Estimate of Genetic and Phenotypic Trends for Some Productive and Reproductive Traits of Friesian Cows in Egypt

Abstract

The purpose of this study was to estimate the genetic and phenotypic parameters in order to obtain the trends of 305˗day milk yield (305˗DMY) lactation period (LP), calving interval (CI) and days open (DO) of Friesian cows. Data consisted of 5728 lactation records for 2040 Friesian cows sired by 139 bulls during the years from 1979 to 2016 at Sakha and El-Karada Farms inherent in the Animal Production Research Institute (APRI), Kafr-Elsheikh Governorate, Egypt. Data were analyzed using Harvey program statistic (Harvey, 1990) to determine the fixed effects to be included in the analytical model. Covariance components were estimated for univariate and bivariate analysis for all traits with derivative-free restricted maximum likelihood (REML) procedures using the MTDFREML program of Boldman et al., (1995). Means for 305-DMY, LP, CI and DO were 2632.09 kg, 300.02 d, 449.92 d and 173.95 d, respectively. Heritability estimates were 0.24, 0.22, 0.16 and 0.17 for the similar previous traits, subsequently. The genetic correlation between all traits studied were moderate and positive, ranging from 0.26 to 0.75. Corresponding phenotypic correlations between different traits under investigation were small and positive and ranged between 0.05 to 0.29. The annual genetic changes in the breeding values (BV's) were positive for 305-DMY (6.10 kg/yr.) while being negative for LP, CI and DO (-0.16,-0.05 and-.06 d/yr, respectively), indicating that there is an achievement superior sires however more attention should be given to reproductive traits to avoid losses related to these traits in the future. The results indicated that the use of top ranking bulls on the basis of their (BV's) for milk yield traits in breeding program will lead to noticeable genetic improvement in productivity of Friesian cows in Egypt.

Assessment of Friesian Cattle Performance Sustainability Through the Evaluation of Phenotypic and Genetic Parameters and Trends of some Economic Traits Under Egyptian Conditions

“…The LSM of CI (15 ±3.3 months) was within the range of 12-15 months stated by El-Awady et al (2017), Hermiz and Hadad (2020), Farrag et al (2020), Sanad et al (2020), Habib et al (2020) and Refaey et al (2022), but shorter than 15.7 mo interval obtained by Farrag et al (2017).…”

“…The current range of BVs for CI was shorter than the ranges from -8.14 to 11.91, -5.72 to 10.60 and -5.92 to 10.6 days obtained by Ayied et al (2011), El-Awady et al (2017 and Abdel-Hamid et al (2017), respectively. However, the slight positive improvement in GT was close to the values of 0.03, 0.06, 1.34 and 0.82 d/yr, as reported by Abdelharith (2008), Ibrahim et al (2009), Ramatsoma et al (2014) and Zahed et al (2019), respectively.…”

“…Table 1 shows that, the least square mean (LSM) of MY (3297.5 kg ± 1163.6 kg) was higher than those of 2632, 3103 and 2939 kg reported by El-Awady et al (2017), Abdelharith and Genena (2017) and Sanad et al (2020), respectively, but lower than 7387.70 and 4646 kg estimated by Kamal El-Den et al (2020) andAbou saque et al (2021), respectively. The differences among the averages of milk production in different studies may be attributed to the diverted genetic potentiality and/or management practices in different herds, in addition to the subtle variability of environmental conditions.…”

“…The current positive PT for CI (0.03 mo/yr) was confirmed with the value of 0.82 d/yr reported by Zahed et al (2019), while, Abdelharith (2008), Ibrahim et al (2009) and Rahbar et al (2016) obtained negative PTs of -0.48 , -0.09 and -2.54 d/yr, respectively. Moreover, El-Awady et al (2017) reported PT for CI between -22.47 and 43.44 d/yr.…”

“…Moreover, genetic and phenotypic correlations between traits are useful to formulate the breeding programs, since they determine the direction and magnitude of genetic improvement in other traits when selection is directed to the trait of concern (Tesfa, 2015). Keeping track of the amplitude progress of any genetic improvement program is very important for optimizing the genetic gain and, consequently farm profitability (Canaza-Cayo et al, 2016) and helps to judge the quality of the breeding programs implemented in the herd (Grosu et al,2014;El-Awady et al,2017). Samaraweera et al (2022) revealed that the genetic improvements in the set of milk yield, age at first calving, calving interval, number of services per conception, and resistance to mastitis traits have a positive impact on the profitability of dairy farms.…”