Effect of lonophore supplementation on selected serum constituents of sheep consuming locoweed

The effects of ionophore supplementation on selected serum constituents of sheep consuming locoweed were investigated. Sixteen sheep were allotted by weight to a 2x2 factorial arrangement of treatments: 1) no locoweed, no lasalocid, 2) no locoweed, 0.75 mg lasalocid/kg BW, 3) 0.5 mg swainsonine/kg BW, no lasalocid, 4) 0.5 mg swainsonine/kg BW, 0.75 mg lasalocid/kg BW. Swainsonine was provided by locoweed (Oxytropissericea), and sheep were fed a blue grama based diet at 2.5% BW for a 35 d treatment period. Diets were formulated to be isocaloric and isonitrogenous. Blood samples were collected on d 1, 7,14, 21, 31 and 35 to determine serum swainsonine concentration, alkaline phosphatase, total iron, aspartate aminotransferase, g-glutamyltransferase, and lactate dehydrogenase activity and total cholesterol, and triglyceride concentrations. No lasalocid by locoweed interaction (P > 0.4) was noted for any response variable measured. Average daily gains (P = 0.4) and orts (P = 0.7) were not affected by the treatments. No lasalocid treatment (P = 0.7) or day (P = 0.1) effect of serum swainsonine was observed. A locoweed by day interaction (P < 0.0001) of serum alkaline phosphatase was detected. Alkaline phosphatase levels were elevated (P < 0.01) for locoweed treated sheep at 24 h following initial exposure and remained elevated throughout the trail. Total iron was suppressed (P < 0.08) in locoweed fed sheep. A day effect (P < 0.02) was observed for serum iron. However, no linear, quadratic, or cubic effects of day were noted (P >0.2). A locoweed by day interaction (P < 0.0001) of serum aspartate aminotransferase and g-glutamyltransferase was detected. Aspartate aminotransferase levels were elevated (P < 0.0001) by d 7 for locoweed treated animals and remained elevated throughout the trial. g--Glutamyltransferase levels were suppressed (P < 0.0001) by day 7 for locoweed treated animals and remained suppressed throughout the trial. A locoweed by day interaction (P = 0.06) of serum cholesterol was detected. However, no linear, quadratic, or cubic effects of day were detected (P = 0.2). Lasalocid treatment had no effect on any serum constituent measured. Use of lasalocid in grazing animals should not increase the likelihood of locoweed intoxication.     

The toxicology mechanism of endophytic fungus and swainsonine in locoweed

Locoweed is a perennial herbaceous plant included in Astragalus spp. and Oxytropis spp. that contains the toxic indolizidine alkaloid swainsonine. The livestock that consume locoweed can suffer from a type of toxicity called locoism. There are aliphaticnitro compounds, selenium, selenium compounds, and alkaloids in locoweed. The toxic component in locoweed has been identified as swainsonine, an indolizidine alkaloid. Swainsonine inhibits lysosomal a-mannosidase and mannosidase II, resulting in altered oligosaccharide degradation and incomplete glycoprotein processing. Corresponding studies on endophytic fungi producing swainsonine have been isolated from a variety of locoweed, and these endophytic fungi and locoweed have a close relationship. Endophytic fungi can promote the growth of locoweed and increase swainsonine production. As a result, livestock that consume locoweed exhibit several symptoms, including dispirited behavior, staggering gait, chromatopsia, trembling, ataxia, and cellular vacuolar degeneration of most tissues by pathological observation. Locoism results in significant annual economic losses. Therefore, in this paper, we review the current research on locoweed, including that on locoweed species distribution in China, endophyte fungus in locoweed, the toxicology mechanism of locoweed, and the swainsonine effect on reproduction.     

The pathogenesis and toxicokinetics of locoweed (Astragalus and Oxytropis spp.) poisoning in livestock

Locoweed poisoning is a chronic disease that develops in livestock grazing for several weeks on certain Astragalus and Oxytropis spp. that contain the locoweed toxin, swainsonine. The purpose of this review is to present recent research on swainsonine toxicokinetics and locoweed-induced clinical and histologic lesions. Swainsonine inhibits cellular mannosidases resulting in lysosomal storage disease similar to genetic mannosidosis. Diagnosis of clinical poisoning is generally made by documenting exposure, identifying the neurologic signs, and analyzing serum for alpha-mannosidase activity and swainsonine. All tissues of poisoned animals contained swainsonine, and the clearance rates from most tissues was about 20 hours (T1/2 half life). The liver and kidney had longer rate of about 60 hours (T1/2). This suggests that poisoned animals should be allowed a 28-day withdrawal to insure complete swainsonine clearance. Poisoning results in vacuolation of most tissues that is most obvious in neurons and epithelial cells. Most of these histologic lesions resolved shortly after poisoning is discontinued; however, some neurologic changes are irreversible and permanent.     

