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- ItemThe Effect of Diet and Farm Management on N2O Emissions from Dairy Farms Estimated from Farm Data(Basel : MDPI, 2021) Menardo, Simona; Lanza, Giacomo; Berg, WernerThe N2O emissions of 21 dairy farms in Germany were evaluated to determine the feasi-bility of an estimation of emissions from farm data and the effects of the farm management, along with possible mitigation strategies. Emissions due to the application of different fertilisers, manure storage and grazing were calculated based on equations from the IPCC (Intergovernmental Panel of Climate Change) and German emission inventory. The dependence of the N2O emissions on fertiliser type and quantity, cultivated crops and diet composition was assessed via correlation analysis and linear regression. The N2O emissions ranged between 0.11 and 0.29 kg CO2eq per kilogram energy-corrected milk, with on average 60% resulting from fertilisation and less than 30% from fertiliser storage and field applications. The total emissions had a high dependence on the diet composition; in particular, on the grass/maize ratio and the protein content of the animal diet, as well as from the manure management. A linear model for the prediction of the N2O emissions based on the diet composition and the fertilisation reached a predictive power of R2 = 0.89. As a possible mitigation strategy, the substitution of slurry for solid manure would reduce N2O emissions by 40%. Feeding cows maize-based diets instead of grass-based diets could reduce them by 14%. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- ItemComparative study of behavioural and milking traits in cows milked with a conventional or individual quarter milking system (Multilactor®) and with different milking persons(Warsaw : De Gruyter Open, 2017-4-28) Hoffmann, Gundula; Liermann, Wendy; Ammon, Christian; Rose-Meierhöfer, SandraThe aim of this study was to investigate the influence of a new type of milking system on the behaviour of cows during milking by comparing a conventional milking system (CON) with an individual quarter milking system (MUL), MultiLactor®. Sixty-eight dairy cows were observed during their milking times (32 cows in CON, 36 cows in MUL) using video recordings to analyse their behavioural traits. The udder preparation duration, milking duration and milk yield were also evaluated. No significant differences were found between the CON and the MUL regarding cows' head posture (P=0.38), body posture (P=0.85), number of steps (P=0.08) and number of kicks (P=0.56). However, the milk yield was lower (P=0.02), just as the udder preparation duration (P<0.01) and milking duration (P=0.01) were shorter in the CON compared to the MUL. In addition, in regard to the milking person, differences were displayed in the head posture of the milked cows, kick-off or loss of teat cup or milking cluster, and frequency of udder preparation. In conclusion, the investigated milking systems did not markedly influence the behaviour of dairy cows; however, udder preparation duration, milking duration and milk yield were significantly greater for the MUL than for the CON. However, the milking person appears to have a greater impact on the behaviour of the cows than the milking system. © 2017 Sciendo. All Rights Reserved.
- ItemChanges in the Spectrum of Free Fatty Acids in Blood Serum of Dairy Cows during a Prolonged Summer Heat Wave(Basel : MDPI, 2021) Mylostyvyi, Roman; Sejian, Veerasamy; Izhboldina, Olena; Kalinichenko, Olena; Karlova, Lina; Lesnovskay, Olena; Begma, Natalia; Marenkov, Oleh; Lykhach, Vadym; Midyk, Svitlana; Cherniy, Nikolay; Gutyj, Bogdan; Hoffmann, GundulaThis experiment was conducted to study the effect of a prolonged hot period on the fatty acid (FA) composition in blood serum of dairy cows. Eighteen multiparous Holstein cows were randomly assigned to the hyperthermia group (HYP, n = 8) in August (summer season) and the control group (CON, n = 10) in October (autumn season). Blood from animals of the HYP group was collected in one heat wave, which was preceded by a long period of heat stress (HS, temperature-humidity index (THI ≥ 72)). Blood from cows of the CON group was collected under thermal comfort conditions (THI < 68). The spectrum of free fatty acids (FFA) in the blood serum was analyzed by gas chromatography. The concentration of FFA increased, including saturated FAs and monounsaturated FAs, in the blood serum of cows under conditions of prolonged HS. This was associated with the mobilization of FA into the bloodstream from adipose tissue, as a consequence of negative energy balance. An increase in the ratio of n-6/n-3 polyunsaturated FAs may indicate biomembrane dysfunction and adversely affect dairy cows. This study showed that prolonged periods of heat can affect the FA composition of blood. How much this leads to changes in the FA composition of milk and the quality of food products remains to be seen in further research.
- ItemSensor-based detection of the severity of hyperkeratosis in the teats of dairy cows(Basel : MDPI AG, 2018) Demba, S.; Hoffmann, G.; Ammon, C.; Rose-Meierhöfer, S.The aim of this study was to evaluate whether the severity of hyperkeratosis (HK) in the teats of dairy cows can be assessed by a dielectric measurement. The study focused on surveying the occurrence of hyperkeratosis in a total of 241 teats of lactating dairy cows. A scoring system consisting of four categories was used to macroscopically assess the severity of HK. Additionally, the dielectric constant (DC) of all teats with milkability was measured in a double iteration with the MoistureMeterD (Delfin Technologies, Kuopio, Finland) on four different days. The Spearman rank correlation coefficient revealed a negative correlation between the DC and HK score (rs = −0.55 to −0.36). The results of the regression analysis showed that the DC values differed significantly between healthy teat ends (≤2) and teat ends with HK (≥3). Thus, the non-invasive measurement of DC provides a promising method of objectively assessing the occurrence and severity of HK.