Fecha/hora: 09/06/2024 18:05:53

Biblioteca(s): 	INIA La Estanzuela.	
Fecha corriente: 	30/08/2022	
Fecha de la última actualización: 	07/10/2022	
Autoria: 	MORALES-PIÑEYRUA, J.; DAMIÁN, J.P.; BANCHERO, G.; SANT`ANNA, A.C.	
Afiliación: 	JESSICA TATIANA MORALES PIÑEYRUA, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; JUAN P. DAMIÁN, Departamento de Biociencias Veterinaria, Facultad de Veterinaria, Universidad de la República. Alberto Lasplaces 1620, Montevideo, 11600, Uruguay.; GEORGGET ELIZABETH BANCHERO HUNZIKER, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; ALINE C SANT`ANNA, Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, 36036-900, Brazil. CNPq Researcher.	
Título: 	The effects of heat stress on milk production and the grazing behavior of dairy Holstein cows milked by an automatic milking system. (Short Communication).	
Año de publicación: 	2022	
Fuente/Imprenta: 	Journal of Animal Science, june 2022, skac225. Doi: https://doi.org/10.1093/jas/skac225	
ISSN: 	1525-3163	
DOI: 	10.1093/jas/skac225.	
Idioma: 	Inglés	
Notas: 	Article history: Published 23 June 2022; Received 15 February 2022; Published 23 June 2022.
Corresponding author: Morales-Piñeyrúa, J.T.; Programa Nacional de Producción de Leche, Estación Experimental INIA La Estanzuela, Instituto Nacional de Investigación Agropecuaria (INIA), Ruta 50 km 11, 70000, Colonia, Uruguay, email: jmorales@inia.org.uy --	
Contenido: 	Abstract:
The objective of the present study was to evaluate the productive performance and grazing behavior of 25 primiparous and 44 multiparous Holstein cows in a pasture-based automatic milking system (AMS) while experiencing heat stress (defined as a temperature-humidity index-THI ? 68). Productive traits were analyzed according to the THI from days 0, -1, -2, and -3 in relation to the milking day, and grazing behaviors (expressed as the % of daily observation time) were related to the average THI only on the day of observation. Milk yield was not associated with the THI on day 0, but a significant linear relationship was found with the THI on the three previous days, decreasing approximately 0.18 kg (primiparous) and 0.40 kg (multiparous) per THI unit increment. In contrast, for multiparous cows only, the milking frequency was positively associated with the THI on the day of evaluation but not on the previous days, increasing 0.01 milking/THI unit increments. Additionally, for each unit of THI increment, cows spent 0.14% more time standing, whereas they exhibited a decrease in grazing, lying, and ruminating behaviors time by 0.30%, 0.04%, and 0.70%, respectively, for both parities. In conclusion, milk loss was related to heat stress conditions from the previous days, but not milking frequency, which increased with the THI of the same milking day. Lower grazing, lying, and ruminating activities and greater standing behavior were observed due to heat stress. © The Author(s) 2022. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved.	
Palabras-Clave: 	Animal welfare; AUTOMATIC MILKING SYSTEM; DAIRY COW; HOLSTEIN; Milking visits; Pasture; Summer.	
Thesagro: 	VACAS LECHERAS.	
Categoría del tema: 	L02 Alimentación animal	
Registro original: 	INIA La Estanzuela (LE)	
Ejemplares: 	LE - (103622-1) - PXI - AP - DD - PP/Journal of Animal Science/ 2022 -  -  - DIS