Effect of subacute swainsonine (locoweed; Oxytropis sericea) consumption on immunocompetence and serum constituents of sheep in a nutrient-restricted state

The subacute dose-response effects of swainsonine (SW) consumption on immunocompetence and serum constituents of sheep in a nutrient-restricted state were investigated. Sheep (23 wethers, 5 ewes) were assigned to 1 of 5 SW treatments (0, 0.2, 0.4, 0.8, or 1.6 mg swainsonine/ kg bw/d). Swainsonine was delivered by feeding locoweed (Oxytropis sericea) with grama grass and alfalfa hays for a 28-d treatment period followed by a 21-d recovery period without locoweed. Body weights were measured weekly and behavioral changes were monitored for clinical signs of SW toxicity. Venous blood was collected weekly for lymphoblastogenesis and serum constituent analyses. Clinical signs (sluggishness, decreased responsiveness) of swainsonine toxicity were observed from d 14 to 35 in the 0.8 and 1.6 mg treatments. Subacute oral exposure did not appear to affect lymphoblastogenic analyses. Acute and subacute alterations in various serum constituents did indicate subclinical effects of SW ingestion. Linear, quadratic and cubic dose-response relationships were detected for some serum constituents (e.g., alkaline phosphatase, aspartate aminotransferase). Subacute SW consumption at the levels investigated does not seem to affect the immunocompetence of nutrient restricted sheep. The lack of change in serum alkaline phosphatase at the 0.2 mg SW/kg bw/d dose indicates the potential for a no adverse effect level of SW consumption in nutrient restricted sheep. In combination with measurable SW in serum, rises in serum alkaline phosphatase and aspartate aminotransferase activities, and declines in serum Fe and cholesterol during subacute exposure to SW establish these markers as potential indicators of subclinical SW toxicosis.     

Locoweeds: effects on reproduction in livestock

Locoweeds (species of Oxytropis and Astragalus containing the toxin swainsonine) cause severe adverse effects on reproductive function in livestock. All aspects of reproduction can be affected: mating behavior and libido in males; estrus in females; abortion/embryonic loss of the fetus; and behavioral retardation of offspring. While much research has been done to describe and histologically characterize these effects, we have only begun to understand the magnitude of the problem, to define the mechanisms involved, or to develop strategies to prevent losses. Recent research has described the effects of locoweed ingestion in cycling cows and ewes. Briefly, feeding trials with locoweeds in cycling and pregnant cows have demonstrated ovarian dysfunction in a dose-dependent pattern, delayed estrus, extended estrous cycle length during the follicular and luteal phases, delayed conception (repeat breeders), and hydrops and abortion. Similar effects were observed in sheep. In rams, locoweed consumption altered breeding behavior, changed libido, and inhibited normal spermatogenesis. Neurological dysfunction also inhibited normal reproductive behavior, and some of these effects were permanent and progressive. In this article we briefly review the pathophysiological effects of locoweeds on reproduction.     

Pathogenesis and preventive treatment for animal disease due to locoweed poisoning

Locoweeds are perennial herbaceous plants included in Astragalus spp. and Oxytropis spp. that contain the toxic indolizidine alkaloid swainsonine. The livestock that consume locoweed feeding can suffer from a type of toxicity called “locoism.” There are aliphatic nitro compounds, selenium, selenium compounds and alkaloids in locoweed. The toxic component in locoweeds has been identified as swainsonine, an indolizidine alkaloid. Swainsonine inhibits lysosomal α-mannosidase and mannosidase II, resulting in altered oligosaccharide degradation and incomplete glycoprotein processing. As a result, livestock that consume locoweeds exhibit several symptoms, including dispirited behavior, staggering gait, chromatopsia, trembling, ataxia, and cellular vacuolar degeneration of most tissues by pathological observation. Locoism results in significant annual economic losses. Recently, locoweed populations have increased domestically in China and abroad, resulting in an increase in the incidence of poisoning. Therefore, in this paper, we review the current research on locoweed, including on species variation, pathogenesis, damage and poisoning prevention measures.     

