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Biomedical subjects

L E Chase

Publications and source records attributed to L E Chase.

At least 19 recordsLinked to original sources
PubMed1998

Evaluation of National Research Council and Cornell Net Carbohydrate and Protein Systems for predicting requirements of Holstein heifers.

This experiment evaluated the effects of prepubertal energy intake and dietary protein source on average daily gain of Holstein heifers. Holstein heifers (n = 273) were assigned to one of three dietary energy treatments that were designed to achieve average daily gains of 0.6, 0.8, and 1.0 kg/d from 90 to 320 kg of body weight. Within each energy treatment, heifers were assigned to diets that were supplemented with animal and plant proteins or plant protein and urea. Diets were formulated using the Cornell Net Carbohydrate and Protein System. Actual mean daily gains by heifers on each energy treatment were 0.68, 0.83, and 0.94 kg/d and were not affected by protein source. Undegradable intake protein was predicted by the Cornell Net Carbohydrate and Protein System to be adequate to support the observed daily gain that was allowed by the amount of energy in the diet and was 13 to 25% lower than the recommendations for undegradable intake protein by the National Research Council. These results suggested that requirements for undegradable intake protein may be met at concentrations that are less than 35% of the dietary crude protein. Energy equations from the National Research Council and Cornell Net Carbohydrate and Protein System were evaluated and accounted for 87 and 86% of the variation in body weight gain that was allowed by the amount of energy in the diet with biases of -7.7 and -5.7%, respectively. The Cornell Net Carbohydrate and Protein System has the primary advantage of improved accuracy in the prediction of nutrient requirements in each unique production situation.

Animal Feed↗
PubMed1998

Effects of three prepubertal body growth rates on performance of Holstein heifers during first lactation.

The effects of body weight (BW) gain, different sources of protein during the prepubertal period (90 to 320 kg of BW), and the performance of Holstein heifers during their first lactation were studied. Heifers (n = 273) were assigned to one of three dietary energy treatments that were designed to achieve average daily gains of 0.6, 0.8, and 1.0 kg/d. Within each energy treatment, different protein sources (plant protein and urea or both plant and animal proteins) were imposed. Actual average daily gains by heifers on each energy treatment were 0.68, 0.83, and 0.94 kg/d for heifers that were fed diets formulated for average daily gains of 0.6, 0.8, and 1.0 kg/d, respectively, which allowed the following ages at first calving: 24.5, 22.0, and 21.3 mo. Breeding was initiated when heifers weighed approximately 340 kg. Protein sources did not affect average daily gain or milk yield. Analysis of the preplanned comparisons of actual 305-d and 4% fat-corrected milk yields indicated that yield was significantly reduced for heifers grown at 0.94 kg/d (9387 and 8558 kg, respectively) compared with that of heifers grown at 0.68 kg/d (9873 and 9008 kg, respectively). However, further regression analysis of fat-corrected milk and residual milk from a test day model on prepubertal BW gain only explained 8 and 2% of the variation in milk yield, respectively. Postcalving BW and body condition score were different among treatments. Posttreatment factors, such as postcalving BW, accounted for more of the variation in milk yield than did prepubertal BW gain. Prepubertal BW gains, when evaluated on a continuum from 0.5 to 1.1 kg/d, explained little of the variation in milk yield; therefore, BW gain during the prepubertal period did not significantly affect milk yield during first lactation.

Adipose Tissue↗
PubMed1997

Evaluation of alternative equations for prediction of intake for Holstein dairy cows.

Six prediction equations for dry matter intake (DMI) were evaluated for accuracy with independent data. The equations were selected based on ease of parameter measurement and practical on-farm use. The equations were assessed for accuracy of predicting individual weekly DMI for primiparous (n = 105) and multiparous (n = 136) cows; three-fourths of these cows were supplemented with a sustained-release form of bovine somatotropin (bST). Large variations in accuracy were identified across the six prediction equations for effects of parity and bST. Prediction accuracy of all equations for cows in wk 1 to 24 of lactation was better for primiparous cows than for multiparous cows. Precision of prediction equations was poor for cows in wk 8 through 12 of lactation and for cows in > 40 wk of lactation. The equation for DMI with the best accuracy measured by a low total lactation mean square prediction error was the modified equation of the National Research Council: DMI (kilograms per day) = -0.293 + 0.372 x fat-corrected milk (kilograms per day) + 0.0968 x body weight 0.75 (kilograms). However, the overall mean bias (predicted minus observed) of the prediction of weekly DMI of a single cow was high for all equations, including the modified equation of the National Research Council. For wk 2, 4, 8, 10, and 20 of lactation, the mean bias for the modified equation was +6, +3.4, -1.3, -2.1, and -2.8 kg/d. The accuracy of prediction was lower for cows treated biweekly with bST. High yielding cows and cows treated biweekly with bST had higher milk yields in relation to body weight, and standardized prediction equations for DMI were less accurate.

