@article { author = {Hussein, A.}, title = {EFFECT OF SPERM SELECTION BY PERCOLL AND SWIM UP TECHNIQUES ON THE SEX RATIO OF RABBIT OFFSPRING}, journal = {Journal of Animal and Poultry Production}, volume = {4}, number = {8}, pages = {469-478}, year = {2013}, publisher = {Mansoura University, Faculty of Agriculture}, issn = {2090-3642}, eissn = {2090-3723}, doi = {10.21608/jappmu.2013.71506}, abstract = {This study was conducted to evaluate rabbit semen characterization before freezing and after thawing. Also, to determine the sex ratio of rabbit offspring’s after artificial insemination (AI) using semen selected by Percoll or swim up method. Semen was collected from New Zealand white rabbit bucks (n=9) and 45 rabbit does in three groups (15 in each) were inseminated with frozen semen (control, G1), semen selected by 67.5% Percoll (G2) or swim up (G3) methods, respectively. Semen was processed in tris-buffer extender at a rate of 1:4. Results showed that percentage of progressive motility, livability and intact acrosome spermatozoa decreased (P<0.05) post-dilution, post-equilibration and post-thawing. Using semen selected by Percoll in does AI resulted in more females (65.8%) and less males (34.2%). Using semen selected by swim up method in AI produced more males (75%) and less females (25%). Control does produced sex ratio of 51.2% males and 48.8% females. In conclusion, present results showed that, regardless sperm characteristics in post-thawed rabbit semen and fertility results, semen selected by Percoll density at 67.5% and 10 min centrifugation or swim-up can be used for determining the sex ratio of rabbits. This may control the desire to male or female production prior to conception.  }, keywords = {Rabbit,Semen,Percoll,swim up,artificial insemination,sex ratio}, url = {https://jappmu.journals.ekb.eg/article_71506.html}, eprint = {https://jappmu.journals.ekb.eg/article_71506_a9d2902fbbd2df7f20d3edcffc5d2077.pdf} } @article { author = {Ayasrah, E. and Abou-Bakr, S. and Ibrahim, M.}, title = {CHARACTERISTICS OF LACTATION CURVE IN DAMASCUS GOATS IN JORDAN}, journal = {Journal of Animal and Poultry Production}, volume = {4}, number = {8}, pages = {479-491}, year = {2013}, publisher = {Mansoura University, Faculty of Agriculture}, issn = {2090-3642}, eissn = {2090-3723}, doi = {10.21608/jappmu.2013.71508}, abstract = {Test day milk yield data on  Damascus goats maintained at Walla station belonging to ministry of agriculture in Jordan were collected over the period from 2002 to 2010 and included 7700 test days (1540 records). Wood model parameters were estimated using non-linear regression and individual curves were fitted. The characteristics of lactation curve were computed.  The initial yield (a), rate of increase (b) and rate of decline (c) parameters in Wood’s model for Damascus goats were 1.12±0.002, 0.35±0.0003 and 0.08±0.00, respectively. The values of peak milk yield (PMY), peak week (PW) and persistency (PS) were 1.29±0.007 kg, 3.93±0.008 and 0.86±0.07, respectively. Heritability estimates were found to be low, being 0.09 ±0.01, 0.07 ±0.01, 0.08±0.01, 0.04 ±0.001 and 0.07±0.01 for a, b, c, PMY and PS, respectively. Repeatability estimates were 0.30, 0.21, 0.25, 0.13 and 0.21 for a, b, c, PMY and PS, respectively.  Positive genetic correlation between the parameter a and parameter b and c were 0.99 and 0.99, respectively. The genetic and phenotypic correlations between b and c were high significant (0.99 and 0.91, respectively). Negative genetic and phenotypic correlation between the parameter a and PS were -0.99 and -0.81, respectively. It is concluded that incomplete gamma function of Wood to Damascus goats milk yields was sufficient in describing lactation curve in Damascus goats.  }, keywords = {Lactation curve,peak milk yield,persistency,Damascus goats}, url = {https://jappmu.journals.ekb.eg/article_71508.html}, eprint = {https://jappmu.journals.ekb.eg/article_71508_c6d09d21d04158a90f64bd41e9700168.pdf} } @article { author = {Mostafa, M. and Bader, Enas and khattab, A.}, title = {VARIANCES OF DIRECT AND MATERNAL GENETIC EFFECTS FOR MILK YIELD AND ITS COMPOSITION IN A HERD OF FRIESIAN COWS IN EGYPT}, journal = {Journal of Animal and Poultry Production}, volume = {4}, number = {8}, pages = {493-499}, year = {2013}, publisher = {Mansoura University, Faculty of Agriculture}, issn = {2090-3642}, eissn = {2090-3723}, doi = {10.21608/jappmu.2013.71512}, abstract = {A total of 3748 normal lactation records of Friesian cows kept at Sakha farm, belonging to Animal Production Research Institute, Ministry of Agriculture, Dokki, Cairo, Egypt during the period from 2000 to 2006 were used in the present study. Data was analyzed by using Multiple Traits Derivative Free Restricted Maximum Likelihood (MTDFREML) according to Boldman et al. (1995) using repeatability animal model.  Two models were used. Model 1 includes month and year of calving and parity as fixed effects and direct genetic, maternal genetic, covariance between direct and maternal genetic and residual as random effects. Model 2 is similar to Model1, while additive maternal and covariance between direct and maternal effects were omitted from the model. Estimates of heritability for 305 day milk yield, lactation period, fat % and protein % were 0.33, 0.02, 0.16 and 0.64, respectively for model 1, while the values were 0.34, 0.03, 0.17 and 0.65, respectively as estimated from model 2. The removal of additive maternal genetic effects and covariance between direct and maternal genetic effects from the model increased estimates for heritability of additive genetic effects by 0.01, for the four traits. Therefore, the additive maternal genetic effect and covariance between direct and maternal genetic effects do not seem to make important contributions to the phenotypic variance for milk yield and it's composition.    }, keywords = {Friesian cows,direct and maternal genetic effects,heritabilityandmilk traits}, url = {https://jappmu.journals.ekb.eg/article_71512.html}, eprint = {https://jappmu.journals.ekb.eg/article_71512_08a163be679aa9a2b44cfe48422cd589.pdf} }