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Biomedical subjects

R G Teeter

Publications and source records attributed to R G Teeter.

34 records · Page 2Linked to original sources
PubMed1993

The use of interferon modulates the negative effects of heat stress on poultry production.

A trial was conducted with broilers reared in two temperature environments; one was thermoneutral and the other had cycling ambient temperatures. Human interferon alpha (HuIFN-alpha) was added to the drinking water daily at four dose levels (0.0, 0.01, 0.1 and 1.0 international units (IU) per ml of drinking water). The trial began with 21 day old chicks housed either in a thermoneutral (24 degrees C) or a cycling ambient temperature (24-36 degrees C) environment. Interferon added to water at the highest concentration (1.0 IU/ml) improved surviability of birds in the cycling ambient temperature (24-36 degrees C) environment (P < 0.05). Birds housed in the cycling (24-36 degrees C) environment, drinking the lowest concentration of IFN-alpha 0.01 IU/ml, had a significantly improved weight gain-to-feed ratio. Oral IFN-alpha reduced the cost of production for birds reared in a cycling ambient temperature environment.

Animals↗
PubMed1992

Mineral balance and urinary and fecal mineral excretion profile of broilers housed in thermoneutral and heat-distressed environments.

Two experiments were conducted utilizing 4- to 7-wk posthatching Vantress x Arbor Acres male broilers to evaluate heat distress effects on mineral balance partitioned into urinary and fecal loss. In the first study, 8 colostomized and 14 intact birds were allotted to two environmental chambers maintained at either a thermoneutral temperature (24 C) or a cycling temperature heat distress (24 to 35 C) in a switch-back design. Birds were precision-fed 2% of body weight thrice daily to equalize consumption prior to and over each 48-h experimental period. Feces and urine for colostomized birds and total excrement for intact birds were collected and analyzed for mineral content. Averaging across surgical classification, heat distress increased (P less than .05) excretion of K, P, S, Mg, Cu, Mo, and Zn. Despite little heat distress effect on urine production, minerals disproportionately excreted in urine included K, Mg, P, and S; Cu and Mg were lost primarily in feces. In the second study 42 colostomized birds were used to expand the urinary excretion data with the period of heat distress held at 35 C for 36 h. Heat distress increased (P less than .05) urine output from 52.3 +/- 5.3 to 109.9 +/- 4.5 mL/12 h and also increased total urinary K, P, S, Na, Mg, Ca, and Mn excretion. The present data provide evidence that heat distress adversely impacts bird mineral balance and that the excretion route for this effect varies with the specific mineral and possibly, heat distress severity.

Animals↗
PubMed1992

Research note: broiler acclimation to heat distress and feed intake effects on body temperature in birds exposed to thermoneutral and high ambient temperatures.

Relationships between ambient temperature, bird acclimation to cycling temperature, heat distress, and feed consumption were evaluated in two experiments. In the first experiment, birds previously acclimated to cycling temperature heat distress (24 to 35 C) for two 24-h cycles were observed to have 24% lower (P less than .01) feed consumption than birds previously housed at 24 C and experiencing their first heat distress exposure. A significant (P less than .01) acclimation history by ambient temperature interaction was detected, with acclimated birds having a higher rectal temperature (42.3 versus 41.2 C) when housed at 24 C and a lower rectal temperature (44.2 versus 44.6 C) when exposed to 35 C than did the unacclimated controls. In the second experiment, feed intake and acclimation effects were separated by precision-feeding birds 0, 5, and 10% of body weight. Rectal temperature in the 24 C and 35 C environments increased linearly (P less than .01) as feeding level increased for both acclimated and unacclimated birds. Similar to the first experiment, an ambient temperature by acclimation history interaction was detected (P less than .01), with acclimated birds exhibiting increased body temperature when housed in thermoneutral environments and lower body temperature when exposed to high ambient temperature distress.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1991

Research note: Maxiban effects on heat-distressed broiler growth rate and feed efficiency.

One study was conducted utilizing 192 male broilers, at 4 to 7 wk posthatching, to evaluate a narasin-nicarbazin drug combination (Maxiban) for effects on bird growth rate, feed efficiency, and survivability during cycling ambient temperature (24 to 35 C) distress. Maxiban did not impact (P greater than .1) live weight gain, but reduced (P less than .05) gain:feed ratio (unadjusted for mortality), from .29 for controls to .21 as bird survivability declined (P less than .05) from 87.5 to 69.8%. Adjusting feed efficiency by adding the gain of birds dying of heat prostration to that for birds surviving the experiment resulted in feed efficiency for Maxiban-supplemented birds being similar (P = .48) to birds not consuming Maxiban. Under the conditions of the present study, Maxiban increased the mortality rate of male broilers exposed to cycling ambient temperature of 24 to 35 C during 4 to 7 wk posthatching.

