Attempted Passive Immunization of Young Calves Against Eimeria bovis

SYNOPSIS. Two experiments attempted to produce passive immunity against Eimeria bovis coccidiosis in Holstein-Friesian calves. Immune serum concentrated by a freezing technique, or serum globulin obtained by a precipitating technique from immune calves, was injected intravenously or intraperitoneally into young calves. Four calves received concentrated immune serum injected intravenously on the day of oral inoculation with sporulated oocysts and again 7 and 14 days later. Four calves were given intravenous injections with some of the same serum on the 7th and 14th days after inoculation and 4 others were given a single similar injection with the same serum 14 days after inoculation.
Three calves in a second experiment received intraperitoneal injections of serum globulins in increasing amounts every 3 days for 2 weeks. The calves were then orally inoculated with sporulated oocysts one week after the last globulin injection. Some calves receiving immune serum had an anaphylactoid reaction characterized by increased respiration rate, dyspnea, coughing, and salivation; however, all affected calves recovered spontaneously within 2 hours. Calves receiving serum globulin had no reactions.
Coccidiosis developed in all of the calves in spite of the injection of immune serum or globulin presumed to carry the immune factor. There was no detectable difference in the rate of oocyst discharge or in clinical symptoms between treated and control calves; therefore, no evidence of passive immunity was observed.     

Protection of calves against cryptosporiosis by oral inoculation with gamma-irradiated Cryptosporidium parvum oocysts

The purpose of this study was to determine whether gamma-irradiated Cryptosporidium parvum oocysts could elicit protective immunity against cryptosporidiosis in dairy calves. Cryptosporidium parvum Iowa strain oocysts (1 x 10(6) per inoculation) were exposed to various levels of gamma irradiation (350-500 Gy) and inoculated into 1-day-old dairy calves. The calves were examined daily for clinical signs of cryptosporidiosis, and fecal samples were processed for the presence of C. parvum oocysts. At 21 days of age, the calves were challenged by oral inoculation with 1 x 10(5) C. parvum oocysts and examined daily for oocyst shedding and clinical cryptosporidiosis. Calves that were inoculated with C. parvum oocysts exposed to 350-375 Gy shed C. parvum oocysts in feces. Higher irradiation doses (450 or 500 Gy) prevented oocyst development, but the calves remained susceptible to C. parvum challenge infection. Cryptosporidium parvum oocysts exposed to 400 Gy were incapable of any measurable development but retained the capacity to elicit a protective response against C. parvum challenge. These findings indicate that it may be possible to protect calves against cryptosporidiosis by inoculation with C. parvum oocysts exposed to 400-Gy gamma irradiation.     

The Results of Parenteral Injections of Sporulated or Unsporulated Oocysts of Eimeria bovis in Calves

SYNOPSIS. Five experiments using newborn Holstein-Friesian and weaner Hereford calves were conducted to observe the effects caused by parenteral injections of oocysts of Eimeria bovis . Sporulated oocysts were given intraperitoneally (IP), subcutaneously (SC), intramuscularly (IM) and intravenously (IV). Unsporulated oocysts or merozoites were given IP or IM.
Coccidiosis developed in calves in three experiments after they were inoculated IP with sporulated oocysts. Immunity to reinfection resulted from these infections. No infections occurred at any time after SC, IM or IV inoculation with sporulated oocysts or after IP or IM inoculation with unsporulated oocysts or merozoites.
Coccidiosis failed to occur in two experiments when special precautions were used to prevent puncture of the intestines during IP inoculations. There was no detectable immunological response to any of the inoculations unless intestinal infections occurred.
In one experiment sporulated oocysts were exposed to 60,000 r irradiation by x-ray in an attempt to attenuate the oocysts. Calves became infected when given orally administered oocysts irradiated at this level.     

