Fecha/hora: 31/05/2024 21:14:41

Biblioteca(s): 	INIA Las Brujas.	
Fecha corriente: 	22/07/2018	
Fecha de la última actualización: 	12/02/2021	
Autoria: 	ROMAN, L.; SARAVIA, C.; ASTIGARRAGA, L.; BENTANCUR, O.; LA MANNA, A.	
Afiliación: 	LORENA CAROLINA ROMAN GAY, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; CELMIRA SARAVIA, Universidad de la República (UdelaR)/ Facultad de Agronomía; LAURA ASTIGARRAGA, Universidad de la República (UdelaR)/ Facultad de Agronomía; OSCAR BENTANCUR, Universidad de la República (UdelaR)/ Facultad de Agronomía; ALEJANDRO FRANCISCO LA MANNA ALONSO, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay.	
Título: 	Shade access in combination with sprinkling and ventilation effects performance of Holstein cows in early and late lactation.	
Año de publicación: 	2019	
Fuente/Imprenta: 	Animal Production Science, 2019, Volume 59, Issue 2, Pages 216-224. Doi: https://doi.org/10.1071/AN16571	
ISSN: 	1836-0939	
DOI: 	10.1071/AN16571	
Idioma: 	Inglés	
Notas: 	Article history: Submitted: 19 August 2016 / Accepted: 15 September 2017 / Published online: 15 December 2017.	
Contenido: 	Abstract-
The negative effect of heat stress on dairy cows, with a temperature humidity index (THI) over 72, has been extensively studied. However, there are few studies on THI values under 72 that compare the effect of heat stress in different lactation stages. The objective of this study was to determine the heat stress effect on two lactation stages with a THI below the threshold 72. Thirty-nine multiparous, non-pregnant Holstein cows with more than 30 kg/cow.day of solid-corrected milk were used in a randomised complete block design to evaluate six treatments. The experimental design had a 3 by 2 factorial arrangement with three heat stress mitigation strategies: No shade (CON), access to shade only, and access to shade combined with sprinkling and ventilation, and two stages of lactation: early (S1) and late (S2), 12 ± 10.3 and 201 ± 45.8 days in milk respectively, for a duration of 81 consecutive days. All treatments, except CON had access to artificial shade from 0900 hours to 0500 hours next day. From 0500 hours to 0900 hours all cows were managed together in a grazing session. Additionally, sprinkling and ventilation cows had two 30-min sessions of ventilation and spray (0900 hours, 1530 hours). The average THI was 70.1 ± 4.46 (minimum THI: 60.4? maximum THI: 81.7) and the average hours above 72 were 7.8 ± 5.98. Animals in S1 presented higher solids-corrected milk reduction (P < 0.0001? 5.4 and 1.9 kg/cow.day), and protein yield (<0.0001? 0.13 and 0.54 kg/cow.day) than animals in S2 when shade was not allowed (CON). It was concluded that under these conditions, animal productivity is more negatively affected in early lactation animals. The use of shade with or without spray and ventilation mitigates heat stress effects on both stages of lactation. 
© CSIRO.	
Palabras-Clave: 	DAIRY COW; HEAT STRESS; MILK PRODUCTION; TEMPERATURE.	
Thesagro: 	GANADO DE LECHE; PRODUCCION DE LECHE.	
Categoría del tema: 	--	
Registro original: 	INIA Las Brujas (LB)	
Ejemplares: 	LB - (101649-1) - PXI - AP - DD - PP/ANIMAL PRODUCTION SCIENCE/2019 -  -  - DIS