Effects of Different Levels of Selenium on Performance, Blood Parameters and Nutrient Digestibility in Mehraban Male Lambs

Two experiments were conducted to evaluate the different levels of selenium supplements on performance, blood metabolites and nutrient digestibility in Mehraban male lambs. The first experiment consisted of 18 lambs, 4-5 months of age and 35.9±2.7 kg average in weight randomly allotted to 3 treatments. Treatments were: 1) Control diet (a diet without selenium, containing 0.06 ppm of selenium), 2) Control diet + 0.2 ppm Se as sodium selenite and 3) control diet + 0.4 ppm Se as sodium selenite. This trial lasted for 70 days. Blood samples were taken on days 0, 35 and 70. In the second experiment, 4 lambs were randomly selected from each treatment group and moved to digestibility boxes to evaluate the effects of different selenium levels on apparent nutrient digestibility. The experiment continued for 18 days with the first 12 days as the adaptation period plus 6 days of sampling. The trial were carried out as a completely randomized design. Supplementations of selenium to diet did not have significant effect on lambs performance. There were no significant differences in concentrations of plasma minerals, serum lipid profile and apparent nutrient digestibility. The serum level of tetra-iodothironine (T4) were decreased significantly. Furthermore, supplementation of selenium increased serum tri-iodothironine (T3) level and whole blood GPX activity. Overall, the results of this study showed that requirement of growing Mehraban lambs, met with 0.2 ppm selenium

Effects of Various Levels of Oxidized Oil on Performance, Egg Quality and Some Blood Metabolites in Laying Hens

The influence of dietary oxidized oil was studied on laying hen performance, egg quality and blood metabolites.  Experiment was conducted on 160 laying hens (Hy-Line W-36, 54-61 wk of age) in a completely randomized design with five treatments and four replicated cages containing eight birds per cage. Dietary treatments replaced fresh soybean oil in the control diet (3% fresh soybean oil, 15.25% crude protein, and 2858 Kcal/kg metabolizable energy) with 0, 25, 50, 75 and 100% oxidized oil. Egg production and egg weight were recorded daily and feed intake, feed conversion ratio, and egg mass were calculated weekly. Egg quality traits were recorded on a biweekly basis. Hen’s body weight was measured individually at the beginning and end of the experiment. Serum metabolites were determined at the end of the experiment. There was a significant difference between diets with different oxidized oil levels in egg weight, egg mass, Egg production, and feed conversion ratio (P < 0.05). Feed intake was not affected by dietary treatments. There was no significant difference between oxidized oil levels on blood serum triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein and very low-density lipoprotein. Malondialdehyde of the liver was not affected by oxidized oils. The results of this study have clearly demonstrated that maximum 25% oxidized oil could be replaced by fresh oil in the diets without any adverse effect on the performance of laying hens

Effect of Dietary Cation-Anion Difference during Prepartum and Postpartum Periods on Performance, Blood and Urine Minerals Status of Holstein Dairy Cow

Twenty four periparturient cows were used to determine the effects of DCAD on acid-base balance, plasma and urine mineral concentrations, health status, and subsequent lactation performance. Each group of 12 cows received either a diet containing −100 DCAD or +100 DCAD for 21 d prepartum. Both anionic and cationic groups were divided into two groups, one received a +200 DCAD and the other +400 DCAD diet for 60 d postpartum. Prepartum reduction of DCAD decreased DMI, urinary and blood pH, urinary concentrations of Na or K and increased plasma and urinary Ca, Mg, Cl and S. Also cows fed −100 DCAD diet consumed the most dry matter in the first 60 d after calving. Postpartum +400 DCAD increased milk fat and total solid percentages, urinary and blood pH and urinary Na and K concentrations, but urinary Ca, P, Cl and S contents decreased. Greater DMI, FCM yields were observed in cows fed a diet of +400 DCAD than +200 DCAD. No case of milk fever occurred for any diets but feeding with a negative DCAD diet reduced placenta expulsion time. In conclusion, feeding negative DCAD in late gestation period and high DCAD in early lactation improves performance and productivity of dairy cows