No abstract

Three diets were formulated, a control diet (C, 40.7% NDF, 15.1% CP), the same diet but medicated (M, 500 mg/kg oxytetracycline and 50 mg/kg thiamulin), and a third diet obtained substituting 4% of barley with inulin (Frutafi t) in C diet (I). Pannon White does and their litters were randomly allocated into three groups (8/group) at 21 d of lactation and diets offered to the does and kids from 21 d of lactation onwards. After weaning (28 d), growing rabbits (30 cages/ treatment, 2 rabbits/cage) were fed the same diet as before weaning. At 28, 35 and 42 d of age, 6 healthy animals from each group (1 animal/cage) were slaughtered. Live body weight, feed intake and feed conversion ratio increased and growth rate decreased with age (P<0.001). Feed intake decreased in rabbits fed I diet compared to those fed M diet (by 11%, P<0.05), with those fed C diet showing an intermediate value. Growth rate from 28 to 35 d of age was not affected by diets, but decreased from 36 to 42 d in rabbits fed I diet compared to those fed C and M diets (P<0.05), with no effect on feed conversion ratio. Inulin did not affect mortality, which was low (≤ 3.3%), but increased morbidity compared to C and M diets (11.7 vs. 2.5%, P<0.05). Diets did not affect caecal weight, pH, cellulase and pectinase activity or microbial counts. Inulin diet decreased caecal xylanase activity (P<0.05) compared to C and M diets, reduced propionic and butyric acid and increased acetic acid concentration compared to M diet, whereas C diet showed intermediate values.Caecal pH and counts of E. coli and total aerobic bacteria increased and pectinase activity decreased (P<0.05) at 35 d of age (compared to 28 and 42 d of age). The number of the strictly anaerobic bacteria decreased and cellulase and xylanase activity increased (P<0.05) at 42 d of age compared to 28 and 35 d. Propionic acid concentration decreased with age from 28 to 42 d (P<0.05) but VFA concentration and acetic and butyric acids proportions did not change. In conclusion, the inclusion of 4% of inulin in the diet of weanling rabbits showed no positive effect.

The effect of different weaning ages, that is, 21 (G21), 28 (G28) or 35 (G35) days, on growth and certain parameters of the digestive tract was examined in rabbits to assess the risk of early weaning attributable to the less-developed digestive system. On days 35 and 42, G35 rabbits had 10% to 14% and 10% higher BW, respectively (P , 0.05), than those weaned at days 21 and 28. In the 4th week of life, early weaned animals had 75% higher feed intake than G28 and G35 rabbits (P , 0.05). The relative weight of the liver increased by 62% between 21 and 28 days of age, and thereafter it decreased by 76% between 35 and 42 days of age (P , 0.05), with G21 rabbits having 29% higher weight compared with G35 animals on day 35 (P , 0.05). The relative weight of the whole gastrointestinal (GI) tract increased by 49% and 22% after weaning in G21 and G28 rabbits, respectively (P , 0.05). On day 28, the relative weight of the GI tract was 19% higher in G21 than in G28 rabbits, whereas on day 35 G21 and G28 animals had a 12% heavier GI tract compared with G35 rabbits (P , 0.05). Age influenced the ratio of stomach, small intestine and caecum within the GI tract; however, no effect of different weaning age was demonstrated. The pH value of the stomach and caecum decreased from 5.7 to 1.6 and from 7.1 to 6.3, respectively, whereas that of the small intestine increased from 6.8 to 8.4 (P , 0.05); the differences between groups were not statistically significant. Strictly anaerobic culturable bacteria were present in the caecum in high amounts (10 8 ), already at 14 days of age; no significant difference attributable to weaning age was demonstrable. The concentration of total volatile fatty acids (tVFA) was higher in G21 than in G28 and G35 throughout the experimental period (P , 0.05). The proportion of acetic and butyric acid within tVFA increased, whereas that of propionic acid decreased, resulting in a C 3 : C 4 ratio decreasing with age. Early weaning (G21) resulted in higher butyric acid and lower propionic acid proportions on day 28 (P , 0.05). No interaction between age and treatment was found, except in relative weight of the GI tract and caecal content. In conclusion, early weaning did not cause considerable changes in the digestive physiological parameters measured, but it resulted in 10% lower growth in rabbits.

