The health, longevity, and performance of dairy cattle can be adversely affected by heat stress. This study evaluated the in-barn condition [i.e., temperature, relative humidity, and resulting temperature-humidity index (THI)] at 9 dairy barns with various climates and farm design-management combinations. Hourly and daily indoor and outdoor conditions were compared at each farm, including both mechanically and naturally ventilated barns. On-site conditions were compared with on-farm outdoor conditions, meteorological stations up to 125 km away, and NASA Power data. Canadian dairy cattle face periods of extreme cold and periods of high THI, dependent on the regional climate and season. The northernmost location (53°N) experienced about 75% fewer hours of THI >68 compared with the southernmost location (42°N). Milking parlors had higher THI than the rest of the barn during milking times. The THI conditions inside dairy barns were well correlated with THI conditions measured outside the barns. Naturally ventilated barns with metal roofs and without sprinklers fit a linear relationship (hourly and daily means) with a slope <1, indicating that in-barn THI exceeded outdoor THI more at lower THI and reached equality at higher THI. Mechanically ventilated barns fit nonlinear relationships, which showed the in-barn THI exceeded outdoor THI more at lower THI (e.g., 55-65) and approached equality at higher THI. In-barn THI exceedance was greater in the evening and overnight due to factors such as decreased wind speed and latent heat retention. Eight regression equations were developed (4 hourly, 4 daily) to predict in-barn conditions based on outdoor conditions, considering different barn designs and management systems. Correlations between in-barn and outdoor THI were best when using the on-site weather data from the study, but publicly available weather data from stations within 50 km provided reasonable estimates. Climate stations 75 to 125 km away and NASA Power ensemble data gave poorer fit statistics. For studies involving many dairy barns, the use of NASA Power data with equations for estimating average in-barn conditions in a population is likely appropriate especially when public stations have incomplete data. Results from this study show the importance of adapting recommendation on heat stress to the barn design and guide the selection of appropriate weather data depending on the aim of the study.

Light from the environment is important for vision and regulating various biological processes. Providing supplemental lighting in the stall area could allow for individually targeted or group-level control of light. This study aimed to determine whether dairy cattle had preferences for short-term exposure to white (full-spectrum) light-emitting diode (LED) light or no LED light, yellow-green or white LED light, and blue or white LED light in the stall area. In total, 14 lactating cows were housed in a free-stall pen with unrestricted access to 28 stalls. LED light was controlled separately for each side of the stall platform. Two combinations of light were tested per week, and each week consisted of three adaptation days and four treatment days. Lying behaviour and video data were recorded continuously using leg-mounted pedometers and cameras, respectively. Preference was assessed by the amount of time spent lying and the number of bouts under each light treatment. No differences occurred between treatments within each week for daily lying time and number of bouts. Similarly, no differences occurred between treatments within each time period. Further controlled studies of long-term exposure to different LED wavelengths and intensities are required to determine potential benefits on metabolic processes.

Kaufman, J., Linington, M., Osborne, V. R., Wagner-Riddle, C. and Wright, T. C. 2015. Short Communication: Field study of air ammonia concentrations in Ontario dairy calf housing microenvironments. Can. J. Anim. Sci. 95: 539–542. The objective of this study was to measure the ammonia concentrations in the microenvironment of the calf housing area on a sample of commercial dairies in Ontario under typical management conditions. Two approaches were used to measure ammonia concentrations: (1) weekly on four farms for a period of 8 wk and (2) one-time samples were taken from the calf areas on 15 other farms. The results indicated that ammonia levels are managed below the existing maximum threshold provided in the national dairy code of practice.

The blue water footprint (WF) is an indicator of freshwater required to produce a given end product. Determining the blue WF for milk production, the seasonal water use and the impact of water conservation are important sustainability considerations for the dairy industry in Ontario (Canada). In this study, a water footprint network (WFN) method was used to calculate the seasonal blue WF’s from in-barn water use data and the fat–protein-corrected milk (FPCM) production. Various water conservation options were estimated using the AgriSuite software. Results showed that the total water use (L of water·cow⁻¹·d⁻¹) and the average blue WF (L of water·kg⁻¹ of FPCM) were 246.3 ± 6.8 L·cow⁻¹·d⁻¹ and 7.4 ± 0.2 L·kg⁻¹, respectively. The total water use and the blue WF could be reduced to 182.7 ± 5.1 L·cow⁻¹·d⁻¹ (25.8% reduction) and 5.8 ± 0.1 L·kg⁻¹ (21.6% reduction), respectively, through adaptive water conservation measures as the reuse of the plate cooler and milk house water. For example, conservation practices could reduce the milk house wash water use from 74.3 ± 8.8 L·cow⁻¹·d⁻¹ to 16.6 ± 0.1 L·cow⁻¹·d⁻¹ (77.7% overall reduction).

An increased risk of anogenital tract malignancies has been noted among renal transplant recipients. A high prevalence of human papillomavirus (HPV) infection of the cervix in the female renal-transplant population has been assumed based on increasing evidence suggesting that HPV infection is the major risk factor for cervical intraepithelial neoplasia (CIN) and cervical cancer. It has been assumed that immunosuppression leads to either a reactivation of latent HPV or a reduction in the host's ability to contain a primary HPV infection, thereby increasing the risk of CIN and cervical cancer. The objective of this study was to evaluate the prevalence of human papillomavirus (HPV) infection in a population of iatrogenically immunosuppressed renal transplant recipients. Twenty-one women were recruited from the renal transplant clinic at Presbyterian Hospital and underwent a gynaecological examination which included colposcopy, a Papanicolaou smear, and a cervicovaginal lavage. Lavage samples were analysed for HPV DNA using L1 consensus primers and the polymerase chain reaction (PCR). No cases of cervical intraepithelial neoplasia (CIN) were detected in this cohort of 21 immunosuppressed renal transplant recipients. HPV DNA was detected in only a single patient. Our data suggests that HPV infection is not highly prevalent among older, cytologically normal renal transplant recipients, particularly those who are currently monogamous or not presently sexually active. This study suggests that recent sexual behaviours are more important than past behaviours as a determinant of HPV status in transplant recipients, and also suggests that education concerning the avoidance of high-risk sexual behaviour is an important part of the care of the female renal transplant recipient. Our data is consistent with previous work suggesting that the incidence of CIN is declining in transplant recipients, and it also suggests that the prevalence of HPV infection may be declining as well.