敌枯双及喷洒敌枯双稻米对罗猴的致畸作用

罗猴(Rhesus monkey)于妊娠d 23～27给予敌枯双及喷洒敌枯双稻米染毒。结果10.0 mg/kg灌胃染毒动物,分别于染毒后d3和d4流产;4.0mg/kg组4只孕猴中,1只孕猴在妊娠d31流产,2只仔猴分别表现为缺肢畸形和短臂畸形;以喷洒敌枯双5次的稻米(残留量分析敌枯唑0.25 ppm)喂饲动物115～120 d,1只孕猴妊娠d46流产,其余2只仔猴检查未见明显异常;对照组动物中,除妊娠d 36流产1只外,其余均未检出明显畸形.     

Implication of agathic acid from Utah juniper bark as an abortifacient compound in cattle

Freshly ground Utah juniper [Juniperus osteosperma (Torr.) Little] bark was given via gavage at a dosage of 2.3 kg per cow twice daily to three pregnant cows starting on day 255 of gestation. All three cows aborted the calves after 4, 5 and 6 days of treatment. A fourth cow was dosed with Utah juniper needles and this cow calved early on day 268 of gestation with complications consistent with pine needle abortion. Chemical analysis of Juniperus osteosperma bark identified the major diterpene acid as the labdane acid known as agathic acid. Agathic acid was measured in the bark at a concentration of 1.5% (dry weight basis). Analysis of sera samples obtained from treated cows found detectable quantities of agathic acid, dihydroagathic acid and tetrahydroagathic acid, which are known serum metabolites of the abortifacient compound isocupressic acid. Based on the high incidence of induced abortion and detection of known metabolites in affected animals, the labdane acid known as agathic acid is considered to be an abortifacient compound in late‐term pregnant cattle. Published in 2009 by John Wiley & Sons, Ltd.     

Swainsonine-induced high mountain disease in calves

Swainsonine, an indolizidine alkaloid in the locoweeds (certain species of the Astragalus and Oxytropis genera), was fed to young Holstein bull calves in their milk at high elevation (3090 m), and the incidence of high mountain disease (HMD) was compared with locoweed-fed and control calves. Five of 5 calves fed swainsonine and 5 of 5 calves fed fresh Oxytropis sericea showed outward signs of HMD, which included edema under the jaws, throat area and brisket and gross and microscopic lesions of HMD and locoweed poisoning. Grossly there were HMD lesions, including congestion of the liver, right ventricular hypertrophy, and dilatation and excessive fluid in the thoracic and abdominal cavities. Microscopically, the severe centrilobular lesions in the liver, edema of the pulmonary artery, severe edema and/or fibrosis of the roof of the right atrium were suggestive of HMD. The mild to moderate neurovisceral cytoplasmic foamy vacuolation of selected tissues and cerebellar neuroaxonal dystrophy in all calves fed swainsonine and locoweed were indicative of locoweed poisoning. In control calves, 1 of 6 showed equally severe outward, gross, and microscopic lesions of HMD, but none had any lesions indicative of locoweed poisoning. The ratio of right ventricle to left ventricle wall weights were significantly higher (P = 0.033) for the swainsonine-fed calves (1.4) and the locoweed-fed calves (1.3) compared to the controls (0.9). Scores indicating the severity of HMD from observations prior to necropsy were significantly higher for the swainsonine and locoweed-fed calves compared to controls (P = 0.032).(ABSTRACT TRUNCATED AT 250 WORDS)     

