Evaluation of a systemic antibiotic treatment of toxic puerperal metritis in dairy cows.

The objective of this study was to evaluate the efficacy and economic efficiency of a systemic treatment of toxic puerperal metritis in dairy cows with ceftiofur. Cows with abnormal vaginal discharge at a postpartum examination (d 4 to 6 after calving) and a rectal temperature > or = 39.5 degrees C were assigned to three treatment groups.

Synchronization of lactating dairy cows with prostaglandin F2 alpha: insemination on observed oestrus versus timed artificial insemination.

The effect of two insemination policies after synchronization of oestrus on reproductive performance in two groups of cows was investigated. Oestrus was synchronized by two treatments with prostaglandin F2 alpha (PGF2 alpha) at a 14-day interval. Cows in Group 1 (n = 234) were inseminated twice on appointment 66 and 90 h after the second treatment.

Effect of one spontaneous estrus cycle (after synchronization with PGF2alpha) on reproductive performance in dairy cows.

The objective of the study was to analyze the effect of a spontaneous estrus cycle after synchronization of estrus with prostaglandin F2alpha (PGF2alpha) in dairy cows on the degree of synchronization and reproductive performance. We assigned 557 Holstein cows to two treatment groups. In Group 1 estrus was synchronized by two treatments with 25 mg of Dinoprost-Trometamol in 14-day intervals.

Effect of teat dipping with a germicide barrier teat dip in late gestation on intramammary infection and clinical mastitis during the first 5 days post-partum in primiparous cows.

The effect of teat dipping with a barrier teat dip prior to parturition on intramammary infection (IMI) and clinical mastitis during the first 5 days post-partum was investigated in a split udder trial in 149 Holstein-Frisian heifers. Their left front and right hind quarters were dipped three times weekly (i.e.

Serum progesterone levels in post-partum dairy cows after repeated application of the prostaglandin F2 alpha analogue D (+) cloprostenol sodium.

Reproductive management programmes based on strategic use of prostaglandin F2 alpha (PGF2 alpha) to induce and synchronize oestrus in post-partum dairy cows are widespread. Repeated shortening of the oestrous cycle during early lactation in high-yielding dairy cows, however, could impair corpus luteum function and thus decrease fertility. The objective of this study was to analyse the effect of repeated treatments with the prostaglandin F2 alpha analogue D (+) cloprostenol sodium on progesterone concentrations indicative of a functional corpus luteum in post-partum dairy cows.

Effect of three programmes for the treatment of endometritis on the reproductive performance of a dairy herd.

Three management programmes to improve the reproductive performance of a dairy herd were compared in a prospective controlled field study on one commercial farm. A total of 542 cows were examined for endometritis 22 to 28 days postpartum and assigned to one of three treatment groups: in group 1 the cows with signs of endometritis were treated with an intrauterine infusion of 100 ml of a 2 per cent polycondensated m-cresolsulphuric acid formaldehyde solution; in group 2 the cows with signs of endometritis were treated with an intrauterine infusion of 125 ml of a 20 per cent eucalyptus compositum solution; and in group 3 all the cows were injected intramuscularly with 0.75 mg of tiaprost, an analogue of prostaglandin F2alpha (PGF2alpha) at two-week intervals, starting on day 43, until they were inseminated.

[Effect of puerperal mastitis in primiparous cows on milk production, cell count and culling].

A retrospective cohort study was performed to investigate the effect of clinical mastitis in heifers during the first week post partum (p.p.) on subsequent health and productivity.

[Individual animal risk factors for Prototheca mastitis in cattle].

Risk factors for mastitis caused by Prototheca zopfii were determined in a retrospective case control study. 248 cows culled for protothecal mastitis in a large dairy herd were included in the study. The diseased cows were compared to their non affected herdmates in respect to age, stage of lactation, production and milk composition.

[Reaction of the pituitary gland to a single GnRH administration in the dependence of energy balance in cattle in the puerperium].

