Effect of Temperature Cumulation on Milk Yield of Czech Fleckvieh-Simmental Cattle

The aim of this study was to asses the effect of temperature cumulation on milk yield of Czech Fleckvieh-Simmental cattle. Experiment for this study was executed on private farm in Czech Republic with permanently open-sided barn, in which were cows stabled (49o12'36.7"N 16o23'42.1"E). Cows were stabled in free stall box system. Experiment lasted three months (May-July) of 2016. In total 114 cows were include in this study. They were divided according to yield to three groups: more than 25 kg of milk per day, 20.1-24.9 kg of milk per day and less than 20 kg of milk per day. The data loggers placed inside the stable collected data about temperature every 30 minutes. Data about milk yield were obtained from software in milk parlour. After data were collected, the sum of effective temperatures (SET) was calculated. The SET was calculated for temperatures surpassing 21 oC. Data shows that all groups were affected by rising SET. The group with yield above 25 kg of milk per day was the most affected by the high SET (r = MINUS SIGN 0.4931) in contrary with the group with less than 20 kg of milk per day (r = MINUS SIGN 0.1380). Our result suggest, that the SET might be better marker for evaluation of the impact of heat stress than temperature itself. The results of this paper also shows, that the high-yield cows are affected by cumulation of temperature more.O

Excitability scores of goats administered ascorbic acid and transported during hot-dry conditions

In this study, we investigated the effect of ascorbic acid (AA) administration on goat excitability due to transportation. Ten goats administered AA (p.o.) at 100 mg/kg of body weight before transportation served as the experimental group, and seven goats administered only 10ml/kg of sterile water (p.o.) served as controls. Excitability scores were recorded for each goat; when weighed, before, immediately after, and 3 h after 8 h of transportation. A score of one to four was allocated to each goat; higher scores represent greater excitability. Immediately after transportation, excitability scores decreased significantly, especially those of control goats (p < 0.001). At 3 h post-transportation, the excitability scores of animals in the experimental group were not significantly (p>0.05) different from their pre-transportation normal values, whereas those of control goats were significantly lower (p < 0.01). The correlation i.e. the relationship between excitability score values and percent excitability (percentage of goat with particular excitability score) for different excitability score group 3 h post-transportation was positive and highly significant (p < 0.001), in both experimental and control goats. Our results indicate that road transportation induces considerable stress (depression) in goats as evidenced by a lower excitability score post-transportation. Moreover, the administration of AA pre-transportation facilitated the transition from a state of depression to excitation. In conclusion, AA administration to animals prior to transportation may ameliorate the depression often encountered after road transportation

Is reticular temperature a useful indicator of heat stress in dairy cattle?

The present study investigated whether reticular temperature (RT) in dairy cattle is a useful indicator of heat stress considering the effects of milk yield and water intake (WI). In total, 28 Holstein-Friesian dairy cows raised on 3 farms in Lower Saxony, Germany, were studied from March to December 2013. During the study, RT and barn climate parameters (air temperature, relative humidity) were measured continuously and individual milk yield was recorded daily. Both the daily temperature-humidity index (THI) and the daily median RT per cow were calculated. Additionally, the individual WI (amount and frequency) of 10 cows during 100d of the study was recorded on 1 farm. Averaged over all farms, daily THI ranged between 35.4 and 78.9 with a mean (±standard deviation) of 60.2 (±8.7). Dairy cows were on average (±standard deviation) 110.9d in milk (±79.3) with a mean (±standard deviation) milk yield of 35.2kg/d (±9.1). The RT was affected by THI, milk yield, days in milk, and WI. Up to a THI threshold of 65, RT remained constant at 39.2°C. Above this threshold, RT increased to 39.3°C and further to 39.4°C when THI ≥70. The correlation between THI ≥70 and RT was 0.22, whereas the coefficient ranged between r=-0.08 to +0.06 when THI70. With increasing milk yield, RT decreased slightly from 39.3°C (30kg/d) to 39.2°C (≥40kg/d). For daily milk yields of ≥40kg, the median RT and daily milk yield were correlated at r=-0.18. The RT was greater when dairy cows yielded ≥30kg/d and THI ≥70 (39.5°C) compared with milk yields30kg and THI70 (39.3°C). The WI, which averaged (±standard deviation) 11.5 l (±5.7) per drinking bout, caused a mean decrease in RT of 3.2°C and was affected by the amount of WI (r=0.60). After WI, it took up to 2h until RT reached the initial level before drinking. In conclusion, RT increased when the THI threshold of 65 was exceeded. A further increase was noted when THI ≥70. Nevertheless, the effects of WI and milk yield have to be considered carefully when RT is used to detect hyperthermia in dairy cattle