The aim of this study was to investigate the use of corn distillers dried grains with solubles (DDGS) (27.11% CP) and Foots (20.84% CP) as corn processing by-products in monosex Nile tilapia, Oreochromis niloticus diets to replace yellow corn as an energy source and its effect on growth performance, nutrients utilization, whole body proximate composition, nutrients digestibility and economic efficiency. Three hundreds and seventy five fingerlings of Nile tilapia (10± 0.05 g) were randomly distributed into 15 circular plastic tanks (1000 L), representing 5 treatments. Isonitrogenous (25 to 25.84%) and isocaloric (4174.79 to 4364.65 Kcal GE/kg) experimental diets were prepared with substitution levels of DDGS 0% (T1), 20% (T2) and 40% (T3) and Foots 20% (T4) and 40% (T5). The experimental period lasted for 18 week. Results showed that both of DDGS and Foots have higher in all measured amino acids content than those in yellow corn except cysteine. Moreover, DDGS and Foots have higher content of linoleic, oleic, stearic and palmitic acids than those in yellow corn. Also DDGS and Foots covered the nutrient requirements of the essential fatty acid linoleic (18:2 ω 6) for Nile tilapia. Feed intake was significantly decreased as corn partially replaced by Foots more than the DDGS. Apparent digestibility coefficient of CP, EE, NFE and energy recorded the highest values for the T4 (75.76, 89.86%, 57.48 and 68.71%), respectively, followed by T3 with significant differences. The increasing in substitution levels of yellow corn by DDGS did not significantly (P˃0.05) had an effect on Nile tilapia performances. However weight gain and specific growth rate SGR were gradually decreased with increasing the substitution levels of Foots. The CP content of Nile tilapia carcass was significantly increased with increasing the substitution levels of DDGS (T3) and Foots (T5). Feed conversion ratio (FCR) of the fish fed diets T4 (20% Foots) was the best followed by T5 (40% Foots). The cheaper feed cost gain was obtained from T5(40% Foots) followed by T4(20% Foots).

The study aimed at estimating feed efficiency of milk production systems in Urban and Peri-urban areas in three main provinces in Egypt. The targeted provinces were: Cairo, Giza and Qaloubeya. A questionnaire has been developed to cover the variables related to the production systems. The total number of interviewers was 72, included the districts: Manshiat Elbakary; Saft Elaban and Shalaquan as peri-urban, and Elmarg; Elomrania and Dar Elsalam as urban areas. As a result of the great significant in the selected samples, a typology has processed gathering similarities in two main groups of producers: land-access and landless producers. Three crop-livestock systems have been classified due to the concepts: land capacity and herd size (group 1, 2 and 3). Dairy systems have been identified as two main urban dairy specialized systems (group 4 and 5) oriented to dairy activities. In order to measure feed efficiency for each system were represented in the groups, the most significant obtained results were: the small and the micro crop-livestock producers related land-access producers (group 2 and 3) which have small herd appear to be more efficient in valorizing feed in relation to milk production per head per year, and as well as milk production per feddan allocated to fodder crops. On contrary, the landless producers (group 4 and 5) have the lowest feed efficiency due to the amount of concentrates included in their feed strategy (intensive feeding system) and inability to produce fodders.             The large mixed crop-livestock system (group 1) represents an intermediate status that producers cultivate fodders inside farm, but remain low economic efficiency in terms of their intensive feed strategy. The results of the study indicated that the small and the micro crop-livestock (group 2 and 3) achieved the highest feed efficiency regarding milk production in Urban and Peri-urban areas and thus the importance of improving productive performance by creating supposed scenarios or technical packages using simulation systems. Nongovernmental organizations (NGOs) and extension programs are essential in performing records and marketing which help to raise product price as well as producers` income and the Gross Domestic Products (GDP).