This study evaluated the effect of lactic acid bacteria (LAB, a mixture of Enterococcus faecium and Lactobacillus plantarum) supplementation, the storage temperature, and storage period on the fermentation characteristics and in vitro ruminal digestibility of a total mixed ration (TMR). The TMR was prepared into two groups, namely, CON (control TMR without the LAB) and ML (supplementing a mixture of E. faecium and L. plantarum in the ratio of 1% and 2% (v/w), respectively). Both groups were divided and stored at 4°C or 25°C for 3, 7, and 14 d fermentation periods. Supplementing LAB to the TMR did not affect the chemical composition of TMR except for the lactate and acetate concentration. Storage temperatures affected (p<0.05) the chemical composition of the TMR, including pH, lactate, and acetate contents. The chemical composition of TMR was also affected (p<0.05) by the storage period. During in vitro rumen fermentation study, the ML treatment showed lower (p<0.05) dry matter digestibility at 24 h incubation with a higher pH compared to the CON. There was no difference in the in vitro dry matter digestibility (IVDMD) of TMR between the CON and ML treatment however, at 24 h, ML treatment showed lower (p<0.05) IVDMD with a higher pH compared to the CON. The effects of storage temperature and period on IVDMD were not apparent at 24 h incubation. In an in vivo study using Holstein steers, supplementing LAB to the basal TMR for 60 d did not differ in the final body weight and average daily gain. Likewise, the fecal microbiota did not differ between CON and ML. However, the TMR used for the present study did include a commercial yeast in CON, whereas ML did not; therefore, results were, to some extent, compromised in examining the effect of LAB. In conclusion, storage temperature and period significantly affected the TMR quality, increasing acetate and lactate concentration. However, the actual effects of LAB supplementation were equivocal.

In recent years, various methods of measuring body temperature have been developed using wireless biosensors to facilitate an early detection of pregnancy and parturition in cows. However, there are no studies on real-time monitoring of cattle body temperature throughout pregnancy. Therefore, we investigated the daily mean ruminal temperature in pregnant cows throughout pregnancy using a ruminal bio-capsule sensor and then evaluated the temperature variation between pregnant and non-pregnant cows. In pregnant cows, the mean and standard deviation of ruminal temperature was 38.86 ± 0.17℃. Ruminal temperature in pregnant cows slowly decreased until 180 to 190 days after artificial insemination and after that, the temperature increased dramatically until just before parturition. Furthermore, the means ruminal temperature was significantly different between pregnant and nonpregnant cows. The mean and standard deviation of ruminal temperature were as follows: 38.68 ± 0.01℃ from days 80 to 100, 38.78 ± 0.02℃ from days 145 to 165, 38.99 ± 0.45℃ from days 200 to 220, 39.14 ± 0.38℃ from days 250 to 270 before parturition. Therefore, our results could provide useful data for early detection of pregnancy and parturition in Korean cows.