Prevalence of gastro-oesophageal ulcers in grower-finisher pigs in the northern province of South Africa.

Ulceration of the gastric pars oesophagea is a common problem in intensive pig production that is often detected at slaughter. A survey was carried out at the Pietersburg abattoir in the Northern Province during a 6-month period. In total, 4320 pig stomachs were examined. Gastro-oesophageal ulcers were observed in 5.1% of the stomachs, gastric erosion in 15.2%, and hyperkeratosis in 18.9%. Time of slaughter was found to affect the prevalence of gastric lesions in the pig.

Differential response of legumes and creep feeding on gut morphology and faecal composition in weanling pigs.

The effects of creep feeding and different levels of soybean meal (SBM) and cowpea meal on the intestinal morphology and faecal characteristics were investigated in weaners. Prior to the feeding trial, one group of piglets was creep-fed and the other noncreep-fed. The two groups of piglets were weaned at 28 days and randomly assigned to four different diets, the main protein sources of which were: T1--skimmed milk power (control); T2--31% soybean meal (high SBM), T3--15% soybean meal and 12% skimmed milk powder (low SBM), and T4--100% raw cowpea meal. Live weight gain was highest in the control group, and least in cowpea-fed piglets. At weaning, only the noncreep-fed weaners showed villus atrophy and crypt hyperplasia but at 7 days postweaning, these changes were evident in all groups except the control and were more severe in the noncreep SBM and cowpea-fed groups. At 21 days postweaning, only noncreep cowpea-fed pigs showed a reduced villus height when compared to the control group. A mild diarrhoea was generally observed in all noncreep-fed weaners, but its onset was more rapid (P < 0.01) and the duration much longer (P < 0.05) in the high SBM and cowpea-fed pigs than in low SBM and control groups. A lower faecal pH was observed in weaners that had diarrhoea when compared with a pH of 7.1 in pigs with normal faecal moisture. The observations of enteropathology and low growth performance in the cowpea group suggest that feeding raw cowpea to weaners may induce antigenicity in the intestinal mucosa, causing damage and a consequent decrease in productivity. However, the introduction of creep feeding before weaning appears to have some ameliorative effects.

Effect of castration on serum concentrations of gonadal hormones, insulin-like growth factor-I and its binding proteins in male pigs.

Ten male pigs (Large White x Landrace), 7 months old, were randomly allocated to two experimental groups. Five of them were castrated and the other five served as controls. Sera were collected on the day of castration and 1, 5, 6 and 7 weeks after castration for hormone assay. There was a significant rise in the splenic and pancreatic weights in the castrates (P < 0.01). The weights of prostate, seminal vesicles and bulbourethral glands were significantly decreased (P < 0.01) in the castrates, which is attributed to a fall in testosterone levels (P < 0.001). The fall in oestradiol concentrations (P < 0.001) in castrates confirms that the testis is the major source of oestrogens in males. Although there was no significant change in the body weight, serum IGF-I levels were elevated in the castrates as compared to the controls after 5, 6 and 7 weeks (P < 0.001). IGFBP bands of 43 and 39 kda predominate in both control and experimental groups indicating that castration had no effect on the IGFBP pattern. It is suggested that the increase in IGF-I levels may be due to uncoupling of GH/IGF-I axis induced by the decrease in steroid concentrations due to castration.

Effects of dietary soybean and cowpea on gut morphology and faecal composition in creep and noncreep-fed pigs.

The effects of creep feeding and different levels of soybean meal (SBM) and cowpea meal on the intestinal morphology and faecal characteristics were investigated in weaners. Prior to the feeding trial, one group of piglets was creep-fed and the other noncreep-fed. The two groups of piglets were weaned at 28 days and randomly assigned to four different diets whose main sources of protein were: T1-skimmed milk powder (control); T2-31 % soybean meal; t(3)-15% soybean meal and 12 % skimmed milk powder; and T(4)-100% raw cowpea meal. Live weight gain was highest in the T1 group, and least in the T(4) group. At weaning only the noncreep-fed weaners showed villus atrophy and crypt hyperplasia, but at 7 days postweaning these changes were evident in all groups except the control and were more severe in the noncreep (T2,T3) and cowpea-fed groups. At 21 days postweaning, only noncreep cowpea-fed pigs showed a reduced villus height when compared to the T1 group. A mild diarrhoea was generally observed in all noncreep-fed weaners but its onset was more rapid (P < 0.01) and the duration longer (P < 0.05) in the T2 and T4 pigs than in T3 and T1 groups. A lower faecal pH was observed in weaners that had diarrhoea when compared with a pH of 7.1 in pigs with normal moisture. The glucose content of the faeces was found to be significantly higher (P<0.05) in the T2 and T4 groups. The observations of enteropathology and low growth performance in the T4 group suggest that feeding raw cowpea to weaners is capable of inducing considerable antigenicity in the intestinal mucosa, causing damage and a consequent decrease in productivity. However, the introduction of creepfeeding before weaning appears to have some ameliorative effects.

Biochemical and haematological values in abattoir pigs with and without subclinical lesions.

The biochemical and haematological profiles of 379 pigs with or without various gross pathological lesions in an abattoir in Zimbabwe were studied to see whether there were any differences between the levels of haematological and biochemical values, and health status (with and without pathological lesions). On the basis of observable gross pathology, 134 pigs were classified as having one or more subclinical lesions (liver milk spot, pneumonia, pleurisy, pericarditis, abscesses and arthritis). Seventy-six of these were males and 58 females. There were observable sex differences in the mean haematological and biochemical values obtained. Erythrocyte counts showed significant differences in mean values (P < 0.05) among groups of pigs found with various pathological lesions. The biochemical values showed significant group differences for ALP, ALT, AST, and LDH.

