Williamsadair7865

Dairy cows with fatty liver exhibit hepatic lipid accumulation and disturbances in fatty acid oxidation and lipid transport. Phosphatase and tensin homolog (PTEN), a lipid phosphatase, regulates intrahepatic fatty acid oxidation and lipid transport in mice. Whether PTEN play a role in fatty acid oxidation and very low density lipoprotein (VLDL) assembly in calf hepatocytes are unknown. Hepatocytes isolated from 3 healthy female Holstein calves (1 d old, 30-40 kg) were infected with empty adenovirus with green fluorescent protein for 48 h (Ad-GFP group) or infected with PTEN knockdown adenovirus for 48 h (Ad-shPTEN group), or cultured in RPMI-1640 without Ad-shPTEN or Ad-GFP (control group). Compared with the Ad-GFP group, PTEN knockdown decreased mRNA and protein abundance and the activity of fatty acid oxidation-related molecules, including acyl-coA synthetase long-chain 1, carnitine palmitoyltransferase 1, carnitine palmitoyltransferase 2, and 3-hydroxy acyl-coA dehydrogenase. Furthermore, PTEN knockdown de PTEN knockdown heightened the increase in triglyceride accumulation of hepatocytes and the decrease in VLDL content in culture medium induced by FFA. Overall, these in vitro data indicate that FFA inhibits PTEN expression, leading to triglyceride accumulation and the inhibition of VLDL assembly in calf hepatocytes. These findings suggest that PTEN may be a potential therapeutic target for FFA-induced hepatic steatosis in dairy cows.Tropical grass hay feeding is related to improved ruminal health; however, it may decrease energy intake. On the other hand, whole-flint corn grain may be an alternative fiber source in the diet of dairy calves. Forty-two Holstein calves were used in a randomized block design, considering sex, birth date, and weight at 21 d of age, when the supply of whole-flint corn grain or tropical grass hay started. Three component-fed solid diets were compared (1) starter concentrate only during the preweaning and starter concentrate with free choice of chopped Tifton-85 hay postweaning (SC), (2) starter concentrate with free choice of chopped Tifton-85 hay pre- and postweaning (SCH), and (3) starter concentrate with free choice of whole-flint corn grain pre- and postweaning (SCW). The animals were evaluated from 21 to 84 d of age. Calves were managed equally during the first 21 d, fed with 6 L/d of whole milk and a commercial starter concentrate (46% nonfiber carbohydrates, small particles, and pelleted) ad libitum. Aftstimulate early solid diet intake, promoting better performance and ruminal and intestinal development, when a highly fermentable and small particle pelleted starter is fed.Ideal digesta markers used for feeding studies are inert, unabsorbable, and move with the digesta they are intended to mark. Both chromium (III) and cobalt (III) salts of EDTA (CrEDTA and CoEDTA, respectively) are used as markers of liquid digesta in dairy cattle research. A small portion is absorbed and excreted in urine, but the markers are assumed to remain unreactive and as inert salts in the digesta and animal. The degree to which these colored salts remain bound in solution can be estimated through spectrophotometric measurement at their wavelength (λ) of peak absorbance. The objective of this in vitro study was to evaluate whether CrEDTA and CoEDTA dissociate under reducing conditions that could be experienced in the rumen. In a completely randomized design with 2 replicate analytical runs and samples in duplicate within run, approximately 26 mg/L Cr from CrEDTA or Co from CoEDTA was incubated in a 26-mL reaction volume containing 20 mL of Goering and Van Soest medium without tryptone, 3 mL of CoEDTA odecrease as RedSol increased. Wavescans from λ = 330 to 700 nm showed CrEDTA retaining its characteristic 2-peak pattern as RedSol increased, whereas CoEDTA curves deformed entirely. learn more We conclude that CoEDTA is not a stable, inert digesta marker under reducing conditions achievable in the rumen and is therefore unsuitable for use in studies with ruminants. Reexamination of the suitability of available liquid digesta markers is advised.During weaning, methionine (Met) supply decreases as liquid feed intake is reduced and ruminal function is developing. During this transition, the calf starter should both promote ruminal development and provide adequate nutrients post-ruminally. In mature ruminants, rumen-protected Met (RPM) and the Met analogs, 2-hydroxy-4-(methylthio)-butanoic acid (HMTBa) and HMTBa isopropyl ester (HMBi), are used to increase Met supply, stimulate ruminal fermentation, or exert both effects, respectively. To evaluate the effects of these forms of Met on calf performance during development of ruminal function, 74 Holstein calves were raised until 91 d of age, in 2 enrollment periods. Calves were individually housed from birth and, at 14 d of age, balanced for sex and randomly assigned to receive a starter with no added Met (CTRL, n = 20) or one supplemented with RPM (Smartamine M, Adisseo USA Inc., Alpharetta, GA; n = 16), HMTBa (RumenSmart, Adisseo; n = 19), or HMBi (MetaSmart, Adisseo; n = 19). Milk replacer [28% crude ps studies, exacerbating the level of HMTBa ingested. No differences were observed in stature, feed efficiency, or non-AA plasma measurements among groups. These results demonstrate that RPM and HMBi are effective sources of metabolizable Met; however, Met was apparently not limiting calves fed the basal diet in this study. The increased feed intake observed with the inclusion of HMBi in the starter during the weaning and early postweaning period might be mediated by its metabolism in the rumen, and further research is needed to determine the mechanisms involved.The objective of this study was to investigate the economic performance of 2 genetic groups (GG) of Holstein-Friesian dairy cows of divergent Economic Breeding Index (EBI), evaluated within 3 contrasting spring-calving pasture-based feeding treatments (FT). The study was a simulated economic appraisal, using the Moorepark Dairy Systems Model, a stochastic budgetary simulation model integrating biological data obtained from a 4-yr experiment conducted from 2013 to 2016. The 2 divergent GG were (1) high EBI representative of the top 5% nationally (elite) and (2) EBI representative of the national average (NA). The 3 FT were reflective of slight restriction to generous feeding. The elite GG had the lowest replacement rate, and therefore had lower replacement costs and an older and more productive parity structure. The elite GG consistently had higher sales of milk (on average +3% or +18,370 kg of milk) and milk solids (milk fat plus protein yield; +8.7% or +4,520 kg) compared with the NA GG across the 3 FT scenarios.