Performance and plasma metabolites of dairy calves fed starter containing sodium butyrate, calcium propionate or sodium monensin

This study was conducted to examine the influence of supplementation of sodium butyrate, sodium monensin or calcium propionate in a starter diet on the performance and selected plasma metabolites (plasma glucose, non-esterified fatty acids and β-hydroxybutyrate) of Holstein calves during pre- and post-weaning periods. Twenty-four newborn Holstein calves were housed in individual hutches until 10 weeks of life, receiving water free choice, and fed four liters of milk daily. Calves were blocked according to weight and date of birth, and allocated to one of the following treatments, according to the additive in the starter: (i) sodium butyrate (150 g/kg); (ii) sodium monensin (30 mg/kg); and (iii) calcium propionate (150 g/kg). During 10 weeks, calves received starter ad libitum, while coast cross hay (Cynodon dactylon (L.) pers.) was offered after weaning, which occurred at the 8th week of age. Weekly, calves were weighted and evaluated for body measurements. Blood samples were taken weekly after the fourth week of age, 2 hours after the morning feeding, for determination of plasma metabolites. No differences were observed among treatments for starter or hay intake, BW and daily gain of the animals. Mean concentrations of selected plasma metabolites were similar in calves fed a starter supplemented with sodium butyrate, sodium monensin and calcium propionate. There was significant reduction in the concentrations of plasma glucose as calves aged. The inclusion of sodium butyrate, calcium propionate or sodium monensin as additives in starter feeds resulted in equal animal performance, before and after weaning, suggesting that sodium monensin may be replaced by organic acid salts.     

Experimental Sarcocystis ovicanis infection in lambs: salinomycin chemoprophylaxis and protective immunity

Salinomycin, administered prophylactically, was effective in controlling clinical sarcocystosis resulting from infection with Sarcocystis ovicanis in two experiments involving a total of 50 lambs. In each experiment, five lambs were used in each of five test groups--uninoculated and unmedicated, inoculated and unmedicated, uninoculated and medicated (2 mg/kg), inoculated and medicated (2 mg/kg), and inoculated and medicated (1 mg/kg). Salinomycin was included in the feed of each medicated group for 30 days beginning on the day of oral inoculation with 10(6) S. ovicanis sporocysts. Lambs were challenged with 10(6) sporocysts 9 wk PI and the experiment was terminated 7 wk later. Data from deaths, weight gains, body temperatures, packed cell volumes, hemoglobin values, serum protein levels, and postmortem and histological examinations indicated that salinomycin at both doses tested reduced the number of deaths and severity of signs of sarcocystosis in infected lambs as compared with unmedicated controls. Infected, medicated lambs developed a protective immunity as determined by challenge inoculation. An additional group of five lambs, each inoculated orally with 10(6) sporocysts, were treated therapeutically with 2 mg/kg per day beginning 21 days after inoculation. All five died from acute sarcocystosis.     

Effect of functional oils on the immune response of broilers challenged with Eimeria spp.

Infection with Eimeria sp. results in the activation of multiple facets of the host immune system; the use of phytogenics can modulate the inflammatory response and improve the performance of the challenged animal. The aim of this study was to evaluate the effect of a commercial blend of cashew nut shell liquid (CNSL) and castor oil on the immune response of broilers challenged with coccidiosis. A total of 864 one-day-old male chicks (Cobb 500) were randomly distributed into six treatment groups (8 pens/treatment and 18 chicks/pen) in a three-by-two factorial design with three additives: control (non-additive), 100 ppm of monensin or 0.15% CNSL–castor oil. Challenge status was determined twice at 14 days of age. Unchallenged birds were inoculated by gavage with oocysts sporulated with Eimeria tenella, Eimeria acervulina and Eimeria maxima. Although the positive control (non-additive and challenged) and CNSL–castor oil treatment groups exhibited similar variation in weight gain (ΔBWG) compared to unchallenged birds fed without additives, the variation observed in birds fed diets containing CNSL–castor oil was associated with a higher maintenance requirement and not feed efficiency. In the second week after infection, ΔBWG of the CNSL–castor oil treatment group did not significantly change compared to the other treatment groups. At days 7 and 14 post-challenge, there was a higher excretion of oocysts in the control group, whereas the CNSL–castor oil and monensin groups did not differ. The CNSL–castor oil group exhibited increased gene expression of interferon (IFN), interleukin 6 (IL-6) and tumor necrosis factor (TNF), while the control group exhibited increased expression of cyclooxygenase (COX) and IL-1. The heterophils/lymphocyte ratio was low for the monensin treatment group. The unchallenged birds that received monensin treatment presented higher gene expression of IFN, COX and IL-1 compared to the other treatments, while the CNSL–castor oil group exhibited reduced gene expression, except for TNF. The commercial blend of cashew nut liquid and castor oil modulated the inflammatory response against Eimeria spp. In the absence of the parasite, there was no stimulation of genes involved in the inflammatory response, demonstrating that the blend is an effective tool in specifically modulating the immune system of birds afflicted with coccidiosis.     

