The objective of the present study was to determine the effects of dietary inclusion of different levels of pawpaw seeds powder (PSP) at different periods on the growth performance, survival rate, feed utilization and carcass composition of fry and fingerlings of Nile tilapia (Oreochromis niloticus). The experiment was divided into two periods; the first was feeding period of Nile tilapia fry with PSP for 71 days; and, the second was rearing period where the Nile tilapia fingerlings fed control diet (0 g/kg diet from PSP) for 84 days. Apparently-healthy 1200 Nile tilapia fry of one day old with an average initial body weight 0.012 g/fry were randomly distributed to 20 treatments. Each treatment was referred to three aquaria. The PSP was added to the basal diet at levels of 0, 2, 4, 6 and 8 g/kg diet for 15, 30, 45 and 60 days, different periods. The results of the first period showed no significant (P ≥ 0.05) differences in all growth performance parameters and feed conversion ratio (FCR) during all periods (15, 30, 45 and 60 day); however, different levels of PSP showed significant (P ≤ 0.01) improvement in all growth performance, survival (intervals SR and final SR) and feed utilization (FI and FCR) by increasing level of PSP till 6 g PSP/ kg diet, then significantly decrease (P ≤ 0.01) till 8 g PSP / kg diet. In case of the second period, all growth performance parameters and feed utilization (FI and FCR) gradually (P ≤ 0.01) improved with increasing feeding periods until 45 day, and then decreased with increasing feeding period (60 day). The interaction between levels of PSP and different periods of treatment indicated that 6 g PSP/kg diet for 45 day had the best (P ≤ 0.01) values of FW, TWG and ADG compared with other treatments. Thus, the results of this study lead to useful and safety recommended use of 6 g PSP /kg diet for 45 day, to be economic and efficient for fish farms.

The present study was carried out to evaluate the ability of using Pawpaw (Carica papaya) seeds powder (PSP) as natural reproductive inhibitor for Nile tilapia (Oreochromis niloticus) to control their propagation. The experiment was divided into two periods; the first was the treating period (1 st) during which the Nile tilapia fry were treated with PSP for 71 days and the second was the rearing period whereas the Nile tilapia fingerlings (2 nd) obtained from the first period until sexual maturation stage for 84 days. The PSP was added to the basal diet at levels of 0, 2, 4, 6 and 8 g/kg diet for 15, 30, 45 and 60 days, different periods (1 st). Results of the 2 nd period showed that there were no significant (P ≥ 0.05) effects on total cholesterol, testosterone and progesterone hormones among all periods; however the testosterone and progesterone hormones were decreased (P ≤ 0.0 1) by increasing levels of PSP. Also, the high levels of PSP (4, 6 and 8 g / kg diet) and increasing exposure periods (30, 45 and 60 day) caused obvious histological alternations of testes and ovaries of O. niloticus which reduce the fertility of both males and females. Consequently, it could be recommended that the effectiveness use of PSP as a natural reproductive inhibitor for O. niloticus.

This research was conducted to evaluate the Friesian cattle performance and study the relationship among different days open periods, total milk yield and days in milk at the first lactation of Friesian cows under different Egyptian conditions. Milk productive and reproductive data were collected from 3258 Friesian cows of six farms. Farm No.1 is a governmental, while other farms are commercial farms located in Kafr El-Sheikh, Cairo-Alexandria desert road, Gharbia, Sharqia, Daqahlia, Beheira governorates and were named from 1, 2, … to 6, respectively. Days open (DO) was classified to 10 classes, each class of 30 days (from < 60 to ≥ 300 d). The overall average of age at first calving, days open, calving interval, days in milk (DIM) and total milk yield (TMY) of all farms were 29.4 mo, 174.4, 472.0 and 359.2 d and 6173.5 kg, respectively. Results of this study showed that, in all examined farms, the 1 st lactation TMY and DIM significantly differed by the differences of the DO lengths. The study recommended that the most appropriate length of DO could be from 60 to <120 d, for Friesian cows under different managerial conditions in Egypt.

This study conducted to evaluate some of non-genetic and genetic parameters that affect the productive and reproductive traits. Total of 3596 records of 1021 Holstein Friesian cows in the first five parities were collected during the period from 2002 to 2016 from a commercial farm. The details values of productive traits (total milk yield (TMY, kg), lactation period (LP, day) and dry period (DP, day)), as well as, details values of reproductive traits (days open (DO, day), number of services per conception (NSC), age at first calving (AFC, months) and calving interval (CI, day)) were considered. The effects of season of calving and parity on productive and reproductive traits were also examined. The results revealed that the season of calving and parity had significant effect on all the studied traits. Heritability estimates for TMY, LP, DP, DO, CI, NSC and AFC are 0.110, 0.089, 0.071, 0.100, 0.103, 0.123 and 0.168, respectively. The phenotypic correlations of all studied traits were positive and ranged from 0.016 to 0.989, except that between TMY and all the reproductive traits as well as DP were negative. The values of genetic correlations among all studied productive and reproductive traits were positive and ranged from 0.031 to 0.998, except DP and TMY was negative. The present study is an effective way for using in improving programs for milk yield of Holstein Friesian cows in commercial farms.

