|PYLES, MORGAN - University Of Kentucky|
|LAWRENCE, LAURIE - University Of Kentucky|
Submitted to: Proceedings of the Equine Science Society
Publication Type: Abstract Only
Publication Acceptance Date: 4/25/2015
Publication Date: 5/26/2015
Citation: Pyles, M.B., Lawrence, L.M., Flythe, M.D. 2015. Changes in fecal lactobacilli after a concentrate meal. Proceedings of the Equine Science Society. Pg. 412.
Technical Abstract: Fecal samples are often used as a non-invasive method of observing the microbial community of the hindgut and how it is influenced by the diet. However, time of sample collection post-feeding may affect the changes observed. The aims of this study were to determine how the viable number of some starch-utilizing bacteria changed after a meal of concentrate in order to inform future sampling protocols. Three mares accustomed to a diet consisting of forage and concentrate were used. Except on collection days, mares were kept in paddocks with ad libitum access to alfalfa hay and were fed a pelleted concentrate (1.7 kg) twice daily. For 2 d prior to fecal collection, mares were brought into box stalls, individually fed concentrate (426 g starch per meal) and returned to the paddock. On the collection days, mares were brought into box stalls and fecal samples were collected prior to the morning meal (0 h), then at the following intervals after feeding concentrate: 2-4 h (3 h sample), 5-7 h (6 h sample), and 8-10 h (9 h sample). The samples were collected by catch or from the middle of a fecal pile immediately following defecation, placed in a pre-warmed insulated cooler and mixed by hand. The samples were transported to the laboratory under CO2 in pre-warmed coolers (37°C). Additional fecal material was retained from each sample for dry matter (DM) analysis. Each mare was sampled on a different day. The samples were homogenized and serially diluted (10 fold) in phosphate buffered saline. Lactobacillus spp were enumerated on Rogosa agar medium (72 h incubation: 37°C). Bile-esculin-azide agar medium was used to enumerate Lancefield Group D Gram positive cocci (LGDGPC), which include Enterococcus spp, Streptococcus bovis, and S. equinus, (72 h incubation: 37°C). Enumerations were log transformed before the effect of time was determined using ANOVA (SAS version 9.3). The statistical analysis indicated that lactobacilli increased from 0 to 6 h post-feeding (P<0.05) and by 9 h they were similar to pre-feeding. The LGDGPC were below the level of quantification for two samples at 0 h and 9 h and one sample at 3 h post-feeding. By 6 h post-feeding all three samples were quantifiable. Due to the inability to quantify several samples, changes in LGDGPC were not subjected to statistical analysis. There was no change in fecal DM post-feeding (P>0.05). The results of the current study indicate a relationship between time of sample collection post-feeding and number of lactobacilli observed in equine fecal samples. From these data it appears that a time interval of 5 to 7 h postfeeding may be appropriate to identify meal effects on some starch-utilizing bacteria in equine fecal samples.