Background & Objectives: Mother ’ s milk is the best food for the newborns and has positive effects on both mother and infant health, decreasing infant mortality, satisfying emotional needs of mother and infant and economizing the domestic as well as social expenditures. Unfortunately, because of different economical, social and cultural reasons in many parts of the world breast feeding and its length of time has decreased. WHO emphasizes breast feeding in the first six months of life in developing countries. This study is an attempt to determine the causes of unsuccessful breast feeding in the first six months after birth in Ardabil.

  Methods : This descriptive analytical�study was conducted on 160 mothers who had 2- month- old or younger infants and did not have exclusive breast feeding until the end of 6 months. The researchers referred to 4 health centers, selected based on cluster sampling, in order to select the qualified mothers and complete the questionnaires in their presence.

 Results: Most of the mothers (37.5%) have begun feedings supplementary nutrition to their infants at the age of 2-4 months. The most common (90.5%) cause for the lack of the exclusive breast feeding was found to be insufficiency of mother milk.Most of the mothers (67%) stated the infant cry as the main reason for this insufficiency. There is a significant relationship between exclusive breast feeding on the one hand and the delivery, time of first feeding, occupation and mother ’ s education on the other (p<0.05).

  Conclusion : Social and economic conditions and misbeliefs have all affected the success of exclusive breast feeding. Most of these problems can be prevented through proper trainings.

  Background & Objective: Hyperlipidemia is one of the main causes of cardiovascular diseases which have a high mortality throughout the world. Consumption of products containing specific strains of microbes as probiotics, produces positive effects in the host by balancing the flora of the digestive system. L.casei is a probiotic and the aim of this study was to evaluate the effects of consumption of milk containing L.casei on serum lipid profile of rats fed high lipid diet.

  Methods : This was an experimental study in which 30 male albino wistar rats with a body weight of 200 ± 15 gr were randomly allocated to two groups of treatment and control each containing 15 rats and adapted to a high lipid diet (11.47%) and water containing milk (25%). Rats in both groups received high lipid diet and water containing 25% milk for 48 days with the difference that rats in the treatment group received water containing L.casei considering that water consumption is created throughout the experiment, the amount of L.casei added to milk was calculated to each rat consumed 10⁹ CFU bacteria per day.

  Results : Independent t-test revealed that at a level of α= 0/05 mean levels of total cholesterol and LDL-C of rats in the treatment group was significantly lower than that of control group (p<0/05), but the mean levels of triglyceride, HDL-C and VLDL-C was not significant. Also increase in body weight was significantly higher in the treatment group compared to the control group (p<0/01).

  Conclusion : Long term daily consumption of milk containing L.casei improve serum lipid profile by lowering total cholesterol level and also increase the rate of body growth.