The effect of PGF-2 alpha on reproductive performance of naturally bred dairy cows with or without pyometra

Five hundred thirty-four naturally bred Holstein dairy cows from two Colorado dairies were examined $\text{per}$$\text{rectum}$ between 21 and 36 days after calving. Alternate cows in each herd received either 25 mg PGF-2 alpha or no treatment at the time of initial examination. No differences were found in days open or pregnancy rates between groups (P>0.25).Days open in 23 cows with pyometra were 98.7 ± 9.4, and 77.0 ± 2.2 in 493 herdmates without pyometra. The large inequalities in numbers precluded valid statistical comparisons between these groups. No overall difference (P>0.25) in reproductive performance was found in cows with pyometra treated at the initial examination compared to those not treated until two to four weeks after the initial examination. Contributing to the lack of significance were a number of cows with pyometra that had spontaneous cures before treatment was considered. Untreated cows that recovered spontaneously had better (P<0.05) reproductive performance than herdmates that required later treatments to initiate uterine evacuation. No overall advantage in reproductive performance was obtained by the routine treatment of postpartum dairy cows with PGF-2 alpha but treatment of cows with pyometra should not be delayed.     

Investigations into the potential for embryo transfer from Brucellaabortus infected cows without transmission of infection

Thirty-six attempts were made to isolate $\text{Brucella}$$\text{abortus}$ from the uterine flushings of culture positive and serologic reactor cows. Sixteen of these attempts were made after cows had been programmed for superovulation and a simultaneous attempt was made to recover eggs. Udder secretion samples for culture and blood for serology were collected at the time of the flushing procedure. In addition, a field isolate of $\text{Brucella}$$\text{abortus}$ suspended in three different solutions (one commonly used for nonsurgical embryo retrieval) was quantitated at various intervals up to 24 hours.Brucellae were not cultured from any of the uterine flushings although it was demonstrated that the organisms would remain viable in the media used for up to 24 hours. Udder secretions contained brucella at the time of flushing in 17 of the 36 attempts. Results indicated that transfer from infected donors might be achieved without transfer of infection. It is cautioned that final evidence of success would have to come after recipients had undergone serologic and cultural surveillance through their gestation period.     

Non-specific uterine infection and bovine fertility. I. Infection patterns and endometritis during the first seven weeks post-partum

From a total of 93 dairy cows which were sampled repetitively throughout the non-gravid period, 14 cows developed persistent purulent endometritis, failed to complete uterine involution and were chronically infertile. The remaining 79 cows had completed uterine involution prior to 50 days post-partum. Forty-seven of these cows subsequently proved to be fertile and 32 cows were infertile. Fertility was not influenced by the variable uterine flora or by the endometritis which was found in all the cows within the first two weeks post-partum. Cows which had uterine infection with $\text{Corynebacterium pyogenes}$ subsequent to Day 21 developed severe endometritis and were almost invariably infertile to the first service. Fertility to subsequent services was not necessarily impaired in those cows which eliminated $\text{C. pyogenes}$ sufficiently early to allow complete uterine involution prior to Day 50. Cows with abnormal oestrous cycles were not particularly susceptible to uterine infection.In all the cows the composition of the uterine flora fluctuated constantly throughout the first 7 weeks pp. as a result of spontaneous contamination, clearance and recontamination. Contamination of the uterus by other non-specific bacteria during the 3 to 4 week period which is required for resolution of severe endometritis induced by $\text{C. pyogenes}$ could lead to a false correlation between the endometritis and the bacterial flora as determined by a single sample. It is concluded that the information which is derived from $\text{in vivo}$ sampling of the uterus in clinically normal cows during the first 7 weeks pp. is of little value in predicting subsequent fertility.     

