Quitosana em dietas para vacas Jersey alimentadas com fontes de ácidos graxos insaturados

Abstract

This study aimed to evaluate the effects of the association of chitosan with unsaturated fatty acids sources on the intake and digestibility of nutrients, ruminal fermentation, microbial protein synthesis, nitrogen balance, blood metabolites, milk production and composition and energy balance in lactating Jersey cows. Five Jersey cows fistulated in the rumen [mean days in lactation = 150 ± 45 days; milk production 22,2 ± 4,5 kg; body weight = 350 ± 25 kg] were distributed in a 5 × 5 Latin square, with periods of 21 days. The cows were fed five diets: 1) CON (CON), consisting of a basal diet based on soybean meal and ground corn, with the inclusion of 3% palm kernel oil; 2)(OS) diet including 3% soybean oil based on total DM; 3) diet (GS) with the inclusion of 16% of raw and whole soybeans based on total DM; 4) diet (SOCHI) with inclusion of 3% soybean oil and 0.02% chitosan (CHI) based on total DM and; 5)(WRSCHI), diet including 16% raw and whole soybeans and 0.2% Q in total DM. Results were considered significant when P<0.05. Higher intakes of CP, pdNDF and CNF were observed in diets containing sources of fatty acids compared to the CON diet. Higher intakes of DM, OM, CP and EE were observed in the SOCHI and WRSCHI diets compared to the SO and WRS diets. Higher concentrations of total SCFA, acetate in Mmol, acetate in %, propionate and methane were observed in diets containing sources of fatty acids compared to the CON diet. Higher N intakes were observed in diets containing sources of fatty acids compared to the CON diet. There were higher N intakes in the OSQ diet compared to the GSQ diet. There were greater fecal N excretions in the OSQ diet compared to the GSQ diet. There were lower SPM and total purine efficiencies in diets containing fatty acid sources compared to the CON diet. There were higher concentrations of GGT in diets containing sources of fatty acids compared to the CON diet. There were lower concentrations of urea and GGT in the GS diet compared to the OS diet. There were lower concentrations of urea and GGT in the GSQ diet compared to the OSQ diet. The GSQ and OSQ diets increased net energy intake compared to the GS and OS diets. Lower concentrations of C16:0 and C18:1 cis-9 and higher concentrations of C4, C6, C8, C10, C12, C14, C18:1 trans-11, C18:1 cis-11, C18:2 n6-cis , C18:3 n3, CLA c-9, t-11, C20:4, <C16, >C16, were observed in diets containing sources of fatty acids compared to the CON diet. Higher net energy intakes were observed in the GSQ and OSQ diets. Higher DM and MO values in the rumen pool were observed in the GS diet compared to the OS diet. Higher NDF values in the pool were found in the GSQ diet in relation to the OSQ diet. Lower rumen renewal rate (TRR) %/h of OM were found in the GS and OS diets compared to the OSQ and GSQ diets. Higher TRR %/h DM values were observed in the OS diet compared to the GS diet. Lower digestion rates %/h of NDF and NDFpd, and lower rumen renewal rates %/h of OM, NDF and NDFpd were observed in the GSQ diet in relation to the OSQ diet. The association between chitosan and sources of long-chain fatty acids alters intake, nitrogen utilization and microbial protein synthesis, ruminal fermentation, milk fatty acid profile, blood metabolites and ruminal kinetics in lactating Jersey cows. Therefore, the results reinforce that chitosan has positive interactions with different forms and sources of fatty acids.