Changes in weight gain, faecal oocyst count and packed cell volume of Eimeria tenella-infected broilers treated with a wild mushroom (Ganoderma lucidum) aqueous extract.

An experiment was conducted to study the effect of a wild Ganoderma lucidum aqueous extract in coccidian-infected broilers. At 6 weeks of age the birds were randomly allocated to 6 treatment groups of 20 Ross broilers each in wire cages. Groups A, B and C were infected with Eimeria tenella Houghton strain at the rate of 36 250 sporulated oocysts/ml per bird. The remaining 3 groups D, E and F were uninfected controls. At 7 weeks the birds in group A were treated with G. lucidum aqueous extract and those in B with amprolium in drinking water ad libitum at the rate of 200 mg/ml each for 7 days consecutively. Body weight gain, feed intake, faecal oocyst output and some haematological parameters were monitored. The result showed that all the infected birds in groups A, B and C had clinical signs of weakness and reduced appetite on day 4 post-infection. By the 5th day post-infection their faeces became bloody and watery, and large numbers of E. tenella oocysts were present in the faeces. On day 3 after treatment the oocysts detected were considerably reduced in both treated groups A and B and slightly higher in the untreated group C. The faeces of the uninfected control groups were normal and free of coccidial oocysts. After treatment for 7 days no coccidial oocysts were found in faeces of the birds that had been treated. Infected, untreated birds showed a slight drop in feed intake and weight gain from 7 to 8 weeks of age. The final mean weight gain recorded in the treated groups A and B was comparable to that of the uninfected birds in the 3 control groups, while it was lower in the untreated group C. The feed to gain ratio was higher in C than in the other groups. A slight drop in packed cell volume was observed in groups A, B and C at 7 weeks of age, 1 week after infection. This study showed that treatment with G. lucidum results in a marked reduction in the number of E. tenella oocysts shed in the faeces, leading to improved weight gain and decreased weight loss. The results confirmed the virulence of the Houghton strain of E. tenella and the effectiveness of both amprolium and G. lucidum extract against E. tenella.

Experimental trypanosomiasis in Yankasa ewes: the body weight response.

Sleeping sickness (African Trypanosomasis) is an anthropozoonosis transmitted primarily by the tsetse fly. It is associated with a host of clinical indices ranging from fever, aneamia and anorexia to reproductive failures in man and his domestic animals. The main objective of this study is to appraise the responsiveness of the body weight as a clinical indicator of sleeping sickness in experimentally infected Yankasa ewes. Twelve mature Yankasa sheep (6 infected and 6 control ewes) were used in this study. Weekly body weights and daily rectal temperature were taken while blood samples for haematology were collected twice a week from all animals before and after the experimental infection. Undulating parasitaemia was observed, two days post infection and was sustained through out the study period of about fifty days in all the infected ewes. Decreased body weight was found to be very prominent in the infected animals. All the infected ewes progressively lost weight during the experiment with a decrease of about 17.9% of the original weights while the control ewes had increased by 4.2% at the end of the study period. The body weight is therefore a very sensitive parameter in the surveillance and management of Trypanosome infections especially in Yankasa ewes as experimental animal models.

A simple field diagnostic smear test for bovine besnoitiosis.

A fast and inexpensive skin biopsy smear was used for confirming suspected clinical cases of bovine besnoitiosis. The technique was based on the demonstration of Besnoitia besnoiti bradyzoites (cystic stages), which appeared stumpy, each organism 6.2 microns by 3.1 microns in size, or banana-shaped, 7.7 microns by 1.5 micron in affected skin smears. A more rapid non-surgical technique, scleral conjunctival scraping, revealed similar bradyzoites, thus enhancing the diagnostic value of conjunctival cysts in more chronic infections. The technique will aid prompt management decisions to contain suspected outbreaks in herds not routinely served by tissue-processor-equipped diagnostic laboratories.

The course of experimental Trypanosoma vivax infection in Uda sheep.

