الفهرس 
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Abstract
The present study was carried out at the experimental farm of Animal and Poultry Production Department, Faculty of Agriculture, Al-Azher University, Assiut Branch, using nine lactating Egyptian buffaloes from parturition to the end of lactation period. This study aimed to evaluate rations supplemented with crushed oil seeds (10%) of either seeds containing high concentration of either oleic (sunflower seed), or linoleic (canola seed) acid through their effect on digestibility of feed nutrients, some blood metabolites, milk yield and composition as well as fatty acids profile of milk fat. Results obtained can be summarized in the flowing items.
1- Although the difference in feed intake as fed was small between control and treatment diets (not more than 0.2kg/day), the statistical analysis showed significant (P<0.05) differences among treatments.
2- Dry matter digestibility (DMD), organic matter digestibility (OMD), crude protein digestibility (CPD), crude fiber digestibility (CFD) and crude ether extract digestibility (EED) values were numerically increased in animals fed supplemented oil seed diets than those fed control diet. The corresponding significant (P<0.05) improve in digestibility due to treatments were 6.8 &6.8; 6.3 &6.7; 9.5 &5.1; 22.6 &20.9; 3.4 &5.0 percentage units for SS and CCS treatments as compared with the control. While NFE digestibility did not differ significantly among diets.
3- Buffaloes body weight change during the experimental period values were numerically higher in animals fed control(C) and crushed sunflower seeds (SS) diets than in those fed crushed canola seed (CCS) diet (2.1, 1.3, and 0.1kg, respectively).
4- Animals received supplemented crushed sunflower seed or crushed canola seed diets had significantly higher (p<0.05) plasma total protein concentrations than those fed the control diet. While, albumin concentration did not differ significantly (P>0.05) among treatments. Plasma globulin concentrations were numerically higher in the supplemented groups than in the control one. However, this difference was significant only between SS group and the control group.
5- Total lipids values were high for those fed diet contained crushed canola seed or crushed sunflower seed diet than the control diet. Plasma triglycerides concentration for groups fed oil seed diets had higher (P<0.05) values than that of control one.
6- Results generally indicate that fat supplemented diets significantly (P<0.05) increased plasma cholesterol level than that of control diet. Plasma HDL-cholesterol and LDL-cholesterol tended to be high in buffaloes fed SS and CCS than that of control.
7- Milk yield and fat-corrected milk (4% FCM) were significantly higher (P <0.05) for buffaloes fed canola diet and those fed sunflower diet than buffaloes fed control diet (55.6%& 60.0%, 35.3%& 36.7% respectively).
8- Data of milk composition showed high milk fat percentage (6.4 %) in milk produced from buffaloes fed the control diet and low value (5.9 %) in those fed crushed canola seed diet, however milk fat percentage produced from buffaloes fed on sunflower diet was intermediate (6.2 %). Milk lactose and ash percentages were similar among treatments. But milk total solids (TS) percentage was significantly lower (P<0.01) for buffaloes fed crushed canola seeds and crushed sunflower seed than the control diet. While, milk solids not fat (SNF) percentage were similar among diets.
9- Oil seeds diets contained over 85% of total fatty acids as C18 unsaturated fatty acids. Most of it in the form of C18:1. More than 50% and 38% of the total fatty acids are present in this form for SS and CCS respectively. Sunflower seed diet is a rich source of oleic acid (52.8g/ 100-1 fat) and canola seed diet is a rich source of linoleic acid (46.34 g/ 100-1fat).
The principal fatty acids expressed as percents of total lipid, in control diet are oleic (31.5%), linoleic (9.3%), while in crushed sunflower seeds are oleic (52.8%), linoleic (26.2%) and linolenic (6.7%) and in crushed canola seed are oleic (38.73%),linoleic (46.34%) and linolenic (4.4%).
10- Fatty acids composition of milk fat:
a) The ratio of omega 6 (C18: 2 n-6) to omega 3 (C18:3 n-3) fatty acids in milk fat was significantly increased when buffaloes were fed crushed sunflower or canola seed diets. This would improve the nutritive value of milk from a human health point of view.
Feeding crushed sunflower seed diet led to increases in the concentrations of oleic and linoleic acid in milk fat and a reduction in the concentrations of SFAs (especially from C8:0 to C16:0) than the control diet.
b) The percentages of short-chain fatty acids (C8:0 and C10:0) in milk fat were different (P<0.05) among the three diets with the highest in control and the lowest in crushed sunflower seed.
c) Long-chain fatty acid concentrations (18:1 to 18:2) were different (P<0.05) among the three diets, the control diet was the lowest and crushed sunflower seed was the highest.
d) Unsaturated fatty acid concentrations in milk fat were different (P<0.05) among all diets. Milk from buffaloes fed crushed sunflower seed diet had the most and those fed the control diet had the least.
e) The concentration of stearic acid (C18:0) was 18% in milk fat from buffaloes fed the control diet while were 19.9 and 19.3% in milk fat from buffaloes fed SS or CCS diets respectively. The opposite was noticed with linolenic acid (C18:3) which were 0.33% in milk fat of the control while it was 1.8% and 2.3% for diets SS or CCS, respectively.
f) Buffaloes fed whole crushed sunflower seed had the highest C18:2 concentration in milk fat.
It could be concluded that feeding the crushed sunflower and canola seed diets resulted in lower concentrations of the saturated fatty acids (SFAs) C8:0 – C16:0 and higher concentrations of the unsaturated fatty acids (UFAs) C16:1, C18:1, C18:2 and C18:3 compared to the control diet.