Indigenous Muscovy ducks in Congo-Brazzaville. 1. A survey of indigenous Muscovy duck management in households in Dolisie City.

A cross-sectional study by means of a questionnaire with open-ended questions and multiple-choice questions was used to collect data on the profile of duck keepers, husbandry practices, and performances, opportunities and constraints of Muscovy duck breeding in households (n = 88) in Dolisie city (Congo-Brazzaville). The study confirmed the common observations on traditional poultry keeping such as scavenging during the day and housing overnight. The flock size (7.7 +/- 3 ducks per unit) showed no specialization of husbandry (100% of surveyed flocks were kept for simultaneous production of ducklings, meat and eggs) and a high drake-to-duck ratio (1:3). The hatchability was close to 80.5% +/- 13%, whereas the average number of eggs was 13.2 +/- 5 per clutch. In addition, a high mortality (80%) was observed in ducklings, which was due to poor feeding, lack of veterinary care and housing conditions. Eggs and live ducks were sold by duck farmers in response to the family needs rather than market price. The three most important findings were as follows: (1) duck keepers were mainly men (80% versus 20% of women); (2) there was no evidence of taboo; and (3) the duck as an exotic bird was not proscribed by cultural beliefs, and therefore development of the Muscovy duck in Congo Brazzaville should be unhindered.

Indigenous Muscovy ducks in Congo Brazzaville. 2. Preliminary observations on indigenous Muscovy ducks reared under moderate inputs in Congolese conditions.

To evaluate the potential of the native Muscovy ducks in Congo, a trial was conducted with closed housing, commercial feeding and veterinary care. The characterization included reproductive performance, daily weight gain, live body weight, feed conversion ratio, body live weight productivity, and meat productivity. The experimental genetic stock was bred under natural mating and natural incubation. The number of eggs recorded per female and per clutch was 14.6 +/- 3 eggs with 2 clutches per year. The average (+/-SD) hatchability was 75% +/- 3% and the average egg weight was 72 +/- 8 g. The sexual dimorphism for body weight appeared after 3 weeks (p < 0.05). The maximum daily weight gain in males reached 55 +/- 8 g/day and occurred at 5 weeks, whereas in females it occurred at 4 weeks and reached 35 +/- 5 g/day. The carcass yield was 70% +/- 5% and 51 +/- 8% in males and females, respectively. The meat productivity was 26.7 and 11.5 kg/m2 per year in males and females, respectively. From these findings, it can be concluded that the incubation by mother duck is preferred in the small farming duck and that males should be raised for meat and females for egg production. Further studies including local poultry-related issues are needed to optimize the performance of the native Muscovy duck in Congo-Brazzaville.

Prevalence of common gastrointestinal nematode parasites in scavenging pigs of different ages and sexes in eastern centre province, Burkina Faso.

The range and infestation intensities of gastrointestinal parasitic nematode species depend on the type of swine production system. The present study focused mainly on nematodes of veterinary importance in scavenging pigs in Burkina Faso, and aimed at determining the prevalence of gastro-intestinal nematode parasites by means of faecal egg per gram (EPG) counts. Between November 2001 and October 2002, faecal samples from 383 pigs of different sexes and ages (< 5 months, 5-12 months and > 12 months) were collected from the rectum and examined for gastrointestinal nematodes parasites using the Mc Master method. Of the 383 pigs examined, 91% were infected by one or more parasites. Ascaris suum (40%; 100-1 400 EPG) was the most prevalent parasite followed by Strongyloides ransomi (21%; 100-4200 EPG), Oesophagostomum spp. (18%; 100-1000 EPG), Hyostrongylus rubidus (11%; 100-1 800 EPG), Globocephalus spp. (10%; 100-400 EPG) and Trichuris suis (1 %; 100-200 EPG). The prevalence was significantly higher in female pigs (n = 239) than in males. In addition, females excreted significantly (P < 0.05) more eggs in their faeces than males, except in the case of Globocephalus spp. The age of the animal had no effect on the prevalence of A. suum whereas there were significant differences in age categories concerning S. ransomi, H. rubidus, Oesophagostumum spp. and Globocephalus spp. Unexpectedly, the high prevalence of these common parasites was not accompanied by elevated EPG values, which suggests the existence of moderate infestations. The present work indicates that the common nematode infestations in pigs do not necessarily need a systematic herd anthelmintic treatment, as only a small number of worms is required to induce immunity. A further study is needed to formulate appropriate and cost-effective strategies for the control of gastro-intestinal nematode parasites in pigs in Burkina Faso.

Correlation between a proteolytic method and a radioimmunoassay for porcine serum pepsinogen concentrations.

