Production, metabolism, and follicular dynamics in multiparous dairy cows fed diets providing different amounts of metabolizable protein prepartum and postpartum.

Our objectives were (1) to determine whether increasing metabolizable protein (MP) supply above requirements in late-gestation cows would benefit health, milk production, and reproduction; (2) to determine whether an increased supply of MP postpartum affects production; and (3) to determine whether supply of MP prepartum interacts with MP supply postpartum. Pregnant nonlactating cows (n = 60) blocked by expected parturition date were assigned to 1 of 3 prepartum diets from 21 d prepartum to parturition: 12% crude protein (CP) soybean meal (SBM) supplement (LSB); 15% CP SBM supplement (HSB); and 15% CP SBM plus animal-marine protein supplement (HMP). Diets were formulated to supply an estimated 924, 988, and 1,111 g/d of MP, respectively, at 11.5 kg of dry matter intake (DMI). After parturition, cows received diets containing 18% CP, either from SBM (SB) or SBM plus animal-marine protein (AMP) supplements, that provided 2,056 (SB) or 2,293 g/d (AMP) of MP at 21 kg of DMI; thus, treatments were in a 3 × 2 factorial arrangement. Milk production and DMI were recorded for 63 d postpartum. Prepartum DMI was lower at wk -3 for cows fed LSB compared with those fed HSB or HMP. Postpartum DMI did not differ significantly between cows fed SB and those fed AMP (20.8 vs. 19.6 kg/d). Milk production did not differ due to prepartum diets or postpartum diets. Milk fat and protein percentages were not affected by prepartum or postpartum diets. Cows fed AMP postpartum tended to produce more milk fat, but 4% fat-corrected milk (FCM) did not differ from SB-supplemented cows (33.6 kg/d vs. 32.2 kg/d). Gross feed efficiency (FCM/DMI) was greater for cows fed AMP postpartum (1.82 vs. 1.68). Prepartum concentrations of urea N in plasma were lower for LSB than for HSB and HMP, and HSB was greater than HMP. Postpartum concentrations of nonesterified fatty acids and ß-hydroxybutyrate were greater for cows fed AMP postpartum than for those fed SB. Postpartum urea N was higher for SB than for AMP (14.4 vs. 12.5 mg/dL). Concentration of total protein in plasma was greater postpartum for cows fed HSB or HMP prepartum than for those fed LSB, and was greater postpartum for cows fed AMP than for those fed SB. Hepatic concentrations of total lipids and triglyceride did not differ among treatments. Hepatic glycogen was greater postpartum for cows fed SB postpartum. Feeding HSB or HMP increased the number of follicles 6 to 9 mm in diameter compared with LSB. The size of the largest follicle was increased by HMP compared with HSB. In conclusion, increasing the amount of MP fed to cows during the last 21 d prepartum did not affect milk production or BCS but increased plasma total protein concentration. Follicular dynamics were improved by increasing the amount of MP prepartum. Feeding HMP prepartum improved follicular dynamics prepartum and increased milk fat yield in wk 1. Feeding AMP postpartum increased efficiency of FCM production and plasma total protein. We found few interactions between prepartum and postpartum MP supply.

Food value of red tide (Gonyaulax polyedra).

Two harvests of ocean-growing red tide, comprised mainly of Gonyaulax polyedra, were evaluated in limited trials of rat feeding. The protein of red tide (25 to 30 percent, dry basis) supported growth satisfactorily. The essential amino acid composition of the protein closely resembles that of casein, the major protein of milk. As a marine resource, plankton represents a challenge for research.

Pathogenic carrier rate in diabetes mellitus.

Thirty patients with diabetes mellitus were compared in terms of carrier rate of four pathogens to a group of matched controls. The diabetics were found to have a significantly increased carrier rate (p less than 0.005). When the blood glucose level was used as an indicator of control an increased rate was found in those with the poorest control (p less than 0.0005). An increased carriage of Candida albicans might be attributed to hypovitaminosis A and its effect on mucous membranes and the skin. Ten percent of diabetics were carrying beta-hemolytic group A streptococci. In a future study these patients will be checked for persistence of these organisms as well as to see if the strains are of the nephritogenic type. A significantly increased carriage rate in diabetes of coagulase-positive Staphylococcus aureus was found. These findings suggest an additional risk factor in the outpatient diabetic population.

An update on reactive hypoglycemia.