Animals↗
PubMed1991

Research note: sodium and potassium chloride drinking water supplementation effects on acid-base balance and plasma corticosterone in broilers reared in thermoneutral and heat-distressed environments.

One experiment utilizing 188 Vantress x Arbor Acres broilers was conducted to evaluate the effects of isomolar KCl (.5%) and NaCl (.39%) drinking water supplementation on venous pH, PO2, PCO2, HCO3-, hematocrit, and plasma corticosterone as well as rectal temperature and water consumption of broilers reared in heat-distressed and thermoneutral environments. Birds were allotted at 5 wk posthatch into either a thermoneutral (TN; 24 C) or cycling temperature (24 to 35 C) environmental chamber. Heat-distressed (HD) controls had elevated (P less than .05) body temperature (42.9 versus 41.7 C) and PO2 (144.5 versus 108.4 mm Hg). Blood pH, PCO2, and HCO3- (P greater than .1) were not affected by high ambient temperature, but hematocrit (31 versus 32%) for HD controls was reduced (P = .07) compared with TN control birds. At 35 C, drinking water NaCl supplementation decreased (P less than .05) venous PCO2 and HCO3-, increased (P less than .05) PO2, and had no effect on venous pH and water consumption relative to HD controls. Potassium chloride lowered (P = .07) venous pH, decreased (P less than .05) HCO3-, and increased water consumption at 35 C, but PO2 and PCO2 were unaffected relative to HD controls. Heat distress increased (P less than .05) plasma corticosterone by 53%. Sodium chloride failed to impact (P greater than .1) plasma corticosterone but KCl reduced (P less than .05) its concentration during heat distress and increased (P less than .05) bird survivability as compared with heat-distressed controls. The data reported herein suggests that KCl and to a lesser extent NaCl reduces HD consequences by a mechanism as yet undefined.

Acid-Base Equilibrium↗
PubMed1988

Failure of naloxone to attenuate fasting induced hyperphagia in broiler chicks.

Subcutaneous administration of naloxone at 1 to 10 mg/kg produced a dose-related decrease in feed intake of broiler chicks. Food deprivation for 3, 6, 12, and 24 hours produced a significant increase in feed intake compared to non-food deprived birds. Subcutaneous administration of naloxone at 1 to 10 mg/kg failed to attenuate hyperphagia of broiler chicks, deprived of food for 12 hrs. These data suggest that opiate receptors are involved in the regulation of spontaneous feeding behavior in broiler chicks. However, in contrast to other mammals and pigeons, a mechanism, other than endorphinergic system, not sensitive to naloxone blockade, might be involved in food deprivation induced hyperphagia in broiler chicks.

Animals↗
PubMed1987

Potassium balance of the 5 to 8-week-old broiler exposed to constant heat or cycling high temperature stress and the effects of supplemental potassium chloride on body weight gain and feed efficiency.

Four experiments were conducted to study the impact of ambient temperature and relative humidity stress upon K excretion and the effects of KCl supplementation of broilers exposed to chronic heat and cycling temperature stress. Potassium excretion, corrected for K intake and body weight, increased by 633% as ambient temperature was elevated from a constant 24 C to a constant 35 C. Feed (.73% K) and drinking water (0% K) were supplemented with KCl so effects of KCl on live weight gain and feed efficiency could be evaluated. In a previous study at thermoneutral temperature, no benefit of supplemental KCl was observed whereas in this study a dietary level of 1.5 to 2% K in the form of KCl improved gain under conditions of chronic high ambient temperature stress. This equals about 1.8 to 2.3 g K per chick daily or about .24 to .3% of the drinking water.

Animals↗
PubMed1986

Detoxification of high tannin sorghum grains.

