Evaluación ultrasonográfica de la tiroides en crías de vacas lecheras tratadas con yodo en el preparto
Evaluación ultrasonográfica de la tiroides en crías de vacas lecheras tratadas con yodo en el preparto
Authors
Noro, M.
Araneda, P.
Mieres, LM
Rudorf, H.
Chihuailaf Vivanco, Ricardo
Wittwer, F.
Araneda, P.
Mieres, LM
Rudorf, H.
Chihuailaf Vivanco, Ricardo
Wittwer, F.
Authors
Date
2014-09-02
Datos de publicación:
Archivos de Medicina Veterinaria, Vol.45, N°3, 299 - 303, 2013
Keywords
Vacas lecheras - Tiroides - Yodo - Terneros
Collections
Abstract
El objetivo del estudio fue determinar ultrasonográficamente el tamaño de la glándula tiroides y la ganancia de peso de terneros crías de vacas suplementadas con yodo (I) en el preparto. Se utilizaron 14 terneros Holstein-Friesian, crías de 7 vacas suplementadas con I a los 7 meses de gestación (I-S, 1,6 g/vaca, Lipiodol®) y de 7 vacas no suplementadas (I-C), pastoreando praderas con bajo contenido de I. A todos los terneros se les realizó un examen ultrasonográfico de la glándula tiroides a los 36 y 128 (± 7,5) días de edad y se determinó el peso y la ganancia diaria de peso (GPD) desde el nacimiento hasta los 26 y 110 (± 7,5) días de edad. El grosor del istmo de la tiroides a los 36 días de edad fue similar entre grupos (P > 0,05), disminuyendo a los 128 días de edad de forma más marcada en el grupo I-C (P < 0,05). El tamaño del lóbulo izquierdo fue mayor en los terneros I-C que en los I-S a los 36 días de edad (P < 0,05), aumentando en ambos a los 128 días (P < 0,05). El tamaño del lóbulo derecho fue similar para ambos grupos, y no se relacionó con el peso vivo (P > 0,05). Los pesos y las GPD de ambos grupos fueron similares. Se concluye que una suplementación con I durante el preparto a vacas mantenidas a pastoreo sobre praderas con bajo contenido de I condicionó en sus crías un menor tamaño del lóbulo izquierdo de la glándula tiroides, sin alterar su peso o la GPD.
The aim of this work was to determine the size of the thyroid gland and the weight gain of calves born from dairy cows supplemented with iodine (I) during prepartum. Fourteen Holstein-Friesian calves were used. They were born from 7 cows supplemented with a single dose of I (I-S, 1.6 g/cow, Lipiodol®) at seven month of pregnancy and 7 non supplemented cows (I-C). Cows grazed a low I content pasture (0.19ppm) until calving. The thyroid gland of the calves was examined by ultrasonography at days 36 and 128 (± 7.5) of age. Calves were weighted at 26 and 110 (± 7.5) days of age and the daily weight gain (DWG) was determined. The thickness of the isthmus of the thyroid at 36 days of age were similar between groups (P > 0.05). A reduction in thickness was observed in both groups at 128 days, more pronounced in I-C group (P < 0.05). The left lobule was larger at 36 days of age in the I-C group than in I-S group (P < 0.05). An increase in size of the left lobule was found in both groups after 128 days (P < 0.05). The size of the right lobule was similar for both groups (P > 0.05) in both periods. Calves of both groups had a similar weight and DWG at 36 and 128 days of age. It was concluded that a single supplementation with I for pregnant dairy cows grazing a low iodine content pasture induced a reduction in the growth of the left lobule of the thyroid in their offspring without affecting the growth of the calves.
The aim of this work was to determine the size of the thyroid gland and the weight gain of calves born from dairy cows supplemented with iodine (I) during prepartum. Fourteen Holstein-Friesian calves were used. They were born from 7 cows supplemented with a single dose of I (I-S, 1.6 g/cow, Lipiodol®) at seven month of pregnancy and 7 non supplemented cows (I-C). Cows grazed a low I content pasture (0.19ppm) until calving. The thyroid gland of the calves was examined by ultrasonography at days 36 and 128 (± 7.5) of age. Calves were weighted at 26 and 110 (± 7.5) days of age and the daily weight gain (DWG) was determined. The thickness of the isthmus of the thyroid at 36 days of age were similar between groups (P > 0.05). A reduction in thickness was observed in both groups at 128 days, more pronounced in I-C group (P < 0.05). The left lobule was larger at 36 days of age in the I-C group than in I-S group (P < 0.05). An increase in size of the left lobule was found in both groups after 128 days (P < 0.05). The size of the right lobule was similar for both groups (P > 0.05) in both periods. Calves of both groups had a similar weight and DWG at 36 and 128 days of age. It was concluded that a single supplementation with I for pregnant dairy cows grazing a low iodine content pasture induced a reduction in the growth of the left lobule of the thyroid in their offspring without affecting the growth of the calves.