Effect of monensin and suckling on the GnRH induced luteinizing hormone surge and the effect of monensin on the postpartum interval in Brangus cows

Twenty-seven fall calving Brangus cows were randomly allotted to one of four treatment groups: nonsuckled monensin (NSM), suckled monensin (SM), nonsuckled control (NSC), and suckled control (SC). Cows were group fed 1.82 kg/hd/day concentrate and Coastal bermuda grass hay $\text{ad}$$\text{libitum}$. Monensin cows received 200 mg monensin/hd/day in the concentrate. At 0800 hr on day 21 postcalving, the calves were separated from the cows. Suckled monensin and SC cows were allowed to suckle their calves for 30 min at 6-hr intervals. Nonsuckled monensin and NSC cows were not suckled. Calves were given free access to the cows after 1400 hr on day 22 postpartum. At 0800 hr on day 22 postpartum, a blood sample was collected. A 100 μg GnRH challenge was administered IM at 0801 hr. Blood samples were collected at 15-min intervals for 6 hr postinjection. Changes in body weight and body condition from day 21 postpartum to the day of first estrus were not different (P>0.10) by dietary treatment. Monensin cows consumed 10.7% less hay than did the control cows. Serum luteinizing hormone (LH) following GnRH was greater (P<0.005) in suckled than nonsuckled cows. Control cows released more (P<0.005) LH in response to GnRH than did the monensin cows. The postpartum interval (to first estrus) for the monensin cows (92.4±14.7 days) was shorter (P<0.025) than the controls (138.5±9.5 days). A greater proportion (P<0.005) of the monensin cows (8 of 14) exhibited estrus by 90 days postpartum compared to the control cows (0 of 13). Monensin and suckling appear to exert independent and agonistic influences on pituitary function in the postpartum beef cow.     

Effect of dietary zinc level on serum carotenoid levels, body and shank pigmentation of chickens after experimental infection with coccidia

Two experiments were conducted to test the effects of a dietary zinc amino acid complex (Zn-AA) and an anticoccidial drug on Eimeria acervulina or Eimeria tenella infections. In each experiment, 288 day-old Three-Yellow-Chickens were used in a 2 x 3 factorial experimental design. Six groups were arranged randomly to receive three levels of Zn-AA (0, 40, or 80 mg/kg) alone or with salinomycin (60 mg/kg). Additionally an uninfected group was set as negative control. At the age of 21 days birds in Exp. 1 were inoculated with 3 x 10(4) sporulated E. acervulina oocysts, while birds in Exp. 2 were inoculated with 1.5 x 10(4) sporulated E. tenella oocysts. In Exp. 1, E. acervulina did not suppress growth performance significantly, but in groups without salinomycin it significantly reduced serum carotenoid levels on day 7 after inoculation and body and shank pigmentation on day 42. Salinomycin medication maintained serum carotenoids and visual colour of inoculated birds, but Zn-AA did not influence these parameters. In Exp. 2, growth performances of infected and uninfected chickens were similar. Infection decreased to only serum carotenoid levels on day 14 after infection, and colour scores on day 42 in the inoculated group without salinomycin and Zn-AA supplementation. The birds that received Zn-AA had significantly higher serum carotenoid levels and colour scores than those that did not. Although supplementation of Zn-AA cannot avoid coccidial damage of caecum, it prevents the reduction of serum carotenoids and pigmentation of Three-Yellow-Chicken infected with E. tenella, but not after infection with E. avervulina. The interactive effects between Zn-AA and salinomycin on growth performance and pigmentation were not significant.     

Immunogenicity and protective efficacy of solubilized merozoite-enriched Theileria sergenti immunogens. II: Protection against natural exposure under field conditions.

