Feed processing effects on digestibility,palatability, excreta fermentation products and blood parameters in blue‐fronted amazon parrots (Amazona aestiva)†

Captive parrots show a high incidence of obesity and other metabolic disorders due to the consumption of unbalanced diets. Therefore, this study evaluated the digestibility and metabolic effects of transitioning blue‐fronted amazons from a high fat diet (sunflower seeds) to processed diets with three degrees of starch gelatinization (SG). The same feed formulation was processed to obtain pelletized feed (PEL) at 27.1% SG; low‐cooked extruded feed (EXT_L) at 81.6% SG; and high‐cooked extruded feed (EXT_H) at 98.5% SG. Thirty adult parrots were fed sunflower seeds for 90 days, then were distributed in a completely randomized design with 10 repetitions per treatment, and fed one of the three prepared diets for 160 days. Feed palatability, apparent digestibility, excreta concentrations of volatile fatty acids, lactate and ammonia, initial and final radiographic examinations, blood cell counts and glucose, triglycerides, cholesterol, total protein, albumin, aspartate aminotransferase (AST) and uric acid levels were evaluated. The data were analysed by an analysis of variance and compared by Tukey's test (p < 0.05). Sunflower seed was more digestible than processed feeds (p < 0.05). Diet processing interfered with fat and starch digestibility (p < 0.001), being higher in the PEL than in the EXT_H and EXT_L respectively. Transitioning from sunflower seeds to balanced diets reduced serum glucose, triglycerides, cholesterol and AST (p < 0.05) and increased red blood cell, haemoglobin, lymphocyte, monocyte and leucocyte counts (p < 0.01). Radiographs indicated a decreased hourglass (p = 0.015) and a reduced heart‐liver ratio after ingesting the processed feeds (p < 0.05). Feed processing did not affect blood cell counts, serum biochemistry or radiographic examinations. In conclusion, parrots preferred the extruded diet and did not require an extensive SG to properly digest the feed. Consuming the processed diets improved the birds’ metabolism and health.     

Feed preparation and pharmacokinetics of chlortetracycline in piglets

18 piglets were fed either a dry, humid or soup diet and each animal was dosed with 40 mg chlortetracycline/kg bodyweight. The chlortetracycline-concentration in the diet was 2500 mg/kg air-dried feed. After a single oral dosage the absorption of chlortetracycline occurred significantly faster from the soup diet, resulting in higher serum levels as well as prolonged elevated serum concentrations of CTC compared with the other two diets. Using a mathematical model, serum concentrations over a 5-day period with repeated dosage of CTC were calculated. Based on this dates we recommend the following dosage regime for chlortetracycline: 20-30 mg CTC/kg bodyweight/12 h for soup feeding and 30-40 mg CTC/kg bodyweight/12 h for dry or humid feeding.     

日粮中添加不同脂肪源对奶牛瘤胃液挥发性脂肪酸及乳脂中共轭亚油酸比例的影响

以3头装有永久性瘤胃瘘管的经产荷斯坦奶牛为试验动物,采用3×3拉丁方设计,研究在日粮中添加不同油料籽实(即葵花籽、亚麻籽、菜籽)的外源脂肪,对奶牛瘤胃液中乙酸、丙酸、丁酸含量变化的影响,以及对乳脂中共轭亚油酸(CLA)、多不饱和脂肪酸(PUFA)的比例以及血浆中长链脂肪酸比例变化的影响。3种日粮的粗脂肪含量基本相同。结果表明:日粮中添加3种不同油料籽实,对奶牛瘤胃液中乙酸、丙酸、丁酸含量及乙/丙比影响差异不显著(P>0.05);对乳脂中的共轭亚油酸(CLA)比例及其他多不饱和脂肪酸(PUFA)比例的影响差异显著(P<0.05)。葵花籽作为外源脂肪显著提高乳脂中CLA的比例;3组间的血浆中C14:0、C16:0、C18:0的比例差异不显著(P>0.05),菜籽组C18:1的比例显著高于亚麻籽组和葵花籽组(P<0.05),而后2组则差异不显著(P>0.05),亚麻籽组和葵花籽组t-C18:1、C18:2的比例与菜籽组的差异达到显著水平(P<0.05),而亚麻籽组和葵花籽组则差异不显著(P>0.05)。     

Effects of dietary flax seed and sunflower seed supplementation on normal canine serum polyunsaturated fatty acids and skin and hair coat condition scores

