Increasing the prepartum dose of rumen-protected choline: Effects of maternal choline supplementation on growth, feed efficiency, and metabolism in Holstein and Holstein × Angus calves.

Feeding pregnant cows rumen-protected choline (RPC) may have the potential to affect the growth and health of offspring, but little is known about the optimal dose, or the potential mechanisms of action. The objectives of this experiment were to 1) determine if increasing RPC supplementation during late gestation in multiparous Holstein cows would improve calf growth and 2) determine if maternal choline supplementation alters global DNA methylation patterns. Pregnant multiparous Holstein cows (n = 116) were randomly assigned to diets targeting 0g choline ion (0.0 ± 0.000 choline ion, %DM, control; CTL), 15g of choline ion (recommended dose; RD) from an established RPC product (0.10 ± 0.004 choline ion, %DM, RPC1RD; ReaShure, Balchem Corp.; positive control), or 15g (0.09 ± 0.004 choline ion, %DM, RPC2RD) or 22g (0.13 ± 0.005 choline ion, %DM, high dose; RPC2HD) of choline ion from a concentrated RPC prototype (RPC2; Balchem Corp.). Treatments were mixed into a total mixed ration and cows had ad libitum access via a roughage intake control system (Hokofarm Group, Marknesse, Netherlands). All female Holstein (n = 49) and Holstein × Angus calves (male, n = 18; female, n = 30) were enrolled and fed colostrum from a cow within the same treatment. Holstein calves and Holstein × Angus calves were fed an accelerated and traditional milk replacer program, respectively, and offered ad libitum access to calf starter. Jugular vein blood samples were collected, and body weight was measured at 7, 14, 28, 42, and 56 d of age. Categorical treatment and continuous effects of actual prepartum maternal choline ion intake were analyzed using mixed effect models. An interaction of treatment with sex, nested within breed, resulted in any choline treatment increasing the proportion of methylated whole blood DNA in male, but not female calves. Although 37% of Holstein calves across all treatments experienced abomasal bloat, no evidence for differences in health measurements (signs of respiratory disease and fecal consistency) were observed across treatments. During the first 2 wk of life in Holstein calves, RPC2HD tended to increase average daily gain (ADG) and feed efficiency (FE) compared with CTL and increasing maternal choline ion intake linearly increased ADG and FE. Maternal choline supplementation increased plasma glucose compared with CTL, while increasing serum insulin-like growth factor-1 and decreasing serum lipopolysaccharide binding protein at 7 d of age in Holstein calves. In Holstein × Angus calves, the effect of treatment on ADG tended to interact with sex: in males, RPC2HD increased ADG after 2 wk of life compared with CTL, without evidence of a treatment effect in female calves. Increasing maternal choline ion intake linearly increased ADG after 2 wk of age in male Holstein × Angus calves, while quadratically increasing FE in both sexes. Altered global DNA methylation patterns in male Holstein × Angus calves, and changes in blood metabolites in Holstein calves, provide 2 potential mechanisms for observed improvements in calf growth. Continuous treatment models demonstrated that the effects of maternal choline supplementation are sensitive to the amount of maternal choline ion intake, with greater benefit to calves observed at higher maternal intakes.

Increasing the prepartum dose of rumen-protected choline: Effects on milk production and metabolism in high-producing Holstein dairy cows.

