Lee C.,Pennsylvania State University |
Hristov A.N.,Pennsylvania State University |
Cassidy T.W.,Pennsylvania State University |
Heyler K.S.,Pennsylvania State University |
And 5 more authors.
Journal of Dairy Science | Year: 2012
The objective of this experiment was to evaluate the effect of supplementing a metabolizable protein (MP)-deficient diet with rumen-protected (RP) Lys, Met, and specifically His on dairy cow performance. The experiment was conducted for 12. wk with 48. Holstein cows. Following a 2-wk covariate period, cows were blocked by DIM and milk yield and randomly assigned to 1 of 4 diets, based on corn silage and alfalfa haylage: control, MP-adequate diet (ADMP; MP balance: +9 g/d); MP-deficient diet (DMP; MP balance: -317. g/d); DMP supplemented with RPLys (AminoShure-L, Balchem Corp., New Hampton, NY) and RPMet (Mepron; Evonik Industries AG, Hanau, Germany; DMPLM); and DMPLM supplemented with an experimental RPHis preparation (DMPLMH). The analyzed crude protein content of the ADMP and DMP diets was 15.7 and 13.5 to 13.6%, respectively. The apparent total-tract digestibility of all measured nutrients, plasma urea-N, and urinary N excretion were decreased by the DMP diets compared with ADMP. Milk N secretion as a proportion of N intake was greater for the DMP diets compared with ADMP. Compared with ADMP, dry matter intake (DMI) tended to be lower for DMP, but was similar for DMPLM and DMPLMH (24.5, 23.0, 23.7, and 24.3. kg/d, respectively). Milk yield was decreased by DMP (35.2. kg/d), but was similar to ADMP (38.8. kg/d) for DMPLM and DMPLMH (36.9 and 38.5. kg/d, respectively), paralleling the trend in DMI. The National Research Council 2001. model underpredicted milk yield of the DMP cows by an average (±SE) of 10.3 ± 0.75. kg/d. Milk fat and true protein content did not differ among treatments, but milk protein yield was increased by DMPLM and DMPLMH compared with DMP and was not different from ADMP. Plasma essential amino acids (AA), Lys, and His were lower for DMP compared with ADMP. Supplementation of the DMP diets with RP AA increased plasma Lys, Met, and His. In conclusion, MP deficiency, approximately 15% below the National Research Council requirements from 2001, decreased DMI and milk yield in dairy cows. Supplementation of the MP-deficient diet with RPLys and RPMet diminished the difference in DMI and milk yield compared with ADMP and additional supplementation with RPHis eliminated it. As total-tract fiber digestibility was decreased with the DMP diets, but DMI tended to increase with RP AA supplementation, we propose that, similar to monogastric species, AA play a role in DMI regulation in dairy cows. Our data implicate His as a limiting AA in high-producing dairy cows fed corn silage- and alfalfa haylage-based diets, deficient in MP. The MP-deficient diets clearly increased milk N efficiency and decreased dramatically urinary N losses. © 2012 American Dairy Science Association.
Stamey J.A.,Virginia Polytechnic Institute and State University |
Shepherd D.M.,Virginia Polytechnic Institute and State University |
de Veth M.J.,Balchem Corporation |
Corl B.A.,Virginia Polytechnic Institute and State University
Journal of Dairy Science | Year: 2012
Fish oil is used as a ration additive to provide n-3 fatty acids to dairy cows. Fish do not synthesize n-3 fatty acids; they must consume microscopic algae or other algae-consuming fish. New technology allows for the production of algal biomass for use as a ration supplement for dairy cattle. Lipid encapsulation of the algal biomass protects n-3 fatty acids from biohydrogenation in the rumen and allows them to be available for absorption and utilization in the small intestine. Our objective was to examine the use of algal products as a source for n-3 fatty acids in milk. Four mid-lactation Holsteins were assigned to a 4 × 4 Latin square design. Their rations were supplemented with 1× or 0.5× rumen-protected (RP) algal biomass supplement, 1× RP algal oil supplement, or no supplement for 7 d. Supplements were lipid encapsulated (Balchem Corp., New Hampton, NY). The 1× supplements provided 29. g/d of docosahexaenoic acid (DHA), and 0.5× provided half of this amount. Treatments were analyzed by orthogonal contrasts. Supplementing dairy rations with rumen-protected algal products did not affect feed intake, milk yield, or milk component yield. Short- and medium-chain fatty acid yields in milk were not influenced by supplements. Both 0.5× and 1× RP algae supplements increased daily milk fat yield of DHA (0.5 and 0.6 ± 0.10. g/d, respectively) compared with 1× RP oil (0.3 ± 0.10. g/d), but all supplements resulted in milk fat yields greater than that of the control (0.1 ± 0.10. g/d). Yield of trans-18:1 fatty acids in milk fat was also increased by supplementation. Trans-11 18:1 yield (13, 20, 27, and 15 ± 3.0. g/d for control, 0.5× RP algae, 1× RP algae, and 1× RP oil, respectively) was greater for supplements than for control. Concentration of DHA in the plasma lipid fraction on d 7 showed that the DHA concentration was greatest in plasma phospholipid. Rumen-protected algal biomass provided better DHA yield than algal oil. Feeding lipid-encapsulated algae supplements may increase n-3 content in milk fat without adversely affecting milk fat yield; however, preferential esterification of DHA into plasma phospholipid may limit its incorporation into milk fat. © 2012 American Dairy Science Association.
Goselink R.M.A.,Wageningen UR Livestock Research |
van Baal J.,Wageningen UR Livestock Research |
Widjaja H.C.A.,Wageningen UR Livestock Research |
Dekker R.A.,Wageningen UR Livestock Research |
And 3 more authors.
