Improving the success of the critical peri-partum transition period in small ruminants : access to physiological and metabolic disturbances and prospection of effects of natural products to prevent them

The peri-partum period is a critical time for small ruminants because nutritional requirements are very high and feed intake is often limited. Nutritional diseases, such as pregnancy toxemia, can develop. Farmers try to limit these problems. β-glucan and saponin-based plant extracts have been shown to have favourable effects on animal production: immune-modulation for the former and reduced methane production and modification of rumen fermentation patterns for the latter. However, little is known about their effects on metabolism. Therefore, the general objective was to better understand the effects of 1) β-glucan injections and 2) dietary saponin, on metabolism and rumen fermentation in small ruminants during the transition period. The influence of β1,3-glucan (i.m. injections, 1ml/animal/week for 60 days) on the metabolic profile of 14 Santa Inês ewes in the last weeks of gestation was studied. Two groups of ewes were formed in late gestation: a glucan group (G, n=7) and a control group (C, n=7). Nutritional requirements during the experiment were covered. Blood samples were collected throughout the study. Blood samples were analysed for metabolites, ions and enzymes. All ewes were clinically healthy. Glucose, L-lactate, non-esterified fatty acids and β-hydroxybutyrate peaked at parturition (p0.05). The ruminal acetate to propionate ratio tended to be affected by treatment (S < C; p=0.057). There was no effect of saponin in experiment 2 on blood metabolites (p>0.05), except for plasma urea (S > C; p=0.054). Total protozoa numbers tended to be affected by treatment (S > C; p0,05). Le rapport acétate/propionate du rumen a eu tendance à être réduit (S 0,05), sauf pour l’urémie (S>C; p=0,054). Le nombre total de protozoaires a eu tendance à être augmenté (S>C, p