Effect of protein source on digestion and growth performance of early-weaned rabbits

Abstract

-Four diets based on different vegetal protein concentrates: soya bean meal 48 (SB48 diet), soya bean protein concentrate (SB61 diet), sunflower meal 36 (SF36 diet) and a combination of soya bean meal 48 and potato protein concentrate (SB48-P77 diet) were formulated for the starter period (25-39 days) in early weaned rabbits (25 days of age). These sources of protein accounted for 30% of the total dietary crude protein (CP) content. All diets were formulated to be isonutritive and to meet or exceed all the essential nutrient requirements of growing rabbits. A feeding trial was conducted to measure the effect of the treatments on growth performance in 204 rabbits that were fed ad libitum the experimental diets in the starter period and thereafter received a common feed until 60 d of age. Faecal and ileal apparent digestibility of dry matter (DM) and CP (9 and 7 replicates, respectively) were determined at 35 d of age. The weights and pH of the stomach and caecal contents, ammonia concentration in the caecum and jejunal morphology were also determined (11 rabbits per diet). The treatments did not affect faecal DM and CP digestibility. However, the source of protein affected ileal digestibilities of DM and CP (P < 0.04), which were around 14 and 7% higher for SB61 and SF36 diets, respectively, than for the SB48 diet, whereas the values obtained for the SB48-P77 diet were intermediate. The ileal flux of CP and the N-NH 3 caecal concentration were (P = 0.08 and 0.05, respectively) affected by the source of protein. The highest values were observed in animals fed the SB48-P77 diet, increasing by around 25 and 35%, respectively, compared to the other three diets. The treatments had no effect on digestive traits and jejunal morphology. The differences in ileal digestion efficacy among treatments led to differences (P = 0.008) in food efficiency the first week after weaning, which was higher (10%, as average) in animals fed the SB61 diet than that observed for animals fed the SB48 and SB48-P77 diets, whereas the value obtained for SF36 was intermediate. In this period, the type of diet tended (P = 0.08) to affect daily gain and food efficiency, with the lowest values obtained for the SB48 diet. The treatments had no effect on mortality in the first two weeks after weaning. However, mortality in the whole fattening period was affected by protein source (P = 0.03), since it was higher in animals fed the SB48-P77 diet after weaning than the animals fed the other three diets (34.6 vs. 16.7%, respectively). In conclusion, SF36 and SB61 are the sources of protein that led 461 * Corresponding author: cdeblas@pan.etsia.upm.es Anim. Res. 52 (2003) DOI: 10.1051 to the best growth performances and the lowest mortality rate. The higher efficiency obtained for these feeds might be mainly related to its higher ileal (CP) digestibility.461-471  INRA, EDP Sciences,sources of protein / digestion / growth performance / early weaning / rabbits Résumé -Effet de la source protéique sur la digestion et la croissance de lapereau...

Effect of dietary soluble fibre level and protein source on growth, digestion, caecal activity and health of fattening rabbits

“…The complete substitution of soybean meal by sunflower meal did not affect growth performance (Table 7) as found in other studies (Gutiérrez et al, 2003). Nevertheless, García-Ruiz et al (2006) observed higher daily weight gain and feed intake in rabbits fed diets based on soybean meal rather than sunflower meal, which were associated to a higher mortality ascribed to the higher ileal flux of soybean protein.…”

“…CP digestibility tended to be lower (P=0.058) in Sun diets than in Soy diets. Other authors (Gutiérrez et al, 2003;García-Ruiz et al, 2006) did not find differences in faecal apparent digestibility in diets based on sunflower meal (36% CP) or soybean meal (46-48% CP), while measuring a higher ileal digestibility of CP and DM in the former than in the latter (Gutiérrez et al, 2003). EE and hemicelluloses were less digested (P<0.001) in Soy diets than in Sun diets, while ADF and soluble fibre resulted more digested in the former ones.…”

“…Contrary to the findings of studies on pigs (Vente-Spreeuwenberg et al, 2004a, b), in our assay the protein source did not affect intestinal mucosa traits. Similarly, Chamorro et al (2007) the contrary, mucosa integrity was improved in early-weaned rabbits fed diets containing animal plasma rather than soybean (Gutiérrez et al, 2000) and possible damage to mucosa depending on feeding legume anti-nutritional factors has been hypothesised (Gutiérrez et al, 2003;Cano et al, 2004).…”

“…As occurs with protein excess, the use of less digestible protein sources may increase the nitrogen flux at caecum and favour the development of pathogenic strains of E. coli and Clostridium spp., thus impairing animal health and performance (Gutiérrez et al, 2003;García-Ruiz et al, 2006;Chamorro et al, 2007).…”

Effect of dietary sodium on digestibility of nutrients and performance in growing rabbits.

“…Dietary levels of the most limiting AA (lysine, methionine+cystine and threonine) were higher (by 22, 32 and 7% , respectively) than recommended levels for the overall fattening period , in order to assure a correct growth in the starter phase (from 25 to 39 days of age). In the post-weaning period, an excess of nitrogen flow in the ileum has been proven to increase intestinal disorders in early weaned rabbits (Gutiérrez et al, 2003;Chamorro et al, 2007). The trend in practical formulation in rabbits is to reduce the level of crude protein increasing in parallel that of limiting synthetic AA (lysine, methionine and treonine) to maintain growth responses.…”