Uterine infections in the postpartum cow: II. Possible synergistic effect of Fusobacteriumnecrophorum and Corynebacteriumpyogenes

Clinical conditions, which were observed in primiparous Angus and Hereford heifers with postpartum uterine infections are reported. Forty-three of sixty-four cows (67%) had uterine infections. $\text{Corynebacterium}$$\text{pyogenes}$ and $\text{Fusobacterium}$$\text{necrophorum}$ were the most frequently isolated aerobe and anaerobe, respectively. Twelve of the sixty-four cows (18.8%) had infections that involved these species. Three of these twelve cows were infected only with $\text{C.}$$\text{pyogenes}$, two were infected only with $\text{F.}$$\text{necrophorum}$, and seven were infected with both organisms. All five of the cows which were infected with either $\text{C.}$$\text{pyogenes}$ or $\text{F.}$$\text{necrophorum}$ showed signs of estrus and four of the five cows conceived by 110 days postpartum. The single cow that did not conceive was infected with $\text{C.}$$\text{pyogenes}$. Three of the seven cows which were infected with both organisms showed signs of estrus and none of the seven cows conceived by 110 days postpartum. In addition, when only $\text{C.}$$\text{pyogenes}$ or $\text{F.}$$\text{necrophorum}$ was isolated from the uterus, cows had either mild or no clinical signs of infection. In contrast, the seven cows which were infected with both organisms had severe clinical signs of infection that included excessive vulvar discharge, uterine abscesses and pelvic adhesions. These observations suggested that a pathogenic synergism between $\text{C.}$$\text{pyogenes}$ and $\text{F.}$$\text{necrophorum}$ might have caused the increased severity of postpartum uterine infections, and the subsequent detrimental effect on return to estrus and conception.     

Postpartum Reproductive Performance in Dairy Cows in Relation to Phosphorus Status

The levels of inorganic phosphorus in blood samples from two cow populations were related to reproductive performance. Group I comprised 305 dairy cows from 17 herds with normal fertility. The herds were visited every 2–4 weeks. Blood samples were collected from animals between 4 weeks prior to expected calving and subsequent confirmed pregnancy. The individual mean plasma phosphorus level in samples collected from 0–90 days after calving in cows which conceived following insemination (n = 262) was related to reproductive performance. Group II comprised cows from 47 herds with reproductive problems. The herds were visited once during the indoor season for blood sampling. Mean herd serum phosphorus levels were related to herd reproductive performance registered during a period from 6 months before to 9 months after the time of blood sampling. Overall mean herd phosphorus levels were 1.51 ± 0.08 mmol/1 plasma (±SD) (Group I) and 1.77 ± 0.16 mmol/1 serum (±SD) (Group II). In Group I (indivu-dual cows), the coefficient of correlation between phosphorus levels and elapsed time from calving to pregnancy was low (r = 0.10, p<0.1). In Group II (herds) significant correlations were observed between the fertility status index (FS), the average number of days from calving to last insemination and phosphorus levels (rs = 0.32, P <0.05 and rs p <0.05, respectively). The mean herd phosphorus levels were within normal limits in both groups. Although increased phosphorus levels were associated with lower fertility in both groups, the amount of the total fertility variation which could be explained by phosphorus levels was small.     

An attempt to isolate Brucellaabortus from uterine flushings of brucellosis-reactor donor cattle

Two experiments were conducted to test for the recovery of brucella organisms from uterine flushings and harvested embryos of sero-positive embryo donor females. In Experiment I, 16 sero-positive cows were superovulated with FSH treatments and artificially inseminated at 12, 24 and 36 hours following the onset of estrus with brucella-free semen. At 48 hours after the onset of estrus, one half the potential donor females were administered an intrauterine inoculation of 3.3 to 4.6 × 10⁴$\text{Brucella}$$\text{abortus}$ (strain 2308) organisms while the remainder received a control inoculation. In Experiment II, the same 16 cows were similarly administered superovulatory treatments and inseminated following estrus. The uterine inoculation was increased to 1.5 to 2.5 × 10⁸ organisms administered 48 hours following estrus. Samples of recovered flushing medium and homogenized embryo residues were placed into a validated $\text{in}$$\text{vitro}$ culture system to detect the presence of brucella bacteria. Uterine flushings and embryos recovered from 31 females exhibiting estrus following FSH treatments were free from either field strain or the inoculated $\text{B.}$$\text{abortus}$ (strain 2308) contamination. The flushings obtained from a single female, which did not respond with estrus following FSH treatment but was inoculated at appointment, did contain $\text{B.}$$\text{abortus}$ which was identified as the inoculated strain 2308 and not field strain organisms. These results indicate that brucella contamination of flushing media and harvested embryos will not likely be incurred when collecting embryos from sero-positive donor females. These findings offer further encouragement for the use of embryo transplantation as a method to produce brucella-free offspring from infected cows.     

