Environmental effects on fertility measures early in lactation, such as the interval from calving to first luteal activity (CLA), proportion of samples with luteal activity during the first 60 days after calving (PLA) and interval to first ovulatory oestrus (OOE) were studied. In addition, traditional measurements of fertility, such as pregnancy to first insemination, number of inseminations pe...

In this study, the effect of polymorphisms in the leptin gene on the hematological variables in periparturient dairy cows was investigated. The hematological profile of 67 Holstein cows was assessed for 6 wk around calving. The DNA of the cows was genotyped at 6 polymorphic loci within the leptin gene, and 7 haplotypes were reconstructed. Significant haplotype substitution effects were found, f...

etritis is an inflammation of the uterus caused by bacterial infection, and is a common, costly, even life-threatening disease of dairy cows. Clinical metritis most commonly occurs in the first 10 days post-calving, and affected cows may subsequently exhibit poor reproductive performance with irregular estrous cycles, lower conception rates, and greater intervals from calving to pregnancy. Clin...

for the current research the records of 62 farms in isfahan province were available. to estimate genetic and phonotypic trends of reproductive traits such as age at first calving, calving interval, days open and number of insemination to conception rate the records of 63,866 cows including 167793 reproductive records were employed. farms were covered by vahdat industrial agriculturists and dair...

Voluntary waiting period and adoption of synchronized breeding (ovulation synchronization followed by timed artificial insemination) were characterized from 33 million services of Holsteins and Jerseys in Dairy Herd Improvement herds. Calving month, calving year, and parity had large effects on days to first service for both breeds. Holstein cows that calved during March and April were bred lat...

The comparison of some hormonal and biochemical blood indices in healthy cows (C) and cows affected with retained foetal membranes (RFM) or puerperal metritis (PM) was the aim of the study. Blood samples were taken between 12 and 24 h (RFM) or 8-10 d (PM) after calving. The progesterone, 17-β oestradiol, cholesterol, glucose, ketone bodies (KB) and free fatty acids (FFA) levels were similar in ...

BACKGROUND Proper calving management of dairy herds is a crucial aspect of the bovine life cycle, as it has profound effects on calf viability and on the post-partum course of the dam. The objectives of this study were to monitor the calving process through the use of a remote alarm system and to determine the impact of prompt emergency obstetric procedures in case of dystocia for the preventio...

Brahman cows were used to evaluate the effects of postpartum nutrition and suckling on reproductive and calf performance. Cows received high or low TDN and once-daily or unrestricted suckling. High TDN (H; 111% of NRC recommendation) cows received a 75% corn: 25% soybean meal diet. Low TDN (L; 93% of NRC recommendation) cows received no concentrates. Once-daily suckled (restricted, R) cows nurs...

Multiparous Holstein cows (n = 60) were used to determine effects of trace mineral source on oxidative metabolism, subclinical endometritis, and performance of transition cows. After a 1-wk preliminary period, cows were assigned randomly to one of 3 topdress treatments from 21 d before expected calving through 84 d post calving: 1) Inorganic sources based upon sulfates of Zn, Cu, and Mn (ITM); ...

A total of 198 cows were randomly assigned to treatment with a single intramuscular injection of 10 ml of a preparation containing vitamin E and selenium or placebo 3 wk before expected parturition. Incidence of retained fetal membranes was 3.0% for the treated group and 10.1% for the control group (P=0.06). Administration of MU-SE also increased the percentage of cows pregnant to the first ser...