Peripartum rumen-protected choline (RPC) supplementation is beneficial for cow health and production, yet the optimal dose is unknown. In vivo and in vitro supplementation of choline modulates hepatic lipid, glucose, and methyl donor metabolism. The objective of this experiment was to determine the effects of increasing the dose of prepartum RPC supplementation on milk production and blood biomarkers. Pregnant multiparous Holstein cows (n = 116) were randomly assigned to one of 4 prepartum choline treatments that were fed from -21 d relative to calving (DRTC) until calving. From calving until +21 DRTC, cows were fed diets targeting 0 g/d choline ion (control, CTL) or the recommended dose (15 g/d choline ion; RD) of the same RPC product that they were fed prepartum. The resulting treatments targeted: (1) 0 g/d pre- and postpartum [0.0 ± 0.000 choline ion, percent of dry matter (%DM); CTL]; (2) 15 g/d pre- and postpartum of choline ion from an established product (prepartum: 0.10 ± 0.004 choline ion, %DM; postpartum: 0.05 ± 0.004 choline ion, %DM; ReaShure, Balchem Corp.; RPC1RD▸RD); (3) 15 g/d pre- and postpartum of choline ion from a concentrated RPC prototype (prepartum: 0.09 ± 0.004 choline ion, %DM; postpartum: 0.05 ± 0.003 choline ion, %DM; RPC2, Balchem Corp.; RPC2RD▸RD); or (4) 22 g/d prepartum and 15 g/d postpartum from RPC2 [prepartum: 0.13 ± 0.005 choline ion, %DM; postpartum: 0.05 ± 0.003 choline ion, %DM; high prepartum dose (HD), RPC2HD▸RD]. Treatments were mixed into a total mixed ration, and cows had ad libitum access via a roughage intake control system (Hokofarm Group). From calving to +21 DRTC, all cows were fed a common base diet and treatments were mixed into the total mixed ration (supplementation period, SP). Thereafter, all cows were fed a common diet (0 g/d choline ion) until +100 DRTC (postsupplementation period, postSP). Milk yield was recorded daily and composition analyzed weekly. Blood samples were obtained via tail vessel upon enrollment, approximately every other day from -7 to +21 DRTC, and at +56 and +100 DRTC. Feeding any RPC treatment reduced prepartum dry matter intake compared with CTL. During the SP, no evidence for a treatment effect on energy-corrected milk (ECM) yield was found, but during the postSP, RPC1RD▸RD and RPC2RD▸RD treatments tended to increase ECM, protein, and fat yields. During the postSP, the RPC1RD▸RD and RPC2RD▸RD treatments tended to increase, and RPC2HD▸RD increased, the de novo proportion of total milk fatty acids. During the early lactation SP, RPC2HD▸RD tended to increase plasma fatty acids and ß-hydroxybutyrate concentrations, and RPC1RD▸RD and RPC2RD▸RD reduced blood urea nitrogen concentrations compared with CTL. The RPC2HD▸RD treatment reduced early lactation serum lipopolysaccharide binding protein compared with CTL. Overall, peripartum RPC supplementation at the recommended dose tended to increase ECM yield postSP, but no evidence was seen of an additional benefit on milk production with an increased prepartum dose of choline ion. The effects of RPC on metabolic and inflammatory biomarkers support the potential for RPC supplementation to affect transition cow metabolism and health and may support the production gains observed.

Long-term neurostimulation of skeletal muscle: its potential for a tether-free biologic cardiac assist device.

Skeletal muscle has a tremendous capacity to adapt. This adaptive phenomenon is seen perhaps to the greatest extent when skeletal muscle is subjected to chronic low frequency stimulation via the motor nerve. There is a decrease in glycolytic enzymes and an increase in oxidative enzymes, as well as a change in the contractile proteins and an increase in the mitochondrial volume fraction of the muscle fiber. These adaptive changes result in a muscle that is considerably more fatigue-resistant. Specifically herein, we report on a pneumatic aortic counterpulsator device powered by skeletal muscle. These muscle pumps functioned continuously and pumped blood effectively in tether-free animals for several weeks.

Effect of the dural application of Zenker's solution on the feline brain.

Zenker's solution is a tissue fixative containing mercuric chloride, potassium bichromate, sodium sulfate, and glacial acetic acid. In 1956, Anderson and Johnson reported its use in clinical neurosurgery. They applied the solution to the exposed dura after craniectomy. Delayed bone formation was thought to be due to the suppression of the osteoblastic activity of the outer layer of the dura. The fixative has since become a well-accepted adjuvant to the treatment of craniosynostosis. In 1972, Pawl and Sugar reported postoperative seizures in 6 of 34 patients treated with this solution. They assumed that the fixative penetrated the dura and irritated or damaged the cortex. To clarify the effect of Zenker's solution on the underlying brain, we performed bilateral parasagittal craniectomies in a group of kittens and adult cats. Zenker's solution was applied to one side and the other side served as a control. The animals were killed after periods varying from 24 hours to 2 months. We then examined the cortex under the craniectomies. There was immediate breakdown of the blood-brain barrier, as evidenced by the penetration of intravenous Evans blue. In the postoperative period investigated, an inflammatory response in the underlying brain with thickening of the arachnoid occurred. The results and implications of these experiments are presented. (Neurosurgery, 6: 45--48, 1980)

Formation of Ca HPO4-2H2O from enamel mineral and its relationship to caries mechanism.

Tooth enamel, when treated with dilute H3P94 solutions, dissolved incongruently with formation of large CaHPO4-2HO2O crystals. Equilibrated solutions were saturated with respect to Ca5(PO4)3OH, probably an impure, defective apatite. The CaHPO4-2H2O crystals formed at considerably higher pH values than expected becuase of enhanced solubility of the apatitic phase in enamel. Pyolysis of carious enamel revealed the presence of acidic calcium phosphate presumed to be CaHPO4-2H2O.

Formation of CaHPO4-2H2O in tooth enamel as an intermediate product in topical fluoride treatments.

Significant amounts of CaHPO4-2H2O (DCPD) were deposited in tooth enamel by pretreatment with a solution saturated with respect to DCPD. When these enamel samples were treated with a given fluoride solution, the fluoride uptake increased with increasing amounts of DCPD produced by the pretreatment. The interactions between enamel and acidic solutions to yield DCPD can be understood as dissolution-precipitation reactions and analyzed through the use of solubility phase diagrams.