After reviewing the relevant literature about the relationship of negative energy balance post partum and the onset of cyclicity the aim of this study will be described. The objective of this trial was to evaluate the influence of negative energy balance on the sensitivity of the pituitary for GnRH. Two groups of Holstein Friesian cows were randomly treated either with GnRH (Fertagyl) or a placebo.

Comparison of a conventional reproductive management programme based on rectal palpation and uterine treatment of endometritis with a strategic prostaglandin F2 alpha programme.

Two reproductive management programmes were implemented on a dairy farm with 780 cows in milk to compare their effects on reproductive efficiency and endometritis. The herd was divided into two groups. All cows in Group 1 received 0.

Culling policies in dairy herds. A review.

The culling decision is one of the most complex decisions in farm animal management. This article reviews concepts of culling, risk factors for cows to be culled, different culling policies and the present knowledge on how to develop an optimal culling policy. It is pointed out that there are major interactions between other management complexes and culling that influence the result of field research concerning risk factors for culling.

[Experiences with an Internet-based lecture script on animal obstetrics].

An internet based lecture script was developed on animal obstetrics to enhance the traditional lecture. The script summarizes the manuscript of the lecturer and contains additional information and reading materials. The script has approximately 600 pages and shows 400 slides, graphs and animations.

Immunohistological examination on the distribution of collagen types I, III, IV and V in bovine post partum placentomes.

This paper describes the in situ presence and distribution of collagen types I, III, IV and V in the bovine placenta. The objective was to determine whether there are qualitative and/or quantitative differences in the collagen content of placentomes originating from cows with retained placenta and cows with normal discharge of placenta. Twelve h post partum discharge of the placenta or the incidence of retained placenta was monitored.

Evaluation of different protocols for prostaglandin synchronization to improve reproductive performance in dairy herds with low estrus detection efficiency.

The objective of this study was to evaluate different PGF2 alpha protocols against control protocols for herds with estrus detection efficiencies of 35, 55, and 75% using modeling and simulation: 1) PGF2 alpha treatments based on the presence of a corpus luteum diagnosed by rectal palpation, 2) PGF2 alpha treatments based on the presence of a corpus luteum diagnosed by an on-farm milk progesterone enzyme immunoassay, and 3) PGF2 alpha treatments based on a 14-d fixed treatment schedule without prior screening for ovarian status. After the start of each protocol, estrus detection efficiency was 75% for 7 d after treatment and 35 or 0% for the following week. For the third protocol, an additional modification at estrus detection efficiencies of 85 and 55%, respectively, in the 1st and 2nd wk after treatment was evaluated to establish a protocol for best case assumptions.

[Evaluation of environmental factors on the fertility of heifers].

The investigations had the aim to find out the environmental influences upon the fertility performance of 8100 heifers in a big heifers farm. The different reproductive parameters were evaluated by the help of biostatistical methods. The evaluation of the different influences showed no effect in the relation of fertility and nutrition and fertility and seasonality.

Relationships between administration of GnRH, body condition score and fertility in Holstein dairy cattle.

The objective of this study was to determine the effect of GnRH treatment in dairy cows differing in body condition score. A total of 2437 primiparous and multiparous cows was allocated randomly to receive either GnRH (100 microg) or placebo at the post partum exam (25 to 35 d) and at the first breeding. Complete records were available from 1906 cows: Group 1 (n = 535) placebo and placebo; Group 2 (n = 489) GnRH and placebo; Group 3 (n = 438) placebo and GnRH; and Group 4 (n = 444) GnRH and GnRH.

Computer based instruction is effective to teach dairy reproductive management.

This paper describes a classroom experiment in a German College of Veterinary Medicine (Tieraerztliche Hochschule Hannover) using an instructional software package designed to increase dairy reproductive problem-solving skills. A pre-test/post-test experimental design demonstrated that learning occurred in an enjoyable environment when 21 4th year veterinary students used the program. Students' perception in respect to content, design, and usability criteria of the program were excellent to good.

A caesarean section model to characterize coagulation in the fetal and uterine circulation during late gestation in dairy cattle.

