Fecha/hora: 30/05/2024 07:47:44

Biblioteca(s): 	INIA La Estanzuela.	
Fecha corriente: 	01/11/2021	
Fecha de la última actualización: 	03/11/2021	
Autoria: 	STIRLING, S.; DELABY, L.; MENDOZA, A.; FARIÑA, S.	
Afiliación: 	MARÍA SOFÍA STIRLING SANTOS, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay.; L. DELABY, INRAE, AgroCampus Ouest, Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Elevage, 35590 Saint Gilles, France.; ALEJANDRO FRANCISCO MENDOZA AGUIAR, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; SANTIAGO FARIÑA, INIA (Instituto Nacional de Investigación Agropecuaria).	
Título: 	Intensification strategies for temperate hot-summer grazing dairy systems in South America: Effects of feeding strategy and cow genotype.	
Año de publicación: 	2021	
Fuente/Imprenta: 	Journal of Dairy Science, September 2021. IN PRESS. doi: https://doi.org/10.3168/jds.2021-20507	
DOI: 	10.3168/jds.2021-20507	
Idioma: 	Inglés	
Notas: 	Article history: Received 23 March 2021/ Accepted 31 July 2021/ Available online 16 September 2021.	
Contenido: 	ABSTRACT: Pasture-based dairy systems present the opportunity to increase productivity per hectare through increasing stocking rate and forage utilization. However, in the temperate hot-summer region of South America, different productive strategies are being adopted by farmers. The aim of this study was to quantify the effect of feeding strategy (FS) and cow genotype (G) on individual animal and whole-farm biophysical performance. A design with 2 × 2 levels of intensification aiming to increase home-grown forage utilization and milk output per hectare was evaluated. The experiment was a randomized complete block design with a 2 × 2 factorial arrangement of treatments, combining 2 feeding strategies with varying proportions of grazing in the annual feeding budget [grass fixed (GFix) and grass maximum (GMax)] and 2 Holstein Friesian cow genotypes [New Zealand (NZHF) or North American Holstein Friesian (NAHF)]. The effects of FS, G, and their interaction were analyzed using mixed models. New Zealand Holstein Friesian cows presented lower individual milk yield and higher milk component concentrations, maintained higher average body condition score, and increased body weight (BW) throughout the experiment, while presenting a better reproductive performance compared with the NAHF cows. Although all farmlets were planned at the same stocking rate on a per kilogram of BW basis, the current stocking rate changed as a result of animal performance and grass utilization resulting in NZHF cows achieving greater BW per hectare. The superior stocking rate led to greater milk solids production and feed consumption per hectare for the systems with NZHF cows. The GFix feeding strategy resulted in greater total home-grown forage harvest and conserved forage surplus than GMax. Overall, it was feasible to increase stocking rate and increase milk production per hectare from home-grown forage with differing feeding strategies and Holstein Friesian cow genotypes within grazing systems located in the temperate hot-summer climate region of South America. The interactions reported between FS × G highlight the superior productivity per hectare of NZHF cows within the GMax feeding strategy based on maximizing grazed pasture, which could represent a competitive intensification strategy in terms of cost of production for this region.	
Palabras-Clave: 	Feeding system home; Genotype; Grown forage; Strain.	
Categoría del tema: 	--	
Registro original: 	INIA La Estanzuela (LE)	
Ejemplares: 	LE - (103464-1) - PXI - AP - DD - PP/Journal of Dairy Science/2021 -  -  - DIS