Evaluation of some reproductive parameters in the indigenous boar of Zimbabwe.

A number of reproductive parameters were evaluated in 12 adult indigenous boars. The seminal vesicles, prostate and bulbourethral glands had masses of 184.41 +/- 18.00 g, 16.69 +/- 2.42 g and 142.05 +/- 16.12 g, respectively, while the penile length measured 45.71 +/- 4.49 cm. The testes and epididymides had masses of 211.82 +/- 26.74 g and 108.81 +/- 11.49 g. The number of sperm averaged 2.78 +/- 0.59 x 10(9) in the testes and 11.76 +/- 2.11 x 10(9) in the epididymides. The daily sperm production per gram (DSPG) of testicular tissue and the daily sperm production rate (DSP) were calculated to be 2.98 +/- 0.31 x 10(6) and 0.62 +/- 0.14 x 10(9) spermatozoa, respectively. The serum level of testosterone measured 11.98 +/- 0.81 ng/ml. These values suggest a reduced reproductive capacity in these animals. However, appropriate selection techniques may be evolved to upgrade this indigenous stock while nutrition and management may be improved to increase body size, and hence, gonadal development.

Osmotic fragility of erythrocytes in clinically normal dogs and dogs infected with parasites.

The osmotic fragility of the erythrocytes was measured in blood samples collected from randomly selected healthy and infected dogs at a dogs' rescue shelter. The dogs were classified into six groups on the basis of the final diagnoses from clinical, post mortem and laboratory findings. The minimum (less than 5 per cent) and maximum (more than 90 per cent) haemolysis of the erythrocytes of the clinically normal dogs (group 1), occurred in 0.60 per cent and 0.30 per cent solutions of sodium chloride (NaCl). For the non-anaemic hookworm-infected dogs (group 2a) the respective values were 0.8 per cent and 0.4 per cent NaCl, and for the anaemic hookworm-infected dogs (group 2b) they were 0.85 per cent and 0.5 per cent NaCl, respectively. The erythrocytes from dogs with Babesia canis (group 3), concurrent hookworm and B canis (group 4) and Ehrlichia canis infections (group 5) had minimum haemolysis in 0.75 per cent NaCl and maximum haemolysis at between 0.20 per cent and 0.35 per cent NaCl solutions. The derivative fragiligrams for groups 2a, 2b, 3 and 4 were shifted to the left, whereas the fragiligram for group 5 was similar to that for the clinically normal dogs (group 1). The left shift for the hookworm-infected dogs was due to the increased osmotic fragility of a minor sub-population of the erythrocytes, but for the dogs infected with B canis major sub-populations of the erythrocytes had an increased osmotic fragility.

Isotopic water dilution technique in body fluid measurement in some domestic animal species.

Dilution procedures using tritiated water and Evans blue dye (T 1824) were applied to estimate total body water and plasma volume in small ruminants, pigs and cockerels during the two different seasons in Zimbabwe. The amounts of total body water (TBW) obtained were between 60% to 85% of the body weight in sheep and goats, 40% to 60% in pigs and 63% to 75% in cockerels. TBW values were significantly higher (P < 0.05) in the small ruminants than in pigs and observed age differences were significant (P < 0.05) in the small ruminants. There were significant (P < 0.05) seasonal differences in the total body water mean values but nonsignificant (P > 0.05) differences in the plasma volume mean values for the domestic species investigated.

The response of pigs experimentally infected with Trypanosoma brucei to isometamidium chloride therapy and the relation to nutrition.

Growing pigs were placed on feeds with high (Group A), medium (B) and low (C) dietary energy and were infected with a virulent stock of T. brucei. Eight weeks later, the infected pigs were treated with isometamidium chloride at 1 mg/kg live weight and all pigs were subsequently placed on a high energy diet to investigate their response to therapy. Clearance of T. brucei from blood was completed 72h after treatment. There was no evidence of relapsed infection up to eight weeks after treatment. Red blood cell parameters returned to normal four to six weeks after treatment with responses being fastest in Group A, B and C had gained about two-thirds of the live weight gains of their non-infected pair-fed controls. It appears that the retarded weight gain as a result of the infection persisted after therapy since drug-treated pigs did not gain as much weight as their non-infected controls.

The relationship between dietary energy levels and the severity of Trypanosoma brucei infection in growing pigs.

Growing pigs were placed on high, medium and low planes of dietary energy and were infected with a virulent strain of Trypanosoma brucei. During an 8-week period post-infection (p.i.), the respective liveweight gains by infected pigs on high, medium and low energy levels were 52.1, 21.2 and 38.5%, respectively, of the corresponding gains by non-infected control pigs. There was a fall in red blood cell values p.i. which worsened with decreasing energy levels. Leucocytosis was observed in all infected pig groups and was mainly due to lymphocytosis. By 6 weeks p.i., the lymphocyte count had returned to near normal values in pigs on high and medium energy levels, but was persistently high in those on a low energy level. Neutropaenia was observed in all infected pig groups and persisted until 8 weeks p.i. The results indicated that nutrition modulates the host response to infection with trypanosomes.