Ecological Aspects of Tabanids (Diptera: Tabanidae) in a Gabonese Cattle Ranch

To embark on an anti-vectorial fight against mechanical vectors of animal trypanosomosis, investigations were undertaken in order to determine the abundance, species diversity and daily activity of tabanids in a cattle ranch in Gabon. The nzi and vavoua traps were used to catch tabanids in three divisions of this ranch. In this study, 616 tabanids were captured: 349 (56.66%) in Division 1, 226 (36.69%) in Division 2 and 41 (6.66%) in Division 3. In the first Division, T. taeniola was the most abundant species with an Apparent Density (ADT) of 2.2, followed by H. pluvialis (ADT = 1.05). In the second Division, H. pluvialis was most abundant with ADT of 1.6, followed by T. taeniola (ADT = 0.38). In the last Division, the most abundant species was H. pluvialis (ADT = 0.15). Comparing the relative abundance of catches with sites (Divisions), we realized that there was no statistically significant difference in catches with trapping sites. It was noticed that Division 3 recorded the highest diversity index values. We realized that the nzi trap recorded higher tabanid catches than the vavoua trap. The diurnal activity rhythm of the most frequent species encountered slightly differed with prospection sites.

Determination of Heavy Metals in Selected Tissues of Cattle Slaughtered across Nasarawa State, Nigeria

This study was conducted to determine the concentrations of some toxic heavy metals in cattle slaughtered from the three agricultural zones of Nasarawa State, Nigeria. Selected tissues of muscle, intestine, skin, kidney and liver were analyzed for the presence of Cadmium (Cd), Chromium (Cr), Lead (Pb), Copper (Cu) and Nickel (Ni) using Atomic Absorption Spectrophotometer (AAS). Thirty cattle were used for sampling. Five samples of the tissues were collected from each of the cattle, making a total of one hundred and fifty samples. Values obtained were compared with that of FAO/WHO guidelines. Statistical analysis was done using descriptive statistics, t-test and ANOVA. The mean concentrations (mg/kg) of Ni, Cd, Pb and Cu in all the sampled tissues were generally low and below the codex standards. Cr was detected above permissible limit with mean concentrations (mg/kg) of 1.19±5.94, 1.07±4.42, 3.01±6.65, 1.18±5.56 and 1.35±6.94 in intestine, kidney, liver, muscle and skin respectively. There was a significant (P < 0.05) difference in the level of Ni and Cd across two agricultural zones. Government and private sectors should establish cattle ranch and colonies across Nigeria so as to reduce pasture contamination. Public enlightenment on the grazing of cattle in heavy metals prone areas such as automobile workshops, construction sites and paint factory premises should be advocated. Measures should be put in place for continuous monitoring of heavy metals in Nasarawa state in order to curtail their potential negative effect in human and animal tissues. Key words: cattle, heavy metals, AAS, Nasarawa state.

AN AGE STRUCTURE MODEL WITH IMPULSE ACTIONS FOR LEPTOSPIROSIS IN LIVESTOCK CATTLE

As a zoonotic disease, leptospirosis has now been identified as one of the emerging infectious diseases. In this paper, we analyze the propagation of leptospirosis and find a schedule for control programs to eradicate the disease in a cattle ranch. A mathematical model has been built with ordinary differential equations (ODEs) to understand the epidemiology of leptospirosis and main factors on its transmission. We investigated the disease free equilibrium of the model and its stability using the basic reproduction number, [Formula: see text], and target reproduction number, [Formula: see text]. Then, the model incorporates vaccination and recruitment control programs in the form of impulse actions as measures to prevent the propagation of leptospirosis in the ranch. Parameter estimation and sensitivity analysis are presented as a part of this study.

Influence of Low and High Temperatures on the Development of Haemonchus Contortus and Oesophagostomum Columbianum Larvae in Nigeria

EGGS of Haemonchus contortus and Oesophagostomum columbianum exposed to a constant temperature of 13.8°C at 100% relative humidity developed to the infective third stage larvae within 15 and 18 days respectively. Exposure of eggs for nine hours at 40.6°C and 100% relative humidity was lethal but development to the infective stage was achieved by culturing at 27°C after six hours of exposure at 400C and 100% relative humidity. The normal Nigerian temperature range of 13.8°C [lowest minimum for Obudu Cattle Ranch] to 40.6°C (maximum for Maiduguri) is therefore suitable for survival and development of these stronglyle eggs to the infective stages at any season in the country.

EVALUATION OF THE GROWTH PERFORMANCE OF CALVES FROM DIFFERENT DAMS SERVED BY SAME BULKL

The growth performance of seve calves from different Mutura dams served by same bull was studied in a mini cattle ranch. Body measurements were taken and observed for growth over a period of 12 months. The result indicates an apparaent difference among the calves in all parameters measured including body weight, body length, height at withers and heratgirth. Growth rate also showed increased differences among the experimental calves. The birth weights of the seven calves ranged from 9.8 to 13.0kg, with a mean value of 11.42+0.44 while the yearling weights were between 107.80 and 129.48kg with an overall mean of 120.57+2.44. The coefficients of variation for body weight at birth and at 12 monthys were 10.16 and 5.36% respectively. The results further revealed that body weight at yearling age correlated positively with all parameters and these include body length (r=0.81889, r2 = 67.09), height at withers (r=0.8837, r2=78.09). Similarly, body length had a positive correlation with height at withers (r=0.9667, r2=93.45) and heartgirth (r=0.8782, r2=77.13). White height at withers correlated positively with heartgirth (r=0.9291, r2=86.42). Similar trends were obtained in the regression of each of the body measurements on the other in which body weight changes depended more on those of body length (0.56) than on heartgirth (0.34). Judging from the observed variations existing among the individual calves resulting from the different cows at birth and at 12 months of age, maternal rather than paternal influences appeared to be more important in the traits studied.