Economic values for calving performance in first and later parities were estimated for the Piemontese cattle. Calving performance is a threshold trait usually recorded using a scoring system with categories corresponding to the rate of difficulty. In the Piemontese breed five categories were adopted (from unassisted to foetotomy). A normal underlying distribution with thresholds corresponding t...

The objectives were to characterize repeat breeding in dairy cows, including reproductive performance and risk factors. Data from 613 Holstein Friesian cows in nine dairy herds across Japan were enrolled. A repeat breeder was defined as a cow that did not become pregnant after three inseminations, despite no clinically detectable reproductive disorders. In contrast, cows that became pregnant wi...

Replacing toxic, wild-type Neotyphodium coenophialum-infected tall fescue (E+) with nontoxic, N. coenophialum-infected tall fescue (NE+) has improved cow performance, but producer acceptance of NE+ has been slow. The objective was to compare performance by spring- and fall-calving cows grazing either E+ or NE+ at different percentages of the total pasture area. Gelbvieh×Angus crossbred cows (n=...

Oestrus and ovarian activity were studied in a group of crossbred SahiwalShorthorn beef cows over four lactation periods of varying length throughout different seasons of the year. In the first lactation, cows were in poor condition (body weight 303 kg) and the mean interval from calving to first oestrus was 2202 16 days. Five COWS were still anoestrus 18 months after calving and were culled. T...

In modern high-yielding dairy herds fertility is of major economic importance. In order to gain maximum profit, calving intervals should not exceed 365 days. The achievement of a 365-day calving interval requires an early resumption of ovarian activity, an excellent oestrus detection, and a high first-service conception rate. Especially the inability to detect oestrus and to mate the cows by 60...

than to calf birth weight alone. Percent calving difficulty is the percentage of births requiring assistance from the herdsman. Calving scores of3 or higher were classified as difficult births based on a scoring system ranging from I = no assistance to 5 = caesarian birth or abnormal presentation. Due to the substantially higher incidence of calving difficulty in 1978 over 1979 (11.3 percent vs...

The aim of this study was to determine the factors affecting stillbirth and the consequences of stillbirth on longevity, production, and reproductive performance in Holstein cows of Iran. Calving records from March 2000 to April 2009 comprising of 220,043 calvings on 102,199 cows in 33 herds were used. The results showed that 4.06% of the newborn calves died within 48 h of birth. The stillbirth...

This thesis consists of studies concerning the effects of dry period energy feeding, and early lactation energy and protein feeding on the metabolic and hormonal status, tissue mobilisation and lactation performance in dairy cows. In all studies, restricted amounts of grass silage were fed during the dry period, and lead feeding with concentrate was applied during the last three weeks of pregna...

Our objective was to compare the effects of different prepartum dietary phosphorus concentrations on periparturient metabolism and performance. Forty-two late pregnant multiparous Holstein cows were fed 0.21, 0.31, or 0.44% P (dry basis) for 4 wk before expected calving. After parturition, all cows were fed a common lactation diet (0.40% P). In the prepartum period, cows fed 0.21% P had lower b...

The effect of bull exposure on the resumption of estrous activity following parturition was studied in an experiment using mature Hereford and Hereford X Angus beef cows. In the spring of 1981 and 1982, cows were assigned by breed and calving date to one of two treatment groups. Cows were exposed to bulls either from 3 to 85 d postpartum (BE; n = 45, 1981; n = 35, 1982) or from 53 to 85 d postp...