Banca de DEFESA: GABRIELA VASCONCELOS BEDESCHI

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : GABRIELA VASCONCELOS BEDESCHI
DATA : 27/04/2018
HORA: 08:30
LOCAL: EMBRAPA GADO DE LEITE - JUIZ DE FORA-MG
TÍTULO:

Agronomic Characteristics, Chemical Forage Composition And Silage Quality Of Elephant Grass BRS Coronel, At Different Age Of Regrowth.

PALAVRAS-CHAVES:

Growth Stage, Tropical Grass, Silage

PÁGINAS: 46
GRANDE ÁREA: Ciências Agrárias
ÁREA: Zootecnia
SUBÁREA: Produção Animal
RESUMO:

BEDESCHI, Gabriela Bedeschi. Agronomic Characteristics, Chemical Forage Composition And Silage Quality Of Elephant Grass BRS Coronel, At Different Age Of Regrowth. 2018. 47p Dissertação (Mestrado em Zootecnia). Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, 2018.
The objective of this study was to evaluate the effect of the age of cutting of new seed propagated elephant grass cultivar, BRS Coronel, on the production of biomass for ensiling, and on the fermentation profile and nutritive value of silage. The experiment was carried out at Embrapa Cattle of Milk under a randomized block design, with four treatments and five replications. The treatments consisted in the evaluation of grass managed at four cutting ages (75, 90, 105 and 120 days of regrowth). The height of the grass and its morphological composition were evaluated, as well as biomass, dry matter (DM) and forage matter. The chemical compositions of forage and silage were evaluated for DM, crude protein (CP), ethereal extract (EE), mineral matter (MM), neutral detergent fiber (NDF), acid detergent fiber (FDA), lignin (LIG), fraction C of PB (PBC), besides the fractionation of carbohydrates. The profile of long chain fatty acids was also evaluated in the forage, while in the silage the pH and the ammoniacal nitrogen content (N-NH3) were evaluated in addition to the fermentative losses. There was no effect of cutting age on forage biomass production based on natural matter. For grass height and yields of DM and dead matter in forage there was an increasing linear increase. Positive linear effect of cut age was observed on DM, NDF, ADF, LIG and PBC levels in forage, while CP and MM levels had a linear negative effect. There was no effect on forage EE content. The carbohydrate fractionation of the forage presented a significant effect for all fractions, being linear positive for total carbohydrates (CT), fraction B2 and fraction C, and linear negative for non-fibrous carbohydrates (CNF). No effect of grass cutting age was observed on the levels of lauric and myristic acids in forage DM, whereas there was a negative linear effect on the contents of palmitic, stearic, oleic, linoleic and α-linolenic acids. In the silage there was no significant difference for the contents of MM, NDF and FDA. PB content presented linear negative behavior, while there was a linear effect increasing on the contents of LIG and PBC. There was no effect of the cutting age of the grass on the CNF content in the silage. However, the CT and the C fraction presented a positive linear response, while the B2 fraction presented a quadratic response. The pH and N-NH3 presented a quadratic response. PG (gas loss) and RMS (dry matter recovery) had a linear negative response. It was concluded that, the increase in cutting age of the BRS Coronel grass results reduction of nutritive value, as well as the fatty acids contents. The best results for silage were obtained for the forage harvested at 90 days of regrowth age.
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MEMBROS DA BANCA:
Presidente - 033.667.877-08 - MIRTON JOSÉ FROTA MORENZ - UENF
Interno - 387749 - JOAO CARLOS DE CARVALHO ALMEIDA
Externo à Instituição - THIERRY RIBEIRO TOMICH - EMBRAPA
Externo à Instituição - MARCO ANTONIO SUNDFELD DA GAMA - EMBRAPA
Externo à Instituição - ALMIRA BIAZON FRANCA - UFJF