RESUMO
The safety of a novel microbial muramidase (Muramidase 007) as a feed additive for swine was evaluated in a target animal safety study (Experiment 1). Forty weanling pigs were allotted to 4 dietary treatments: T1 control group, and 3 groups receiving Muramidase 007 in increasing doses: T2 65,000 (1X), T3 325,000 (5X) and T4 650,000 (10X) LSU(F)/kg feed. The efficacy of Muramidase 007 on growth performance was evaluated in a feeding experiment (Experiment 2). A total of 288 piglets were allotted to two groups: T1 control group and T2 receiving Muramidase 007 at 50,000 (LSU(F)/kg feed. In Experiment 1, no growth depression of pigs was observed. No adverse effects of Muramidase 007 were observed for any of the hematology and serum chemistry parameters measured or on pig health status. Post-mortem evaluation showed no adverse effects due to Muramidase 007 supplementation in the gross pathology or in the histological examination. In Experiment 2, Muramidase 007 significantly increased overall (d 0-42) average daily gain (ADG) and tended to improve overall average daily feed intake (ADFI) and day 42 body weight of nursery pigs and had no effect on feed conversion ratio (FCR). Overall, results of these studies show that there were no adverse effects of Muramidase 007 compared to the control group.
RESUMO
In dairy cows, exogenous α-amylase is suggested to improve starch utilization and positively affect performance and health traits linked to energy balance and fertility. In a 1-year feeding experiment, 421 cows were orally supplemented with α-amylase (treatment: 12.5 g/kg dry matter (DM) addition rate to a concentrated feed) or non-supplemented (control) on the basis of an ad libitum total mixed ration (TMR). Every cow was allocated to a high- (≥32 kg milk/day) or late-lactation group (<32 kg milk/day), in which the TMR starch content was 220 ± 20.8 g/kg DM and 183 ± 24.8 g/kg DM, respectively. The energetic effect of α-amylase supplementation seemed to be exclusively related to the high-lactation stage (5-100 days in milk) in primiparous cows, where the daily milk yield was 32 ± 0.49 versus 31 ± 0.50 kg per cow in the treatment versus control group (P < 0.05). The pluriparous cows did not benefit from the supplementation that way. In neither primiparous nor pluriparous cows, was the milk composition, the fat-to-protein ratio, the somatic cell score, the backfat thickness, serum total bilirubin, ß-hydroxybutyrate and the fertility found to be systematically affected by α-amylase supplementation.
