Many of the reproductive traits in cows are affected by a group of factors, the most important of which are climatic conditions and the management of the herds. In this paper, the reproductive status of imported Holstein - Friesian cattle breed was evaluated in terms of breeding through the investigation for some traits under the influence of some factors. The records involved cow birth to first service trait (CBFS) (1101 records), cow birth to first days open trait (CBFDO) (1091 record), and age at first calving trait (AFC) (1083 record). The results of the study showed significant differences in CBFS, CBFDO, and AFC traits according to the year and season of birth (p <0.01), the lowest values were 19.33, 21.29 and 30.29 months (the year 2000) and 19.40,21.30 and 30.32 months (winter) respectively. Also. a significant difference (p <0.01) was noticed through the interaction between the year and season of birth and between the year of birth and total milk yield level (TMYL). Estimated heritability(h2) for CBFS, CBFDO, and AFC traits were 0.22,0.25 and 0.17 respectively. The study showed variation in estimated breeding values (EBVS) across sires within the reproductive traits. The first three lowest values were achieved by the sires 13,25 and 20, the values were -1.97, -1.87 and -1.86 months (CBFS trait), -2.33, -2.21 and -2.19 months (CBFDO trait), -2.32, -2.20 and -2.18 months (AFC trait) respectively. Based on current given results, it is advised to direct and intensify births during winter and spring seasons to obtain optimal reproductive performance of the herd later.
In the current study, the hypothesis of the effects of luteinizing hormone (LH) and follicular fluid (FF) derived from follicles of varying size on in vitro embryo production of the Shami goat breed were tested. The caprine follicular fluid (cFF) was obtained from healthy female’s ovaries by aspiration method and classified into two main classes (follicles with a diameter of ≤ 2mm and ≥3mm). The resulting cFF was added to the culture medium TCM-199 through six Treatments (A, B and C with a source of follicle size of ≤ 2mm; D, E and F with a source of size of ≥3mm). LH was added only to four of the previous Treatments with the levels of 50 µg ml-1 (B and E) and100 µg ml-1 (C and F). Results of the study showed that the oocytes incubated in Treatment F achieved a clear superiority (p=0.001) in the rates of maturation (87.0%), fertilization (80.0%) and cleavage (82.3%). The oocytes incubated in the same Treatment (F) continued to outperform (p= 0.006) by achieving the best rates across cleavage stages at 2-16 cell (16%; the lower value of arrest) and blastocyst (42%). Significant differences (P=0.03) were observed among the rates of Type 1embryos (the highest rate: 45.3%; Treatment F) and Type 3 embryos (the highest rate: 45.1%; Treatment A). No significant differences were observed in the rates of morula and Type 2 embryos. It is advised to add 15% of the cFF derived from follicles with a diameter of ≥3mm and 100 µg of LH ml-1 in the maturation media to obtain higher rates of maturation and cleavage of goat oocytes.
Growth factors and vitamin-like substances have great positive importance in most biological interactions in the cellular level. The addition of these elements in the culture media will increase the yield of the resulting embryos and improve quality. We examined the effects of epidermal growth factor (EGF) and myo-inositol (MI) on meiotic maturation and yields of blastocyst of Awassi sheep oocyte across two experiments. The oocytes obtained were subjected into three treatments: A (without EGF nor MI), B (10 ng/ml EGF + 20 mmol/l MI) and C (50 ng/ml EGF +40 mmol/l MI). Oocytes were then cultured in Ham's F-10 medium supplemented with 5% (v: v) fetal calf serum and 40 ng/ml follicle - stimulating hormone. In the first experiment, during the 27-h culture period, the oocytes were assessed for germinal vesicle break down, metaphase-I and metaphase-II stages across three-time intervals (9, 21 and 27-h). Results of the experiment showed that EGF and MI enhanced the rates of germinal vesicle break down phase (1.53%; 27-h interval; lowest value), metaphase-I (33.87%; 21-h interval) and metaphase-II (89.23%; 27-h interval). In the second experiment, the oocytes incubated in treatment B achieved the highest rates of cleavage (81.96%), 2-8 cell (62.35%) and blastocyst (45.09%). It is concluded from the present study that incubating sheep oocytes in culture media containing a cocktail of EGF (10 ng/ml) and MI (20 mmol/l) significantly improves the rates of metaphase-II, fertilization and blastocyst rates.
There was a difference in the genetic profiles of the CYP21 genotype, it showed three genetic polymorphisms: 250/240, 260/251 and 270/261 bp, and their distribution ratios were 51.72, 29.31, and 18.96%, respectively. The percentages showed highly significant differences (P≤0.01), and the total of the studied alleles was 116. The study showed that there were no significant differences in the production of total milk and its components between the genetic polymorphisms, as well as in the rate of milk flow. There were significant differences (P≤0.05) between the different genetic polymorphisms of cows in the heat endurance factor, as the cows carrying the genotype 250/240, 260/251 bp outperformed the genotypes 270/261 bp so the value of the thermal endurance factor was 99.73 for the genotype 270/261 bp, as for the genotypes 250/240, 260/251 bp, the coefficient of heat endurance was 101.82 and 102.43, respectively. There were a significant differences (P≤0.05) between the genotypes for the California test for mastitis, cows carrying the genotype 250/240, 270/261 bp outperformed the genotype 260/251 bp. The test values were 1.77 and 1.00 for genotypes 270/261, 250/240 bp respectively, and the value of the California test for genotype 260/251 bp was 2.45.
This study was conducted at the College of Agriculture/University of Al-Muthanna for the period between 1/10/2020 until 30/6/2020, 60 buffaloes were used in the experiment with the aim of determining the genotypes and their distribution ratios for the PIT-1 gene. The genotypes were altered (P<0.01), which amounted to 18.52 and 81.48 respectively, and the allelic frequency was 0.10 and 0.90 for each of the two alleles A, B, respectively. Daily milk production and fat percentage were not significantly affected, milk protein percentage was significantly affected (P<0.05) in the eleventh week, reaching a maximum of 3.88±0.28 (BB), as well. Significant differences (P<0.05) were found in the percentage of genetic non-fatty solids in the first week of the study, with a maximum of 23.28 (BB). BB genotype.
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