Teratological research at the USDA-ARS poisonous plant research laboratory

Research on teratogenic plants started at the USDA-Agricultural Research Service-Poisonous Plant Research Laboratory in the mid 1950s when Dr. Wayne Binns, Director of the laboratory, was asked to investigate the cause of a cyclopian facial/skeletal birth defect in lambs. Dr. Lynn F. James joined the staff shortly after. These two people worked as a team wherein most planning was done jointly with Binns supervising most of the laboratory work and James the field studies. It was determined that when pregnant ewes grazed Veratrum californicum on day 14 of gestation a significant number of lambs had the cyclopic defect. Skeletal and cleft palate birth defects in calves was associated with pregnant cows grazing certain lupine species during 40-70 days of gestation. Shortly thereafter research work was initiated on locoweed which caused abortions, wasting, right heart failure, skeletal birth defects, and fetal right heart failure. Dr. Richard F. Keeler, a chemist who joined the staff in the early 1960s, isolated and characterized the teratogens in V. californicum as the steroidal alkaloids cyclopamine, jervine, and cycloposine. He also described the teratogen in lupines as the quinolizidine alkaloid anagyrine and the piperidine alkaloid ammodendrine. Drs. Russell Molyneux and James identified the toxin in locoweed as the indolizidine alkaloid swainsonine. In 1974 the editor of Nutrition Today (Vols. 9 and 4) wrote "The idea that birth defects occurring in humans may be in some way related to diet is not widely held ..." Dr. Lynn James pointed out in this issue that such defects in animals can be produced with absolute predictability and regularity by foods ordinarily beneficial to livestock. Management strategies have been developed to prevent or minimize the economic impact of the cyclopian lamb and the crooked calf condition on livestock producers and well on the way to doing the same with locoweed. It is of interest to note that livestock research on Veratrum, lupines and locoweed and toxins therefrom are now significant research tools for specific human health problems.     

Locoweed grazing

Locoweed is the most widespread poisonous plant problem in the western U. S. Eleven species of Astragalus and Oxytropis (and many varieties within these species) cause locoism. Many locoweed species are endemic and are restricted to a narrow niche or habitat. Other locoweed species experience extreme population cycles; the population explodes in wet years and dies off in drought. A few species, such as O. sericea, are relatively stable and cause persistent poisoning problems. Knowledge of where locoweeds grow and the environmental conditions when they become a threat is important to manage livestock and avoid poisoning. Locoweeds are relatively palatable. Many locoweeds are the first plants to begin growth in the spring and regrow in the fall. Livestock generally prefer the green-growing locoweeds to other forage that is dormant in the late fall, winter, and spring. The most effective management strategy is to deny livestock access to locoweeds during critical periods when they are more palatable than the associated forage. Herbicides can control existing locoweed populations and provide "safe" pastures for critical periods. However, locoweed seed in soil will germinate and re-establish when environmental condition are favorable. Good range management and wise grazing strategies can provide adequate forage for livestock and prevent them from grazing locoweed during non-critical periods of the year when it is relatively less palatable than associated forages.     

Estrous cycle and food availability affect feeding induced by amygdala 5-HT receptor blockade

We have recently reported that bilateral infusions of the 5-HT receptor antagonist metergoline (MET) into the posterior basolateral amygdala (pBLA) elicit feeding in female rats tested at mid-light cycle. The present study was performed to determine whether (1) testing at two different phases of the estrous cycle, and/or (2) the palatability of the food might modify this effect. Subjects were 18 adult females with bilateral pBLA cannulae. Following familiarization with Froot Loops cereal, a within-subjects design tested all animals for 1- and 2-h food intake under 2 Drug (0.3 nmol MET vs. Vehicle), 2 Estrous Cycle (diestrus vs. estrus) and 2 Food (lab chow vs. Froot Loops) conditions. Rats weighed more at diestrus than at proestrus (P<.05) or estrus (P<.005). Multivariate analyses of variance (MANOVAs) revealed a preference for Froot Loops over lab chow (P<.0001). MET increased feeding regardless of food type (P<.0001). Rats ate more Froot Loops (P<.01), but not lab chow, at diestrus vs. estrus. A three-way interaction (P<.05) showed rats ate more during the first hour in estrus than in diestrus to lab chow but not Froot Loops. These data suggest pBLA MET differentially affects feeding over the estrous cycle depending on the palatability of food available.     

The relationship of Oxytropis sericea (green and dry) and Astragalus lentiginosus with high mountain disease in cattle

All calves fed locoweed (green and dry Oxytropis sericea Nutt and dry Astragalus lentiginosus Dougl) at high elevation developed clinical signs, gross and microscopic lesions of congestive right heart failure. Clinical signs and microscopic lesions of locoweed intoxication were also evident. Control calves did not develop the clinical signs, gross or microscopic lesions demonstrated in the locoweed fed calves.     

