//05 Aug 2011
The effects of yeast and yeast protein concentrate on the production performance of broiler chickens exposed to heat stress and challenged with Salmonella enteritidis, has been investigated by scientists at the West Bengal University, India.
In cooperation with AB Vista an experiment of 35 d duration was conducted to evaluate the effects of dietary supplementation (1 g/kg) of yeast (Saccharomyces cerevisiae), yeast protein concentrate (YPC) and YPC-pellets on production performance of heat stressed broilers.
Trial setup
For this experiment 128 Cobb 400 broilers were used. Ambient temperature was constantly maintained at 32–34C. At 21 d, all the birds were orally challenged with Salmonella enteritidis (10 × 107 cfu/ml) and the numbers of total Salmonella were enumerated in excreta at periodic intervals.
Results
Dietary supplementation of YPC and YPC pellets improved body weight at 21 and 35 d of age and FCR in 35 d.
Salmonella numbers decreased in the pooled digesta and excreta due to dietary supplementation of yeast and YPC additives particularly in the YPC-pellets group.
E. coli numbers in digesta also decreased in the treated groups. Humoral immune response against Newcastle disease was improved by dietary supplementation of YPC and YPC-pellets at 14 d, 28 d and 35 d.
The effect of dietary yeast supplementation on humoral immune response was evidenced on 35 d of age. Severity of panting was comparatively less when the YPC additives were supplemented in diet and this was corroborated by a lower serum CO2 concentration in the YPC and YPC-pellets groups at 21 d of age as compared with the control.
Supplementation of YPC and YPC-pellets increased serum T3 level at 21 d and decreased serum cortisol at 21 and 35 d vis-à-vis the control group.
Yeast supplementation was also as effective as the YPC additives in reducing serum cortisol level. Villus height increased by supplementation of YPC-pellets as compared with the other dietary groups although the implication of this increment was not discernible in terms of production performances.
Conclusion
Although, converting the yeast protein concentrates into YPC-pellets did not offer any substantial advantage in terms of enhancing production performance of the heat stressed broilers, it may be concluded that YPC additives may effectively sustain the production performance in heat stressed broilers than the conventional yeasts probably by modulation of the levels of circulatory thyroid hormones and cortisol.
Full research was published in Animal Feed Science & Technology (Aug 2011)
Showing posts with label Yeast. Show all posts
Showing posts with label Yeast. Show all posts
20 May 2011
Research: Effect of yeast protein on piglet intestines
//19 May 2011
Australian scientists studied the use of nucleotides, vitamins and functional amino acids to enhance the structure of the small intestine and circulating measures of immune function in the post-weaned piglet.
Ninety individually-housed castrated pigs (Large White × Landrace × Duroc mixed crossbred, n=18) were used in a randomised block experiment to determine the effect of yeast protein concentrate (YPC) or its major active components, nucleotides (NCL), inositol (INS), and glutamate (GLU), on pig performance, indices of gut structure and circulating measures of immune function.
Results
Daily gain and feed intake were not affected by diet, however pigs fed the YPC diet had a lower feed conversion ratio compared to those fed the control (CON), INS and NCL diets in the feeding period.
Villous height in the duodenum was increased in pigs that received the YPC diet compared to the CON and INS diets.
In addition, immunoglobulin G levels were increased in pigs that received the INS and GLU diets compared to the CON and NCL diet on day 21.
Conclusion
These data suggest that although the effect was limited on the duodenal villous structure, pigs fed the YPC diet showed an improved duodenal villous height and the positive effect of YPC is most likely attributable to glutamate and nucleotides in the yeast protein concentrate
Australian scientists studied the use of nucleotides, vitamins and functional amino acids to enhance the structure of the small intestine and circulating measures of immune function in the post-weaned piglet.
Ninety individually-housed castrated pigs (Large White × Landrace × Duroc mixed crossbred, n=18) were used in a randomised block experiment to determine the effect of yeast protein concentrate (YPC) or its major active components, nucleotides (NCL), inositol (INS), and glutamate (GLU), on pig performance, indices of gut structure and circulating measures of immune function.
Results
Daily gain and feed intake were not affected by diet, however pigs fed the YPC diet had a lower feed conversion ratio compared to those fed the control (CON), INS and NCL diets in the feeding period.