A Theileria sergenti soluble merozoite preparation containing the 29, 34, 35 and 105 KD as the immunodominant polypeptides, was evaluated for efficacy, safety and protectivity in Holstein calves against virulent field tick challenge. The soluble antigens (100 mg/dose) were fortified with either complete or incomplete Freund's adjuvant. Twenty naive calves, aged one month, were subcutaneously inoculated with the preparation and a booster dose was administered 4 weeks later. Twenty additional calves served as controls. Five weeks after the booster dose, vaccinates and uninoculated controls were moved to a pasture, a heavily tick infested area in Cheju-do, Korea. The vaccinates showed negligible change in hematocrit and total RBC count whereas control animals showed significant (p < 0.05) hematological changes and associated anemia. Only 30% of vaccinates required chemotherapy after the experiment was terminated. All control animals required chemotherapy and 25% received blood transfusion. The highest percent parasitized erythrocytes in vaccinated cattle was 0.4% as compared with 3.6% among controls during the month of July. A significant difference (p < 0.05) was observed in the rate of body weight increase. Significant differences were also noted in serum albumin, aspartate aminotransferase, total protein and bilirubin. Significantly more vaccinated cattle maintained normal ranges of hematological and biochemical values as compared with the control group. It is suggested that soluble merozoite T. sergenti antigens may be potential vaccine candidates for developing a genetic vaccine in Korea.     

Efficacy of hyperimmune bovine colostrum for prophylaxis of cryptosporidiosis in neonatal calves

Twelve neonatal calves were experimentally infected with oocysts of Cryptosporidium parvum. Six calves in group A fed hyperimmune colostrum at birth had significantly less diarrhea and shed oocysts for less time than did 6 calves in group B fed colostrum from cows that were not hyperimmune. Calves in group A had diarrhea for 0-4 days (means = 2.3 days), whereas calves in group B had diarrhea for 4-6 days (means = 5.0 days). Calves in group A shed oocysts for 4-9 days (means = 6.2 days), whereas calves in group B shed oocysts for 7-11 days (means = 8.5 days). These findings indicate that passive lacteal immunity conferred partial protection against cryptosporidiosis. Whether such protection was provided by the immunoglobulins that were highly elevated in the colostrum (greater than 1:200,000 for IgG1, IgM, and IgA) and constituted a large part of the circulating antibody in the calves, or by other biologically active factors, such as cytokines, is undetermined.     

Trypanosoma evansi: Therapeutic efficacy of diminazine aceturate in crossbred calves, Bos taurus and B. indicus

The therapeutic efficacy of diminazine aceturate (Berenil) against Trypanosoma evansi infection (surra) in calves was determined. Seven crossbred calves, 8 to 12 months old, were inoculated subcutaneously with 5 × 10⁷ parasites of a virulent strain of T. evansi. All of the calves developed clinical infection and exhibited symptoms associated with chronic surra. Forty-one to forty-four days after inoculation, five of the calves were treated with a single dose of diminazine aceturate at 10 mg/kg body weight intramuscularly. The two remaining calves were left as infected but untreated controls. The treated calves were found free of the infection on repeated blood smear examinations and diagnostic challenge tests in mice 12 hr to 16 days later. One of the five calves, which was treated at an advanced stage of the disease, died on the fifth day after treatment. Splenectomy of the treated calves, 16 to 19 days after treatment, did not result in relapse of parasitemia, indicating that diminazine aceturate at 10 mg/kg had a rapid trypanocidal effect in surra of calves. Both of the controls died of the disease on the 45th and 47th day.     

Neospora caninum in cattle: experimental infection with oocysts can result in exogenous transplacental infection, but not endogenous transplacental infection in the subsequent pregnancy

Whilst it is presumed that infection of pregnant cattle with Neospora caninum oocysts can provoke abortion and is the likely cause of epidemic abortion outbreaks, only two previous experiments have involved inoculation of pregnant cows with oocysts (and only one abortion was provoked in 22 pregnancies). Here, we describe the oral oocyst challenge of 18 cows synchronously bred and inoculated precisely at 70 (n = 6), 120 (n = 6) and 210 (n = 6) days in pregnancy with a nominal dose of 40,000 oocysts. Only one abortion occurred (at the 120 days challenge) which could be definitively ascribed to N. caninum and no transplacental infection (TPI) was detected in any of the other 11 calves born in the 70 and 120 day challenge groups. In contrast, 4/5 live calves born to cattle challenged at 210 days were transplacentally infected. When cows which had transplacentally infected their calves in the first pregnancy were rebred, no TPI occurred. The results show that the timing of challenge influences clinical and parasitological outcomes and that cattle in late pregnancy are exquisitely sensitive to oocyst challenge leading to exogenous TPI and congenitally infected calves. However, cattle which were indisputably systemically infected in their first pregnancy did not induce endogenous TPI in their subsequent pregnancy. This confirms previous results with experimental tachyzoite challenge and suggests that post-natal infection does not lead to persisting infections which can recrudesce in pregnancy.     

