GASTROINTESTINAL PARASITE CONTROL DURING PREPUBERTY IMPROVES MAMMARY PARENCHYMA DEVELOPMENT IN HOLSTEIN HEIFERS

ADRIÁN F. PERRI A,B, MIGUEL E. MEJÍAA, NICOLÁS LICOFF A, SANTIAGO S. DIABC, NÉSTOR FORMÍAD, ANA ORNSTEIN, DAMASIA BECÚ-VILLALOBOSA, ISABEL M. LACAU-MENGIDOA,∗

VETERINARY PARASITOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 198 p. 345 - 350

0304-4017

Parasitism during development impairs normal growth and delays the onset of pubertythrough altered hormone profiles, including insulin-like growth factor one (IGF-1). As mammarygland development during prepuberty is strongly dependent on IGF-1, we determinedif antiparasitic treatment during this stage of growth improved mammary gland development.One group of Holstein heifers was treated monthly, rotationally with antiparasiticdrugs from birth to 70 weeks of age, a second group was untreated. Treated heifer calves hadbetween 56% and 65% less EPG counts than untreated ones. Presence of Ostertagia, Cooperia,Haemonchus and Trichostrongylus was demonstrated. Treatment effectively advanced theonset of puberty and increased IGF-1 levels. At 20, 30, 40 and 70 weeks of age biopsiesfrom the mammary gland were taken and histological sections were prepared and stainedwith hematoxylin?eosin. Pictures were analyzed to compare parenchyma area in relation tototal mammary tissue between groups. Mammary samples from treated heifers had higherratios of parenchyma/total area than untreated ones. As mammary development duringprepuberty is crucial for mammary performance during lactation, these results add newevidence to the importance of gastrointestinal parasite control in heifers.