Journal of Dairy Science | Year: 2013
We previously reported that supplementation of rumen-protected choline (RPC) reduces the hepatic triacylglycerol concentration in periparturient dairy cows during early lactation. Here, we investigated the effect of RPC on the transcript levels of lipid metabolism-related genes in liver and adipose tissue biopsies, taken at wk -3, 1, 3, and 6 after calving, to elucidate the mechanisms underlying this RPC-induced reduction of hepatic lipidosis. Sixteen multiparous cows were blocked into 8 pairs and randomly allocated to either 1 of 2 treatments, with or without RPC. Treatments were applied from 3. wk before to 6. wk after calving. Both groups received a basal diet and concentrate mixture. One group received RPC supplementation, resulting in an intake of 14.4. g of choline per day, whereas controls received an isoenergetic mixture of palm oil and additional soybean meal. Liver and adipose tissue biopsies were taken at wk -3, 1, 3, and 6 to determine the mRNA abundance of 18 key genes involved in liver and adipose tissue lipid and energy metabolism. Milk samples were collected in wk 1, 2, 3, and 6 postpartum for analysis of milk fatty acid (FA) composition. The RPC-induced reduction in hepatic lipidosis could not be attributed to altered lipolysis in adipose tissue, as no treatment effect was observed on the expression of peroxisome proliferator-activated receptor γ, lipoprotein lipase, or FA synthase in adipose tissue, or on the milk FA composition. Rumen-protected choline supplementation increased the expression of FA transport protein 5 and carnitine transporter SLC22A5 in the liver, suggesting an increase in the capacity of FA uptake and intracellular transport, but no treatment effect was observed on carnitine palmitoyl transferase 1A, transporting long-chain FA into mitochondria. In the same organ, RPC appeared to promote apolipoprotein B-containing lipoprotein assembly, as shown by elevated microsomal triglyceride transfer protein expression and apolipoprotein B100 expression. Cows supplemented with RPC displayed elevated levels of glucose transporter 2 mRNA and a reduced peak in pyruvate carboxylase mRNA immediately after calving, showing that supplementation also resulted in improved carbohydrate metabolism. The results from this study suggest that RPC supplementation reduces liver triacylglycerol by improved FA processing and very-low-density lipoprotein synthesis, and RPC also benefits hepatic carbohydrate metabolism. © 2013 American Dairy Science Association.
Sinclair L.A.,Harper Adams University College |
Weerasinghe W.M.P.B.,Harper Adams University College |
Weerasinghe W.M.P.B.,Veterinary Research Institute |
Wilkinson R.G.,Harper Adams University College |
And 3 more authors.
Journal of Nutrition | Year: 2010
Conjugated linoleic acids (CLA) have been demonstrated to be a potent inhibitor of milk fat synthesis in ruminants, but effects on carcass composition and organ weight are unknown. Our objectives in this experiment were to determine the dose response of ruminally protected CLA on the performance, organ weight, and fatty acid (FA) composition of early lactation dairy ewes. Twenty-four multiparous dairy ewes were fed a basal diet for 10 wk that was supplemented with a lipid-encapsulated CLA at 1 of 3 levels: no CLA (control, CON), low CLA (L-CLA), or high CLA (H-CLA) to supply 0, 1.5, or 3.8 g/d, respectively, of both trans-10, cis-12 and cis-9, trans-11 CLA. Dry matter intake was not affected (P > 0.05) by dietary treatment. Ewes fed H-CLA had a 13% higher milk yield compared with those receiving either CON or L-CLA. Compared with CON, milk fat yield (g/d) was 14 and 24% lower in ewes fed L-CLA or H-CLA, respectively. Supplementing ewes with CLA did not affect carcass or organ weights, carcass composition, or organ FA content. Compared with ewes receiving the CON diet, CLA supplementation had little effect on the FA composition of the Longissimus dorsi, although cis-9, trans-11 and trans-10, cis-12 CLA were increased in ewes receiving H-CLA. The current findings are consistent with the view that the energy spared by the CLA reduction in milk fat content was mainly partitioned to milk yield and there was no evidence of organ hypertrophy or liver steatosis. © 2010 American Society for Nutrition.
Thomas P.C.,University of Maryland University College |
Cipriano B.H.,University of Maryland University College |
Cipriano B.H.,Balchem Corporation |
Raghavan S.R.,University of Maryland University College
Soft Matter | Year: 2011
We describe the remarkable capabilities of polymer-nanoparticle hybrids for cation binding and separation. The materials investigated here are hydrogels of N-isopropylacrylamide (NIPA) prepared using nanoparticles of the synthetic clay, Laponite® RD, as the crosslinkers. When immersed into an aqueous solution containing a cationic amine-based dye (methylene blue), the gel rapidly soaks up the dye from solution. Additionally, the gel is able to selectively extract the above cationic dye from a mixture of cationic and anionic dyes. These ion-exchange properties are driven by the strong binding affinity of certain cations for the anionic surfaces of the clay nanoparticles within the gel matrix. A comparison of the nanostructured gel with a typical cation-exchange resin (polystyrene-sulfonate) shows that the former is quicker and more efficient at extracting cationic species from solution. We also show that the solute adsorbed within the gel can be further concentrated by exploiting the shrinking property of NIPA gels when heated. Additionally, we demonstrate the disassembly of Laponite-crosslinked gels by exposure to an organic solvent or a hydrophilic oligomer, which allows the adsorbed solute to be released and thereby recovered. © 2011 The Royal Society of Chemistry.