Dairy At Glance

PROBIOTICS IN LIVESTOCK FEEDING: A BOON

Dr. SD Kalyankar and Dr. CD Khedkar 

College of Dairy Technology, Warud(Pusad)-445 204

Maharashtra Animal & Fishery Sciences University, Nagpur-6

Probiotics: The term probiotic is derived from a Greek word, meaning “for life” originated to describe substances produced by one microorganism which stimulate the growth of others. An expert panel commissioned by FAO and WHO (2002) defined probiotics as “Live microorganisms which when administered in adequate amounts confer a health benefit on the host”.

Ban on use of Antibiotics in Animal Feeds: The use of antibiotics in the ration of livestock is being discouraged or even banned in some countries due to their adverse effects on the health of animals, residual left over in the animal products and a risk of creating resistance of microbes against these antibiotics. Milk from such animals cannot be marketed due to residual antibiotics, as very severely stringent regulations came into existence since implementation of WTO. Due to harmful side effects of antibiotics, use of probiotics as dietary adjuncts/therapeutic agents to restore the normal microflora of the gastro-intestinal tract of livestock animals came into existence. They offer a potential replacement for sub therapeutic levels of antibiotics in livestock diets.

Why Probiotics? The gastro-intestinal tract of the newly born ruminant is completely sterile but when it comes in the contact with its surroundings, adult animals or contaminated feed, the calf is inoculated with the microbes that colonize the gastrointestinal tract. This microbial environment inside the gastro-intestinal tract contributes to the overall performance of the animals. A fully developed rumen has a complex microbial eco-system, which enables the ruminants to utilize lignocellulosic feeds. The studies on the microbial eco-system of buffalo are very few as compared to those with buffaloes. Any disturbance in the microbial balance may affect the performance of the animal adversely and any improvement in the microbial environment may lead to the improvement in the productivity of the animals. Various attempts have been made in this direction by using feed additives like, antibiotics, microbial growth factors, methane inhibitors, etc. The concept of microbial feed additives came into light due to a belief that the longevity of Bulgarian peasants was related with large consumption of viable cells of L.  acidophilus.

Probiotic Organisms in Cattle Feed: Probiotics used for livestock often are referred to as direct-fed microbials. There is currently great inter­est in the use of probiotics for the livestock industry. Even though the idea of using probiotics as livestock feed supplements is not new, there is much to be learned about the proper selection of strains of microbial species for use as probiotics to produce the desired effect. A mixture of bacterial species or strains may be required to yield such desired effects as improved growth and performance. Lactobacillus and Bifidobacterium are the bacterial genera and Saccharomyces is the principal yeast genera central to both probiotic and prebiotic approaches to dietary modulation of the intestinal microflora of the warm-blooded animals. In addition, there are many different microorganisms currently used as probiotics.

Probiotics to Reduce the Buffalo Calf Mortality: Buffalo calf mortality is one of the most serious problems in Indian subcontinent. An attempt has been made to improve the friendly microbiota of rumen, to improve the growth rate and reduce the rate of calf mortality. A low-cost probiotic preparation was prepared from whey by using healthy calf origin Lactobacilli and Saccharomyces. It was used for feeding 105 randomly selected buffalo calves of 1-15 weeks.  The investigation came with a conclusion that the feeding of probiotic can eliminate the harmful microflora of the rumen, it notably improve the growth rate and drastically reduce the mortality. Thus the use of probiotics will prove to be a boon in calf feeding management.  

Proven Benefits of Probiotics in Livestock: Much of the research reports are published on potential of probiotics to control intestinal pathogens using animal models. Many reports are appeared on the use of probiotic to control intestinal pathogens in poultry birds than in any other animal species. With germ-free chicks as an animal model, for example, it was demonstrated that L. acidophilus exerted control over Salmonella species and E. coli. Using conventional chicks (1­ day-old), successful use of L. salivarius to prevent colonization of chicks with Salmonella enteritidis also has been shown.

The use of a probiotic-like product made up of intesti­nal flora of healthy chickens to inoculate baby chicks, competitive exclusion concept was accomplished by administering the mixed intestinal flora from healthy adult chickens to newly hatched onesThe idea was once established; the flora from healthy chickens could exclude infection by Salmonellae. This approach is currently being advocated in the poultry industry in the United States.

Probiotics for Efficient Feed Utilization: Probiotics could provide some specific nutrients that enhance growth or increase appetite so the animal consumes more feed. Feeding of a mixture of yeast and lactobacilli improved dry matter intake, live weight gain, feed conversion efficiency, increase in fibrolysis of feed, increased VFA production in the rumen, reduced ammonia nitrogen in rumen liquor, enhanced microbial protein synthesis in the rumen, changes in amino acid profile of microbes in favourable direction, higher microbial protein from rumen and better mineral utilization. Improved growth rate in the farm animals, improved nutrient utilization and improved milk production in dairy animals and reduction in diarrhoea in day old calves. The possible health benefits conferred on supplementation of lactic acid producing bacteria (a mixture of L. acidophilus, and L. jugurti and L. casei) is that the incidence of diarrhoea was significantly reduced. The number of coliform bacteria was much lower in the rumen liquor and faeces of the calves given fermented milk indicating that the microbial feed supplement was able to successfully control calf diarrhoea in crossbred animals by competing with the pathogens in the gastro-intestinal tract.  Lactoba­cilli as feed supplements also improved feed intake and weight gain in lambs.

Inclusions of viable yeast cells in animal feeds can provide benefitsa, for example, both meat and milk production have thus been increased in cattle.   The stress of weaning young animals in most livestock species results in development of scours. Probiotics containing lactobacilli such as L. acidophilus can reduce or eliminate this problem in calves as well as in pigs and lambs. Control of intestinal pathogens, for instance, could involve direct inhibitory action by the probiotic bacteria or could result from stimulation of the immune system. Improved growth and performance are more difficult to explain. It may result from control of undesirable microorganisms, it is likely that it involves far more. Some microor­ganisms in a probiotic mixture could provide an enzyme in a manner similar to that involved in improvement of lactose digestion in humans.

Conclusion

Under conditions of additional heat stress, calves had improved performance when given probiotics. This conclusion was based on visual observation of stress on the calves and on the average daily temperature and average daily relative humidity readings for the two periods. The differences in temperature and humidity supported our visual observations of additional stress on the calves in the hotter and more humid summer period. 

Akshay Sadana

Posted Date : 31/03/2015 Posted By : Admin