ABSTRACT
The main goal of this experiment was to study the effect of milk fat depression, induced by supplementing diet with plant oils, on the bovine fat metabolism, with special interest in cholesterol levels. For this purpose 39 cows were divided in three groups and fed different rations: a control group (C) without any oil supplementation and two groups with soybean oil (SO) or rapeseed oil (RO) added to the partial mixed ration (PMR). A decrease in milk fat percentage was observed in both oil feedings with a higher decrease of -1·14 % with SO than RO with -0·98 % compared with the physiological (-0·15 %) decline in the C group. There was no significant change in protein and lactose yield. The daily milk cholesterol yield was lower in both oil rations than in control ration, while the blood cholesterol level showed an opposite variation. The milk fatty acid pattern showed a highly significant decrease of over 10 % in the amount of saturated fatty acids (SFA) in both oil feedings and a highly significant increase in mono (MUFA) and poly (PUFA) unsaturated fatty acids, conjugated linoleic acids (CLA) included. The results of this experiment suggest that the feeding of oil supplements has a high impact on milk fat composition and its significance for human health, by decreasing fats with a potentially negative effect (SFA and cholesterol) while simultaneously increasing others with positive (MUFA, PUFA, CLA).
Subject(s)
Cattle/metabolism , Cholesterol/analysis , Lipid Metabolism , Milk/chemistry , Plant Oils/administration & dosage , Soybean Oil/administration & dosage , Animals , Cholesterol/blood , Diet/veterinary , Dietary Supplements , Fats/analysis , Fatty Acids/analysis , Fatty Acids, Monounsaturated , Female , Lactation , Lactose/analysis , Milk Proteins/analysis , Rapeseed OilABSTRACT
Locomotion scoring (Sprecher et al., 1997) and measurements with a tri-axial accelerometric device were performed in 15 cows before and after digit amputation (Group 1_AMP) as well as in 26 lame cows with different lameness scores (Group 1_LAHM). The evaluated data of Group 1_AMP, documented directly before and on days 2, 5, 10 and 14 after amputation were compared with reference values of 16 non-lame cows (Group 2). For this purpose the Root Mean Square (RMS) as well as the mean minimum (gMin) and maximum (gMax) acceleration were calculated for each measurement (n = 117). Basing on this data, forecast models were performed to predict lameness scores as well as to differentiate between lame and non-lame cows in order to verify the suitability of accelerometry as a technical tool for automated lameness detection in cows. The preoperative locomotion score in Group 1_AMP averaged 4.2. During the period of convalescence, lameness improved significantly (p < 0.01) to a mean score of 1.9 on day 14 after amputation. Statistically, score 1 can be expected on day 20 after surgery (95% CI). On day 35 an amputated cow can be assumed to be non-lame with aprobability of 95%. Acceleration values showed different approximation to those recorded for the reference group. Forecast models enabled prediction of determined scores of lameness with each category of measurement (RMS, gMin, gMax) as well as considering the entire data set with an accuracy of up to 61.7%. Differentiation between lame and non-lame cows was successful with a percentage of up to 91.7%, depending on the applied data. The results of this study showed that accelerometry is a suitable technical tool for automated lameness detection in cows, especially using the acceleration values (RMS, gMin, gMax) and forecast models employed in this study.