Animal Nutritional Physiological Phenomena↗
PubMed1997

Development and evaluation of equations for prediction of feed intake for lactating Holstein dairy cows.

Improved prediction equations for dry matter intake (DMI) of Holstein cows that consume high energy diets were developed using regression techniques applied to a comprehensive database. The equations for predicting DMI, which were dependent on parity, accounted for the effects of milk yield, milk protein, body weight (BW), BW change, days pregnant, ambient temperature, relative humidity, and night cooling. A simplified prediction equation of DMI for farm application was developed and based on milk protein yield and BW at calving. An ambient temperature and a lag adjustment factor for early lactation were developed to improve accuracy of prediction of DMI of dairy cows in early lactation. The developed equations for DMI were evaluated against six independent data files. These equations accounted for 55 to 98% of the variation of the weekly group DMI of the independent validation data. The remainder of the variation in intake was attributed to diet, management, and undescribed animal factors. The equations developed in this study had a mean proportional bias of 5.6% and a mean square prediction error of 5.45 kg2/d. Predicted intake using the new equations was within 3 to 8% of actual intake. The new equations must be applied to situations in which Holstein dairy cows are fed highly digestible diets because dietary fill effects are not considered in these equations. The relationship of milk protein yield and DMI warrants further investigation.

Animal Nutritional Physiological Phenomena↗
PubMed1993

Developing nutrition programs for high producing dairy herds.

Herd average milk production continues to increase in the US. Average milk production in Holstein herds enrolled in DHI testing programs surpassed 9000 kg in some states in 1991. Individual dairy herds have produced > 14,000 kg per cow per lactation. The upper limit for milk production per cow continues to increase. A challenge exists in developing nutrition programs for these herds. The goal is to attain efficient and profitable levels of milk production while maintaining herd health and reproductive performance. Evaluation of rations currently fed to high producing herds indicate that these rations are consistent with current nutrient requirement guidelines. Many high producing herds have average DMI > 4% of BW. Ration formulation principles and nutrient requirements used in development of feeding programs for high producing herds are similar to methods already in use. Optimizing DMI, optimizing rumen fermentation, and providing supplemental nutrients are key factors in meeting tissue nutrient demands in this formulation process.

Animal Feed↗
PubMed1991

Comparison of in vitro techniques to the in situ technique for estimation of ruminal degradation of protein.

The accuracy with which the Streptomyces griseus, ficin, and neutral protease with amylase in vitro methods could be used to predict in situ protein degradation of concentrate feeds was evaluated. Four types of soy products and two types of distillers grains were incubated using each of the four techniques for .5, 1, 2, 4, 8, 12, 24, and 48 h. The percentages of initial CP that remained undegraded over time were determined. Comparison of the degradation curves and contrast analysis of the data indicated that the in vitro methods generated degradability estimates in conflict with those obtained by the in situ method. However, the neutral protease with amylase method ranked the test feeds according to the extent of CP degradation at 24 h most similar to that in situ. Regression equations developed with the neutral protease with amylase degradability estimates explained 78, 76, and 74% of the variation in the in situ estimates obtained after 12, 18, and 24 h of incubation, respectively. At least 69% of the variation in the 18-h in situ estimates could be explained by the neutral protease with amylase estimates obtained after 1, 2, 4, 8, and 12 h of incubation. Little relationship was found between the ficin and S. griseus versus in situ results. Although none of the in vitro methods resulted in degradation curves consistently related to those generated by the in situ technique, relationships were found between protein degradability estimates obtained by the neutral protease with amylase method at specific time points and those obtained by the in situ technique.

Amylases↗
PubMed1990

Relationship of changes in condition score to cow health in Holsteins.

The relationship of body condition score with disease occurrence was examined in 561 cows in nine herds. Cows were body condition scored on a five-point scale (1 = thin, 5 = obese) every 2 wk from drying off until 150 d in milk. Cows scored between 3- and 3+ were considered to be in average or good condition. Cows scored less than or equal to 2+ were considered to be underconditioned, whereas those scored greater than or equal to 4- were considered to be overconditioned. Relationships of health and condition score were examined using multiple logistic regression for dichotomous outcomes (e.g., diseased or healthy). Cows that developed dystocia or were culled lost more condition during the dry period than those that did not develop dystocia or were not culled. Cows overconditioned at drying off were more likely to develop cystic ovarian disease and reproductive problems. Cows underconditioned or overconditioned at drying off were more prone to foot problems after calving. Cows overconditioned at 30 d postpartum were more likely to have metritis.

Animals↗
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↗