The effect of modified roofing on the milk yield and reproductive performance of heat‐stressed dairy cows under hot‐humid conditions

Abstract

The objective was to measure the effects of cooling techniques (shade cloth vs. normal roof) on performance and physiology of 16 Friesian crossbred cows (87.5% Holstein Friesian × 12.5% Brahman) located at Sakol Nakhon Livestock Research and Testing Station, Department of Livestock Development, Ministry of Agriculture and Cooperatives (Sakol Nakhon, Thailand). They were divided randomly into two groups of eight. The two groups were used to evaluate the effects of modified roofing (normal roof fitted with woven polypropylene shade cloth) on the subjects' milk yield and reproductive performance under hot humid conditions. Results indicated that the modified roofing offered a more efficient way to minimize heat stress than the normal roof. The difference was sufficient to enable the cows to have a significantly lower mean rectal temperature and respiration rate (38.56 °C, 61.97 breaths/min) than that of the cows housed under normal roofing (39.86 °C; 85.16 breaths/min). The cows housed under modified roofing produced more milk (P < 0.05) but did not differ significantly in reproductive performance from the cows housed under normal roofing.

Effect of shade materials on microclimate of crossbred calves during summer

“…Inability to eliminate excess heat might probably have led to the rise in rectal temperature. The present finding are in agreement with [19] who concluded that cows provided with more protection (99% shade) from solar radiation as compared to 50% shade and no shade) had lower rectal temperature with higher level of ambient solar radiation [20] reported significantly higher (p<0.05) differences among the mean values of rectal temperature during summer under thatch roof (39.49±0.05) and under tin shed (39.54±0.05), which clearly indicated the inability of the kids housed in tin shed to make up with the higher environmental temperature [21] also reported significant difference among thatch roof shed, literoof and asbestos roof shed during hot summer [6], found significantly lower mean rectal temperature (38.56°C) in shade cloth than that of the cows housed under normal roofing (39.86°C). On the other hand [22] reported that in crossbred calves body temperature was not affected (p<0.05) by modification in the housing system.…”

“…The present finding is also in agreement with the observation of [25] who reported higher RR during afternoon than morning hr. in crossbred calves during summer [22] observed higher (p<0.05) respiration counts in loose house as compared to those animals kept in thatch house [6], found significantly lower respiration rate (61.97 breaths/min) in shade cloth than that of the cows housed under normal roofing (85.16 breaths/min) [26] reported increased respiration rate with increase in surrounding heat and observed that this increase was more marked in the 2.4 m 2 shade/ cow and no shade treatments than in the 9.6 m 2 shade/ cow treatments. These results indicated that cattle use shade to prevent an increase in internal body temperature, but this heat mitigation strategy is only effective if a sufficient amount of shade is provided.…”

“…Costs of improving the animal's environment must be realized by the benefits gained in improved animal productivity [5] used woven polypropylene fabric materials providing 80% shade for animal shades. Normal roof fitted with woven polypropylene shade cloth offered a more efficient way to minimize heat stress than a normal roof [6]. Plastic and fabric covered arch-frame structures (commonly referred to as alternative structures or greenhouses) represent the newest trend of housing systems used to raise calves.…”

The effects of high temperature and wallow on physiological responses of swamp buffaloes (Bubalus bubalis) during winter season in Thailand

“…It is less tolerant to extremes of heat and cold than various breeds of cattle (Marai and Habeeb, 2010). There are reports indicating that milk yield, growth and fertility of both cattle (De Rensis and Scaramuzzi, 2003;Khongdee et al, 2010) and swamp buffalo (Marai and Habeeb, 2010) are all reduced during periods of high ambient temperature. Each of these variables shows a direct relationship with rectal temperature (Goswani and Nair, 1964), for example, there were increases in rectal temperature from 38.5 to 39.7 1C when swamp buffalo and cows (340-375 kg, 4-7 years old) were subjected to acute heat exposure (41 1C; without wallow) for 5 h (Chaiyabutr et al, 1987).…”

Effect of time of progesterone supplementation on serum progesterone and the conception rate of cooled Holstein heifers during the summer

“…A study conducted in Thailand during the summer reported a higher milk yield and a lower rectal temperature in crossbreed cows (87.5% Holstein Friesian × 12.5% Brahman) under an open shed fitted with corrugated iron roof and covered with shade cloth with 70% shade factor and that was stretched at 100 cm above the entire roof, compared to cows under a normal roof (Khongdee et al . ).…”