Broiler excreta composition and its effect on wet litter : aspects of nutrition

In commercial broiler farms, birds are usually housed on litter, composed of bedding materials like wood shavings. Wet litter is a condition in which the litter reaches its saturation threshold for water and cannot hold more moisture. It causes increased microbial activity and, as a result, ammonia is produced and emitted into the air. Wet litter can result in negative welfare issues (e.g., footpad dermatitis) and also a reduced performance. Wet litter is a multifactorial problem, involving management, housing, disease, diet, and gut health factors. In this thesis, nutritional aspects on excreta moisture content were studied in four different experiments. Different dietary compositions were evaluated and the results show that reductions in excreta water content were related to increased transit time and/or reduced water reabsorption in the hindgut. Insoluble fibers, if they are combined with a coarse diet, can be used to slow down transit time and optimize digestibility, thereby improving both excreta and litter quality. Minerals (e.g., Mg) and other undigested nutrients increase the osmotic load of the digesta in the hindgut and, as a result, more water is moving into the gut lumen. Changing the type or level of nutrients that reach the hindgut by varying dietary ingredients (medium-chain fatty acids, nonstarch polysaccharides, and starch) had limited effects on the ileal microbiota composition. Additionally, no effects of variations in commensal bacteria and excreta quality were observed. In this thesis, different parameters to assess the status of water in excreta and litter samples were evaluated. Water in the excreta or litter can be present in free form or bound, therefore solely total moisture content may not be sufficient to describe excreta and litter quality. Water activity correlates well with microbial growth. However, its use is limited in high moisture (> 30%) content samples. Free water, even though this parameter is dependent of the centrifugal speed applied, seems to be a more valuable parameter to assess excreta quality. The results from this thesis show that nutrition can be used to manipulate excreta and litter moisture content. The effects of nutritional manipulation can be related to (in)digestibility of nutrients, although transit time also seems to be an important factor determining excreta moisture output. Current feed strategies need to aim at optimizing the gastro-intestinal tract functions via the diet. Besides assessment of litter quality, also monitoring excreta quality throughout the growing period is highly recommended for managing litter quality, broiler health, and environmental impact. This should not be limited to measuring total excreta moisture, as the results of this thesis show that the status of the water in the excreta can be different.</p

Інформаційне суспільство як нова утопічна модель розвитку світу

У статті аналізується утопія як нова суперечлива інформаційно-технічна ідилія. Автор розглядає утопію інформаційного суспільства як орієнтацію на те, що відсутнє у суспільстві. Досліджується формування утопій ХХ ст., котрі, залежно він поставленої мети, впливають на особистість і творять нові цінності.The article examines utopia as a new contradictory information and technical idyll. The utopia of the information society is considered to be an orientation on what is missing in society. The author investigates the formation of utopias of the twentieth century, which affect personality and create new values depending on their persecuted goals

The multidimensional causal factors of ‘wet litter’ in chicken-meat production

The problem of ‘wet litter’, which occurs primarily in grow-out sheds for meat chickens (broilers), has been recognised for nearly a century. Nevertheless, it is an increasingly important problem in contemporary chicken-meat production as wet litter and associated conditions, especially footpad dermatitis, have developed into tangible welfare issues. This is only compounded by the market demand for chicken paws and compromised bird performance. This review considers the multidimensional causal factors of wet litter. While many causal factors can be listed it is evident that the critical ones could be described as micro-environmental factors and chief amongst them is proper management of drinking systems and adequate shed ventilation. Thus, this review focuses on these environmental factors and pays less attention to issues stemming from health and nutrition. Clearly, there are times when related avian health issues of coccidiosis and necrotic enteritis cannot be overlooked and the development of efficacious vaccines for the latter disease would be advantageous. Presently, the inclusion of phytate-degrading enzymes in meat chicken diets is routine and, therefore, the implication that exogenous phytases may contribute to wet litter is given consideration. Opinion is somewhat divided as how best to counter the problem of wet litter as some see education and extension as being more beneficial than furthering research efforts. However, it may prove instructive to assess the practice of whole grain feeding in relation to litter quality and the incidence of footpad dermatitis. Additional research could investigate the relationships between dietary concentrations of key minerals and the application of exogenous enzymes with litter quality

Evaluation of free water and water activity measurements as functional alternatives to total moisture content in broiler excreta and litter samples