Villous height in the duodenum was increased in pigs that received the YPC diet compared to the CON and INS diets.
In addition, immunoglobulin G levels were increased in pigs that received the INS and GLU diets compared to the CON and NCL diet on day 21.
Conclusion
These data suggest that although the effect was limited on the duodenal villous structure, pigs fed the YPC diet showed an improved duodenal villous height and the positive effect of YPC is most likely attributable to glutamate and nucleotides in the yeast protein concentrate
18 April 2011
Yeast extracts possible alternative for antibiotics
//18 Apr 2011
A dietary yeast extract could be an effective alternative to antibiotics for poultry producers, according to a U.S. Department of Agriculture (USDA) study.
Microbiologist Gerry Huff with USDA's Agricultural Research Service (ARS) in Fayetteville, Ark., and her colleagues have been studying the effects of yeast extract as an immune stimulant and alternative to antibiotics in conventional turkeys.
Non-pharmaceutical remedies and preventatives are particularly needed for organic poultry production, according to Huff, who works in the ARS Poultry Production and Product Safety Research Unit (PPPSRU) in Fayetteville.
Quail cheaper than turkey
Initial studies suggest that dietary yeast extract has good potential as a non-antibiotic alternative for decreasing pathogens in organic turkey production. A larger study was needed to confirm its efficacy.
But it is expensive to work with turkeys because they eat more than other birds, according to Huff.
So the researchers are testing yeast extract in Japanese quail to test the extract's efficacy against Salmonella and Campylobacter.
The quail serve as a model system to evaluate natural treatments that will be beneficial for chicken and turkey production.
Huff's current study, in collaboration with Irene Wesley at the ARS National Animal Disease Center in Ames, Iowa, involves 800 Japanese quail.
Kill bacteria
Yeast extracts help boost the immune system's ability to kill bacteria, but there is also a downside.
According to Huff, yeast ramps up certain aspects of the immune response, but body weight may be decreased in some birds. That's because the energy normally used for growth is redirected toward the immune system.
The researchers are looking for a balance between enhancing immune response and maintaining growth.
Use in organic farming
Organic poultry farms can only use compounds on the National List of allowed substances for organic production. Yeast extract is on that list.
Alternatives to antibiotics are also needed for conventional poultry production, since regulations for the usage of antibiotics are being tightened in response to the prevalence of antibiotic resistance in pathogens.
A dietary yeast extract could be an effective alternative to antibiotics for poultry producers, according to a U.S. Department of Agriculture (USDA) study.
Microbiologist Gerry Huff with USDA's Agricultural Research Service (ARS) in Fayetteville, Ark., and her colleagues have been studying the effects of yeast extract as an immune stimulant and alternative to antibiotics in conventional turkeys.
Non-pharmaceutical remedies and preventatives are particularly needed for organic poultry production, according to Huff, who works in the ARS Poultry Production and Product Safety Research Unit (PPPSRU) in Fayetteville.
Quail cheaper than turkey
Initial studies suggest that dietary yeast extract has good potential as a non-antibiotic alternative for decreasing pathogens in organic turkey production. A larger study was needed to confirm its efficacy.
But it is expensive to work with turkeys because they eat more than other birds, according to Huff.
So the researchers are testing yeast extract in Japanese quail to test the extract's efficacy against Salmonella and Campylobacter.
The quail serve as a model system to evaluate natural treatments that will be beneficial for chicken and turkey production.
Huff's current study, in collaboration with Irene Wesley at the ARS National Animal Disease Center in Ames, Iowa, involves 800 Japanese quail.
Kill bacteria
Yeast extracts help boost the immune system's ability to kill bacteria, but there is also a downside.
According to Huff, yeast ramps up certain aspects of the immune response, but body weight may be decreased in some birds. That's because the energy normally used for growth is redirected toward the immune system.
The researchers are looking for a balance between enhancing immune response and maintaining growth.
Use in organic farming
Organic poultry farms can only use compounds on the National List of allowed substances for organic production. Yeast extract is on that list.
Alternatives to antibiotics are also needed for conventional poultry production, since regulations for the usage of antibiotics are being tightened in response to the prevalence of antibiotic resistance in pathogens.
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