Effect Of Including α-linolenic Acid Oilseeds In Concentrates On Sheep Serum Biochemical Indices, Rumen Microflora And Body Fatty Acid Composition

The high α-linolenic acid content oilseeds were well selected from numerous species of plant in Inner Mongolia in view of constraints of α-linolenic acid sources in animal diets.Twelve rumen-fistulated wethers were randomly divided into four groups each with one-year age, average 30-35 kg body weight. Experimental method of three 4×4 Latin square design was conducted by feeding oilseeds(uncooked, cooked, ground and control)with level of 75 g, 150 g and 225 g respectively and experimental time was 180 days totally.Effect of including α-Linolenic acid oilseeds in concentrates on sheep rumen microflora fatty acid composition and rumen fermentation function were studied in trial 1.The results showed as follows.(1) On sheep rumen microflora fatty acid composition:increasingα-linolenic acid content, USFA in rumen PB and R sections and odd carbon fatty acid significantly(P<0.01) increased, but ratio ofω-6/ω-3 decreased. The content of USFA in rumen PB and R sections were grinding > uncooked > control > cooked group,respectively, which indicated that USFA had the highest digestibility in grinding form, and USFA in cooked groups exhibited the lowest influence by rumen microbes.Increasingα-linolenic acid content enhanced USFA hydrogenation levels but decreased synthesis of fatty acid content.Content of USFA in PB and R section significantly(P<0.01)increased during the periods before feeding to after feeding 1.5h, and followed by a significant(P<0.01)decrease after this period. The degradation levels of USFA after feeding 1.5-6h was significantly higher than that after feeding 6-12 h.The sequence of USFA content was P > B >R section(P<0.01), and the sequence of odd carbon fatty acid content was B > P >R(P<0.01), respectively. Ratio ofω-6/ω-3 in R section significantly(P<0.01) higher than that in PB sections, and there was no significant difference between P and B sections. Based on the content of level of hydrogenation and free fatty acids, it was clearly that number of ciliate highly overmatched that of bacterium.From the view of ability of synthesizing fatty acid, bacteria was better than ciliate. Fatty acids synthesized by bacteria and ciliate were transformed to R section by some unknown approaches and was reciprocal to fatty acid in diets. Bacterium and ciliates had higherdegradation capacity on free C18:3n3 than on C18:2n6. There was no CLA in P rumen section. CLA content in B section was significantly(P<0.01) higher than that in R section.Diet fat content, composition of fatty acids and content of C18:2n6 had the positive effect on composition of CLA in rumen BR sections.(2) On sheep rumen fermentation function:After feeding, rumen p H exhibited an decreased trend then followed a significant(P<0.01)increased tide. The sequences of p H was grinding > uncooked > cooked > control(P<0.01),and in parallel, 225g>150g>75g(P<0.05).The number of ciliates gradually decreased after feeding(P<0.05), which was cooked>uncooked>control>grinding group, respectively. And with increasing feeding levels, ciliate number showed decreasing trend except in cooked group. Rumen oilseed degradation ratio in grinding group, nutrients degradation were significantly(P<0.01) higher than those in cooked and uncooked groups. The nutrients apparent digestibility was cooked>control>grinding>uncooked groups, respectively.In short, the sheep rumen fermentation environment and the digestibility of die nutrients were improved by feeding cooked oilseeds much better.Effect of including α-Linolenic acid oilseeds in concentrates on relationship of sheep serum lipoproteins and lipid metabolism related biochemical indices were studied in trial 2.The results showed as follows.(1) On relationship of sheep serum lipoproteins related biochemical indices: blood serum HDLc content, APO-A concentration and HDLc in cooked group significantly(P<0.01) higher than those in uncooked and grinding groups,and both of them higher than that in control group(P<0.01). With increasing feeding levels,all serum index related to lipoprotein metabolizing significantly(P<0.01) enhanced.During the periods after feeding 1.5 to 18 hours, VLDLc and APO-A(P<0.01), LDLc(P>0.05) and other biochemistry index(P<0.05) had experienced some extent of up and downs.(2) On relationship of sheep serum lipid metabolism related biochemical indices:Blood serum INS and HSL content in cooked group significantly(P<0.01) higher than those in uncooked and grinding group, both of which higher than that in uncooked group(P<0.01). The sequence of ACCase content was control>grinding>uncooked>cooked groups. FAS, ACCase and HMGR content in three experimental groups significantly(P<0.01) decreased after feeding 1.5 to 7 hours. During the time from 7h to 18 h after feeding, those of them gradually increased. Blood HSL and INS exhibited a contrary trend when comparing with FAS, ACCase and HMGR.In short,feeding oilseeds can strongly improved body HDLc nutritional value and weakened the negative effect resulted from LDLc. Furthermore, oilseeds also improved sheep serum lipid metabolism related biochemical indices, especially in cooked group.Effect of including α-Linolenic acid oilseeds in concentrates on sheep body fatty acidcomposition was studied in trial 3. The results showed as follows: fat values of ω-6/ω-3was control(12.81)> grinding(4.72)> uncooked(3.21)>cooked(1.63:1), significantly(P<0.01). The values of ω-6/ω-3 in body location followed subcutaneous fat(3.64)>suet(3.52)> intestinal fat(3.05)>tail fat(2.69)(P<0.05).Subcutaneous fat MCFA was on the top of the list(P<0.01). Intestinal fat and suet had high C18:0 content but low in C16:0(P<0.01). On the opposite, C16:0 content in subcutaneous fat was higher than that of C18:0(P<0.01). In tail fat, C18:1c9 was more abundant than C18:1t9 and C18:2t6. Intestinal fat and suet had higher C18:1t9 and C18:2t6content but was lack of C18:1c9. In short, the nutritional value of PUFA in tail fat was obviously higher than that in intestinal fat and suet, and the worst one was subcutaneous.The best flavor of fatty acids was in tail fat and the worst in subcutaneous.In conclusion, the best process of oilseed utilization was thermal treatment, and the including levels was 150 to 225 g/d.