Adding Bio-Mos® to broiler breeder diets and to starter diets for broiler chickens improves breeder and broiler performance, hatchability, economics and immune status

Ensuring high levels of hatchability resulting in viable, strong chicks is crucial for efficient broiler production systems. Several factors influence this, including health, nutrient availability and utilization in the parent stock.

The transfer of maternal immunoglobulins (Ig) to the embryonic chick is important if the hatchling is to be suitably robust to survive the first days of life, before its acquired immune system is mature enough to protect it. A well developed innate immunity helps in initiating the adaptive immune response (Goddeeris, 2005).

Mannan oligosaccharides are active within the gut. They bind certain types of pathogenic bacteria (Newman, 2006). Such activity is linked to better health, nutrient availability and digestibility in chickens, manifested as improved weight gain and feed conversion. Carbohydrates, such as ß-glucans from yeast cell walls, have been shown to stimulate both specific (vaccine adjuvants) and nonspecific immune responses (Williams et al., 1989; Suzuki et al., 1990).

Factors governing the performance response include feeding from one day old, however there are few trials examining the influence of Bio-Mos® supplementation of breeders. Relevant trials in commercial breeder flocks conducted in Ireland and the United States showed that breeders receiving Bio-Mos® in feed consistently laid more eggs, which resulted in larger numbers of progeny over the observed period. However the effect on the chicks was not studied.

Binding pathogens influences the immune system via the gut associated lymphatic tissue. It is known that specific carbohydrates are important in switching on certain immunological functions (Kelly, 2004). This explains why supplementation with ßglucans has been observed to raise Ig in blood, intestines and milk, including promoting the transfer of maternal antibodies to progeny.

Feeding trials in broiler breeders conducted in India have shown that Bio-Mos® not only improved hatchability and fertility characteristics of eggs from supplemented parent stock, but also that antibody responses in breeders fed Bio-Mos® were significantly higher (Shashidhara and Devegowda, 2003). This improvement in antibody titer was passed onto progeny, resulting in significantly higher titers in broiler chicks from supplemented parents.

Studies regarding the relationship between maternal performance and immunity in broiler breeders and the impact on their progeny are not often conducted. The aim of the trial with breeders was to examine the benefits of Bio-Mos® supplementation on the performance of broiler breeder hens, egg quality and hatchability and subsequent performance of chicks produced from those breeders. The aim of the trial with broilers was to examine the carry-over effect of the Bio-Mos® in the breeder diet and to examine the effect of a starter diet supplemented with or without Bio-Mos® on performance, immune status and economics.


Materials and methods


BREEDER TRIAL

The breeder trial was conducted in an experimental house, split into 12 pens, with 125 females and 12 males in each pen. All birds were the same crossbreed (Ross 308), and had been moulted. The trial lasted from 81 to 91 weeks of age.

There were six treatments total in this trial, but the results of only two treatments are in this report. One group received a control diet, in the form of a commercially prepared pelleted breeder feed formulated to the specifications of De Heus Feeds. The experimental group was fed the same diet supplemented with 1 kg Bio-Mos® per ton of feed (Bio-Mos®, Alltech Inc.). Within pens males and females got the same feed.

Chick viability was evaluated by recording the number of fertile eggs (by candling), embryonic mortality, non-viable and viable chicks. The economics of producing eggs from both treatment groups were calculated and compared at the end of the eleven week trial period.


BROILER GROWTH TRIAL

For the broiler experiment, 400 one-day-old sex separated chicks were housed in 16 floor pens of 25 birds. Of this numer, 200 were sourced from breeders that had received no Bio- Mos® in feed and 200 were from breeders that had received Bio-Mos® in the diet in the previous experiment. Another 800 broilers coming from the other (unpublished) treatments were also subject to the experiment with Bio-Mos® in the starter diet.

Two factors were considered in the trial. The first factor considered was the influence of supplementing the parent flock with Bio-Mos® on broiler chick performance. The second examined the benefit of Bio-Mos® fed in the starter diet on the whole growth performance of the chick to 36 days of age. Bio-Mos® was included in the starter feed at 1.5 kg/t and fed days 1 to 14. Feed costs and the economics of production were assessed from day 1 to 36.

