Risk factors of Salmonella infection in laying hens in Menoua Division, Western region of Cameroon (Central Africa)

Salmonella infections in poultry farms are overlooked in many African countries; yet these infections are mostly zoonotic with impact on both poultry industry and public health. Considering the impact of Salmonella in laying hens, and the role of laying hens as a source of Salmonella outbreak in human, knowledge of the status of Salmonella on laying hen farms as well as the factors influencing the presence of Salmonella is important. In a cross sectional study, cloacal swabs were collected from 270 commercial laying hens on 27 farms located in Menoua Division. These samples were cultured on standard media. A questionnaire was used to collect information on animals, farms and farmer's characteristics. The prevalence of Salmonella was 93.34%; three zoonotic isolates namely S. Enteritidis (75.90%), S. Paratyphi (11.90%), and S. Typhimurium (5.60%) were identified. The location of farms was significantly associated with presence of Salmonella, and the risk of infection was 10-fold higher in Nkong-ni than Santchou (p < 0.05). Other potential risk factors such as flock size, age of the farm (infrastructure), or water source were not associated with Salmonella infection. The prophylactic measures against avian diseases in the country must include measures against Salmonella to protect poultry industry and public health.

Effects of heat stress on some reproductive parameters of male cavie (Cavia porcellus) and mitigation strategies using guava (Psidium guajava) leaves essential oil

Climate changes, particularly the increase of temperature are among the main causes behind the decline of fertility in humans as well as animals. In this study, the effects of heat stress on some reproductive parameters of male cavies and mitigation strategies using guava leaves essential oil (GLEO) were studied. For this purpose, 40 male cavies aged 2.5-3 months and weighing between 348 and 446g were divided into 4 groups of 10 animals each and subjected to the following temperatures: Ambient temperature (20-25°C) for the control group, 35°C for group 1, 45°C for group 2 and 45°C+100µl GLEO/kg body weight, administered by gavage to animals for group 3. Exposure time of heat was 7h per day for 60 days. Results reveal that the relative weights of testes, epididymis, vas deferens and seminal vesicles were hardly affected by the temperature levels considered (P>0.05). The mass and individual sperm motility was significantly lower (P<0.05) in cavies exposed to the temperature of 35 and 45°C as compared with those which received GLEO and controls. The percentages of abnormal sperm and altered sperm DNA were higher in animals exposed to temperature of 35 and 45°C as compared with the controls. The activity of superoxide dismutase significantly increased (P<0.05) in animals exposed to temperature of 45°C and in those of 45°C and orally treated with GLEO, compared with cavies exposed to temperature of 45°C without receiving GLEO. The level of malondialdehyde was significantly increased (P<0.05) in animals exposed to temperature of 35 and 45°C, whereas the level of nitric oxide was significantly lower (P<0.05) in exposed animals as compared with controls. It was concluded that the exposure of male cavies at 35 and 45°C for 60 days induce heat stress that causes deterioration of sperm characteristics. These effects that can be mitigated by the administration of guava leaves essential oil.

Assessment of aflatoxin contamination of maize, peanut meal and poultry feed mixtures from different agroecological zones in Cameroon

Mycotoxins affect poultry production by being present in the feed and directly causing a negative impact on bird performance. Carry-over rates of mycotoxins in animal products are, in general, small (except for aflatoxins in milk and eggs) therefore representing a small source of mycotoxins for humans. Mycotoxins present directly in human food represent a much higher risk. The contamination of poultry feed by aflatoxins was determined as a first assessment of this risk in Cameroon. A total of 201 samples of maize, peanut meal, broiler and layer feeds were collected directly at poultry farms, poultry production sites and poultry feed dealers in three agroecological zones (AEZs) of Cameroon and analyzed for moisture content and aflatoxin levels. The results indicate that the mean of the moisture content of maize (14.1%) was significantly (P < 0.05) higher than all other commodities (10.0%–12.7%). Approximately 9% of maize samples were positive for aflatoxin, with concentrations overall ranging from <2 to 42 µg/kg. Most of the samples of peanut meal (100%), broiler (93.3%) and layer feeds (83.0%) were positive with concentrations of positive samples ranging from 39 to 950 µg/kg for peanut meal, 2 to 52 µg/kg for broiler feed and 2 to 23 µg/kg for layer feed. The aflatoxin content of layer feed did not vary by AEZ, while the highest (16.8 µg/kg) and the lowest (8.2 µg/kg) aflatoxin content of broiler feed were respectively recorded in Western High Plateau and in Rainforest agroecological zones. These results suggest that peanut meal is likely to be a high risk feed, and further investigation is needed to guide promotion of safe feeds for poultry in Cameroon.

Guinea-pig productivity under traditional management

Results of a 12 month study of traditional guinea-pig production in the western highlands of Cameroon are reported. The mean age of guinea-pigs (Cavia porcellus L.) at first parturition, kidding interval and litter size at birth were 126.30 +/- 10.40 d, 64.8 +/- 1.70 d and 1.63 +/- 0.26 kids respectively. The annual reproductive rate was 9.18 kids/breeding doe while the doe post-partum weight was 530 g. Mean body weights at birth, presumed weaning (21 d) and 15 weeks of age were 78.36 +/- 3.20, 147.51 +/- 8.10 and 418.88 +/- 32 g respectively. Type of birth and sex had a significant effect on body weight at all ages. Birth weight dropped significantly from 83.88 +/- 2.87 g for singles to 81.57 +/- 3.40 g for twins, 74.25 +/- 2.39 g for triplets and 73.75 +/- 4.12 g for quadruplets. These differences were maintained to maturity (15 weeks). Males were generally heavier than females. Mortality rates were relatively high among kids: 24% at birth, 39% at 3 weeks and 40% at 15 weeks. Productivity indices were 0.827 kg of young weaned per doe per year, 1560 g of young weaned per kg of doe per year and 2.52 kg of young weaned per kg metabolic weight (kg 0.75) of female per year.

Effects of feeding cattle manure on growth performance and carcass characteristics of large white pigs

Thirty-six weaner Large White piglets were randomly assigned to 3 replicates of 3 treatments to determine the effects of feeding 0, 10 or 20% of cattle manure in partial replacement of ground maize in the diet. The trial lasted 15 weeks. Feed efficiency was not significantly affected. However, pigs fed on the control diet consumed significantly more feed than pigs on the experimental diets containing cattle manure, and although their higher daily weight gain was not statistically significant, at the end of the trial they were significantly heavier (P < 0.05) than those fed the diet containing 20% cattle manure. Carcasses from pigs fed on the diets containing cattle manure were leaner than pigs fed on the control diet.