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Biomedical subjects

L E Chase

Publications and source records attributed to L E Chase.

32 records · Page 2Linked to original sources
PubMed1984

Effects of dietary chloride restriction in lactating dairy cows.

Early-lactation Holstein cows fed a corn silage-based diet low in chloride and supplemented with sodium bicarbonate were observed for clinical, metabolic, and production alterations over the course of 8 to 11 weeks. In 3 of the more severely affected cows, metabolic derangements included a rapidly developing primary hypochloremic, secondary hypokalemic and hyponatremic metabolic alkalosis, and hemoconcentration. Clinical signs included severe hypophagia, weight loss, muscle weakness, hypogalactia, dehydration, constipation, cardiopulmonary depression, and a depraved appetite. It was concluded that the rapid progression of these derangements, apart from any anatomic abnormalities or infectious causes, emphasizes the need for rapid assessment and therapeutic intervention in primary imbalance associated with body chloride depletion and metabolic alkalosis.

Alkalosis↗
PubMed1984

Restricted dietary chloride with sodium bicarbonate supplementation for Holstein cows in early lactation.

Over 2 wk, beginning 3 wk postpartum, daily changes of feed and water intake and milk production and composition were monitored in 25 cows allotted randomly among four dietary treatment groups differing in sodium chloride, sodium bicarbonate, and ad libitum supplementation by salt block. The basic complete diet was 54% corn silage, 27% shelled corn, and 16% soybean meal, dry basis. The four dietary treatments were control, .42% chloride; low, .10% chloride; low plus salt block, complete ration same as low with ad libitum salt block consumption; and control plus .7% sodium bicarbonate. Differences were consistently significant only for electrolyte concentrations in blood serum, urine, and feces of cows fed the low diet. In blood serum, chloride declined from 96.4 +/- 3.5 to 83.4 +/- 4.5 meq/liter, and serum total carbon dioxide rose from 28.4 +/- 1.9 to 36.9 +/- 2.6 meq/liter. Anion gap increased from 19.0 +/- 2.9 to a high of 23.4 +/- 3.5 meq/liter in blood serum at day 11. Metabolic derangements of cows fed the low diet may be summarized as subclinical primary hypochloremic, secondary hypokalemic metabolic alkalosis.

Animals↗
PubMed1984

Nutritional chloride deficiency in early lactation Holstein cows.

Beginning 1 wk postpartum, weekly changes of feed and water intake, body weight, milk production, and electrolyte concentrations in serum, saliva, urine, milk, and feces were observed for 8 to 11 wk. Three dietary treatments differing in sodium chloride and sodium bicarbonate supplementation but containing equal sodium concentrations were used. Dietary chloride percents were low .10%, medium .27%, and high .45%. Consistently changes were significant for feed and water intake, body weight, milk production, and electrolyte concentrations in serum, urine, milk, and feces of cows fed the low chloride diet. By wk 8, body weight had declined from 575.0 +/- 56.7 to 476.7 +/- 54.3 kg, and daily milk production decreased from a peak of 27.7 +/- 2.4 to 19.2 +/- 3.9 kg for cows fed the low chloride diet. Serum chloride decreased from 106.0 +/- 2.8 to 75.5 +/- 6.7 meq/liter during the same time. Cows on the low chloride diet developed clinical signs of a deficiency characterized by depraved appetite, lethargy, hypophagia, emaciation, hypogalactiae, constipation, and cardiovascular depression. Metabolic alterations could be summarized as a severe primary hypochloremic, secondary hypokalemic, metabolic alkalosis.

Animals↗
PubMed1980

Increasing selenium in bovine blood by feed supplements or selenium injections.

A study was made of the relative effectiveness of including various feed supplements or selenium injections on increasing the blood level of selenium in pregnant Holstein cows. The dietary treatment included the addition of soft coal fly ash, western grown grains, high selenium sweet clover or sodium selenite to the rations. Whereas each of the treatments caused a progressive increase in blood selenium the addition of 4% by weight of fly ash to the ration raised the concentration of selenium in blood the highest. Increases in the concentration of selenium in milk as a result of the treatments were very small.

Administration, Oral↗
PubMed1979

Effect of a low chloride diet on lactating Holstein cows.

Twenty primiparous lactating Holstein cows were fed diets supplemented with either .5% sodium chloride or .75% sodium bicarbonate. Those fed the latter diet conserved chloride by reducing the chloride concentration in urine, feces, and, to a small but nonsignificant amount, in milk. The low chloride diet did not affect consumption of feed dry matter and water or milk production and composition. There was no indication of pica or other aberrant taste behavior. One half of the cows in each diet group was given free choice salt block of trace elements. Those fed the low chloride diet consumed more salt (337 versus 149 g/cow per wk). When chloride requirements have been established and data on chloride composition become more widely available, it will be possible to include both sodium and chloride in diet formulations and omit salt. This will reduce the amount of salt needed as either a sodium or chloride supplement.