Effect of Dermatophiluscongolensis infection on reproductive performance of dairy cattle

The effect of $\text{Dermatophilus}$$\text{congolensis}$ on reproductive performance and milk production of dairy cattle was investigated using a prospective cohort study design. The following results were obtained: the calving to conception interval was 122 vs 104 days (P<0.05) for cows with lesions (cases) and those without lesions (non-cases), respectively; the 180-day pregnancy rate was 70.3% vs 84.3% (P<0.02) for cases and non-cases, respectively; the interval to first service was 69 days for cases and 64 days for non-cases (P<0.05) and the interval from first to second service was 32.7 days for cases and 49.4 days (P<0.01) for non-cases. The prevalence of cows with lesions was 33% ($\text{66}\text{200}$). Lesions were most commonly found on the skin covering the coccygeal and sacral vertebrae and the gluteal muscles. White skin had a greater prevalence of lesions than did black skin (P<0.05).     

Synchronized breeding in cattle using PGF2α and LHRH/FSHRH stimulatory analogs

Two studies were conducted to synchronize breeding in cattle using PGF₂α and LHRH/FSHRH analogs. In the first study, 60 mature lactating Angus cows were assigned at random to 4 treatment groups: saline and saline (SS); 30 mg PGF₂α tham salt + saline (PS); saline + 2 mg D-ala⁶-des-GlyNH₂¹⁰ LHRH/FSHRH ethylamide (D-ala⁶) (SA); 30 mg PGF₂α tham salt + 2 mg D-ala⁶ (PA). The first letter of the two-letter code for each group always indicates a dual injection at an 11-day interval. PGF₂α or saline was administered intramuscular (im) twice at an 11 day interval. D-ala⁶ or saline was administered 48 hr after PGF₂α treatment. In the SA group, the D-ala⁶ was administered at first signs of estrus, and cows were then artificially inseminated (AI) 24 hr later. All cows in the PS group were inseminated 72 hr after the second PGF₂α injection. In the SS group, cows were inseminated 24 hr after first signs of estrus. An additional 6 mature lactating Angus cows were added equally to the PS and PA groups to evaluate changes in serum LH. The percent calf crops was: SS = 40% (frsol|6/15); PS = 47% ($\text{7}\text{15}$); SA = 47% ($\text{7}\text{15}$); PA = 53% ($\text{8}\text{15}$). In the second study, 51 mature lactating Angus cows and 39 Holstein heifers were assigned at random to 3 treatment groups: saline + saline (SS); 33.4 mg PGF₂α tham salt + saline (PS); 33.4 mg PGF₂α tham salt + 1 mg D-leu⁶-des GlyNH₂¹⁰ LHRH/FSHRH ethylamide (D-leu⁶) (PL). PGF₂α tham salt or saline was administered im twice at an 11 day interval. D-leu⁶ or saline was administered 68 hr following the second PGF₂α treatment. Cows pretreated with PGF₂α were inseminated 80 hr after the second PGF₂α injection. In the SS group, cows were administered saline at the time of natural estrus and were artificially inseminated 12 hr later. Calving percent to the first AI was SS = 70% ($\text{21}\text{30}$); PS = 53% ($\text{16}\text{30}$) and PL = 40% ($\text{12}\text{30}$). An additional 10 mature lactating Angus cows were used to evaluate changes in serum LH. Five of the cows were assigned to the PS treatment and five to the PL treatment. Sequential blood samples were collected to monitor serum LH levels. Using the Chi-square test, there were no significant differences between calving percentages of the control and PGF₂α treated cows in either study. These results indicate that the PGF₂α treatments were successful in timed artificial insemination of cows without detection of estrus. The LHRH/FSHRH analogs did not improve the conception even though they appear to induce a pituitary release of LH simultaneously in all cows within 1 hr of treatment.     