A study was conducted to measure a coagulation profile including prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen concentration (FIB), and plasminogen activity (PLA) in the jugular vein, umbilical vein and artery and uterine vein of 18 Holstein Friesian cows during late gestation. A caesarean section was performed on all cows before term in order to obtain blood samples from the different sources and to deliver the calves. Blood plasma obtained from the umbilical vein and artery had a longer prothrombin time but shorter activated partial thromboplastin time and lower concentrations of fibrinogen and plasminogen than peripheral blood plasma.

A dystocia and caesarean section model to characterize uteroplacental prostaglandin concentrations associated with retained placenta in dairy cattle.

Plasma concentrations of prostaglandin F(2a) (PGF(2a), 13, 14-dihydro-15-keto-prostaglandin F(2a) (PGFM), prostaglandin E(2) (PGE(2)) and 13,14-dihydro-15-keto-prostaglandin E(2) (PGEM) were determined by RIA in blood samples taken from the jugular vein and the uteroplacental circulation (umbilical vein, umbilical artery and uterine vein) of 13 Holstein Friesian cows during caesarean section. According to discharge of placenta cows were divided in 2 groups. Group I (shedding of placenta within 12 hours, NRP, n=8) and Group II (retained placenta, RP, n=5).

Maternal and fetal prostaglandin concentrations during late gestation in dairy cattle.

A study was conducted to measure the blood plasma concentrations of prostaglandin F2 alpha (PGF2 alpha), 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM), prostaglandin E2 (PGE2) and 13,14-dihydro-15-keto-prostaglandin E2 (PGEM) in the jugular vein, umbilical vein and artery and uterine vein of 18 Holstein Friesian cows during late gestation. A caesarean section was performed on all cows before term in order to obtain blood samples from the different sources. Plasma PG concentrations in the uterine or fetal circulation were significantly higher than in jugular vein plasma.

A comparison between in vitro fertilization and microinjection of immobilized spermatozoa from bulls producing spermatozoa with defects.

The objectives of this study were to compare the fertilization rate of bovine in vitro matured oocytes by in vitro fertilization (IVF) and by microinjection of a single spermatozoon (MI) and to relate these rates with fertility reported for these bulls in artificial breeding. Bull A (Holstein) had a nonreturn rate of 75%. Semen from this bull is routinely used in our standard IVF procedure.

Blood levels of prostaglandin metabolites (PGFM, PGEM) after parturition in cows with and without retained placenta considering spontaneous calving and dystocia.

Blood samples were taken from 71 Holstein Friesian cows at 0, 3, 24 and 48 hours after parturition. Peripheral plasma concentrations of prostaglandin F2 alpha and E2 metabolites (PGFM, PGEM) were determined by radioimmunoassay. The cows were divided into 4 groups, according to type of calving (spontaneous, dystocia) and discharge of placenta.

Fertilization of bovine oocytes after microsurgical injection of spermatozoa.

The objective of this study was to compare the fertilization rate of bovine oocytes matured in vitro (22, 25 or 28 hours) and in vivo (30 to 35 hours after standing estrus) following the microinjection of a single spermatozoon. A single motile spermatozoon was injected into the perivitelline space (Experiments 1 to 9), and a single immotile spermatozoon was injected into the ooplasm (Experiments 10 to 15). A single ejaculate of frozen-thawed semen was used throughout.

[The effect of gonadotropin releasing hormone (GnRH) and analogs on the conception rate in cattle. A critical literature review].

The objective of this article was to review the current literature of the influence of gonadotropin releasing hormone (GnRH) and GnRH agonists on conception rate in dairy cattle. The application of GnRH or agonists at artificial insemination (first and subsequent) and between days 7 and 34 after parturition were considered. The variations between studies were discussed as well as different mechanisms concerning the influence of GnRH for establishing pregnancy.

Coagulation profile in different stages of pregnancy and under consideration of placental expulsion in dairy cattle.

It was the aim of the present study to determine different parameters of blood coagulation in dairy cattle in the course of gestation (n = 19) and during 9 days post partum (n = 40). The coagulation profile comprised prothrombin time, partial thromboplastin time, thrombin time, fibrinogen concentration, and platelet count. Prothrombin time was shorter in the 2nd month of gestation (13.