Animal Feed↗
PubMed1977

Changes in portal blood metabolites and insulin with feeding steers twice daily.

Four Holstein steers surgically prepared with a device for sampling from the portal vein were used to examine changes in concentrations of metabolites and insulin in portal blood with scheduled meals. The animals were fed a complete mixed ration (3.4 kcal/g digestible energy) twice daily at three intakes. Blood was sampled at 30, 15, 10, and 5 min before feeding and at 1, 3, 5, 10, 15, 30, 45, 60, and 120 min after feeding began. Average intakes of food at 30 min for the three intakes were 0 (control), 889 g (restricted), and 1425 g (fed). Packed cell volume increased rapidly within 15 min of initiation of the meal in fed steers, but the maximum change from pre-feeding was 6.6%. Insulin increased within 5 min with the restricted intake and at 15 min in fed steers. Portal volatile fatty acids and beta-hydroxybutyrate also increased within 15 min of initiation of the meal in fed steers, and glucose tended to decrease after feeding. Certain metabolites and insulin of portal bood changed rapidly with feeding. Additional studies are required to establish any role of these blood components in the short-term control of feed intake in steers consuming concentrate feeds.

Animal Feed↗
PubMed1977

Portal blood insulin and metabolite changes with spontaneous feeding in steers.

Four Holstein steers surgically prepared with a device for sampling blood from the portal vein were used to study changes in metabolites and insulin of portal blood associated with spontaneous meal feeding. The animals were fed a complete mixed ration (3.4 kcal/g digestible energy) in individual, electronically controlled feeding units. Blood was sampled before, during, and after meals. During the meal, blood samples were at 2-min intervals. Blood was sampled at 50 individual meals. Average meal length was 15.0 min and average consumption per meal was 631.7 g. Portal insulin increased within 2 min of meal initiation and remained elevated for the first 14 min of meals. Free fatty acids also increased at 8, 10, 12, 16, and 18 min after meal initiation. There were no consistent changes in packed cell volume, glucose, beta-hydroxybutyrate, or volatile fatty acids during this time. On control days when no feed was consumed, there were no significant changes in concentrations of metabolites or insulin. The increase in insulin of portal blood, which occurs upon meal initiation, preceded changes in metabolites. Therefore, the rapid change in insulin may be the result of a reflex neural stimulation rather than the result of a metabolite stimulating release of insulin.

Animal Feed↗
PubMed1977

Use of urea by early postpartum Holstein cows.

Thirty-nine lactating Holstein cows were fed high-energy complete rations ad libitum with crude protein: 1) 11.7% (negative control); 2) 13.9% (1% urea); 3) 16.6% (1% urea); or 4) 16.6% (positive control) in a continuous 12-wk study beginning at wk 5 postpartum. Milk production of 27.7, 31.8, 34.0, and 30.4 kg/day showed the use of urea nitrogen by groups 2 and probably 3. Two digestion-nitrogen balance trials with each cow also provided evidence that urea nitrogen was used for milk secretion. Energy digestibility averaged 59.4, 64.2, 65.4, and 65.8; and lower for the negative control diet. Nitrogen solubility in the diets was 28, 36, 32, and 21%, which reflects the objective of selecting ingredients with low nitrogen solubility for use in urea diets. Concentrations of ammonia nitrogen before and after feeding were 1.1, 3.3, 3.5, 4.2, and 2.2, 11.2, 11.9, and 9.3 mg/100 ml of rumen fluid. The prefeeding amounts were probably too low for maximum microbial growth. Urea-nitrogen concentrations in plasma were 8.65, 10.32, 18.00, and 17.03 mg/100 ml. These results lend support to the postulate that lactating cows in early lactation can use urea nitrogen when high-energy complete rations with ingredients of low nitrogen solubility are fed ad libitum.

Animal Feed↗
PubMed1976

Feeding behavior of steers fed a complete mixed ration.

Feeding behavior of five Holstein steers fed a complete mixed ration was studied by use of individual, electronically controlled feeding behavior units. Both individual meal and daily behavioral parameters were measured. Number of meals, size of each individual meal, time spent eating, and intervals between meals were measured. Eating rates were then calculated. Diurnal feeding patterns were observed with 60.9% of the meals occurring between 0600 and 1800 h. For individual meals, body weight accounted for less than 30% of the variation in meal size. Average meal size was 414.5 g. Respective means for overall meal duration, actual meal duration, overall eating rate, and actual eating rate were 20.3 min, 13.7 min, 23.1 g/min, and 30.0 g/min. Meal size per body weight (g/kg or g/kg.75) was relatively constant during observation. Both increased eating rate and increased meal length were associated with larger meals. However, eating rate tended to plateau while meal length continued to increase with larger meals. Steers consumed 10.01 meals per day while total daily overall meal duration and actual meal duration were 220.9 and 156.4 min.

Animal Feed↗