Abstract #T294
Section: Small Ruminant
Session: Small Ruminant II
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Exhibit Hall B
Session: Small Ruminant II
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Exhibit Hall B
# T294
Milk fatty acid profile of dairy ewes fed contrasting sources of energy supplementation.
F. E. Miccoli*1,2, C. D. Perez3,4, D. Colombatto4,2, J. Danelon2, R. A. Palladino4,2, 1School of Agriculture Science, National University of Lomas de Zamora, Buenos Aires, Argentina, 2Department of Animal Production, University of Buenos Aires, Buenos Aires, Argentina, 3Food Technology Institute-INTA, Buenos Aires, Argentina, 4Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
Key Words: milk fatty acids, energy supplementation, sheep
Milk fatty acid profile of dairy ewes fed contrasting sources of energy supplementation.
F. E. Miccoli*1,2, C. D. Perez3,4, D. Colombatto4,2, J. Danelon2, R. A. Palladino4,2, 1School of Agriculture Science, National University of Lomas de Zamora, Buenos Aires, Argentina, 2Department of Animal Production, University of Buenos Aires, Buenos Aires, Argentina, 3Food Technology Institute-INTA, Buenos Aires, Argentina, 4Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
Polyunsaturated fatty acids are biohydrogenated in the rumen producing diverse intermediates according to diet. Thus, milk fatty acid (FA) composition could be affected by diet manipulation with special attention on those FA with positive effects on human health. The aim of the study was to evaluate the effect of 2 contrasting sources of energy supplementation (soybean hulls and corn grain) on milk FA profile of dairy ewes fed fresh ryegrass. Ten mature dairy ewes (30 DIM; 65.8 ± 8.67 kg) were assigned to 2 treatments in a complete randomized design: SH (soybean hulls) and CG (corn grain). Daily ration was offered at 4% BW in a 50:50 forage to concentrate ratio and balanced with soybean meal to meet 16% CP. Milk samples of 50 mL were collected at each milking (0800 and 1600 h) during 7 consecutive days, after a diet adaptation period of 14 d. Samples were pooled per animal and a 50 mL subsample was taken for analysis. Fat extraction was assessed for further FA methylation and gas chromatography analysis. Data were analyzed in a complete randomized design using the MIXED procedure (sheep was included as a random effect) and means compared by Tukey test (P < 0.05; SAS Institute, 2008). No differences were observed for SCFA, MCFA, C16:0, C16:1, C18:0, C18:1c9, C18:1t10, C18:1t11, C18:2c9t11 and C18:2t10c12 (P > 0.05), although the supplement had a significant effect on linoleic and linolenic acid, being 3.38 vs. 1.86 g/100g FA and 0.71 vs. 0.42 g/100 g FA in SH and CG, respectively (P < 0.05). Despite having similar milk FA profiles, PUFA concentration was higher in SH than CG (6.77 vs. 4.49 g/100 g FA; P < 0.05). The C20:5 did not differ between treatments (P > 0.05) whereas C22:6 tended to be higher in SH than CG (0.043 vs. 0.031 g/100 g FA; P < 0.1). The SH showed higher n3 (0.89 vs. 0.58 g/100g FA) and n6 (3.43 vs. 1.94 g/100g FA) concentrations (P < 0.05). Regarding the delta-9-desaturase and atherogenicity indexes, no effect was obtained (P > 0.05). The results indicate that SH constitute a promising supplementation strategy for dairy ewes to obtain higher PUFA and omega-3 levels in milk.
Key Words: milk fatty acids, energy supplementation, sheep
