SAFETY STUDIES WITH BROILER BREEDERS
Data collected in previous studies with broilers and laying hens have documented the safety of Improved Milbond-TX® (IMTX) when supplemented at or above the recommended dietary concentration of 0.25% (2.5 g/kg diet). The summarized results of these studies have been the focus of previous issues of Milwhite’s Journal. Even though IMTX has successfully been used for many years at the recommended concentration in broiler breeder diets without any detrimental effects being reported by the poultry industry, no safety studies have been conducted to ensure that higher than recommended concentrations are safe for breeders. The data collected in these studies would be of extreme importance since breeder birds are not only consuming nutrients and energy required for their own maintenance and well-being, the hen is also producing eggs which must also contain adequate nutrients and energy to insure proper embryo development and survival. If IMTX was responsible for binding any one or more nutrients in the diet and limiting nutrient absorption by the hen then some aspect of production and chick development should be noticed. Therefore, in 2013 at the University of Arkansas Center of Excellence for Poultry Science, Dr. Craig Coon initiated a study specifically designed to investigate the safety of IMTX when added to diets of broiler breeders at higher than the recommended amount.
The Cobb 500 broiler breeder pullets and MX males used in this study were fed a diet adequate in all nutrients and energy on a skipa-day feeding schedule during their growing period. The pullets were fed an amount of feed required for them to attain the body weight necessary to maintain their weight according to the growth curve recommended by the primary breeder. Males were also fed according to the recommendations of the primary breeder. At 21-weeks of age, birds were allocated randomly to 12 floor pens with four pens per dietary treatment each containing 25 hens and 2 roosters, switched to a breeder diet and light stimulated. The experimental breeder diets were then offered to each pen of birds with each pen receiving the same quantity of feed/bird daily up to peak egg production and the quantity of feed adjusted for any mortality. Experimental treatments consisted of a cornsoybean meal-based control diet (0% IMTX) and two other diets containing IMTX supplemented at twice the recommended amount (0.5%) and four times the recommended amount (1.0%), respectively. The diets contained 15.5% crude protein and 2915 kcal AME/kg diet and were formulated on an ideal protein basis using digestible amino acids. At peak egg production each hen was consuming 450 kcal of AME and 23.9 grams of crude protein in 154 grams of feed. Following peak egg production feed allocation gradually declined to quantities necessary to maintain egg mass and body weight.
Egg collection began at week 24 and three times each day all eggs laid were collected and marked by pen number during the entire 12-week experimental period. All eggs collected each week were set in an incubator for hatching.
Egg weights were determined on all eggs laid for two days during each week. At egg transfer, on day 18 of incubation, eggs were candled to determine those that were infertile and early embryo mortality. At hatch, each chick was examined visually for any abnormality and weighed individually using a digital scale.
Results : After the data collected during the study were analyzed statistically, it was found that supplementing IMTX at a higher dietary concentration than recommended did not have any effect on egg production expressed as eggs per hen housed. In fact, the value for egg production was numerically higher in hens consuming the diets containing IMTX. The number of eggs per hen housed during the entire experimental period for the three dietary treatments of 0%, 0.5% and 1.0% IMTX was 55.5, 57.8 and 56.9, respectively.
Egg weights, fertility, hatchability and chick weights were not affected by the addition of IMTX to the diet of broiler breeders. At the end of the 12-week experimental period egg weights for the dietary treatments of 0%, 0.5% and 1.0% IMTX were 62.8, 62.2 and 62.2 grams, respectively. Percent egg fertility was 98.4, 97.5 and 98.6% for the three dietary treatments, respectively, and percent hatchability of all eggs set was 89.0, 87.4 and 87.7%, respectively, for the three dietary treatments. Chick weights were not significantly affected at any week throughout the entire 12 week experimental period by the addition of the high dietary levels of IMTX. Averaging chick weight for the experimental period for the three dietary treatments was 40.1, 40.1 and 40.4 grams, respectively.
In summary, feeding up to 4 times the recommended dietary concentration of IMTX for 12 consecutive weeks, beginning at first egg, did not cause any negative effects on any aspect of broiler breeder performance.
Note: A complete description of the experiment conducted at the University of Arkansas and the data collected in the experiment can be found in the referenced publication (to be written) located in the footnote below. The information presented in this issue of Milwhite’s Journal was compiled by Dr. Orlando Osuna, Director of Health Science at Milwhite, Inc. and Dr. Richard Miles, Professor Emeritus, University of Florida, Gainesville, FL,USA.
Schlumbohm, M.J., England, J.A., Kriseldi, R., and Coon, C.N. Safety of Improved Milbond-TX® mycotoxin binder when fed to broiler breeders above the recommended levels. International Journal of Poultry Science 13 (10): 597-601, 2014.