Effects of a tunnel ventilation system within the tie-stall barn environment upon the productivity of dairy cattle during the winter season

Abstract

Objective: The objective of this study was to examine the effect of using a tunnel ventilation system within the dairy barn environment upon the productivity of dairy cows during the winter season.

Methods: The study was performed at the University Farm, Faculty of Agriculture, Utsunomiya University. Twenty-one Holstein dairy cows (5 heifers and 16 multiparous) were enclosed in a stall barn. Unventilated (UV) and tunnel-ventilated (TV) was operated by turns every other week, and a number of key parameters were measured in the barn, including tunnel ventilation output, temperature, relative humidity, gas concentrations (oxygen [O2], carbon dioxide [CO2], and ammonia [NH3]). Also, skin and rectal temperature, respiratory rate, blood gas concentrations, and bacterial count were measured from nipple attachments on ten cows. The amount of fodder left uneaten, and general components and somatic cell count of the milk were measured.

Results: As for our dairy barn environment, air temperature dropped significantly with the passage of time with TV. Humidity was significantly higher with TV at 0600 h compared to UV, while CO2 and NH3 concentrations with UV were significantly higher than with TV at 0000 h and 0600 h. Skin temperature was significantly lower with TV compared to UV at 0000 h and 0600 h. Respiratory rate was also significantly lower at 0600 h with TV than with UV. Bacterial count for the nipple attachments was significantly lower with TV than with UV at 0600 h. The amount of leftover fodder was significantly less with TV in comparison with UV.

Conclusion: Our results suggest that a TV system in the winter barn results in environmental improvements, such as reductions in unfavorable gas concentrations and bacterial growth. Consequently, it is expected that barns utilizing a TV system will be beneficial for both animal health and production.

Keywords: Barn Environment; Dairy Cows; Tunnel Ventilation; Winter Season.

Figure 1

Tunnel ventilation system at the University Farm, Faculty of Agriculture, Utsunomiya University. (a) and (b) represent floor plans of the tunnel ventilation system (width (○—○) : 9 m, length (○—●) : 43 m. The walls of the barn were made of plaster (15 mm thick) or concrete blocks (154 mm thick), while the roof was made form corrugated galvanized irons, asbestos cement plates, and insulating materials (0.4 mm thick) (a). System viewed from above (b) Different sections of the barn (height [□—□]: 5 m). Arrows show images of the direction of air flow from the tunnel ventilation system.

Figure 2

Schematic showing the location of sampling points in the cow shed for wind velocity, temperature and humidity. Sampling point (A) was outdoors, while (B, C, D) were indoors.

Figure 3

Changes in the dairy barn environment in unventilated (UV □) and tunnel-ventilated (TV ♦) systems. (A) Humidity, (B) O₂ concentration, (C) CO₂ concentration, and (D) NH₃ concentration. Values represent the mean±standard error (n = 21). * Represents statistical difference with respect to TV at p<0.05.

Figure 4

Changes in the dairy barn environment in unventilated (UV □), tunnel-ventilated barn (TV ◆) and the environmental temperature outside of the barn (Outside; ○). Values represent the mean±standard error (n = 21). * Represents statistical difference with respect to TV at p<0.05.

Figure 5

Changes in bacterial count upon nipple attachments in unventilated (UV) and tunnel-ventilated (TV) systems. Values represent the mean±standard error (n = 30). Values with different superscripts (^a,b) differ significantly (p<0.05).

Figure 6

Changes in residual feed in the unventilated (UV) and tunnel-ventilated (TV) systems. Values represent the mean±standard error (n = 21). Values with different superscripts (^a,b) differ significantly (p<0.05).