Effect of respiratory tract disease on pharmacokinetics of tilmicosin in rats.

BACKGROUND AND PURPOSE: In rats, murine respiratory mycoplasmosis is caused by Mycoplasma pulmonis. Tilmicosin, a macrolide antibiotic, has good tissue penetration and reaches high concentration in the lungs. Therefore, a model for studying the effects of disease on pharmacokinetics of tilmicosin was developed, using LEW rats. METHODS: Seventy-two LEW rats were assigned at random to two groups: one group was inoculated with M. pulmonis, and the other served as an uninoculated control group. On postinoculation day 31, all rats received a single dose of tilmicosin (20 mg/kg of body weight, subcutaneously). RESULTS: Concentration of tilmicosin in the lungs of both groups of rats was significantly higher than serum tilmicosin concentration at all times. Infected rats had significantly higher lung tilmicosin concentration than did noninfected rats. No correlation was found between pH of the lungs and tilmicosin concentration in the lungs in either treatment group, nor did treatment have any effect on pH of the muscle. CONCLUSION: Tilmicosin accumulates in the lungs, and infection/inflammation further improves its tissue penetration.     

Giardiasis in dairy calves: effects of fenbendazole treatment on intestinal structure and function

Twelve Giardia duodenalis-infected Holstein dairy calves were allocated into a treatment (n=6) and placebo group (n=6) according to pre-study faecal cyst counts. Calves in the treatment group received an oral dose of 5 mg/kg fenbendazole once daily for 3 days, while placebo calves received a sterile saline solution. Calves were euthanised 7 days following the initiation of treatment and intestinal were collected and prepared for trophozoite quantitation, histology, electron microscopy, and disaccharidase assays. In all calves treated with fenbendazole, intestinal trophozoites were below detection limits, while in saline-treated calves, trophozoites were observed in all intestinal segments. Histologically, no significant difference was observed between treatment groups with respect to intestinal villus height or crypt depth. However, a significant decline in the number of intraepithelial lymphocytes (IEL) was observed in fenbendazole-treated calves when compared with placebo-treated calves in the duodenum (13.9+/-1.2 vs. 17.0+/-1.1 IEL/100 enterocytes) and jejunum (21.6+/-0.8 vs. 30.7+/-1.0 IEL/100 enterocytes). In addition, measurements from TEM micrographs demonstrated a significant increase in microvillus surface area in the jejunum of fenbendazole-treated calves compared with saline-treated calves (31.2+/-10.2 vs. 22.8+/-7.6 microm(2)). This increase in microvillus surface area was also associated with an increase in jejunal maltase activity in fenbendazole-treated calves compared with calves treated with saline. These results demonstrate that fenbendazole is an effective treatment for giardiasis in calves. fenbendazole treatment eliminated Giardia trophozoites from the small intestine of calves resulting in increased microvillus surface area and greater intestinal enzyme activity. This study also demonstrates that the pathogenesis of giardiasis in calves is similar to that observed in humans and laboratory animals, and provides further evidence that Giardia is a pathogen of cattle with potential economic importance.     

Examination of attachment and survival of Toxoplasma gondii oocysts on raspberries and blueberries

The consumption of Toxoplasma gondii oocysts on fresh produce may be a means of its transmission to humans. Cats shed T. gondii oocysts, which contaminate produce directly or contaminate water sources for agricultural irrigation and pesticide and fertilizer applications. Cyclospora cayetanensis is a related coccidial parasite, and outbreaks of diarrhea caused by C. cayetanensis have been associated with the ingestion of contaminated raspberries. The oocysts of these coccidians are similar in size and shape, indicating that they may attach to and be retained on produce in a similar manner. In the present study the attachment and survival of T. gondii oocysts on 2 structurally different types of berries were examined. Raspberries and blueberries were inoculated individually with 1.0 x 10(1) to 2.0 x 10(4) oocysts of sporulated T. gondii. Berries inoculated with 2.0 x 10(4) oocysts were stored at 4 C for up to 8 wk. Oocyst viability and recovery were analyzed by feeding processed material to mice. Mice fed T. gondii-inoculated berries stored at 4 C for 8 wk developed acute infections. In other experiments mice fed raspberries inoculated with > or = 1.0 x 10(1) oocysts became infected, whereas only mice fed blueberries inoculated with > or = 1.0 x 10(3) oocysts became infected. This study demonstrates that T. gondii oocysts can adhere to berries and can be recovered by bioassays in mice and that raspberries retain more inoculated oocysts than do blueberries. The results suggest that T. gondii may serve as a model for C. cayetanensis in food safety studies.     