The measurement of serum pepsinogen concentrations by enzymatic method and immunoassay provides diagnostic values and should be helpful in the detection of gastric diseases related to a rise of blood pepsinogen. In the present study, the correlation between a conventional enzymatic method and a recently developed radioimmunoassay (RIA) for serum pepsinogen A was investigated. A total of 123 sera samples of porcine foetuses (n = 28), adult healthy pigs (n = 56), pigs with parakeratosis (n = 25) and pigs with ulceration of the pars oesophagea (n = 14) were tested. Overall, there was a slight correlation between the two methods (r = 0.60). In relation to individual animal groups, the correlations (r) were 0.39 (P>0.05), 0.74 (P<0.001), 0.19 (P>0.05) and 0.34 (P>0.05) in foetuses, healthy pigs, pigs with parakeratosis and pigs with ulcers, respectively. In both methods, pepsinogen concentrations (means+/-SE) were significantly higher (P<0.05) in pigs with parakeratosis (1778 +/- 86.00 mUTyr/L; 690 +/- 53.00 ng/mL) and in pigs with ulcers (2026 +/- 153.00 mUTyr/L; 1747 +/- 94.00 ng/mL) when compared to healthy pigs (935 +/- 58.00 mUTyr/L; 275 +/- 35.00 ng/mL). The proteolytic method gave a significant increased activity (P<0.05) in foetuses (1150 +/- 82.00 mUTyr/L) vs. (935 +/- 58.00 mUTyr/L) in healthy adult pigs, indicating an additional proteolytic activity in the sera of foetuses or neonates.

Survey of gastric lesions and blood pepsinogen levels in pigs in Burkina Faso.

The purpose of the study was to investigate the prevalence of gastric lesions and to provide diagnostic values for serum pepsinogen in non-infected pigs and in pigs with gastric disease. In an abattoir survey, the pepsinogen concentrations were measured in the serum from 62 non-infected pigs, 33 pigs with gastric lesions and 17 pigs infected with Hyostrongylus rubidus, using a specific radioimmunoassay (RIA). The mean (+/- SE) pepsinogen concentrations in the serum of non-infected pigs, in pigs with gastric ulcers, and in pigs with a heavy H. rubidus infection were 630.8 +/- 39.2 ng/ml, 1084.5 +/- 166.2 ng/ml and 1095.2 +/- 102.3 ng/ml, respectively (p<0.05). Because of the higher concentrations of pepsinogen in the blood of pigs with gastric ulcers or parasitic infections, it is suggested that the measurement of serum pepsinogen by RIA may be an effective biochemical approach to the diagnosis of chronic gastric disorders in pigs.

An improved radioimmunoassay for measurement of pepsinogen in porcine blood samples.

The study was conducted to develop a sensitive and specific radioimmunoassay (RIA) for the measurement of pepsinogen in porcine serum, and to use this test for the determination of pepsinogen concentrations in serum samples from fetuses and pigs of different ages. Compared to a previously described RIA, major improvements were made concerning the use of specific polyclonal antibodies and the use of an appropriate buffer. The assay was able to detect pepsinogen concentrations of >/=0.2 ng/mL. The recovery of pepsinogen was close to 95%. The intra-assay coefficients of variations ranged between 3.9 and 7.5% whereas the interassay ranged between 8.8 and 11.9%. These percentages correspond to a satisfactory accuracy and reproducibility of the assay. No cross-reactions were observed with the main commercially available products of the aspartic proteases family except porcine pepsin cross-reacted over 62.5 microg/mL. Pepsinogen concentrations increased steadily with increasing age of the fetuses and the pigs (P<0.05). Pepsinogen concentrations (+/-SE) in fetuses of 90-100 (n=24) and 100-110 days of pregnancy (n=36) were 0.5+/-0.1 and 5.3+/-1.3 ng/mL, respectively. In pigs of 21, 98, and 213 days of age, the pepsinogen concentrations were 290.6+/-10.8, 343.1+/-17.9 and 383.5+/-15.3 ng/mL, respectively. The results demonstrate that RIA is accurate and can be used easily to assess pepsinogen concentrations in pig sera. The test may constitute a valuable tool in epidemiological surveys and in studies related to gastric diseases in pigs.

Aspartic proteinase members secreted by the ruminant placenta: specificity of three radioimmunoassay systems for the measurement of pregnancy-associated glycoproteins.

Pregnancy-associated glycoproteins (PAGs) isolated from the placenta of various ruminant species are enzymatically inactive members of the aspartic proteinase family. The measurement of these proteins in the maternal blood can be a good indicator of the presence of a live embryo. As certain aspartic proteinases are present in biological fluids in physiological and pathological conditions at various concentrations, it was necessary to determine the specificity of three radioimmunoassay (RIA) systems currently used for the detection of PAG molecules. Commercially available members of the aspartic proteinase family like pepsinogen, pepsin, chymosin, rennet, cathepsin D and renin were tested in a wide concentration range (10 ng/ml - 1 mg/ml). Pepsinogen cross-reacted in RIA 1, RIA 2 and RIA 3 over 1 mg/ml, 50 microg/ml and 500 microg/ml concentrations, respectively. In the presence of pepsin, cross-reaction was observed in RIA 1, RIA 2 and RIA 3 over 1 mg/ml, 500 microg/ml and 1 mg/ml concentrations, respectively. Chymosin and rennet could cross-react in RIA 2 and RIA 3, while renin and cathepsin D did not decrease the binding of the tracer to antisera more, than that of the minimal detection limit. As the plasma/serum concentrations of the examined aspartic proteinases reported in the literature were outside the concentration range where cross-reaction was observed, it can be concluded that these RIA systems were specific for the detection of PAGs in biological fluids.