Studies of bovine genital tracts: Mycoplasma isolations from dairy cows

Mycoplasma was isolated from the genital tracts of 8 of 96 culled dairy cows. Procedures were used to reduce the possibility of uterine contamination by vaginal fluids. The mycoplasma isolates were identified by the fluorescent antibody technique as: $\text{Mycoplasma bovigenitalium}$ (4), $\text{M. canadense}$ (1), an untyped bovine pathogen from the mammary gland designed as ST-6 (2), and an isolate that could not be identified with the labeled antibodies used in this study. All isolations were made from vaginal swabs, except in one case of pyometra where $\text{M. bovigenitalium}$ was isolated concurrently from the uterus and vagina, along with $\text{Pasteurella hemolyticum}$. These results suggest that mycoplasma may be found in the cervico-vaginal flora of some cattle but are rarely isolated from the uterine environment.     

Intestinal calcium and phosphate transport in genetic hypophosphatemic mice

Serum phosphate, serum calcium, intestinal phosphate and intestinal calcium transport were measured in normal ($\text{C57BL}\text{6J}$ +/Y) and genetic (X-linked) hypophosphatemic mice ($\text{C57BL}\text{6J}\text{Hyp}\text{Y}$). The hypophosphatemic mice had low serum phosphorus levels and dramatically decreased intestinal phosphate transport compared with normal controls. On the other hand, normal and hypophosphatemic mice had equivalent levels of intestinal calcium transport. The hypophosphatemic mice did illustrate a slightly decreased serum calcium concentration, however. Administration of 1,25-dihydroxy-vitamin D₃, the principal active metabolite of vitamin D, stimulated intestinal calcium transport but not intestinal phosphate transport in the genetic hypophosphatemic mice. The results obtained are consistent with the hypothesis that the primary metabolic disturbance in familial hypophosphatemia involves a defect in phosphate transport mechanisms.     

Uterine infections in the postpartum cow: I. Effect of dietary crude protein restriction

The relationship between adequate (0.96 kg per head daily) and deficient (0.32 kg per head daily) intake of crude protein between 150 days prepartum and 110 days postpartum and the incidence of postpartum infections in the bovine uterus was studied. The incidence of infection at 25 days postpartum was 52.2% and 48.1% (P > .10) for cows in the protein adequate and protein deficient groups, respectively. However, at 40 days postpartum, 21.7% of cows in the protein adequate group had infections $\text{vs}$ 51.9% (P < .05) of cows in the protein deficient group. In addition, the incidence of infection within the protein adequate group between sampling times was different (P < .10); whereas, the incidence within the protein deficient group between sampling times was not different (P > .10). Eighty-three bacterial isolates representing 27 species were recovered from the total of 100 samples. $\text{Corynebacterium}$$\text{pyogenes}$ and $\text{Fusobacterium}$$\text{necrophorum}$ were the most frequently isolated aerobe and anaerobe, respectively. Although there was no difference between diets (P > .10), these two organisms occurred most frequently in cows on the protein deficient diet and were associated with clinically severe uterine infections. These data suggest that the amount of crude protein in the diet affects both the incidence and duration of postpartum infections in the bovine uterus.     

Chronic treatment with valium (diazepam) fails to affect the reproductive system of the male rat

Male rats treated chronically with high doses of Valium (50mg/ Kg/day; 10 days) failed to exhibit changes in their reproductive system. Testicular and prostate weights, serum testosterone (T) and LH were unaffected. Testes and pituitary tissue stimulated $\text{in}$$\text{vitro}$ with LH and GnRH, respectively, released normal amounts of T, LH and FSH. Brain benzodiazepine receptors were slightly but significantly elevated by Valium treatment as well as by castration. We conclude that the male reproductive system is resistant to chronic Valium treatment even though the brain levels of benzodiazepine receptors are not.     

