Vahid Vahedi; Babak Naderi; Ciyamak Ghazaie; Azadeh Boustan
Abstract
The aim of this study was the comparison of two protocols of estrus synchronization in two natural climates and heat stress condition on reproductive performance and concentration of plasma estrogen and progesterone hormones in Holstein dairy cows. One hundred and ten multiparous Holstein dairy cows ...
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The aim of this study was the comparison of two protocols of estrus synchronization in two natural climates and heat stress condition on reproductive performance and concentration of plasma estrogen and progesterone hormones in Holstein dairy cows. One hundred and ten multiparous Holstein dairy cows (28 kg average daily milk yield and parity one to four calved) were randomly assigned to two protocol groups: 1) Double-Ovsynch (DO; n=60), the cows received GnRH-7d-PGF2α-2d-GnRH and Ovsynch (GnRH-7d- PGF2α-56h-GnRH-16h-AI) was initiated 7 d later; 2) Presynch-Ovsynch (PO; n=50), the cows received PGF2α-14d-PGF2α and Ovsynch was initiated 12 d later. The both of the protocols were done in two seasons of summer and winter. The calving rate in cows that were synchronized at winter season was greater than cows synchronized in summer (36.4 vs 18.2%; P= 0.04). Mean of the number of insemination to conception was lower in cows that synchronized in winter compared to cows synchronized in summer (1.46 vs 1.74; P= 0.02). Mean of measured estrogen and progesterone hormones concentrations was higher in cows that synchronized in winter compared to summer (P < 0.05). Overall, mean of reproductive traits and hormones concentration is higher in cows that synchronized in winter than in summer and the protocol of estrus synchronization had no effect on reproductive performance.
sara Ataei Nazari; abdollah mohammadi sang cheshmeh; Mohammad Reza Bakhtiarizadeh; ali assadi-alamouti; Ali Fouladi Nashta
Abstract
This study was conducted to evaluate the effect of various concentrations of lipopolysaccharide (LPS) in maritaruta medium on oocyte maturation, oocyte developmental competence and metabolites related to maturation medium including glucose, pyruvate, lactate and glutamine. The experimental ...
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This study was conducted to evaluate the effect of various concentrations of lipopolysaccharide (LPS) in maritaruta medium on oocyte maturation, oocyte developmental competence and metabolites related to maturation medium including glucose, pyruvate, lactate and glutamine. The experimental treatments were 0 (control), 0.01, 0.1, 1 and 10 μg/ml of LPS in oocyte maturation medium. The cumulus oocytes complex (COC) were cultured with various concentrations of lipopolysaccharide. After 24 h of oocyte maturation, the medium was collected and the rates of oocyte maturation, cleaved oocyte and oocytes reached to blastocyst stage were analyzed. Oocyte maturation rate was lowest in the treatment with 10 μg/ml of LPS (P<0.05). Among the measured metabolites, only glucose concentration was linearlydecreased in response to increasing levels of LPS in the maturation medium (P<0.05) as treatment with 10 μg/ml of LPS had lower glucose concentration comparing to other treatments. The percentage of oocyte cleavage was significantly lower in treatment with highest level of LPS compared to other treatments (P<0.05). In addition, the treatment with 1 and 10 μg/ml of LPS significantly reduced blastocyst rate compared to control group (P<0.05). According to results of this study, lipopolysaccharide could have detrimental effects on oocyte development and these influences seems to be mediated through pathways related to energy metabolism. Acquiring managerial approaches to control LPS enhancing agents during reproductive season could prevent animal's reproductive failure.
Hamed Kermani Moakhar; Armin Towhidi; Saeed Zeinoldini; Hamid Kohram
Abstract
The aim of this study was to evaluate the effect of glycogenic diets supplemented with different poly unsaturated fatty acids on reproductive performance of Iran Black ewes in two different managing programs. Ewes were allocated in two different groups; group A (n = 75) and group B (n = 25). Ewes from ...
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The aim of this study was to evaluate the effect of glycogenic diets supplemented with different poly unsaturated fatty acids on reproductive performance of Iran Black ewes in two different managing programs. Ewes were allocated in two different groups; group A (n = 75) and group B (n = 25). Ewes from group A were stopped from suckling followed by introducing to the rams on days 80 and 90, respectively. Melatonin implant was laid under the skins ear of these ewes 40 days before introducing them to the rams. Animals from group A were divided into three groups (25 ewes/sub-group) and were fed by high starch diets supplemented with saturated fatty acids (control diet), extruded linseed (omega 3 diet), and full fat soybean (omega 6 diet). Ewes from group B were stopped from suckling on day 120, introduced to the rams on day 180 after parturition and fed as described for the control diet. Data for the rates of Estrus cycle, ovulation, lambing and twining were recorded for each group. The weight of lambs was measured at the birth time of birth, and also at 3 and 4 months of age. The lambing and twining rates were higher in omega 3 and omega 6 diets as compared with the control diet and group B. Animals in group B indicated a higher lamb weight at 3 and 4 months of age compared to all treatments in group A. In conclusion, data from current study suggested that using management program of group A along with feeding omega 3 and 6 could improve the reproductive performance of Iran Black ewes.