Commercial artificial insemination (AI) is arguably one of the greatest animal biotechnologies introduced in the 20 century. The benefits of improved genetics and reduced disease transmission have been readily recognized and accepted by the dairy producer, and at present, approximately 70% of the US dairy cattle population are bred by AI. Since the introduction of commercial AI in the early 194...

Reproductive failure in inseminated cattle results from poor fertilization and embryo survival. Recent studies utilizing dairy and beef cattle indicate that fertilization rates are higher for nulliparous dairy and beef heifers and nonlactating beef cows than lactating beef and dairy cows and nonlactating dairy cows. Several factors affect fertilization rates, but the greatest impact was observe...

Dairy cattle production requires great intensification, which has been demonstrated to affect negatively on the reproduction. One calf by cow and year is the reproductive objective in these animals. It means that cows must get pregnant after AI, maintain the pregnancy, have parturition after 270 days approx., and wait for a period of 40-50 days to be successfully inseminated again. Nevertheless...

The present cattle population of Bangladesh is 24.17 million (DLS, 2009). More than 80 percent of this cattle population is indigenous and rests of them are purebreds and crossbreds of different exotic breeds (Friesian, Jersey and Shahiwal) cattle, which is contributing a major share of livestock sub-sector and playing multi-functional roles (supply of milk, meat, skin, manure, carting etc.) in...

The aim of this study was to evaluate the effect of body weight (BW) change during the early postpartum period and BW on day 50 post partum on the subsequent expression of estrus and fertility at first insemination before day 90 post partum. The data were derived from 1036 postpartum cows reaching 90 days in milk. The following data were recorded for each animal: lactation number, daily milk pr...

In this paper, the potentials and constraints on estrus synchronization (ES) artificial insemination (AI) practice for dairy cattle producers were overviewed. Compared to other African countries, Ethiopia has large numbers of population. However, self-sufficiency in milk production is not yet attained due presence a lot limitations that hamper success ES mass AI many parts country such as impro...

The objective of this study was to compare the reproductive performance of anoestrous dairy cows treated just prior to the mating start date (MSD) with a Controlled Internal Drug Releasing Device (CIDR) which was placed intravaginaly for either 6 or 8 days, and a combination of oestradiol benzoate. Lactating dairy cows (n = 926) that had been diagnosed with anovulatory anoestrus were divided in...

The study was conducted to assess the effect of milk production, parity, stage of lactation, season and individual milk components themselves on milk urea nitrogen (MUN) concentration and other milk components of 3,219 Holstein dairy cows in Korean dairy farms. The MUN concentrations in Korean dairy cows were estimated to 16.68±5.87 mg/dl. Milk yield was negatively correlated with fat and prote...

Fertility data were collected every four weeks for 10 years from 40 herds of Holstein-Friesian dairy cattle. The data collected during 925 lactations from cows with cystic ovarian disease which were treated with 500 microg gonadorelin were compared with data from a control group of 13,869 normal lactations. The intervals between parturition and first insemination and between parturition and con...