Effects of prostaglandins on peripheral progesterone and uterine diamine oxidase in the pregnant hamster

Serum progesterone and uterine levels of diamine oxidase (DAO) activity were determined during pregnancy in hamsters. Progesterone was elevated on Day 1 of pregnancy, had a transient peak on Day 5, remained relatively constant on Days 6–10, and then increased on Days 13 and 14. Uterine DAO activity could not be detected until Day 7 of pregnancy, approximately 1 $\text{1}\text{2}$ days after the initiation of implantation. DAO activity was associated with placental tissue, and more than 90% of the activity was localized in the maternal placenta. The temporal relationship between changes in serum concentrations of progesterone and uterine levels of DAO activity following PG administration also was studied. Serum progesterone was significantly depressed by 6 hr after treatment with PGs on Day 7 of pregnancy. However, uterine levels of DAO activity at 6 hr in the treated animals were not different from those in control animals. In contrast, both the serum progesterone concentrations and uterine levels of DAO activity were significantly lower at 24 hr after PG treatment. The effects of PG treatment on uterine DAO activity were completely blocked by concomitant administration of progesterone. However, concomitant administration of Provera® only blocked the effect of one PG analog that was tested (9-deoxo-9-methylene-16,16-dimethyl0-PGE₂). The data indicate that changes in uterine DAO activity following treatment with the PGs used here are primarily a consequence of a decrease in peripheral progesterone (i.e. a luteolytic effect of the PG).     

Estradiol-17β effects on lipid and carbohydrate metabolism and on the induction of a yolk precursor in goldfish, CarassiusAuratus

The effects of estradiol-17β treatment on plasma lipid levels, liver lipid and glycogen reserves were examined during different phases of the reproductive cycle in goldfish, $\text{Carassius}$$\text{auratus}$. Estrogen therapy resulted in increased plasma and hepatic lipid levels except during the spawning season. Hepatic glycogen deposits were depleted by estradiol injections during all seasons. Treatment of fish with the estrogen antagonist, CI-628, during the spawning season caused a reduction in plasma and liver lipid levels. Electrophoretic studies conducted during the post-spawning season showed that estrogen induces the appearance of a specific lipoprotein, probably a yolk precursor, in the serum and liver of goldfish.     

Attachment of porcine blastocysts to fibroblast monolayers in vitro

The objective of this study was to compare the ability of porcine blastocysts to attach to various cellular and non-cellular substrates $\text{in vitro}$. One hundred twenty-two hatched blastocysts were collected from 17 handmated gilts and sows at slaughter. Blastocysts were randomly assigned to one of four treatments: Minimal Essential Medium (MEM) supplemented with 10% (v/v) heat treated fetal calf serum (HTFCS), monolayers of bovine uterine fibroblasts in MEM + 10% HTFCS (Buf), monolayers of bovine testicular fibroblasts in MEM + 10% HTFCS (Btes), and MEM + 10% HTFCS exposed to uterine fibroblasts for 24 hr to condition the medium (cMEM). Embryos were cultured individually in 24 well Linbro culture plates at 37 C in a humidified gas atmosphere of 5% CO₂ in air. Embryos were observed at 24 hr intervals by phase contrast microscopy (100X) and measured with an ocular micrometer. Blastocyst attachment was greater (P < .01) in Buf ($\text{21}\text{35}$) compared to MEM ($\text{7}\text{32}$), cMEM ($\text{9}\text{28}$), and Btes ($\text{1}\text{27}$). Embryo diameter was greater (P < .05) 24 hr prior to attachment in Buf compared to the other treatments. In addition, trophoblast monolayers continued to proliferate for 20 days when cocultured with uterine fibroblasts. These observations suggest that uterine fibroblasts provide a superior substratum for blastocyst attachment and the maintenance of swine trophoblast cells $\text{in vitro}$.     