One in vitro and two in vivo experiments were conducted to determine appropriate methodology for and effects of detoxifying Darset, Redlan, and one commercial hybrid brown sorghum grain variety in threonine-deficient and nutritionally complete poultry rations. The detoxification procedure, which involves adding water to sorghum grain to bring dry matter to 70% and subsequent anaerobic incubation at 32 C, removes up to 100% of the chemically detectable tannin. Rate of tannin elimination was dependent upon sorghum grain variety with commercial brown sorghum requiring approximately 3 days longer than the Darset for tannin elimination. Detoxification of high tannin sorghum grains improved (P less than .05) growth rate and feed efficiency dramatically in threonine-deficient, crystalline amino acid-fortified rations; the same process applied to low tannin sorghum grains was without benefit. The desirable effects of this type of grain processing appear to be due to the reduced grain tannin content. Including detoxified sorghum grains in a practical-type broiler ration failed to elicit a weight gain response although feed efficiency was improved by 13% over untreated sorghum and 3% over corn grain. Lack of a gain response was likely due to the excess protein included in the basal diet. This type of grain processing offers an alternative method of reducing sorghum grain tannin content and is likely of greatest value in rations containing marginal indispensable amino acid and protein levels.

Amino Acids↗
PubMed1986

High chronic ambient temperature stress effects on broiler acid-base balance and their response to supplemental ammonium chloride, potassium chloride, and potassium carbonate.

Four experiments were conducted to evaluate the effect of heat stress on acid-base status and the birds' response to supplemental KCl and KCO3. The corn-soybean meal fish-meal basal ration (.73% K+) contained more K+ and Cl- than is recommended by the National Academy of Sciences for chicks reared under near optimal conditions (24 C and 55% relative humidity). Chicks reared under continuous thermostress (35 C, 70% relative humidity) exhibited panting phase blood alkalosis (pH of 7.46). Supplementing drinking water with .2% NH4Cl reduced panting phase blood pH to normal values and increased live weight gain (23%) and feed efficiency (7.7%). Supplementing drinking water with .15% KCl also increased (P less than .05) live weight gain (46%) and feed efficiency (15.4%) but did not affect (P less than .46) blood pH. A significant (P less than .01) interaction existed between NH4Cl and KCl for body weight gain. Adding .2% NH4Cl to broiler drinking water reduced the level of KCl required in drinking water to optimize weight gain to .1% KCl. Potassium chloride alone, or with NH4Cl, can alleviate some consequences of heat stress, but supplementing drinking water with a high level of NH4Cl (.5%) decreased (P less than .05) blood pH to acidotic levels and reduced body weight gain. Potassium chloride supplementation exacerbated NH4Cl toxicity. Potassium carbonate reduced (P less than .05) body weight gain indicating that the response may not be attributed to K+ alone. Beneficial effects of NH4Cl therapy for heat stressed broilers are speculative.

Acid-Base Equilibrium↗
PubMed1985

Chronic heat stress and respiratory alkalosis: occurrence and treatment in broiler chicks.

The occurrence of respiratory alkalosis and potential benefit derived from treatment were examined in thermostressed 4-week-old broiler chicks. Blood pH was greater (P less than .05) in heat-stressed (32 C) panting birds (7.395) than either nonpanting (7.28) or birds raised at 24 C (7.28). Acute thermostress, obtained by elevating ambient temperature from 32 to 41 C over a 20-min period further elevated (P less than .05) blood pH to 7.521. Chronic heat-stressed broiler chicks suffer from intermittent respiratory alkalosis during panting; with acute heat stress, chicks pant continuously and suffer from alkalosis. Including .5% sodium bicarbonate (NaHCO3) in the diet of birds subjected to chronic heat stress enhanced body weight gain by 9% even though it tended (P less than .10) to increase blood pH in nonpanting birds. Adding .3 or 1% ammonium chloride (NH4Cl) to diets decreased blood pH (P less than .01) to 7.194 and increased (P less than .05) body weight gains by 9.5 and 25%, respectively. Effects appeared linear with NH4Cl dose to 1% NH4Cl, but 3% NH4Cl elevated weight gains by only 8% and precipitated blood acidosis (pH 7.09) in nonpanting birds. Supplementing the 1% NH4Cl diet with .5% NaHCO3 increased weight gains an additional 9%. Manipulating sodium: chloride ratios by addition of calcium chloride increased body weight gain 8% and slightly reduced severity of alkalosis. Data indicate that blood alkalosis limits growth rate of broiler chicks reared under chronic thermostress and that the respiratory alkalosis and weight gain depressions attributed to thermostress can be partially alleviated dietarily.

Alkalosis, Respiratory↗
PubMed1985

Feed intake effects upon gain, carcass yield, and ration digestibility in broilers force fed five feed intakes.