Twenty-week exposures to the drinking water disinfection by-product dibromoacetic acid: reproductive cyclicity and steroid concentrations in the female Sprague-Dawley rat

Elevated gavage exposures to the drinking water disinfection by-product dibromoacetic acid (DBA) have been found to disrupt estrous cyclicity in the rat and induce increases in estradiol concentrations in both cycling (day of estrus) and ovariectomized/estradiol-implanted females. The present study was designed to investigate both effects in Sprague-Dawley rats following an extended 20-week treatment with lower dosages of DBA administered in the drinking water (calculated mean intake concentrations of 5, 16, and 33 mg/kg/d). No treatment-related effects on cyclicity were present, although elevations in serum estradiol on the day of vaginal estrus were noted in regularly cycling rats when assessed at the 3rd and 11th weeks of exposure. By the 19th week, this effect was no longer present in cycling animals, but its absence was attributable to a marked increase in control estradiol concentrations, which may be associated with endocrine alterations that precede a disruption in estrous cyclicity in middle-aged females. In the 20th week, diestrous estrone levels were elevated at all dosages without effects on serum androstenedione or progesterone. Uterine and pituitary weights were unchanged at this time, although there were modest increases in liver weights at the two highest dosages. A small number of rats in persistent estrus (PE) did show a general increase in pituitary weight associated with DBA exposure, possibly reflecting an added layering of treatment on the PE-associated rise in estradiol normally seen in these females. The results indicate that increases in circulating estradiol from drinking water exposures to DBA were not linked to a premature disruption of estrous cyclicity in this moderately estrogen-sensitive rat strain.     

Apparent zearalenone intoxication in a dairy herd from feeding spoiled acid-treated corn

High-moisture corn was treated with a propionic acid preservative and stored in a 40,000 bushel steel bin. This corn heated and spoiled in storage and subsequently was retreated with the preservative. The out-of-condition corn was used as an ingredient in the ration for a dairy herd of cows and replacement heifers. The finished feed was cultured for fungi and assayed for mycotoxins. Results were 750,000 Fusarium spp colonies/g of feed, and 1.5 mg zearaleonone and 1.0 mg deoxynivalenol/kg of feed. Frequent episodes of behavioral estrus of 2 to 5 d duration, that were not synchronized with the ovarian cycle, were observed. Cows in the second and third trimester of pregnancy also has episodes of behavioral estrus. Idiopathic vaginitis was diagnosed. Mammary development occurred in the prepubertal heifers. Cows bred in true estrus were found in true estrus 35 to 55 d later. All of the heifers with precocious mammary development were subsequently culled from the herd because of sterility.     

Estrogen concentrations in bovine and porcine tissues.

Using an estrogen antiserum that measures biologically active estrogen (estradiol-17beta + estrone), a series of studies have been completed to describe the normal plasma levels of estrogen in cows and sows during various stages of reproduction. The levels are lower in the nonpregnant cow (less than 25 pg/ml) than in most species. Only during late pregnancy are the levels easily assayed. The levels in the nonpregnant sow are 2-3 times greater than in the cow. In both species there is a preovulatory peak of estrogen that is responsible for estrus. Plasma estrogen concentrations were also determined after induction of multiple ovulations by exogenous gonadotropin (PMSG) in the cow and sow and after treatment of cows with either a progestin (MGA) or a prostaglandin (PGF2alpha). (These two drugs have been used to synchronize estrus in the cow.) Estrogen levels rise greatly after treatment with PMSG but show little effect from MGA or PGF2alpha. Data are also presented on the validation of an assay for E2beta and E1 in beef tissue. Less than 20 pg of E2beta and E1 was measured per gram bovine muscle tissue. Considerable effort must be expended to apply radioimmunoassay to the assay of estrogens in tissues.     

Effects of Tall Fescue Endophyte Type and Dopamine Receptor D2 Genotype on Cow-Calf Performance during Late Gestation and Early Lactation

