Comparison of oestrus synchronisation programmes in dairy cattle using oestradiol benzoate, short-acting progesterone and cloprostenol, or buserelin and cloprostenol

Controlled breeding and reproductive management in water buffaloes (Bubalus bubalis) using Eazi Breed controlled internal drug release

Buffalo reproduction is considerably affected by late maturity, poor oestrus symptoms and long postpartum periods. This study was undertaken to evaluate the efficiency of Eazi Breed controlled internal drug release (CIDR), an intravaginal progesterone-releasing device, in relation to oestrus and fertility. Five hundred true anoestrus buffalo cows, in the age group 4–6 years in 10 villages of Dharwad district in Karnataka state in India, were randomly selected and treated with CIDR for 9 days. Two mL of Cidirol (1 mg oestradiol benzoate) was administered intramuscularly to all animals on day 10. Forty-two buffaloes (8.4%) that failed to show oestrus signs (1.6%) or showed weak signs of oestrus (6.8%) after the first treatment were treated again 72 h after the Cidriol injection with a new device, and inseminated after the expression of oestrus. After the second treatment all the animals showed oestrus signs. The percentage of buffaloes showing intense oestrus was 67.40%, intermediate oestrus was shown by 25.80%, whilst 6.80% buffaloes showed weak oestrus even after the second treatment. The buffaloes showing oestrus signs were inseminated twice with an interval of 12 h, starting 12 h after the start of the oestrus signs. In 86 buffaloes showing prolonged oestrus signs a third insemination was done. The conception rates were 85.16%, 60.47% and 44.11% respectively in buffaloes showing intense, intermediate and weak oestrus. Transrectal palpation of the genital tract was performed 45–60 days post-insemination to diagnose pregnancy status, and in doubtful cases pregnancy was reconfirmed at 90 days after insemination. Out of 500 buffaloes treated in this way 380 animals became pregnant and the pregnancy rate was 76%. This study revealed the usefulness of Eazi Breed CIDR along with Cidirol treatment in buffaloes to improve their reproductive performance.

Advances in bovine theriogenology in New Zealand. 2. Breeding management and technologies for improved reproduction

The importance of submission rates (SR) on conception patterns in dairy herds during a short artificial breeding (AB) programme was first reported in 1973. Subsequent research has focussed on achieving 3-week SRs of 90% through improved detection of oestrus utilising tailpainting and vasectomised bulls fitted with chin-ball harnesses. Despite nutritional limitations of spring pasture as a sole diet, conception rates to first insemination of 65% have been recorded in cycling cows in many trials. Anovulatory anoestrus (AA) has become a major factor compromising SRs as well as reducing average conception rates and herd in-calf rates by 4-7 weeks after the planned start of mating (PSM). Whole herd synchronisation programmes have been developed but not widely used on dairy cows and have had only limited use on dairy heifers, despite a focus on concentrated conception patterns. The related technologies have become most commonly used to increase the SR of AA cows. Extreme variation in the weekly demand for processed semen in seasonally-intensive AB programmes has been accommodated by the development of a unique semen diluent, Caprogen. Its use has allowed sperm to be temporarily stored without freezing and used at dose rates of 1 million sperm/insemination. Sire variation with this form of semen processing is lower than with deep frozen semen. The greater use of production genes derived from Holstein-Friesian sires of North American origin in most AB programmes has left progeny with reduced reproductive performance. This effect has been greater than that associated with the increased productivity of dairy cows achieved through continued use of semen from intensively selected groups of progeny tested sires.