All chicks were vaccinated at day 14 against Newcastle disease (NCD) with Clone 30 spray and against Gumboro at day 15 with D78. At 30 days of age, two birds were taken from each pen for blood sampling by wing vein puncture. Titers to NCD were recorded at the Animal Health Service in The Netherlands using HAR analysis from the blood samples.


Results and discussion


BREEDER PERFORMANCE AND ECONOMICS

Despite the limited number of replicates, some numeric improvements were observed in the breeder hens during the trial period, particularly regarding the economics of production (Table 1 and 2).










The higher number of eggs produced by hens fed Bio-Mos® during the experimental period was not accompanied by a concurrent increase in feed intake, leading to an improvement of laying efficiency and a savings of 9 g of feed per egg laid. This savings had a direct impact on the economics of production for the experimental flock (Table 2).

Egg production from hens receiving the supplemented diet resulted in an extra € 0.17 profit per hen compared to those in the control flock. This value was extrapolated for a complete laying period, calculating an improvement in profits equivalent to approximately€ 0.50 per hen in lay.

The improved financial return in the Bio-Mos® flock agrees with results observed in other trials using laying hens, whereby Bio-Mos® significantly improved egg production and conversion of feed into eggs (Gracia et al., 2006).

Similar improvements in egg production have been reported for older breeder hens who have been moulted (Berry and Lui, 2000). Cragoe and Olsen (1994) showed that commercial Ross breeders fed Bio-Mos® laid more eggs per day with lower feed consumption compared to birds fed a diet containing an antibiotic (bacitracin). When they calculated the economic benefits of increased breeder production from this commercial trial, they found that throughout the 14-week monitored period, feeding Bio-Mos® gave consistently better financial returns compared to published breed expectations.


EGG QUALITY

The ratio of egg white:egg yolk is considered a useful indicator of the viability of the resulting chick at hatch. Eggs from hens fed Bio-Mos® had significantly less white (P<0.05) and numerically more yolk compared to eggs from the control flock (Table 3). This led to a significant white:yolk ratio improvement, which may have resulted in better chick hatchability and viability.






The increase in the weight of the egg yolk and its ratio with egg white may be due to stimulation of Ig production by ß-glucans,which are concentrated in the yolk in spite of the albumen in the egg white. This increase in egg yolk enhances the immune system, so the offspring responds better to a pathogenic challenge.


HATCHABILITY

Hatchability of the eggs sampled from each treatment group was assessed six weeks into the trial, i.e. when the hens reached 87 weeks of age (Table 4). The number of viable chicks increased and the number of infertile, dead and non-viable chicks were reduced in eggs sampled from the flock receiving the supplemented diet. This may be a reflection of the significantly higher yolk weight recorded for the eggs from Bio-Mos®-fed hens.






The financial implications of increasing the numbers of viable chicks from parent breeder stock are considerable. Previous reports have shown that improvements in hatchability may be up to 4%, similar to the responses observed in this experiment.


BROILER PERFORMANCE AND ECONOMICS

Broiler performance and the economic implications of supplementing the parent stock or the starter feed with Bio-Mos® at 1 kg/t was monitored at 14, 28 and 36 days of age. The broilers sourced from Bio-Mos®-fed parent flocks showed no significant differences in performance at any of the three ages, although performance was numerically higher and economic calculations revealed a reduced feed cost per kg weight gain for the chicks from the Bio-Mos®-fed parent flock (Table 5).






To compare the treatments at a certain weight the FCR was corrected for differences in liveweight (LW) with 0.03 per 100 g LW, and then the feed costs are calculated for a broiler of 2 kg LW. The feed costs decrease by € 0.008 per broiler of 2 kg LW, when Bio-Mos® is added to the breeder diet.

