Health and growth of veal calves fed milk replacers with or without probiotics

Enumeration of some cultivable bacterial groups and characterization of some abiotic variables in the jejunoileal content of Prim'Holstein veal calves

A study was conducted to characterize the bacterial and biochemical composition of the jejunoileal content of veal calves and the effect of pre-slaughter fasting time. At 22 wk of age, 22 preruminant Prim'Holstein calves fed milk replacer and pellets (mainly composed of corn) were slaughtered at 6, 12, or 24 h after their last meal. Chyme samples were collected from the jejunoileal compartment just after slaughter, and pH and redox potential were immediately measured. Culture-based methods were used to determine the concentrations of total anaerobic microflora, lactate-utilizing bacteria, Bacteroides fragilis group, Lactobacilli, Bifidobacteria, Enterococci, and 2 potential pathogenic species, Escherichia coli and Clostridium perfringens. Concentrations of l-lactate, ammonia, and short-chain fatty acids (SCFA) were determined on frozen samples. The biochemical composition (DM, total protein, lactose, galactose, glucose, minerals, AA profile, and fatty acid profile) of the jejunoileal content was determined only on samples from the 6-h fasted group. Microflora concentrations were greater (P < 0.01) in the 6-h fasted group compared with the 12- and 24-h fasted groups, involving a decreased pH (P < 0.05) and greater lactate and SCFA concentrations, both linked directly to the fermentative state of the microorganisms. The 6-h fasted group showed the least interanimal variability in bacterial group levels, except for Cl. perfringens, which presented increased interanimal variability regardless of fasting time. At 6 h postprandial, the jejunoileal content of veal calves seemed to be in a stable state, allowing the creation of a database on its biochemical composition. This study is a key first step in the development of an in vitro system for modeling the jejunoileal ecosystem of veal calves. This model will provide a useful tool for assessing the effects of feed additives on intestinal microflora.

Calf nutrition from birth to breeding

The general principles of growth and nutrients required are no different for young calves than for any other species. Additional complexity is introduced, however, by the need to transition the young preruminant to functioning ruminant. The nutritional and digestive physiology of dairy calves as future ruminants needs to be the governing factor in designing practical feeding systems to meet nutrient requirements. Key aspects common to all systems include the composition and amount of liquid feed, water availability, and the first starter feeds offered. This article focuses on nutrition of calves before weaning and to breeding age, with primary emphasis on the preweaning and transition phases.

IgA production, coliforms analysis and intestinal mucosa morphology of piglets that received probiotics with viable or inactivated cells

Two types of probiotics were used in piglets. One product is a mixed culture of viable Lactobacillus acidophilus, Enterococcus faecium e Bifidobacterium bifidum. The second product is composed of inactivated Lactobacillus acidophilus cells. The piglets received two weekly oral doses for 30 days while a control group did not receive probiotics. All piglets were euthanized at the 30th day of life and the mesenteric lymph nodes, the small intestine, and blood samples were collected. The tissue samples were studied by light microscopy and the blood serum was analyzed by ELISA method. The treatment with the probiotic with viable cells produced higher serum levels of IgA (P<0.05) and more IgA expressing cells were found in the mesenteric lymph nodes than observed in the inactivated cells treatment or control groups (P<0.05). Also, intestinal villi were longer, crypts were deeper (P<0.05) and fecal coliform count was lower than found in the inactivated product (P<0.05). These results suggest that viable probiotics are more efficient than inactivated probiotics to induce immunostimulation and intestinal modifications in piglets, thus improving their health and development.

Mortality and growth performance of broilers given drinking water supplemented with chicken-specific probiotics

For application in broiler production, we developed a multispecies (MSPB) and a chicken-specific (CSPB) probiotic preparation in fluid form. The MSPB contained different probiotic species of human origin, whereas the CSPB consisted of 7 Lactobacillus species isolated from the digestive tract of chickens. In a field trial with broilers, MSPB treatment resulted in a slight increase (by 1.84%) in broiler productivity based on an index taking into account daily weight gain, feed efficiency, and mortality. The CSPB treatment reduced mortality in 2 subsequent field trials and raised productivity by 2.94 and 8.70%. In a controlled trial with broilers showing a high index of productivity, probiotic treatment further raised productivity by 3.72%. Based on the present 4 studies in combination with 9 studies published earlier, it is suggested that with higher productivity rates of the broilers the effect of probiotics becomes smaller.

Beneficial lactobacilli in food and feed: long-term use, biodiversity and proposals for specific and realistic safety assessments

Lactobacilli have played a crucial role in the production of fermented products for millennia. Their probiotic effects have recently been studied and used in new products. Isolated cases of lactobacillemia have been reported in at-risk populations, but lactobacilli present an essentially negligible biological risk. We analyzed the current European guidelines for safety assessment in food/feed and conclude that they are not relevant for the Lactobacillus genus. We propose new specific guidelines, beginning by granting a 'long-standing presumption of safety' status to Lactobacillus genus based on its long history of safe use. Then, based on the available body of knowledge and intended use, only such tests as are useful will be necessary before attributing 'qualified presumption of safety' status.

Growth during the first 6 months of life in infants using formula enriched with Lactobacillus rhamnosus GG: double-blind, randomized trial

BACKGROUND

Probiotic bacteria have beneficial effects on the immune system and gastrointestinal tract, but the impacts of their long-term consumption on health and growth in early infancy are not well documented. The aim of this study was to evaluate the influence of Lactobacillus rhamnosus GG (LGG)-enriched formula on growth and faecal microflora during the first 6 months of life in normal healthy infants.

MATERIALS AND METHODS

One hundred and twenty healthy infants (up to 2 months) received LGG-supplemented formula or regular formula in a double-blind, randomized manner until the age of 6 months. Weight, length and head circumference were measured monthly and transformed into standard deviation scores (SDS). Faecal samples were obtained from a random sample of infants (n=25) at entry and at the end of the study.

RESULTS

One hundred and five infants (51 in the LGG group) completed the study. Children receiving LGG-supplemented formula grew better: their changes in their length and weight SDS (DeltaSDS) at the end of the study were significantly higher than those receiving regular formula (0.44+/- 0.37 versus 0.07+/- 0.06, P< 0.01 and 0.44+/- 0.19 versus 0.07+/- 0.06, P< 0.005, respectively). The LGG group had a significant, higher defecation frequency 9.1+/-2.06 versus 8.0+/- 2.8 (P<0.05). More frequent colonization with lactobacilli was found in the LGG group, 91% versus 76% (P<0.05) at the end of the study. CONCLUSIONS Infants fed with LGG-enriched formula grew better than those fed with regular formula. Further studies are necessary to clarify the mechanism of LGG in infant growth.