Reproductive activities of female albino rats treated with quassin, a bioactive triterpenoid from stem bark extract of Quassia amara

To evaluate the effect of quassin on female reproductive functions, 42 albino rats (35 females and 7 males) were used. The female albino rats were divided into seven groups of five rats each. Group I served as the control group and received distilled water while Groups II, III and IV rats were treatedorally with 0.1mg/kg, 1.0 mg/kg and 2.0 mg/kg body weight of quassin for 60 days respectively. Groups V, VI and VII rats were also treated orally with 0.1 mg/kg, 1.0mg/kg and 2.0 mg/kg body weight of quassin for 60 days but were left untreated for another 30 days, to serve as the recovery groups. At the end of each experimental period, blood samples were collected from each rat. Fertility study was done by cohabiting one untreated male with the five female rats in each group for 10 days. Quassin did not adversely affect the weight of the kidney, heart, liver and the body of the rats. However there was a significant decrease in the weight of the ovary and uterus in all the groups relative to the control. There was also a significant decrease in serum estrogen levels in quassin treated rats. The quassin treated rats had a significantly decreased mean litter number and weight. Histological studies show a disorganization and degeneration in the ovary while the uterus showed signs of vacuolation and disorganization. However, these effects were ameliorated after quassin was withdrawn from the rats. The results suggest that quassin has female anti-fertility properties, possibly acting via inhibition of estrogen secretion. Keyword: Quassin, Female rat, Reproduction, Estrogen.     

Pharmacokinetics and effect of intravenous meloxicam in weaned Holstein calves following scoop dehorning without local anesthesia

ABSTRACT: BACKGROUND: Dehorning is a common practice involving calves on dairy operations in the United States. However, less than 20% of producers report using analgesics or anesthetics during dehorning. Administration of a systemic analgesic drug at the time of dehorning may be attractive to dairy producers since cornual nerve blocks require 10 -- 15 min to take effect and only provide pain relief for a few hours. The primary objectives of this trial were to (1) describe the compartmental pharmacokinetics of meloxicam in calves after IV administration at 0.5 mg/kg and (2) to determine the effect of meloxicam (n = 6) or placebo (n = 6) treatment on serum cortisol response, plasma substance P (SP) concentrations, heart rate (HR), activity and weight gain in calves after scoop dehorning and thermocautery without local anesthesia. RESULTS: Plasma meloxicam concentrations were detectable for 50 h post-administration and fit a 2-compartment model with a rapid distribution phase (mean T1/2alpha = 0.22 +/- 0.087 h) and a slower elimination phase (mean T1/2beta = 21.86 +/- 3.03 h). Dehorning caused a significant increase in serum cortisol concentrations and HR (P < 0.05). HR was significantly lower in the meloxicam-treated calves compared with placebo-treated calves at 8 h (P = 0.039) and 10 h (P = 0.044) after dehorning. Mean plasma SP concentrations were lower in meloxicam treated calves (71.36 +/- 20.84 pg/mL) compared with control calves (114.70 +/- 20.84 pg/mL) (P = 0.038). Furthermore, the change in plasma SP from baseline was inversely proportional to corresponding plasma meloxicam concentrations (P = 0.008). The effect of dehorning on laying behavior was less significant in meloxicam-treated calves (p = 0.40) compared to the placebo-treated calves (P < 0.01). Calves receiving meloxicam prior to dehorning gained on average 1.05 +/- 0.13 kg bodyweight/day over 10 days post-dehorning compared with 0.40 +/- 0.25 kg bodyweight/day in the placebo-treated calves (p = 0.042). CONCLUSIONS: To our knowledge, this is the first published report examining the effects of meloxicam without local anesthesia on SP, activity and performance of calves post-dehorning. These findings suggest that administration of meloxicam alone immediately prior to dehorning does not mitigate signs of acute distress but may have long term physiological, behavior and performance effects.     

