| 1 | Effect of exogenous fibrolytic enzymes on performance and blood profile in early and mid-lactation Holstein cows显示文摘The supplementation of exogenous fibrolytic enzymes(EFE) to dairy cows diets could be a strategy to improve fiber degradation in the rumen which is especially important for the early lactating cows characterized by a high milk energy output and an insufficient energy intake. The objective of this study was to examine the effects of a fibrolytic enzyme product(Roxazyme G2 Liquid, 3.8 and 3.9 mL/kg total mixed ration [TMR] DM) supplemented to a TMR on production performance and blood parameters of dairy cows during early(trial 1) and mid-lactation(trail 2). In addition, rumination activity was measured in trial 2. The nutrient digestibility of the experimental TMR was obtained by using wethers. In the digestibility trial, EFE was supplemented at a rate of 4.4 m L/kg Roxazyme G2 Liquid TMR-DM. The TMR contained 60% forage and 40% concentrate(DM basis). Twenty eight 50 ± 16 days in milk(DIM)and twenty six 136 ± 26 DIM Holstein cows were used in two 8-wk completely randomized trails,stratified by parity and milk yield level. One milliliter of the enzyme product contained primarily cellulase and xylanase activities(8,000 units endo-1,4-? glucanase, 18,000 units endo-1,3(4)-? glucanase and 26,000 units 1,4-? xylanase). No differences in digestibility of DM, OM, CP, NDF and ADF were observed(P >0.05) between the control and the EFE supplemented TMR. Addition of EFE to the TMR fed to early(trial 1) and mid-lactation cows(trial 2) did not affect daily dry matter intake(DMI), milk yield,4% fat-corrected milk, energy-corrected milk(ECM), concentration of milk fat, protein, fat-protein-quotients, somatic cell score, energy balance, and gross feed efficiency of early and mid-lactation cows(P >0.05). Mid-lactation cows(trial 2) fed with TMR enzyme showed a tendency of a slightly higher ECM yield(P = 0.09). The tested blood parameters were not affected by treatment in trials 1 and 2(P >0.05).Exogenous fibrolytic enzymes supplementation did not alter daily time spent ruminating in trial 2(P =0.44). In conclusion, under the conditions of this study, no positive effects of enzyme supplementation on dairy performance and health status of dairy cows during early and mid-lactation were observed. | Anja Peters Ulrich Meyer Sven Danicke | 2015 | Animal Nutrition2015，，3： | 5 |
| 3 | Changes of the liver metabolome following an intravenous lipopolysaccharide injection in Holstein cows supplemented with dietary carnitine显示文摘Background:Carnitine facilitates the flux of long-chain fatty acids for hepatic mitochondrial beta-oxidation,which acts to ameliorate the negative energy balance commonly affecting high-yielding dairy cows.Inflammation triggered by lipopolysaccharide(LPS)load can however pose a challenge to the metabolic integrity via the expression of pro-inflammatory mediators,leading to immune system activation and respective metabolic alterations.The effect of enhanced carnitine availability on hepatic metabolome profiles during an inflammatory challenge has not yet been determined in dairy cows.Herein,Holstein cows were supplemented with 25 g/d rumen-protected carnitine from 42d prepartum until 126 d postpartum(n=16)or assigned to the control group with no supplementation during the same period(n=14).We biopsied the liver of the cows before(100 d postpartum)and after(112 d postpartum)an intravenous injection of 0.5μg/kg LPS.Liver samples were subjected to a targeted metabolomics analysis using the AbsoluteIDQ p180 Kit(Biocrates Life Sciences AG,Innsbruck,Austria).Results:Multivariate statistical analyses revealed that hepatic metabolome profiles changed in relation to both the carnitine supplementation and the LPS challenge.Comparing the metabolite profiles on 100 d,carnitine increased the concentration of short-and long-chain acyl-carnitines,which may be explained by an enhanced mitochondrial fatty acid shuttle and hence greater energy availability.The LPS injection affected hepatic metabolite profiles only in the carnitine supplemented group,particularly altering the concentration of biogenic amines.Conclusions:Our results point to interactions between an acute hepatic inflammatory response and biogenic amine metabolism,depending on energy availability. | Wei Xu Sandra Grindler Akos Kenez Sven Danicke Jana Frahm Korinna Huber | 2023 | Journal of Animal Science and Biotechnology2023，14，1： | 0 |
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