The course of experimental Trypanosoma vivax infection in eight Uda rams was studied. All the infected animals became parasitaemic 2 days post-inoculation and remained so throughout the study period. A three-phase disease pattern was recognized, i.e. acute, subacute and chronic stages lasting 17-85 days. The disease was characterized by fever and a terminal decrease in rectal temperature despite an increase in parasitaemia with time for rams with acute and subacute infections. Mean weight loss was most marked in subacute followed by chronic cases. Gross pathological changes observed in some infected rams with subacute and chronic trypanosomosis were oedema of the face and lower jaw, hydropericardium and atrophy of the pericardial fat. Petechial haemorrhages were observed on the surfaces of the heart and kidney of rams with acute infection. Anaemia was most severe in infected rams with acute disease, followed by those with subacute infections. Also, hypoproteinaemia was observed in all infected rams. Severe clinical findings associated with the death of all the infected rams during this study might indicate that the Uda breed of sheep in very susceptible to trypanosomosis. It is, therefore, recommended that this breed of sheep, which is strictly bred and reared in tsetse-free Sahel savannah, should not be introduced into endemic areas devoid of therapeutic cover and strict tsetse fly control.

Effect of chemotherapy on elevated ejaculation time and deteriorated semen characteristics consequent to bovine trypanosomiasis.

The effect of the trypanocidal drug Novidium on elevated ejaculation time and deteriorated semen characteristics was studied in Zebu cattle infected with T. vivax and T. congolense. Two groups, comprising six bulls per group, were infected with Trypanosoma vivax or Trypanosoma congolense while three bulls served as controls. Chemotherapy was carried out 12 weeks post-infection on three bulls from each group, leaving three bulls untreated while three bulls served as uninfected controls. Blood samples from treated bulls were all negative for trypanosomes 3 days post-chemotherapy. The animals also had normal body temperature. As the study progressed, clinical signs associated with trypanosomiasis, such as anaemia and cachexia, disappeared gradually in treated bulls. There was some improvement in semen characteristics of some of the bulls at 10 weeks post-chemotherapy with Novidium. However, all bulls infected with T. vivax or T. congolense irrespective of Novidium chemotherapy still had poor semen characteristics manifested by all or some of the following: decreased volume of semen, oligospermia, azoospermia and elevated incidence of spermatozoa morphological abnormalities. They were thus unsuitable for breeding.

Acute toxicity studies with Jatropha curcas L.

The seeds of Jatropha curcas L. ingested accidentally by two children aged 3 and 5 years led to a clinical syndrome of restlessness, severe vomiting and dehydration. A systematic study of the seeds indicated that they produced toxic effects in mice. Macroscopic anal haemorrhage and death occurred when the seeds were administered with the feed. Post-mortem examination revealed infarction of various parts of the gastrointestinal tract with congested vessels. Sodium chloride solution (150 mmol/l: saline) extract of the dried seed administered intraperitoneally into mice caused death in doses as low as 1 mg/kg. Post-mortem studies in this case showed widespread haemorrhages involving the colon, lungs as well as infarction of the liver. Larger intraperitoneal doses (greater than 30 mg/kg) were lethal rapidly but not associated with gross gastrointestinal haemorrhage.

Field observations on adult zebu bulls immunised against anaplasmosis by infection and treatment plus integrated tick control.

Fourteen adult zebu bulls which were negative for Anaplasma marginale infection both serologically and on blood smear examinations were infected with a virulent Nigerian isolate of A. marginale. Forty days following the immunising infection when clinical reactions were established groups of seven animals were treated with either two doses of imidocarb dipropionate (2 X 5 mg/kg given intramuscularly 14 days apart) or a single intramuscular dose of long-acting oxytetracycline (5 mg/kg). Following clinical recovery, two weeks after the first treatment the immunised animals and seven susceptible controls were then introduced into a tick-infested area and held there for 15 months with regular tick control. There were significant differences between the mean weight gains of surviving animals in the oxytetracycline group and the controls and surviving animals in the imidocarb group and control cattle. The protective effect of tick control alone was inferior to that of integrated tick control plus anaplasmosis control by either method of immunisation. Losses occurred in all groups due mainly to the effects of other tick-borne diseases, babesiosis and heartwater.