Effect of BST administration on milk production and metabolism of dairy cows in 3 consecutive years of IVO trials (Institute for Animal Husbandry Research)
Oldenbroek, J.K.; Garssen, G.J.
Tijdschrift Voor Diergeneeskunde 115(13): 613-624
1990
ISSN/ISBN: 0040-7453 PMID: 2371710 Document Number: 355891
The effect of subcutaneous administration of recombinantly derived bovine somatotropin (somidobove) in a sustained delivery vehicle was studied in three successive lactations. After a preliminary period of three months, cows of different breeds and parities were treated during six periods of treatment of 28 days. The efficacy of BST application was equal in Jerseys (n = 35), Red and Whites (n = 54) and Friesians (n = 149); was slightly higher in cows (n = 211) than in heifers (n = 32); was higher on concentrates- (n = 105) than on roughage (n = 138) based diets and was slightly lower in a third successive lactation. After the start of treatment body tissues were mobilised for the increased milk production, however after some weeks of treatment, energy intake increased and compensated for the higher food requirements. Somatic cell counts in milk were higher in treated than they were in control cows. Calves of treated cows (n = 80) showed a five per cent lower birth weight than those of control cows (n = 80). No differences were found between treated and control cows in disease frequency and in reasons for culling. Administration of BST improved efficiency of milk production in three lactations, without adverse effects on health or culling rates of cows and without negative effects on the quality of the milk.