الفهرس 
INTRODUCTION
Follicular dynamicsOnly 14 pages are availabe for public view
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Abstract
The present work was carried out at Sakha Animal Production Research Station and International Livestock Management Training Center, Animal Production Research Institute, Ministry of Agriculture, and Department of Animal Production, Faculty of Agriculture, Mansoura University. The work included in this thesis was designed to: Part I: examine the effects of dietary dicalcium phosphate supplementation alone or along with yellow maize and soya bean supplementation on postpartum reproductive performance of Friesian cows.Twenty seven Friesian cows were assigned randomly immediately after calving to three similar groups (9 in each) as follow: Group 1: Cows were fed on a basal ration, which consisted of 40% concentrate mixture, 35% berseem and 25% rice straw which provide calcium and phosphorus contents of 0.90 and 0.4 % on dry mater basis, respectively, as a control group. Group 2: like G1 along with 50 gm dicalcium basic phosphate supplementation.Group 3: like G2 along with 3 kg yellow maize and 0.500 kg soya bean. In analyzing the data obtained in this study, the effects of weight at calving, and 120d milk yield were included as dependent regression factors were also included on postpartum reproductive performance. In addition, the relationships between some blood parameters; namely calcium, phosphorus, total protein and urea and postpartum reproductive performance were also studied. Part II: was considered as extension of part I, but on response to superovulation and embryo recovery. In addition, the relationships between some blood parameters; namely calcium, phosphorus, total protein and urea and response to super ovulation were also studied. Twelve Friesian cows were assigned randomly immediately after calving to three groups (4 in each) as described in part I. Part III: was mainly devoted to study follicular waves characteristics during oestrous cycle through ultrasonography, and to examine the effect of the presence of dominant follicle, as monitored by ultrasonography, at the time of PMSG injection on the response to superovulation. The results obtained could be summarized as follows: 1 The effect of group on each of SP, DO and CI was statistically significant (P < 0.05) and approached significant for NSC (P = 0.076). However, such effect on DFS was statistically insignificant (P 0.05). 2 Cows in G3 had shortest SP, NSC, DO and CI compared with G1 or G2. 3 The prolongation in reproductive traits was associated with higher concentrations in each of U and P than TP or Ca which was higher in G3, and this was related with longer periods in each of DFS, DO and consequently CI, but these periods were lower than that in G1. 4 G1 (control) had higher number of RE G2 or G3. The differences may be related to the effect of feed on blood U concentrations, where G3 had highest concentrations compared to G1 or G2. 5 G2 had higher number of CL than G1 or G3. 6 The results in number 4 and 5 related to the effect on each of U concentrations and Ca : P ratio. 7 Follicular development during oestrous cycle occurred mainly in a pattern of two or three waves. 8 The length of the oestrous cycle ranged from (1824 days) according to the number of waves of oestrous cycle. 9 The diameter of the dominant follicle was higher in cows with two than those with three waves. 10 The dominant follicle which had diameter 10 mm on the day of PMSG injection had negative effect on the response to SO treatment.