ABSTRACT Several prediction equations for methane (CH 4 ) emissions from enteric fermentation in cattle have been proposed for individual‐level prediction using the breath CH 4 to carbon dioxide (CO 2 ) concentration ratio and for herd‐level prediction using animal and/or feed information, owing to the difficulty of measuring CH 4 emissions. In dairy cattle, most equations have been developed for lactating cows and are restricted for heifers, whose physiological status and diets differ from those of lactating cows. The present study developed prediction equations for CH 4 emissions from dairy heifers using variables readily obtainable on farms. Equations were developed by fitting a linear regression model including metabolic body weight (MBW), dry matter intake (DMI), estimated daily gain (DG), metabolizable energy intake‐to‐DMI ratio, and/or the CH 4 :CO 2 emission ratio as explanatory variables. Data were collected using respiration chambers ( n = 103; mean age, 13.0 months; mean body weight, 312 kg). The best‐performing models for both individual‐ and herd‐level prediction included MBW and DMI as explanatory variables. Replacing DMI with estimated DG resulted in only a slight reduction in model performance. Consequently, the developed equations offer flexible applications on farms based on data availability.
ABSTRACT Noninvasive sampling methods are recommended in animals as far as possible. However, there has been no way to safely measure long‐term stress in all horses including foals and stallions. Currently, nail cortisol in humans has been reported to be a promising noninvasive long‐term stress indicator. This study aimed to evaluate the usefulness of a horse's hoof as a noninvasive long‐term stress indicator by determining whether hoof cortisol levels varied similarly to hair cortisol levels noted in a previous study. All hooves were sampled by one farrier after a foal's birth. They were divided into three groups: (1) hooves reflecting cortisol levels 1 month prior to birth of fetuses ( n = 18), (2) the 1 month‐period immediately after birth ( n = 11), and (3) the 1 month‐period more than 1 month after birth ( n = 9). Cortisol levels in the fetal period markedly exceeded those of the other two periods ( p < 0.05). Moreover, the changes of cortisol levels in this study were consistent with those of similar periods in previous studies. Therefore, the hoof would be useful to obtain noninvasive long‐term stress indicators in the horse.
ABSTRACT To evaluate the utility of open‐access meteorological observation records to estimate on‐farm thermal information, temperature and humidity data during June 5, 2024–April 15, 2026 were collected on the Kyoto University Livestock Farm in Japan. Data loggers were installed in breeding barn, calf barn, and paddock. Daily average dry‐bulb temperature (T db ), relative humidity (RH), volumetric humidity (VH), and temperature‐humidity index (THI) were measured. Ambient temperature and humidity were estimated using meteorological observations from the two nearest weather stations. NASA POWER daily average T db and RH data at the location of farm were downloaded. Correlations of on‐farm data were 0.86–0.91 for RH and > 0.99 for T db , VH, and THI with estimated values from meteorological observations, while 0.73–0.74 for RH, 0.99 for VH, and > 0.99 for T db and THI with NASA POWER data. Downward biases for T db and THI and upward biases for RH and VH were observed and the degree of biases for humidity‐related indices tended to be more pronounced during the cold season, while bias in RH was greater for NASA POWER data. Our results could provide novel insight into thermal information on cattle farms and using public databases to infer on‐farm temperature and humidity.
ABSTRACT This study evaluated the effects of classical music as auditory environmental enrichment on chronic stress and anxiety‐related responses in broiler chickens. Two hundred Cobb 500 chicks were assigned to a control group (no enrichment) or an enriched group exposed to classical music for 6 h daily from 1 to 40 days of age. At 40 days, affective states were assessed using the attention bias test (ABT), while chronic stress was evaluated through feather corticosterone (CORT) concentrations. Music‐exposed birds had significantly lower feather CORT concentrations than controls ( p < 0.0001), indicating reduced chronic stress. No significant treatment effects were detected for ABT behavioral measures. However, music‐exposed birds showed a numerically longer latency to take the first step ( p = 0.055), although this difference did not reach statistical significance. Overall, these findings demonstrate that classical music enrichment can reduce physiological indicators of chronic stress in broilers, while evidence for effects on anxiety‐related behavior remains inconclusive. The results suggest that auditory enrichment may help reduce chronic stress in broilers under the conditions evaluated and highlight the need for further replicated studies to clarify its effects on affective states and behavioral responses.
ABSTRACT In this study, the productivity and post‐transfer pregnancy rates of bovine embryos in vitro‐produced (IVP) by a two‐step culture system were compared with those of in vivo‐developed (IVD) embryos. Ovum pick‐up was designated as Day 0, presumptive zygotes were cultured in modified synthetic oviduct fluid without glucose (mSOFaa), whereas late‐stage embryos from Day 5 onward were cultured in TCM 199 supplemented with 5% fetal calf serum and 100 μM β‐mercaptoethanol. An average of 5.9 ± 4.8 blastocysts was obtained from 26 donors. A total of 46 fresh and 18 vitrified IVP embryos were transferred individually, resulting in 27 pregnancies (42.2%). Although the pregnancy rate of OPU–IVP embryos was lower than that of IVD embryos (35/60, 58.3%), it was within the range typically reported for commercially available IVP embryos. These findings indicate that the two‐step culture method enables efficient production of Japanese Black IVP embryos and is a practical and reliable method for beef cattle production in the field.
