Fecha/hora: 11/06/2024 17:46:14

Biblioteca(s): 	INIA La Estanzuela.	
Fecha corriente: 	18/12/2020	
Fecha de la última actualización: 	02/09/2022	
Autoria: 	BANCHERO, G.; STEFANOVA, K.; LINDSAY, D.R.; QUINTANS, G.; BALDI, F.; MILTON, J.T.B.; MARTIN, G.B.	
Afiliación: 	GEORGGET ELIZABETH BANCHERO HUNZIKER, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; UWA School of Agriculture and Environment, The University of Western Australia, Crawley 6009, Australia.; UWA Institute of Agriculture, The University of Western Australia.; K. STEFANOVA, UWA School of Agriculture and Environment, The University of Western Australia, Crawley 6009, Australia.; D.R. LINDSAY, UWA School of Agriculture and Environment, The University of Western Australia, Crawley 6009, Australia.; GRACIELA QUINTANS ILARIA, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; FERNANDO BALDI, Departament of Animal Science, College of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal/SP, CEP 14870-720, Brazil.; UWA School of Agriculture and Environment, The University of Western Australia, Crawley 6009, Australia; UWA School of Agriculture and Environment, The University of Western Australia, Crawley 6009, Australia.	
Título: 	Ovulation and ovulation rate in ewes under grazing conditions: factors affecting the response to short-term supplementation.	
Año de publicación: 	2021	
Fuente/Imprenta: 	Animal, Volume 15, Issue 2, February 2021, Article number 100100.  OPEN ACCESS. Doi: https://doi.org/10.1016/j.animal.2020.100100	
ISSN: 	1751-7311	
DOI: 	10.1016/j.animal.2020.100100	
Idioma: 	Inglés	
Notas: 	Article history:Received 11 July 2020/Received in revised form 22 September 2020/Accepted 24 September 2020/
Available online 14 dic 2020.  Corresponding author : E-mail address: gbanchero@inia.org.uy (G.E. Banchero).	
Contenido: 	Abstract:
The relationships between ovulation rate and nutrition remain confused, probably because of uncontrolled variation in experimental conditions. To help resolve the problem, we analyzed data from 20 experiments conducted between 2002 and 2016, in Uruguay with grazing ewes. All experiments were carried out by a single laboratory under comparable conditions of experimental design and measured variables. The studies used a total of 3?720 ewes, of purebred Corriedale, Polwarth, or East Friesian x Polwarth genotypes. In all experiments, a control group grazed native pastures and extra nutrition was provided to the treatment groups using either improved pastures or supplements. Ovulation rate was measured by counting corpora lutea using laparoscopy or rectal ultrasound or by counting foetuses at ultrasound on day 45 of gestation. For statistical analysis, data were grouped according to nutritional treatment (control or supplemented) and, within these groups, type of supplement to provide energy or protein (protected or not from rumen degradation). Across all experiments, 92?99% of the ewes ovulated and the effects of diet, length of supplementation, and initial live weight and genotype are reported. Within diets, ovulation was most affected by overall energy intake during supplementation (P?<?0.01). Ewes that grazed native pastures supplemented with protein supplements had higher ovulation rates (P?<?0.05) than control ewes grazing only native pastures. The addition of tannins to the protein supplement, to protect it from degradation in the rumen, did not further increase the ovulation rate. In unsupplemented ewes that had access to legume pastures, ovulation rates did not increase when the legume pasture was rich in tannins although only ewes that grazed tanniniferous legumes had marginally higher ovulation rates than the control ewes (P?<?0.05). When ewes grazing native pastures were supplemented with energy, their ovulation rate did not increase above those of nonsupplemented ewes. Live weight at the start of supplementation also affected ovulation rate. We conclude that ovulation was most affected by overall energy intake, whereas the factors that affected ovulation rate during short-tern nutritional supplementation were intake of protein from highly digested supplements or dietary protein protected from ruminal degradation.	
Palabras-Clave: 	ENERGY; OVINE; PASTURES; PROTEIN; TANNINS.	
Thesagro: 	OVINOS.	
Categoría del tema: 	--	
URL: 	http://www.ainfo.inia.uy/digital/bitstream/item/16665/1/1-s2.0-S1751731120301026-main.pdf
https://www.sciencedirect.com/science/article/pii/S1751731120301026	
Registro original: 	INIA La Estanzuela (LE)	
Ejemplares: 	LE - (103262-1) - PXI - AP - DD - PP/Animals/2021 -  -  - DIS