No abstract

A total of 820 Zaraibi goats in the first parity were collected from El-Serw Experimental Station (North Nile Delta) belonging to Animal Production Research Institute, Ministry of Agriculture, Egypt, during the period from 1990 to 2000.Genetic parameters and breeding values for total milk yield (TMY, Kg), lactation length (LL, days), age at first kidding (AFK, months), number of kids born (NKB, kids), number of kids weaned (NKW, kids), litter weight at birth (LWB, Kg) and litter weight at weaning (LWW, Kg) in the first kidding were investigated. The statistical analyzes were performed using the MTDFREML (multivariate derivative free restricted maximum likelihood, Boldman et al., 1995). Firstly, single trait animal models were fitted for all traits to obtain heritability estimates. In the second approach, a multi-trait animal model (four traits model) was used to consider NKB, LWB, LWW and TMY traits.The overall means for number of kids born, weaned, litter weight at birth and litter weight at weaning per doe in the first kidding were 1.97, 1.77 kid, 3.6 and 17.67 Kg, respectively. The average of age at first kidding, total milk yield and lactation length were 22.66 months, 269.8 kg and 258.9 days, respectively. The estimates of coefficient of variations of studied traits ranged between 12.88% for age at first kidding and 50.71% for milk production.Heritability estimates and their standard errors obtained from single-trait of NKB, LWB, LWW, TMY, LL, NKW and AFK were 0.18±0.05, 0.09±0.06, 0.06±0.05, 0.24±0.10, 0.12±0.09, 0.15±0.07 and 0.09±0.06, respectively. While, the obtained estimates from multi-trait animal model analysis of NKB, LWB, LWW and TMY were 0.22±0.08, 0.16±0.04, 0.14±0.07 and 0.28±0.10, respectively. The heritabilities obtained from multi-trait animal model analysis were higher than those obtained from single-trait animal model analyses. All genetic and phenotypic correlations among production and reproduction traits in the first kidding of Zaraibi goats obtained from multi-trait animal model analyzes (four traits) were positive. The genetic correlations ranged between 0.21 and 0.82, while the phenotypic correlations ranged between 0.13 and 0.71. The estimates of genetic correlations between milk yield and each of NKB, LWB and LWW were 0.21±0.10, 0.23±0.08 and 0.82±0.09, respectively.The ranges of estimated breeding values (EBVs) obtained from multi-trait animal model analysis for NKB, LWB, LWW and TMY were 0.84 kid, 1.21, 7.44 and 164.8 kg, respectively. While, the corresponding values obtained from single-trait analysis 0.65 kid, 0.73, 2.64 and 151.61 kg, respectively. The obtained higher estimates of coefficients of variation, heritability estimates of low to moderate values and wider range of animals breeding values of the Zaraibi goats traits in the first kidding, indicating that potential genetic improvement through selection can be achieved in this flock, especially with multi-trait animal model analysis.

This study was conducted to assess the effect of different levels of Aqua-Max Plus ® on growth performance, feed efficiency, body chemical composition, hematological, and biochemical of the mono-sex Nile tilapia (Oreochromis niloticus, L. 1758) for 147 days (21 weeks). Aqua-Max Plus ® was added at five levels (0, 1, 2, 3, 4 g/kg diet). Results exhibited that the addition of Aqua-Max Plus ® at levels 2, 3, and 4 g/kg diet (T 3 , T 4 , and T 5 ) led to significantly improve the growth performance and feed efficiency parameters compared to the control group. By increasing the levels of Aqua-Max Plus ® , ash and protein contents were significantly increased, while fat and energy content contents were decreased. No significant differences among treatments in hematological and serum biochemical parameters were detected. Thus, based on the obtained results, it could be concluded that the beneficial addition of 2 g Aqua-Max Plus ® / kg diet as a growth promoter agent for the Nile tilapia.

Personal interviews with 40 goat owners were conducted in three representative areas (Damietta, Port Said and Dakahlia) located in north delta, where Zaraibi goats are prevailing. The survey was carried out using structured questionnaires, during the period from February to August 2010, containing a total of 90 items grouped into goat owner production resources, management practices, goat production performance and their production constraints. The majority of households (75%) kept only goat herds and 25% owned both sheep and goats. The mean flock size was 12.6 heads, of which 53.74% consisted of does, 22.82% male kids, 19% female kids and 4.3% bucks. About 60% of the goat keepers keep goats mainly for saving purpose, the second main reason for income generation (30%), however, keeping goats for meat and milk purposes were ranked as third (5.9%) and fourth (4.5%) order, respectively. Usually the rate of majority of farmers supplementing females at suckling and late pregnancy stages 82.5 and 70%, respectively. In studied areas, 74.4% of breeders have their Zaraibi bucks. Average weaning age and marketing age were 4 and 7.5 months, respectively. Average weaning weight under household conditions was estimated as 14.8 kg. Average litter size has been recorded as 2.16 kids. Pre-weaning and post-weaning mortality were estimated as 11.47 and 2.76%, respectively. Kidding interval of goat farmer's is estimated as 250 days. Female post-weaning sales (14.19%) was found to be lower than selling adult does. Female kids growth rate and physical characteristics had higher reasons for disposal of 67.5 and 50%, respectively. On the other hand, cash need, disease, slaughter for home consumption and injury had lower reasons for disposal of 12.5, 5.0, 2.5 and 2.5%, respectively. The poor fertility performance and cash need had higher reason for disposal for adult Zaraibi females. Goat milk is used mainly for suckling kids (58%), home consumption (39%) and supplementary income to the smallholder (3%).