Although the number of dairy farms is decreasing, that of large farms is increasing in Japan. Milk production in Japanese dairy cows has increased from 62 kg/year to 88 kg/year over the last 2 decades. However, Japanese dairy cows are experiencing a sustained decline in reproductive performance, calving intervals, and days open; further, the number of inseminations required for conception have ...

Oocyte fertilization rates in bovines following artificial insemination or natural mating are generally good (~90%). Curiously, only about one third of these pregnancies remain until 30 days post-AI in dairy cows. Thus, most pregnancies are lost between fertilization and early embryonic growth. Although classical pathways describing that lower progesterone post-AI is the main culprit to these e...

Reproductive efficiency in the dairy herd is the most important factor for its economic success and a major concern for dairy farmers when using artificial insemination (AI) or natural service (NS). Our objectives were to estimate, compare and analyse the costs associated with breeding cattle by do-it-yourself (DIY) AI and NS and identify the factors that influence them, under typical dairy far...

Uterine diseases in dairy cows can be classified as puerperal metritis, clinical metritis, clinical endometritis, and subclinical endometritis. These diseases are highly prevalent (affect between 20 and 30% of dairy cows) in high producing dairy cows and have been associated with decreased pregnancy per artificial insemination (AI), extended interval to pregnancy, increased culling, and economi...

treatments the cows were randomly assigned to two groups. One group of cows (n= 281) was fed 0.5 mg of melengestrol acetate (MGA) per head per day for ten days while the other group of cows (n= 257) served as controls. All cows were bled for progesterone concentrations at the beginning of the MGA feeding (d -21), before the SMB treatment, and at the time of artificial insemination (AI). Twenty-...

The investigation was expected to assess various mineral mixture supplementation impacts on Brahman crossbred cows' blood biochemical, hematological profiles and pregnancy rate. This study used ninety cows divided into three dietary treatment groups (n = 30/group). treatments were: Concentrate rice straw only as control treatment; diet + A-formulation MM-A B-formulation MM-B treatment. concentr...

the aim of this study was to evaluate the effect of ecg, pgf2α, and combination of ecg and pgf2α early postpartum on reproductive performance in high producing dairy cows. three hundred sixty eight postpartal holstein dairy cows were divided in 4 groups. cows in groups 1 and 2 received 500 iu ecg on day 8 ± 2 and cows in groups 3 and 4 received saline. cows in groups 1 and 3 received injections...

Efficient pasture-based milk production systems require a compact calving pattern aligned to the onset of the grazing season, a 365-day calving interval and low culling rates for infertility. Achievement of these targets requires high herd reproductive performance. While high genetic merit Holstein cows produce more milk in grass-based systems their fertility is compromised. Management of the m...

The failure of cows to successfully establish pregnancy after insemination is an important limiting factor for the efficiency of dairy production systems. The physiological reasons for this are many and pertain to the post partum and early pregnancy periods. Cows that suffer severe negative energy balance after parturition are prone to diseases (including uterine infection) that are, in part, e...

Large-scale artificial insemination services in Queensland date from 1955. In that year a bull-proving project was inaugurated for the purpose of locating dairy sires of outstanding genetic merit from Queensland studs. The project requires the artificial insemination of at least 1,000 cows each year in the Nambour region of south-east Queensland. In September, 1957, an artificial insemination c...