Browsing by Subject "Body Condition Score"

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Untersuchungen zur Körperzusammensetzung von Fleckviehkühen und Validierung verschiedener Methoden der Schätzung des Körperfettgehaltes
(2019) Schneider, Mariana; Rodehutscord, Markus
The aim of the present work was to gain knowledge about the body composition of adult Fleckvieh cows and to validate different methods for the indirect estimation of the empty body crude fat content (LKXL). For this purpose, 30 multiparous, non-pregnant Fleckvieh cows were slaughtered and subjected to a whole-body analysis. These cows were specifically selected according to their body condition score to cover a wide range of body conditions. For processing, the empty bodies were divided into fractions, of which the gastrointestinal tract, liver, organs (including blood), kidney fat and udder were completely homogenized, while only the right half of the body was sampled from the fractions skin, muscles (and adherent tissue) and bone. On the day of slaughter, the following methods for estimating the empty body crude fat content were tested: Body Condition Score (BCS), sonographic measurement of back fat thickness at three measuring points, sonographic measurement of muscle thickness (Musculus longissimus dorsi), intramuscular fat content, Bioelectrical Impedance Analysis (BIA, five measuring points), skin fold thickness using a caliper (eleven measuring points), fat cell size in retroperitoneal and subcutaneous fat tissue and serum leptin concentration. The live and empty body masses averaged 736 ± 101 kg and 654 ± 106 kg, respectively, with a considerable range of 414 – 865 kg and 340 – 804 kg respectively. These values are comparatively high and can be attributed to breeding progress. The empty body crude fat content was 17.1 ± 5.9 % (2.3 - 28.9 %) and 117 ± 52 kg (10 – 231 kg) respectively. The corresponding proportions for crude protein, crude water and crude ash were 18.6 ± 1.9 %, 57.9 ± 4.7 % and 4.7 ± 0.4 % and accordingly 121 ± 16 kg, 386 ± 45 kg and 30 ± 4 kg. Thus the Fleckvieh cows examined tend to be leaner than those reported in earlier studies, although it should be noted that lean cows were also specifically tested. The most important depots of the LKXL are, in accordance with literature reports, the fractions muscle, bone and gastrointestinal tract. The proportion of the LKXL from the bones decreased with increasing obesity, while it increased in all other depots. The largest changes in the absolute crude fat content as a function of LKXL were found in the fractions muscle (124 kg), gastrointestinal tract (43 kg) and kidney fat (27 kg). The concentrations of the examined minerals in the empty bodies were as follows: 37.2 g Ca/kg dry matter (DM), 20.9 g P/kg DM, 5.11 g K/kg DM, 4.28 g S/kg DM, 0.95 g Mg/kg DM, 195.7 mg Fe/kg DM, 87.0 mg Zn/kg DM and 13.1 mg Cu/kg DM. Significant regression equations could be derived for all tested methods for estimating the empty body crude fat content, but there were large differences in the estimation accuracy. The most accurate in vivo estimation of the empty body crude fat content in a direct comparison was performed with the Bioelectric Impedance Analysis (RMSE = 14.7 kg). Therefore, the method is recommended for scientific issues. The measurement of the retroperitoneal fat cell size also provided fairly accurate estimates of the empty body crude fat content (RMSE = 21.5 kg). As this is an invasive and very complex method, no recommendation for use can be made, as a non-invasive method is available in the form of Bioelectrical Impedance Analysis. The Body Condition Score (RMSE = 28.4 kg) allowed relatively good estimates of the empty body crude fat content compared to the other methods tested. The suitability of this method in practical feeding management is therefore confirmed. The survey of the live mass also provided a good estimation result (RMSE = 23.6 kg), while the methods muscle thickness (RMSE = 29.5 kg) and intramuscular fat content (RMSE = 3.19 %) were classified in the midfield with regard to their estimation accuracy. The estimation of the empty body crude fat content by means of back fat thickness, serum leptin concentration or skin fold thickness cannot be recommended due to the comparatively high estimation errors (RMSE = 32.1 kg, 36.0 kg and 38.2 kg respectively). In the course of the evaluation of the available results, a close correlation between the amount of kidney fat and the empty body crude fat content was also found. With an RMSE of 14.4 kg, this method is the most accurate of the tested methods and should therefore be preferred if slaughter of the cows is planned. It should be noted, however, that even the better estimation methods for individual animal-related statements are too inaccurate, since the extent of normal mobilization of body fat during lactation is only slightly above the level of the estimation errors determined. The results of the present study should not be applied directly to pregnant Fleckvieh cows, as the data were only collected from non-pregnant animals. The classification of the results in literature reports also showed that data on body fat content and its relationship to the estimation methods tested should be collected for the corresponding target species. Therefore, the expansion of the database for the available animal material should be aimed at. In particular, the methods of Bioelectrical Impedance Analysis and the in vivo recording of kidney fat should be developed further in the future, as these are promising methods.