Broiler chicks were force fed 75, 100, 125, 140 and 160% of the consumption observed by ad libitum-fed controls to examine feed intake effects upon productivity. Live body weight gain increased with feed intake up to the 140% consumption but was depressed above this point. Feed efficiency and fat, ash, ration (corrected for uric excretion mass), protein (corrected for uric acid excretion nitrogen), and starch digestibility estimates declined by 30, 56, 25, 16, 16, and 2%, respectively, as feed consumption increased from 75 to 160% of ad libitum consumption. Neutral detergent fiber digestibility was not affected by amount of feed consumption. Initial digesta passage rate, estimated by first appearance of ferric oxide in feces, averaged 215 min and was not correlated (P greater than .4) with feed intake. Gastrointestinal tract mass plus contents increased with feed intake and accounted for up to 67% of the increased live body weight gain. Birds apparently adjusted to feed intake level by varying gastrointestinal tract size (mass) and not passage rate. Dressing percentage declined from a high of 73% for birds fed at the lowest feed intake to a low of 63% at the highest feed intake. Carcass gain was 50% greater for the 160 vs 75% group, but most of this (41%) was reached at the ad libitum consumption level. Carcass gain-to-feed ratios were .42, .41, .32, .27, and .21 for the five intakes, respectively. Drumstick, breast, and thigh gains were not (P greater than .01) influenced by increased feed consumption above the ad libitum-fed controls but were depressed (P greater than .05) at the 75% feed intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Characteristics of water soluble markers for measuring rumen liquid volume and dilution rate.

The utility of five water soluble markers (WSM) for measuring rumen liquid volume and dilution rate was examined in nine in vitro and in vivo experiments. The WSM tested included polyethylene glycol (PEG) and ethylenediaminetetraacetic acid (EDTA) complexes of Cr, Co, Fe and Yb. Feedstuffs incubated in vitro absorbed variable amounts of distilled H2O and autoclaved rumen fluid with roughages imbibing greater (P less than .05) amounts of fluid than feeds higher in starch. Liquid present in the feeds tested reached equilibrium with added WSM in about 20 min. Corn grain in the whole or ground form appeared to exclude 4 to 16% of the WSM while imbibing water. Cottonseed hulls reduced detectable PEG due to some water soluble substance present. The WSM tested did not produce different estimates of dilution rate (P = .65) and volume (p = .29) of steers fed either 80% whole shelled corn, 90% chopped alfalfa hay or 90% prairie hay diets. Ruminal liquid measured by hand removal was about 4% greater than volume estimated by WSM. The percentage of total ruminal water associated with solids varied from 27 to 86% among steers. Compared with steers fed an 80% whole shelled corn diet, steers fed equal dry matter from alfalfa hay had 15% more dry matter in the rumen, 21% larger liquid volume, 80% greater ruminal liquid dilution rate and 116% greater rate of liquid flow from the rumen. Dilution rate of ruminal liquid during feeding was examined with six steers fed a 90% chopped alfalfa hay diet once daily at 1.8% of body weight. Dilution rate estimated with Co EDTA increased by 166% during the 4 h after feeding. The WSM did not influence (P greater than .10) digestibility of dry matter with steers fed a 90% roughage or a 90% concentrate ration. Recovery of WSM administered via a rumen cannula ranged from 96.8 to 99.7% in feces and 1.2 to 3.4% in urine. All WSM examined appeared suitable for estimating rumen liquid volume and dilution rate for diets not containing cottonseed hulls.

Animals↗
PubMedDate not supplied

Effect of oxygen level on ascites incidence and performance in broiler chicks.

An experiment was conducted using male Cobb x Cobb broiler chicks to evaluate the effect of two oxygen levels on the incidence of ascites, performance, and blood chemistry. Ascites occurred in the 13.6% oxygen groups on the fifth day of the experiment. Body weights and survivability were significantly lower (P < 0.05) in chicks maintained at the low oxygen level than in controls (20.6% oxygen). Hematocrits were significantly higher only in chicks with ascites at the 13.6% oxygen level. Hemoglobin was significantly higher (P < 0.05) in chicks with ascites at 13.6% oxygen than in chickens at 20.6% oxygen. Lactate dehydrogenase values were significantly higher in non-ascitic chicks maintained at 13.6% oxygen and in chicks with ascites at 20.6% oxygen than in non-ascitic chicks 20.6% oxygen.

Altitude↗