Effects of high air temperatures on milk efficiency in dairy cows

Abstract

The average temperature of the Earth surface keeps increasing and the hot summer 2003 may have a bearing on global warming. The majority of farmers were not ready to cope with such situation, so it could bring about significant economic losses. The number of days with extremely high temperatures which substantially influence the performance of animals is increasing, and this tendency will continue according to predictions. The above assumption will influence the management of dairy husbandry. We will have to consider housing and technological systems that will reduce this negative effect of climatic extremes when designing an optimum farm environment.It is apparent that performance, welfare and health of the animal are influenced by biometeorological factors. The most important climatological factors are high temperatures and relative humidity during the hot season and the wind-chilling factor during the cold season of the year (Gregoriadesová and Doležal, 2000). In the majority of barns for cows and heifers, the limits of air relative humidity were exceeded (Šoch et al., 2000).Summer climates cause the stress of dairy cows resulting in milk production depression. Heat stress occurs when the ambient temperature is higher than that of the animal's thermal neutral zone. The heat load is greater than their ability to lose heat (Šoch et al., 1997;Dolejš et al., 2000a). The potential for heat stress exists when the air temperature rises above the comfort zone, particularly if humidity is also high. When the tem- Effects of high air temperatures on milk efficiency in dairy cowsJ. BROUČEK, Š. MIHINA, Š. RYBA, P. TONGEĽ, P. KIŠAC, M. UHRINČAŤ, A. HANUS Research Institute of Animal Production, Nitra, Slovak Republic ABSTRACT: 26 herds with 71 586 individual records were used. We tested a hypothesis that milk efficiency was influenced by the elevation of the farm, housing system, breed, area of altitude, and by the cooling of dairy cows. There were 20 herds from lowlands and 6 herds from mountains, 20 herds from free-stall housing, 6 herds from tie-stall housing. 8 herds consisted of Slovakian Pied cattle, 4 herds of Red Holstein cattle, 11 herds of Black-Pied Lowland cattle and 3 herds of Slovakian Pinzgau cattle. The herds were divided into 4 groups according to the nearest meteorological station, and they were distributed according to the type of cooling. 10 herds were cooled by misting, 16 herds by fans. We recorded from 96 to 117 summer days and from 49 to 63 tropical days in lowlands for this summer period. Ninety days with temperature-humidity index (THI) above 72.0 were found in the lowest-elevation area. During 55 days we recorded the values higher than 78.0. Production of milk was higher in lowlands than in mountains (8 761.4 kg vs. 6 372.0 kg; P < 0.01). Differences were also recorded in the evaluation of fat and protein production (346.0 kg vs. 275.9 kg; P < 0.01; 282.6 kg vs. 205.9 kg; P < 0.001). Milk and protein production was higher in free-stall housing than in tie-stall housing (8 656.3 kg vs. 6 722.1 kg...

Effect of average diurnal barn airspace temperatures on prediction of their development during the day

“…According to Kadzere et al (2002) values below 70 are considered as comfort, 75 to 78 stressing, and above 78 extremely dangerous to lethal. Similar values were mentioned also by Brouček et al (2006), cit. Du Prezz et al (1990.…”

Karakteristik Sapi Madura Betina Berdasarkan Ketinggian Tempat Di Kecamatan Galis Dan Kadur Kabupaten Pamekasan

“…Cekaman panas pada sapi ditandai dengan meningkatnya pernafasan, suhu rektal (Broucek et al 2006). Rataan suhu rektal, frekuensi pernapasan dan HTC sapi Madura betina dapat dilihat pada Tabel 3.…”

Comparison of Conventional and Automatic Milking Systems at Extreme Conditions by Thermographic Method

“…THI was calculated according to Brouček et al (2006) (1): where: T max -maximum temperature per day (ºC) RH -average relative humidity per day (%)…”

“…Extremely low and high temperatures have a negative impact on dairy cows. The impacts of low temperatures were observed by several experiments (Angrecka and Herbut, 2015;Brouček et al, 1991), while Brouček et al (Brouček et al, 2006), Noordhuizen and Bonnefoy (Noordhuizen and Bonnefoy, 2015) and other authors were focused on impacts of extremely high temperatures. For dairy cows, the exposure to higher temperatures causes the decrease in milk output and reduces the content percentages of fat, solids, lactose, and protein in milk (Kadzere et al, 2002;St-Pierre et al, 2003;West, 2003).…”