Reactive hypoglycemia usually occurs in response to a carbohydrate load, rather than presenting as fasting hypoglycemia. The clinical picture may be that of excess circulating epinephrine or decreased cerebral cortical function. The principal causes are alimentary, "functional" (a debatable diagnosis) or early diabetes mellitus. The diagnosis is confirmed by simultaneous serum insulin and blood glucose levels and a five-hour oral glucose tolerance test. Simple management regimens are tailored to each type of hypoglycemia.

Addison's disease secondary to North American blastomycosis.

Reported is the fifth known case of Addison's disease due to adrenal involvement by North American blastomycosis (Blastomyces dermatitidis infection). The fact that amphotericin B therapy precipitated an addisonian crisis suggests that patients with disseminated blastomycosis should have their adrenal function and reserve evaluated before undergoing systemic chemotherapy.

Outpatient self-management of severe diabetes.

We initiated a five-point program to decrease acute and chronic complications in 25 unstable, insulin-dependent diabetics (study group A). The five points were home monitoring of blood glucose, use of multiple injections of a complex insulin mixture, strict dietary control with high protein feedings, carbohydrate loading before exercise, and use of purified insulin preparations. There was an 80% decline in detected hypoglycemic reactions over the succeeding six months. The hospitalization rate fell from 3.4 times per year to 0.64 times a year. An additional five extremely unstable diabetic patients (study group B) were treated with the same program except for the use of an open-loop continuous infusion system for insulin. Although results in this group were favorable in terms of improving glucose homeostasis, mechanical, physical, and psychologic problems can limit usefulness current devices.

Response to labeled precursor amino acids, varying cell density, and graded amino acid complement for protein synthesis in mammary cell culture.

Effect of labeled precursor amino acids, varying cell densities, graded quantities of amino acid complement, and incubation environment on milk protein synthesis were studied with cultures of mammary cells isolated from Sprague Dawley rats. The essential amino acid complement of Eagle's minimal essential medium was used as base. Protein synthesis, measured by incorporation of labeled lysine, leucine, and phenylalanine, was affected by source of label for the "beta-lactoglobulin fraction" and beta-casein but not alpha-lactalbumin. Cell numbers between 6 X 106 and 6 X 107 per 5 ml of culture medium did not significantly alter rates of synthesis. Increasing amounts of amino acid concentration from one to three-fold increased synthesis of "beta-lactoglobulin fraction" and alpha-lactalbumin regardless of cell population. Response to addition of essential amino acid for "beta-lactoglobulin fraction" synthesis was linear over one to five-fold with 30.9 mug/flask per fold addition (linear regression coefficient; squared correlation = .91). Results were similar for beta-casein synthesis; 25.9 mug/flask and squared correlation = .91. No culturing effects between carbon dioxide and conventional incubators were significant.

Increased serum calcium levels induced by furosemide.

Thirteen male patients were treated with furosemide at a dosage of 40 mg by mouth daily for three weeks. Atomic absorption serum calcium determinations before and after treatment revealed a consistent elevation of the serum calcium level. It is suggested that at low dosages, furosemide is likely to raise the serum calcium level, while at daily dosages greater than 60 mg given orally, furosemide may depress the serum calcium level because of urinary losses.

Long-term application of intermittent urethral catheterization to the neurogenic bladder of diabetes mellitus.

Two case reports are presented of patients who utilized long-term intermittent urethral catheterization as a primary management of diabetic neurogenic bladder. The results indicate fewer complications than with a continuous indwelling Foley catheter. Further, only two urinary tract infections occurred during 39 months of patients utilization. No renal or vesical lithiasis occurred. One patient had a remission and went on drug therapy alone. The other patient may use this technique indefinitely.

Limiting amino acids for milk protein synthesis by bovine mammary cells in culture.

Experiments are presented to determine the effect of labeled precursor amino acid on synthesis of beta-lactoglobulin and beta-casein and to identify the most limiting amino acids in Eagle's minimal essential medium for synthesis of milk protein. Protein synthesis was measured by incorporation of carbon-14 labeled amino acids into milk protein from bovine mammary cell culture. Mammary tissue from 13 Holsteins (12.7 kg milk/day) was dispersed and cultured for 18 h. In Experiment 1, three replications (cows) with three amino acid mixtures, utilizing labeled lysine or leucine as the marker amino acid, showed that labeled lysine overestimated the effect of medium lysine, and labeled leucine overstimated the effect of leucine on beta-lactoglobulin and beta-casein synthesis. Subsequently Experiment 2 utilized 10 replications (cows) to determine the effect of a three-fold increase of each of 13 amino acids in Eagle's medium. Increased threonine or methionine improved beta-lactoglobulin synthesis and cystine increased beta-casein. Second and third best response in beta-casein were from addition of methionine and threonine. Combined analysis from 10 cows and two protein responses by multivariate procedures identified, in order of decreasing magnitude, cystine, threonine, and methionine as limiting amino acids in the dispersed cell culture.