Uteroplacental dysfunction and prostaglandin metabolism in zinc deficient pregnant rats

Relationships between perinatal mortality, disrupted uteroplacental function and prostaglandin metabolism have been studied in Zn-deficient rats. Uterine contractility $\text{in vitro}$, placental blood flow $\text{in viro}$, and uterine and placental prostaglandin synthesis from [1?¹⁴C] arachidonic acid $\text{in vitro}$ were investigated at day 22 of pregnancy. High amplitude uterine contractions were almost completely eliminated and utero-placental blood flow was decreased by 85% by Zn deficiency. Synthesis of [1?¹⁴C]-prostaglandin E₂, F_2α and 6-keto-F_1α from [1?¹⁴C] arachidonic acid decreased significantly in uterine tissue but increased in placentae. These possibly inter-related effects may contribute to the high perinatal mortality observed in Zn deficiency.     

Effect of dietary phosphorus on reticuloendothelial clearance of salmonella organisms in endotoxin treated guinea pigs

Guinea pigs fed purified diets that contained either 0.4% or 1.0% of phosphorus were injected intraperitoneally with crude $\text{Salmonella typhimurium}$ endotoxin. Functional activity of the RES was evaluated after endotoxin administration by determining the initial clearance rates of non-viable ³²P-labeled $\text{Salmonella typhimurium}$. Three days after administration of endotoxin the RES clearance rates were approximately $\text{2}\text{1}\text{2}$ times greater in animals fed 1.0% than in those fed 0.4% of dietary phosphorus. After the RES response had risen to a maximum (5–6 days), there was no difference between dietary groups and RES clearance rates remained high throughout an 18-day period. The increased clearance rate induced by endotoxin involved largely the liver RES. Endotoxin administration led to a decrease in blood inorganic phosphorus in both dietary groups but the concentration in those fed the higher phosphorus level remained significantly higher. It was concluded that the protective action of high phosphorus is mediated at least in part by its beneficial effect on RES function.     

Release of LH after administration of an analog of synthetic LH-RH in cattle

The $\text{in vivo}$ effect of an analog of LH-RH, (Des-Gly-NH₂¹⁰, Proethylamide⁹)-LH-RH, on LH release, was studied in one bull with azooapermia, and one cow with cystic follicle. The single intravenous injection of 100 μg LH-RH analog caused abrupt and marked increase in serum LH and the high levels of LH were maintained for 3 hours. The highest levels of serum LH were 48 and 114 times as high as the pre-treatment levels in a bull and a cow, respectively. Further studies are being undertaken to evaluate this compound for improving reproductive function in cattle.     

Induced parturition in dairy cattle: A comparison of a corticoid (flumethasone) and a prostaglandin (PGF2α) in different age groups

Parturitions were induced in 66 dairy cows and heifers of the German Black Pied breed, 11 to 13 days before term, using either a highly potent corticosteroid (flumethasone: 2 × 5 mg, 10 to 14 hr apart), or prostaglandin F_2α (20 mg i.v.) and initiating treatments either in the morning (A.M.) or late afternoon (P.M.). At those dose levels parturition was induced in $\text{50}\text{50}$ animals treated with flumethasone, and in $\text{9}\text{9}$ heifers, but only in $\text{5}\text{7}$ cows treated with PGF_2α; placentas were retained in all cases in which parturition was induced. Intervals between initiation of treatments and parturition were shorter in flumethasone-treated animals (flumethasone: 42.5 hr; PGF_2α 57.2 hr); with both drugs, they were approximately 10 to 15 hr shorter in younger animals. The first flumethasone treatment at P.M. prolonged the intervals to parturition in cows (first treatment A.M.: 37.8 hr; P.M.: 52.9 hr), but not in normal age heifers (A.M.: 27.6 hr; P.M.: 25.9 hr); in early bred heifers, this trend was reversed (A.M. 41.6 hr; P.M.: 31.8 hr). No circadian differences in response to PGF were noted. Mean intervals to postpartum conceptions were 93 and 94 days for PGF_2α-treated cows and heifers, and 123.5 and 125 days for flumethasone-treated cows and heifers, respectively.