Lactating dairy cows have unique reproductive responses compared to when they were heifers that result in distinctly different reproductive measurements and pregnancy outcomes that can be partially overcome with pharmacological strategies. These parameters include circulating progesterone and estradiol concentrations, ovulatory follicle and corpus luteum diameter, incidence of anovulation and d...

Many of the diseases that affect dairy cattle either in confinement or pasture-based systems typically occur in the first two months of lactation, before the first postpartum insemination. The increased susceptibility to metabolic and infectious diseases with parturition and the onset of lactation poses a major challenge to reproduction. A wealth of information in the scientific literature is a...

Our objective was to evaluate the effect of a progesterone-releasing intravaginal device (PRID) in 7-d Ovsynch protocol on pregnancy per artificial insemination (P/AI) and loss, compared with standard without progesterone supplementation. We hypothesized that supplementation during an would increase P/AI decrease loss. Data were collected lactating Holstein cows (n = 716) either received (contr...

In a large herd of dairy cattle and young stock the bacteriological examination of 109 cases of abortion which included a relatively thorough study of the fetus and a study of the membranes, or swabs from the uterus whenever obtainable, gave the following results. 62, or 57 per cent, were associated with Bacillus abortus. 26, or 23.8 per cent, were associated with spirilla. 2, or 1.8 per cent, ...

The objectives of this study were to evaluate replacing GnRH with hCG and the effects of 48-h calf removal (CR) on pregnancy rates of cows synchronized with the CO-Synch protocol. Suckled beef cows (n = 467) at two locations were assigned to treatment by breed, age, and calving date. Treatment included either GnRH with (n = 121) or without CR (n = 117) or hCG with (n = 115) or without CR (n = 1...

introduction cattle are a monotocous species meaning that, under most circumstances, a successful pregnancy results in the birth of one calf. twinning rate has been reported in dairy cows from 3 to 5 percent, which can be influenced by maternal age.the birth of twins is detrimental to the majority of beef and dairy cattle producer. financial loss arising from any of twinning has been reported i...

Gunay A., U. Gunay: Effects of Clinical Mastitis on Reproductive Performance in Holstein Cows. Acta Vet. Brno 2008, 77: 555-560. The objective of this study was to determine the effects of clinical mastitis on reproductive performance in 135 early lactation cows. The animals were divided into two groups according to the occurrence of mastitis as follows: group I (n = 45), clinical mastitis prio...

The present study determined whether a 5-day CO-Synch + controlled internal drug release (CIDR) protocol with two doses of PGF2α would improve timed artificial insemination (AI) pregnancy rate compared with 7-day CO-Synch + CIDR protocol in beef cows. Angus cross beef cows (N = 1817) at 12 locations were randomly assigned to 5-day CO-Synch + CIDR or 7-day CO-Synch + CIDR groups. All cows receiv...

The association of birth type (single vs. double) and pregnancy type (single vs. double) with lactation performance and lactation curve was investigated in Holstein cows in Iran. Data of 243298 lactations on 138021 cows in 261 herds collected during January 2000 to December 2012 were used. The average twinning rate was 3.64% and ranged from 1.44% (primiparous) to 5.41% (multiparous). Factors as...

BACKGROUND In June of 2010, an antenatal ultrasound program to perform basic screening for high-risk pregnancies was introduced at a community health care center in rural Uganda. Whether the addition of ultrasound scanning to antenatal visits at the health center would encourage or discourage potential patients was unknown. Our study sought to evaluate trends in the numbers of antenatal visits ...