Inulin stimulates intestinal bifidobacteria in humans and rodents but its effect in pigs is inconsistent. We assessed the effect of inulin on the intestinal microbiota by fluorescent in situ hybridization in growing pigs (age 9–12 wk). Pigs (n = 64) were assigned to 2 types of basal diets [wheat and barley (WB) or corn and wheat gluten (CG)] with or without 3% inulin (WBI or CGI) for 3 and 6 wk (n = 8/group) to test whether naturally occurring dietary fibers influence the inulin effect. Intestinal organic acids, pH values, and residual inulin were determined. The composition of the microbiota was highly individual. The duration of feeding did not affect any of the variables tested; therefore, data for the 2 periods were pooled. Bifidobacteria were detected in less than half of the pigs. Inulin did not stimulate lactobacilli and bifidobacteria numbers irrespective of the basal diet, although 20–50% of inulin was degraded in the jejunum. The number of pigs with colonic bifidobacteria was higher in those fed diets containing inulin (40 vs. 13%; P < 0.05). Total colonic short-chain fatty acid (SCFA) concentrations were lower in both inulin-fed groups due to reduced acetate (P < 0.05). Proportions of colonic butyrate were higher in pigs fed inulin-supplemented diets (P < 0.05). Colonic pH tended to be lower in the WB groups (WB; 6.6 ± 0.6), and was higher due to inulin (CGI, 7.1 ± 0.1; P < 0.05). In conclusion, inulin affected intestinal SCFA and the number of pigs harboring bifidobacteria; this effect was independent of the basal diet.

In recent years, interest in the larvae of black soldier fly (BSF) (Hermetia illucens) as a sustainable protein resource for livestock feed has increased considerably. However, knowledge on the nutritional and physiological aspects of this insect, especially compared to other conventional farmed animals is scarce. This review presents a critical comparison of data on the growth potential and efficiency of the BSF larvae (BSFL) compared to conventional monogastric livestock species. Advantages of BSFL over other monogastric livestock species includes their high growth rate and their ability to convert low-grade organic waste into high-quality protein and fat-rich biomass suitable for use in animal feed. Calculations using literature data suggest that BSFL are more efficient than broilers, pigs and fish in terms of conversion of substrate protein into body mass, but less efficient than broilers and fish in utilization of substrate gross energy to gain body mass. BSFL growth efficiency varies greatly depending on the nutrient quality of their dietary substrates. This might be associated with the function of their gastrointestinal tract, including the activity of digestive enzymes, the substrate particle characteristics, and their intestinal microbial community. The conceived advantage of BSFL having an environmental footprint better than conventional livestock is only true if BSFL is produced on low-grade organic waste and its protein would directly be used for human consumption. Therefore, their potential role as a new species to better close nutrient cycles in agro-ecological systems needs to be reconsidered, and we conclude that BSFL is a complementary livestock species efficiently utilizing organic waste that cannot be utilized by other livestock. In addition, we provide comparative insight into morpho-functional aspects of the gut, characterization of digestive enzymes, gut microbiota and fiber digestion. Finally, current knowledge on the nutritional utilization and requirements of BSFL in terms of macro- and micro-nutrients is reviewed and found to be rather limited. In addition, the research methods to determine nutritional requirements of conventional livestock are not applicable for BSFL. Thus, there is a great need for research on the nutrient requirements of BSFL.

Epidemiologic results suggest that protein intake in infancy and later adiposity might be related. We examined whether high dietary protein exposure in utero and/or during postnatal life affects body fatness. Two groups of female rats were mated and pair-fed isocaloric high (40% protein; HP) or adequate protein (20% protein; AP) diets throughout pregnancy. The male offspring were suckled (3 wk) by foster mothers pair-fed HP or AP diets, resulting in 4 pre-/postnatal groups (AP-AP, AP-HP, HP-AP, HP-HP). Subsequently, they were pair-fed the same diets their nurses received during lactation until wk 9. Offspring of HP dams had a lower body weight on d 2 of life than their AP counterparts (7.6 ± 0.7 vs. 8.3 ± 0.8 g; P < 0.001). HP-AP rats had a higher body weight than AP-AP controls at wk 3, 5, and 6 (P < 0.05), in contrast to HP-HP which did not differ from controls. Prenatal HP exposure resulted in a greater total and relative fat mass and decreased total energy expenditure at wk 9 (P < 0.05). Postnatal HP alone had no significant effect on body composition or metabolic rate. These results indicate that in utero exposure to a high protein level reprograms body weight and energy homeostasis.

Analysis in individual mouse milk samples is restricted by small sample volumes and hindered by high fat contents. Miniaturized methods were developed for the analysis of dry matter (DM), crude fat, crude protein (CP), and lactose in individual samples of