Pannon White (n 5 12) male rabbits (weight: 4050 to 4500 g, age: 9 months) received 2 ml of a suspension containing purified T-2 toxin by gavage for 3 days. The daily toxin intake was 4 mg/animal (0.78 to 0.99 mg/kg body weight (BW)). Control animals (n 5 12) received toxin-free suspension for 3 days. Since a feed-refusal effect was observed on the second day after T-2 administration, a group of bucks (n 5 10) were kept as controls (no toxin treatment) but on a restricted feeding schedule, that is, the same amount of feed was provided to them as was consumed by the exposed animals. On day 51 of the experiment (i.e. 48 days after the 3-day toxin treatment), semen was collected, and pH, concentration, motility and morphology of the spermatozoa, as well as concentration of citric acid, zinc and fructose in the seminal plasma, were measured. After gonadotropinreleasing hormone (GnRH) analogue treatment, the testosterone level was examined. One day of T-2 toxin treatment dramatically decreased voluntary feed intake (by 27% compared to control, P , 0.05) and remained lower ( P , 0.05) during the first 2 weeks after the withdrawal of the toxin. BW of the contaminated rabbits decreased by 88% on days 17 and 29 compared to controls ( P , 0.05). No effect of toxin treatment was detected on pH and quantity of the semen or concentration of spermatozoa. The ratio of spermatozoa showing progressive forward motility decreased from 65% to 53% in the semen samples of toxin-treated animals compared to controls ( P . 0.05). The ratio of spermatozoa with abnormal morphology increased ( P , 0.05) in the ejaculates collected from the toxin-treated animals. T-2 toxin applied in high doses decreased the concentration of citric acid in seminal plasma ( P , 0.05). No effect of T-2 toxin on the concentrations of the other seminal plasma parameters (fructose and zinc) was observed. T-2 toxin decreased the basic testosterone level by 45% compared to control ( P , 0.01) and resulted in lower ( P , 0.05) GnRH-induced testosterone concentration. Feed restriction, that is, less nutrient intake, resulted in more morphologically abnormal spermatozoa in the semen, but it did not cause significant loss in BW, motility of the spermatozoa, composition of the seminal plasma or testosterone concentration -its effect needs further examination.

Growing rabbits' (42 rabbits/group, 3 rabbits/cage, 14 cages/treatment) diet was supplemented with 5% spirulina (Arthrospira platensis) and 3% thyme (thymus vulgaris l.) powder single (s or t) and in combination (st) between 35 and 77 days of age. on day 0 (weaning at 35 days of age) 14 rabbits were vaccinated with 100 µg/animal ovalbumin to provoke immune response. blood samples were taken on days 0, 14, 28 and 42 of the experimental period. Sampling dates significantly influenced total protein, albumin, glucose, cholesterol, urea, creatinine concentration and enzyme (AST, ALT, GGT) activities, with a significant age × diet interaction in the case of tp and CREA. There was a significant increase in ALT (+45 and 74%) and GGT (+87 and 102%) activity after immunisation. While Spirulina and thyme significantly ameliorated the rise in AST activity, their effect was inefficient in the case of GGT. Spirulina, both single and in combination showed a tendency in higher IgG level as compared to control (P<0.05). No significant effect of sampling date or treatment on phagocytic activity or secretory iga was demonstrable (p>0.05). higher mda concentration was measured in the red blood cells of S, T and ST animals, while no other significant diet effect on the antioxidant parameters was detected, however, significant sampling date × diet interaction was found in the case of Gpx activity. plasma GGt (increase by 19-66%) was inversely associated with Gsh (decrease by 66-113%) between days 0 to 42 of the experimental period (r=-0.57, p<0.05). it can be concluded that spirulina supplementation alone resulted in higher IgG production, but none of the phytobiotics, at the dose used, affected significantly the antioxidant status of blood.