Litter moisture contents vary greatly between and within practical poultry barns. The current experiment was designed to measure the effects of 8 different dietary characteristics on litter and excreta moisture content. Additionally, free water content and water activity of the excreta and litter were evaluated as additional quality measures. The dietary treatments consisted of nonstarch polysaccharide content (NSP; corn vs. wheat), particle size of insoluble fiber (coarse vs. finely ground oat hulls), viscosity of a nonfermentable fiber (low- and high-viscosity carboxymethyl cellulose), inclusion of a clay mineral (sepiolite), and inclusion of a laxative electrolyte (MgSO4). The 8 treatments were randomly assigned to cages within blocks, resulting in 12 replicates per treatment with 6 birds per replicate. Limited effects of the dietary treatments were noted on excreta and litter water activity, and indications were observed that this measurement is limited in high-moisture samples. Increasing dietary NSP content by feeding a corn-based diet (low NSP) compared with a wheat-based diet (high NSP) increased water intake, excreta moisture and free water, and litter moisture content. Adding insoluble fibers to the wheat-based diet reduced excreta and litter moisture content, as well as litter water activity. Fine grinding of the oat hulls diminished the effect on litter moisture and water activity. However, excreta moisture and free water content were similar when fed finely or coarsely ground oat hulls. The effects of changing viscosity and adding a clay mineral or laxative deviated from results observed in previous studies. Findings of the current experiment indicate a potential for excreta free water measurement as an additional parameter to assess excreta quality besides total moisture. The exact implication of this parameter warrants further investigation

In ovo inoculation of chicken embryos with probiotic bacteria and its effect on posthatch Salmonella susceptibility

The feasibility of establishing probiotic bacteria in the intestine of broiler chickens by in ovo inoculation was investigated, followed by verifying possible subsequent protection against Salmonella Enteriditis infection. In a first study, 7 commercially available probiotics were screened for compatibility with in ovo inoculation. Two of these probiotics, one being a Enterococcus faecium and the other a Bacillus subtilis, were selected for colonizing the chick gut without compromising hatchability. In a second study, these 2 products were administered in ovo and in the feed to chicks reared until 18 d in comparison with noninoculated chicks and with chicks fed an antibiotic. All chicks were orally challenged with Salmonella Enteritidis at 4 d of age. Results showed reduced performance of Salmonella Enteritidis challenged chicks fed no additives compared with challenged chicks fed antibiotic, but no significant differences in mortality was observed. Probiotics offered in ovo or through the diet could only partially recover performance compared with antibiotic-fed chicks. A significant reduction in the number of Salmonella Enteritidis positive chicks was observed when chicks were in ovo inoculated with E. faecium and continued receiving it in the diet. This work establishes standards for future in ovo colonization research and emphasizes its value as a promising method to deliver individual precise dose of probiotics to poultry in mass scale at the earliest possible age based on the competitive exclusion concept. In ovo colonization with probiotic can therefore become an important ally in combination with other approaches to combat Salmonella and other intestinal bacterial infections in poultry © 2014 Poultry Science Association Inc

Ileal microbiota composition of broilers fed various commercial diet compositions

Microbiota plays a role in the release and absorption of nutrients from feed components, thereby affecting digesta composition and moisture content of the excreta. The objective of the current study was to determine the effects of 5 different diets varying in ingredients (medium-chain fatty acids, nonstarch polysaccharides, and starch) on the microbiota composition of ileal digesta of broiler chickens and excreta DM content. Each treatment was repeated 6 times in cages each containing 18 Ross 308 broilers, with growth performance measured from 0 to 34 d of age and excreta DM and ileal microbiota composition analyzed at 34 d of age. Microbiota composition was evaluated using a novel ribosomal RNA microarray technology containing 370 different probes covering various genera, groups of microbial species, and individual species of the chicken gut microbiota, of which 321 had a signal above the background threshold. Replacing part of the animal fat and soybean oil in the wheat-based diet with medium-chain fatty acids (MCFA; 0.3% C10 and 2.7% C12) improved feed efficiency compared with the other dietary treatments. This coincided with a suppression of gram-positive bacteria belonging to the phylum of the Firmicutes, including Lactobacillus species, and species belonging to the family of the Enterococcaceae and Micrococcaceae, whereas the gram-negative bacteria belonging to the family of the Enterobacteriaceae were promoted. None of the other diets used in the present study notably changed the ileal digesta bacteria composition. Excreta DM content was not affected by dietary treatment. The variation between individual birds per dietary treatment was more pronounced than variation caused by feed composition, with the exception of the digesta microbiota of the birds fed the MCFA diet. It is concluded that a diet with MCFA significantly changes the ileal microbiota composition, whereas the effect of the other diets on the composition of the microbiota and excreta DM content is small in broiler chickens