSOS; LACTACION; LACTATION; Lactation - drug effects; LOCOMOCION; LOCOMOTION; MATIERE GRASSE DU LAIT; Milk - chemistry; Milk and cheese industries. Ice creams; Mother. Fetoplacental unit. Mammary gland. Milk; NUMERATION CELLULAIRE SOMATIQUE; NUMERO DE LACTACION; NUMERO DE LACTATION; PERFORMANCE DE REPRODUCTION; PESO; POIDS; Pregnancy. Parturition. Lactation; PRISE ALIMENTAIRE (ANIMAUX); PROTEINAS DE LA LECHE; PROTEINE DU LAIT; RACE (ANIMAL); RAZAS (ANIMALES); RENDEMENT LAITIER; RENDIMIENTO LECHERO; REPRODUCTIVIDAD; SANIDAD ANIMAL; SANTE ANIMALE; SOLIDE; SOLIDOS; SOMATOTROPINA; SOMATOTROPINE; TENEUR EN LIPIDES; TENEUR EN PROTEINES; Time Factors; VACAS LECHERAS; VACHE LAITIERE; Vertebrates: reproduction
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(96)76428-7

Beginning at wk 5 of lactation, 136 cows (34 per treatment) were supplemented daily for 38 wk with 0, 10.3, 20.6, or 41.2 mg of recombinantly derived bST monomer. Cows were obtained from University of Kentucky, University of Minnesota, University of Pennsylvania, and The Ohio State University. Nine cows (4 at 0 mg/d, 1 at 10.3 mg/d, 1 at 20.6 mg/d, and 3 at 41.2 mg/d) did not complete the experiment because of health problems. Data from these cows were included in the reproduction and health databases but not in the production database. Cows supplemented with bST produced more milk, consumed more feed, had lower rates of BW gain, and had improved efficiencies of milk production (conversion of feed and NE(L) to milk). Additional increases in productivity were modest at 20.6 and 41.2 mg/d versus productivity at 10.3 mg/d of bST. Concentrations of fat, protein, and TS in milk were unaffected. At 10.3 mg/d, bST did not adversely affect reproduction or health