Grazing endophyte-infected, toxic tall fescue reduces cow/calf production; therefore, this study examines alternate strategies such as use of novel endophyte fescue varieties during late gestation and early lactation or genetic selection of resistant cows. Pregnant cows (n = 75) were randomly assigned to fescue endophyte type: 1) endophyte-infected ergot alkaloid producing tall fescue (E+) or 2) novel endophyte-infected, non-toxic tall fescue (NOV) within maternal (A|A, n = 38 and G|G, n = 37) DRD2 genotype to examine changes in cow/calf performance and milk production during late gestation and early lactation. Grazing E+ fescue pastures during late gestation reduced cow body weight gain but did not alter calf birth weight compared to NOV. Milk production and calf ADG during the first 30 day of lactation were lower for E+ than NOV. The calving rate was reduced, but not calving interval for E+ cows. The adjusted 205-day weight of calves was lower in those grazing E+ with their dams compared to NOV. There were no interactions between DRD2 genotype and fescue endophyte type indicating that genotype was not associated with response to E+ fescue in this study. Overall, grazing NOV tall fescue pastures rather than E+ during critical stages of production improved cow gain during late gestation, calving rate, early milk production and calf growth.     

Effects of sodium selenite on methylmercury embryotoxicity and teratogenicity in mice.

Female IVCS mice were fed food containing methylmercury (MeHg) at 0, 15.9, or 31.9 nmol/g food and drinking water containing sodium selenite at 0, 11.4, or 22.8 nmol/ml for 30 days before gestation and thereafter up to Day 18 of gestation. Groups receiving MeHg had (1) affected estrus cycles, (2) decreased litter size accompanied by increased implantation sites, resorptions, dead embryos, and dead fetuses, (3) increased incidence of cleft palate, and (4) retarded fetal growth. Selenite was not teratogenic and even at the high dose, generally only retarded fetal growth. The low dose of selenite when combined with the high dose of MeHg, increased the incidence of resorptions and implantation sites. Embryolethality was decreased and the incidence of cleft palate was increased in the group receiving the high dose of selenite combined with the high dose of MeHg.     

Effects of swainsonine on the humoral immune response of lipopolysaccharide

Effects of swainsonine (SW; 8α, β-indolizidine-1α, 2α, 8-triol from Locoweed) on the humoral immune responses of lipopolysaccharide (LPS) were studied in ICR mice. Mice were divided into 4 groups (10mice/group), and LPS was given to each mouse 1 hr after i.p. injection with 3.7 mg/kg of swainsonine, by i.p. injection twice a week for 14 days at a dose of 2 mg/kg. Humoral immune responses were evaluated by hemagglutination (HA) titer and splenic plaque forming cells (PFC). The results of this study were summarized as follows: Mice administrated each of LPS and SW showed significant enhancement of the weight ratios of spleen to body, HA titer, 2-mercaptoethanol-resistant HA (MER-HA) titer and PFC compared with those in controls. However, the LPS plus SW treatment decreased HA titer, MER-HA titer and PFC corresponding to humoral immunity, as compared with those in the mice treated with LPS alone. These findings indicated that LPS significantly enhanced humoral immune responses, but their enhancement effects were lowered somewhat by SW.     

Efficacy of Spirulina platensis in improvement of the reproductive performance and easing teratogenicity in hyperglycemic albino mice

Objectives:

The present study evaluates the therapeutic efficacy of cell suspension of Spirulina platensis (SP) on estrous cycle, fetal development and embryopathy in alloxan (AXN) induced hyperglycemic mice.

Materials and Methods:

Diabetes was induced by intra-peritoneal administration of AXN. Mice with blood glucose level above 200 mg/dl were divided into Group I (control), Group II (diabetic control), Group III (diabetic control mice fed with SP), and Group IV (control mice fed with SP). Litter counts, estrous cycles, percent survival of litter, and gestation length were recorded.

Results:

In hyperglycemic mice, a significant (P < 0.05) increase in duration of diestrus (14.48%), estrus (84.21%), and metestrus (164.15%) with concomitant decrease in proestrus phase by 26.13% was recorded when compared with control. Reduction in litter count and survival of litter was 68.67% and 88.38%, respectively, whereas gestation length increased to 14.51% day in diabetic mice, but recovery in these parameters was observed (P < 0.05) when subjected to SP treatment. SP resulted in increased fertility rate from 77.5% to 82.5% and dropped off resorption of the fetus to 33.73% while the survival rate of offspring of diabetic mice went up to 88.89% from 83.61%.

Conclusions:

These findings suggest that SP is effective in improving the reproductive performance and easing teratogenic effects in diabetic mice and hence warrants further detailed dose-dependent studies to understand its mechanism of action.KEY WORDS: Diabetes, estrous cycle, fertility rate, fetal development, gestation length, Spirulina platensis