Year: 2025
Type: article
Abstract: When trying to achieve optimum production, lactating, and dry dairy cows must be provided with relief from heat stress. The most practical and common methods to alleviate the negative effects of heat and humidity on lactating and dry dairy cows consist of 3 main approaches: shade, natural ventilation, and active cooling; with active cooling being the most advantageous. Our objective was to determine if an automated "smart" system (Agpro, Paris, TX) for control of soaker output, is as effective as the conventional approach to control soakers which rely on a set frequency after a threshold temperature is reached. Nulliparous (n = 12) and Multiparous (n = 30) pregnant Holsteins cows were dried off 40 ± 9 d (multiparous only) before expected calving and randomly assigned to one of 3 treatments in the same barn: 5 min intervals (30s on, 5 min off) cooling period with shade, fan, and soakers ( CL , n=14), Agpro smart cooling with shade, fan, and soakers ( SS , n=14), and heat stress with only shade and natural ventilation, no active cooling system ( HT , n=14) during the dry period until parturition. Daily dry matter intake (DMI) of individual cows, pen water intake, and pen water usage from soakers were measured daily. Blood samples for hematocrit were taken weekly. Respiration rate (RR) and rectal temperature (RT) were measured 3 times weekly. Calf birthweight and gestation length were recorded upon parturition. No differences were observed for gestation length, calf birthweight, dry period length, or hematocrit among the treatments. However, HT cows had lower overall DMI than SS (8.6 vs. 10.1 ± 0.4 kg/d; P = 0.01) and tended to be lower than CL (8.6 vs. 9.5 ± 0.4 kg/d; P = 0.11). Water usage per cow was lowest in the HT group compared with the CL and SS groups (89.6 vs. 225.3 vs. 80.6 ± 156.5 L/cow/d). Respiration rate (RR; 68 vs. 53 vs. 48 ± 1.2 bpm; P < 0.01), RT (38.8 vs. 38.4 vs. 38.3 ± 0.03°C; P < 0.01), and vaginal temperatures (38.9 vs. 38.6 vs. 38.7 ± 0.09) were affected by treatment with HT, having the higher values relative to CL and SS, respectively. Compared with conventional cooling, the SS system effectively cooled the animals, decreased the estimated total water usage per cow, and maintained adequate animal welfare.
Source: JDS Communications
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $1,310
OpenAlex ID: W4417013786