The objectives of this presentation are to review results of our previous and on-going research with respect to the risk factors and consequences of poor reproductive performance in dairy cows, and to develop an economic framework to optimize decisions related to dairy cow reproductive performance. To make profitable breeding and replacement decisions, the farmer must account for factors includ...

This study was designed to determine the effects of GnRH administration alone at time artificial insemination (AI) or in combination with hCG 5 days after injection on conception rates postpartum dairy cows. Cows estrus, without any reproductive health problem, between 70-120 were randomly assigned 3 equal groups. Buserelin acetate (10 µg), administered AI Group I (n=40). II (n=40) first μg) an...

Vinkler A., E. Kudlac, A. J ii'icek: Some Factors Influencing the Results of Conception in Cows and Heifers in Estrus Synchronized by the Synthetic Analogue of PGF2<x Cloprostenol. Acta vet. Brno, 51, 1982: 81-89. A study of the contribution of the breeding bull, the work of the operator and the influence of the size of the synchronized group on the conception rate in breeding cows after a firs...

This trial evaluated the reproductive performance in an early routine oestrus induction programme using two different PGF2α preparations in dairy cattle. D-cloprostenol sodium (n = 192; Group A) or dinoprost (n = 187; Group B) was administered between days 35 and 42 post partum. Also, a group of non-treated cows (n = 135; Group C) was included as control. Pedometers were used to detect oestrus,...

This study investigated the improvement in genetic evaluation of fertility traits by using production traits as secondary traits (MILK = 305-d milk yield, FAT = 305-d fat yield, and PROT = 305-d protein yield). Data including 471,742 records from first lactations of Denmark Holstein cows, covering the years of inseminations during first lactations from 1995 to 2004, were analyzed. Six fertility...

A reproductively efficient beef cow herd is fundamental to meeting the protein and specifically, red meat demand of an ever increasing global population. However, attaining a high level of reproductive efficiency is underpinned by producers being cognisant of and achieving many key targets throughout the production cycle and requires significant technical competency. The lifetime productivity o...

The objective of this study was to determine the effect of dietary P concentrations of 0.37 (recommended) or 0.57% (excess; dry matter basis) on reproductive performance. At calving, Holstein cows were randomly assigned to 1 of 2 dietary treatments (n = 134 for 0.37% P and n = 133 for 0.57% P). Cows were fitted with a radiotelemetric transmitter (50 d in milk [DIM]) to record mounting activity ...