Effect of dietary zinc level on serum carotenoid levels,body and shank pigmentation of chickens after experimental infection with coccidia

Abstract

Two experiments were conducted to test the effects of a dietary zinc amino acid complex (Zn-AA) and an anticoccidial drug on Eimeria acervulina or Eimeria tenella infections. In each experiment, 288 day-old Three-Yellow-Chickens were used in a 2 × 3 factorial experimental design. Six groups were arranged randomly to receive three levels of Zn-AA (0, 40, or 80 mg/kg) alone or with salinomycin (60 mg/kg). Additionally an uninfected group was set as negative control. At the age of 21 days birds in Exp. 1 were inoculated with 3 · 10⁴ sporulated E. acervulina oocysts, while birds in Exp. 2 were inoculated with 1.5 · 10⁴ sporulated E. tenella oocysts. In Exp. 1, E. acervulina did not suppress growth performance significantly, but in groups without salinomycin it significantly reduced serum carotenoid levels on day 7 after inoculation and body and shank pigmentation on day 42. Salinomycin medication maintained serum carotenoids and visual colour of inoculated birds, but Zn-AA did not influence these parameters. In Exp. 2, growth performances of infected and uninfected chickens were similar. Infection decreased to only serum carotenoid levels on day 14 after infection, and colour scores on day 42 in the inoculated group without salinomycin and Zn-AA supplementation. The birds that received Zn-AA had significantly higher serum carotenoid levels and colour scores than those that did not. Although supplementation of Zn-AA cannot avoid coccidial damage of caecum, it prevents the reduction of serum carotenoids and pigmentation of Three-Yellow-Chicken infected with E. tenella, but not after infection with E. avervulina. The interactive effects between Zn-AA and salinomycin on growth performance and pigmentation were not significant.     

Experimental Transmission of Caryospora simplex (Apicomplexa: Eimeriidae) to Palestine Vipers, Vipera xanthina palestinae (Serpentes: Viperidae)

ABSTRACT. Four littermate, laboratory-reared Palestine vipers, Vipera xanthina palestinae (#149, #150, #151, #152) (Serpentes: Viperidae) were used to determine modes by which Caryospora simplex (Apicomplexa: Eimeriidae) could be transmitted to snakes. Viper #149 was inoculated orally by stomach tube with 5.0 x 10⁴ sporulated oocysts of C. simplex obtained from the feces of an Ottoman viper, V. x. xanthina and began passing unsporulated oocysts of C. simplex 121 days post-inoculation (DPI). Viper #150 was fed five mice that had been inoculated orally £25 days previously with 5.0 x 10⁴ sporulated oocysts of C. simplex and it began passing unsporulated oocysts of C. simplex 33 days after being fed the first two of five mice. Viper #151 was inoculated orally with sporulated oocysts of C. simplex obtained from viper #150 and began passing oocysts 52 DPI. Viper #152 served as an uninoculated control and did not pass oocysts of any species of coccidian. This study demonstrates that snake/snake and mouse/snake transmission of C. simplex readily occurs.     

Ostertagia ostertagi: establishment of patent infections in calves by intravenous inoculation

In two experiments calves raised free of parasite infection were given parenteral injections of Ostertagia ostertagi infective larvae to determine if patent infections might result. Patency was achieved by intravenous injection of larvae. Ten calves of different age (3–8 months) and sex were given intravenous, subcutaneous, and intraperitoneal injections of infective larvae. These calves were not necropsied; patency was based on fecal egg counts. Six calves injected intravenously all achieved patency (17–21 days after inoculation). Two calves each were inoculated subcutaneously and intraperitoneally; patency was observed in none. Calves given primary intravenous inoculation responded with higher levels of ova production to subsequent oral challenge inoculation.In a second experiment, six 2–3-month-old calves were injected intravenously with 186,000 infective larvae. Calves were killed at 2, 7, 12, 20 and 30 days after inoculation and had a tissue reaction in the lungs to migrating larvae characterized by focal granulomas, interstitial thickening of alveolar walls, and some hemorrhage. Infective larvae were recovered from the lungs at 2, 7 and 12 days, fourth stage larvae from the abomasum at 7 and 12 days, and adults only from the abomasum at 20 and 30 days. It was considered that larvae reached the abomasum by way of the trachea and by then being swallowed. Clinical signs of disease were not observed.