MILK PRODUCTION OF HOLSTEIN COWS TREATED WITH BOVINE SOMATOTROPIN (bST) UNDER SEVERE HEAT STRESS

Authors

  • Miguel Cervantes-Ramírez
  • Luis Rafael Véjar-Orcí

Keywords:

Holstein cows, bST, heat stress, milk production

Abstract

An experiment was conducted to evaluate the response of Holstein cows to bST administration, under severe heat stress conditions. Average, maximum and minimum temperatures under the shade, registered during the experiment (June, July and August, 1994) were 41.2 and 24.1 oC, respectively. Sixty nine pregnant cows (average 3.5 parities and 180 days in milk; DIM) were used. Treatments were: a) bST administration, 0 or 500 mg (i.m. injection) every 14 d, during eight weeks, and b) days in milk, 120 - 180 and 180 - 240 days. Effect of treatments and days on treatment (14, 28, 42 and 56) on milk production was measured 3 d after bST was administered. bST treated cows with 120-180 DIM, produced more milk (p

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Published

30-06-1997

Issue

Vol. 31 No. 2 (1997): 1997-abr-jun

Section

Notes

License

Agrociencia is published every 45 days, in an English format, and it is edited by the Colegio de Postgraduados. Mexico-Texcoco highway Km. 36.5, Montecillo, Texcoco, Estado de México, CP 56264, Telephone (52) 5959284427. www.colpos.mx. Editor-in-Chief: Dr. Fernando Carlos Gómez Merino. Rights Reserved for Exclusive Use: 04-2021-031913431800-203, e-ISSN: 2521-9766, granted by the National Institute for Author Right.