The effect of feeding Bio-Mos® in the starter diet of broiler chicks was more marked (Table 6). Although Bio-Mos® was only fed for the first 14 days of age, (at 1.5 kg/t) the benefit in terms of performance was a significant improvement in weight gain at 36 days owing to more replicates in this comparison. Although not significant, the feed cost was reduced by € 0.006 per broiler of 2 kg LW.






EFFECT OF BREEDER AND STARTER FEED BIO-MOS® SUPPLEMENTATION ON IMMUNITY

Broilers were vaccinated against NCD and the effects of adding Bio-Mos® to either the parent stock feed or directly in the starter feed were examined. The highest antibody titers against NCD were recorded for birds that were sourced from Bio-Mos®- supplemented breeder flocks and that also received Bio-Mos® in the starter feed from 1-14 days (Table 7).

Birds receiving no Bio-Mos® either in the starter or in parent stock feed had the lowest titers. Birds receiving Bio-Mos® via parent stock or through the starter feed had comparable titer levels, with starter feed supplementation giving slightly higher titers. In Indian breeder trials, Shashidhara and Devegowda (2003) saw an improved Ig titer for infectious bursal disease in chicks from Bio-Mos®-supplemented hens, which agrees with these findings.






The results suggest that feeding Bio-Mos® to parent stock improves immune response to challenges simulated by vaccination, indicating a better immune status in progeny. These improvements can be cumulative when combined with feeding Bio-Mos® in starter feeds.


Conclusions and applications

• Economic comparisons of the breeders fed Bio-Mos® showed a much higher financial return compared to the control flock.
  
• Eggs from the parent stock fed Bio-Mos® had a proportionally larger ratio of yolk:egg white, which may be related to the improved viability of chicks at hatch.
  
• Adding Bio-Mos® to a starter feed resulted in higher weights at slaughter and a higher financial return compared to the control flock.
  
• Analysis of the Ig titers against NCD demonstrated that the best immune response was obtained in broilers sourced from Bio-Mos®-supplemented breeders that received Bio-Mos® in starter feed.
  
• For commercial purposes and animal welfare reasons, these findings are important as they relate to the successful production of viable broiler eggs from parent stock breeders, as well as enhancing the robustness of progeny immune response.
  
• Further work is necessary to show that the immune status of the young broiler chicken can be improved by using Bio-Mos® in the breeder feeds by analyzing the IgY in the egg yolk.

References

Berry, W.D. and P. Lui. 2000. Egg production, eggshell quality and bone parameters in broiler breeder hens receiving Bio-Mos® and Eggshell™ 49. Poult. Sci. 79(Suppl. 1):124.

Cragoe, R. and R. Olsen. 1994. Effect of Bio-Mos® on feed consumption and egg production of leghorn breeders. Poster presentation at Alltech’s 10th Annual Symposium on Biotechnology in the Feed Industry, Lexington, KY, USA.

Gracia, M.I., P. Cachaldora, A. Kocher, P. Spring, F. Baucells and P. Medel. 2006. Effect of mannan oligosaccharide supplementation to laying hen diets in environmental or naturally-controlled barns. Poul. Sci. 85 (in press).

Kelly, D. 2004. Regulation of gut function and immunity. In: Interfacing Immunity, Gut Health and Performance (L.A. Tucker and J.A. Taylor-Pickard). Nottingham University Press, UK, pp. 61-76.

Newman, K. 2006. Quantifying the efficacy of MOS. Feed Mix 14(1):2-4.

Shashidhara, R.G. and G. Devegowda. 2003. Effect of dietary mannan oligosaccharide on broiler breeder production traits and immunity. Poult. Sci. 82:1319-1325.

Suzuki, I., H. Tanaka, A. Kinoshita, S. Oikawa, M. Osawa and T. Yadomae. 1990. Effect of orally administered ß-glucan on macrophage function in mice. Int. J. Immunopharmacol. 12:675.

Williams, D.L., R.G. Yaeger, H.A. Pretus, I.W. Browder, R.B. McNamee and E.L. Jones. 1989. Immunization against Tryponosoma cruzi: adjuvant effect of glucans. Int. J. Immunopharmacol. 11:403.