1769
Effect of Phytogenic Feed Additives on Performance Parameters and Health of Bull Calves under Commercial Conditions
The increased emphasis on achieving a good health status for adequate growth rates in calves and the ban on sub-therapeutic antibiotics in the European Union in 2006 have resulted in growing interest in alternative feeding strategies. Phytogenic feed additives (PFA) exert strong anti-inflammatory, anti-oxidative and anti-microbial activities, and all of which offer potential benefits for improving performance and preventing intestinal disorders. The aim of the study was to evaluate the efficacy of PFA on growth performance, feed-to-gain ratio and number of medical treatments in commercial calves. During the trial period of 56 days, 53 calves with an average initial body weight of 93.2 kg were assigned to either the control (n=26) or treatment group (n=27) based on their initial body weight and breed (Simmental and Belgian Blue). Calves were housed in groups (1 pen/group) and were fed twice a day receiving calf milk replacer (CMR), calf starter (CS), corn silage, hay and a concentrate mixture consisting of corn, cereals, soybean and rapeseed meal. Control calves received a standard non-medicated CMR and CS. Experimental calves received CMR and CS supplemented with two different mixtures of PFA including herbs, spices and plant extracts [Digestarom® Milk in CMR (500 g/t) and Digestarom® Calf in CS (300 g/t), BIOMIN Phytogenics GmbH, Stadtoldendorf, Germany]. Feeding CMR was restricted during the first 3 wk, whereas CS was offered ad libitum. Calves were weighed individually on d 1, 21, 42 and 56. Feed intake was determined per group on a weekly basis. Medical treatments were recorded throughout the trial. Data for body weight and weight gain was statistically analyzed with the independent t test using SPSS. Calves offered CMR and CS containing PFA were superior in average daily gain (1.33 vs. 1.23 kg; p = 0.06) and exhibited a higher average final body weight (168.1 vs. 161.2 kg; p = 0.02). Adding PFA resulted in a slightly increased average dry matter intake (2.46 vs. 2.41 kg) and improved feed efficiency (feed-to-gain ratio 1.86 vs. 1.97). Moreover, PFA supplementation positively influenced the health status of calves, as indicated by a reduced number of animals treated for health problems (fever and diarrhea). This led to reduced medication costs and higher farm profits. In conclusion, PFA supplementation in the CMR and CS is a suitable tool to improve growth rates and reduce medication costs in commercial beef calves.
Keywords:
phytogenic feed additive, calves, performance