Diabetic neuropathic cachexia.

A case of diabetic neuropathic cachexia is presented. This unusual syndrome within the broad group of diabetic neuropathies is characterized by extreme loss of body mass and severe neuropathic pain. The loss of body weight is unassociated with glycosuria or ketoacidosis. Initially, the patient may present a confusing picture suggestive of carcinomatous neuropathy.

Feeding value and nutrient preservation of high moisture corn ensiled in conventional silos forlactating dairy cows.

Sixty-one Holstein cows were used at varying stages of lactation to evaluate the feeding value of high moisture shelled corn ensiled in conventional silos. Control rations consisted of comparable amounts of conventional shelled corn dried in commercial drying facilities. Cows fed high moisture corn produced milk of higher fat content (3.09 versus 2.64%) and greater quantities of fat (.73 versus .64 kg) while they consumed less concentrate (9.28 versus 9.84 kg), resulting in the crude fiber content of the dry matter being 14.60% compared to 13.82% for control cows. Covariate adjustment of treatment means to equal intake of crude fiber eliminated differences above. Milk, 4% fat corrected milk, silage, total dry matter intake, and rumen volatile fatty acids were not significantly different between groups. Dry matter recovery following the ensiling process was 96.0 plus or minus 1.9% with 3.0 plus or minus 1.1% classified as spoiled corn, resulting in a total of 7% loss. Recoveries of all proximate constituents were similar to dry matter with the exception of ash (82.4%). Costs of the two systems were evaluated for varying corn prices and moisture.

Optimum amino acid complement for protein synthesis by rat mammary cells in tissue culture.

The amino acid requirement of rat mammary cells for milk protein synthesis was investigated in dispersed cell culture. A three-dimensional central composite design utilizing three variables (X1 = lysine; X2= methionine, valine, and arginine; X3 = isoleucine, tryptophan, threonine, phenylalanine, and histidine) at five concentrations each, was duplicated twice with mammary cells from lactating Sprague-Dawley rats. The optimum combination of amino acids for maximum milk protein synthesis from multiple regression models was X1 15.0-, X2 4.5-, and X3 1.5-fold their quantities in Eagle's minimal essential medium with leucine, tyrosine, cystine, and glutamine at the base 1-fold in the medium.

Limiting amino acid for protein synthesis with mammary cells in tissue culture.

To identify the limiting amino acid in the minimal essential medium as published by Eagle (Science 130:432, 1959) for milk protein synthesis in rat mammary cells in tissue culture, two different experimental approaches were used. The first study involved the reduction of amino acids singly from the total amino acid complement of the medium for milk protein synthesis. The second study was to investigate the effect on milk protein synthesis of single amino acid addition to the basic complement of amino acids. Order of limiting amino acids was lysine (first) and possible methionine, valine, or arginine (second).

Extracellular amino acid effects on milk protein synthesis and intracellular amino acid pools with bovine mammary cells in culture.

Increases in free intracellular amino acids are associated with increased protein synthesis. Responses in synthesis of beta-casein and beta-lactoglobulin and of intracellular amino acid pools to graded concentrations of amino acids in the medium were observed. Mammary tissue from two Holstein cows was dispersed and cultured for 18 h with Eagle's minimal essential medium containing 1, 3, 5, or 7 times the basic concentration of amino acids. Synthesis of beta-casein and beta-lactoglobulin increased with concentration of amino acids in the medium. Intracellular pools of amino acids not provided by the medium (serine, proline, alanine, glycine, glutamic acid, ornithine) generally decreased with increased concentrations of amino acids in the medium, the exception being ornithine which increased with extracellular amino acids. Lysine, histidine, tyrosine, leucine, valine, phenylalanine, isoleucine, arginine, and threonine intracellular pools increased with increased amino acids in medium. Intracellular cystine responded with a small linear increase to increased amino acids in the medium, while intracellular tryptophan and methionine did not respond, indicating potential limitations from these amino acids.