This prospective study involved supplementing 18 normal dogs with flax seed (FLX) and sunflower seed (SUN) and evaluating their effects on skin and hair coat condition scores and serum polyunsaturated fatty acids (PUFA) concentrations. Skin and hair coat were evaluated in a double-blinded fashion using a numeric scoring system and serum PUFA concentrations were determined. Our hypothesis was that changes in serum PUFA concentrations are associated with improvements in skin and hair coat and that serum PUFA would provide an objective method for making dietary fatty acid supplement recommendations. Although a numerical improvement was found in hair coat quality in both groups, this improvement was not sustained beyond 28 days. The relative per cent of 18:3n-3 concentrations in serum phospholipids increased in the FLX treated dogs but these concentrations remained unchanged in the SUN treated dogs. Also, elevations in relative per cent of 18:2n-6 concentrations in serum phospholipids were seen in the FLX group. The ratio of serum polyunsaturated to saturated fatty acids also showed a transient increase. These increases preceded the peak skin condition score peak value by approximately 14 days. It was concluded that a 1-month supplementation with either flax seed or sunflower seed in dogs provides temporary improvement in skin and hair coat. These changes appeared to be associated with increased serum 18 carbon PUFA.     

Yeast Culture Supplementation to Laying Hen Diets Containing Soybean Meal or Sunflower Seed Meal and Its Effect on Performance,Egg Quality Traits,and Blood Chemistry

This study was designed to investigate the effects of yeast culture supplementation to laying hen diets containing 2 oilseed meals on performance, egg traits, and some blood parameters. A total of 180 Lohmann Brown laying hens 21 wk of age were allocated to 4 dietary treatments and fed for 16 wk. Two different basal diets were prepared; one contained soybean meal and the other contained sunflower seed meal. Both of the basal diets were supplemented with 0 and 2 g/kg commercial yeast culture product (Saccharomyces cerevisiae). Yeast culture supplementation to diets containing either oilseed meal did not significantly affect feed intake, hen-day egg production, feed efficiency, interior and exterior egg quality characteristics, serum levels of total protein, triglyceride, cholesterol, alanine amino transferase, aspartate amino transferase, and alkaline phosphatase. Body weight gain (P < 0.05), egg weight (P < 0.001), and serum uric acid (P < 0.05) were increased with yeast culture supplementation. The reduction in egg yolk cholesterol was significant (P < 0.001) in the groups fed yeast-supplemented diets. The results in this study demonstrated that yeast culture supplementation to the diets containing soybean meal or sunflower seed meal increased egg weight and decreased egg yolk cholesterol without affecting performance and egg traits, but serum uric acid concentration was increased.     

Ruminal biohydrogenation of fatty acids from high-oleate sunflower seeds.

The objective of these experiments was to examine methods of modifying the fatty acid composition of bovine tissues. In the first experiment, four steers were fitted with duodenal fistulas and were assigned to four diets in a Latin square design. The steers were fed a control diet or the same diet containing 10% high-oleate partially crushed sunflower seeds, serum-coated sunflower seeds, and heat-treated, serum-coated sunflower seeds for 5 d. Samples of digesta and feces were collected on d 5. The inclusion of sunflower seeds (plain or serum-coated) in the diet increased (P less than .05) the digesta concentration of stearate. The percentage of stearate in the digesta and feces was increased (P less than .05) from 51 to 67% and from 64 to 74%, respectively, when steers were fed the untreated sunflower seed. The fecal concentration of oleate was increased (P less than .05) by dietary sunflower seeds in steers that were fed the serum-coated, unheated sunflower seeds. In a second experiment, heifers (four per group) were fed a corn-based control diet or diets containing 10% of high-oleate sunflower oil encapsulated with calcium alginate, either plain, coated with blood meal, or with blood meal integrated into the pellet. After 50 d on treatment, samples of perianal adipose tissue were obtained by biopsy. The fatty acid composition of the adipose tissue was not modified by the inclusion of the encapsulated oleate in the diet. In summary, limited ruminal bypass of sunflower seed oleate was accomplished with sunflower seed but not with encapsulated oleate.     

Plasma lipids and fatty acid composition in parrots in relation to the intake of alpha-linolenic acid from two feed mixtures

The main objective of this study was to find out whether the content of alpha-linolenic acid (ALA) in plasma cholesteryl-esters (CE) or triglycerides (TG) in parrots might serve as an index of ALA intake. The intake of ALA might be a risk factor for atherosclerosis, but on the basis of the fatty acid composition of seed mixtures the intake is difficult to assess due to selective eating of seeds. Parrots were fed two seed mixtures that differed in ALA content according to a cross over design. The macronutrient composition of the diets supplied differed from that of the diets consumed. The diets consumed had higher levels of dry matter, crude protein, crude fat and energy, and lower levels of crude fibre and crude ash. The ALA content, expressed as g/kg diet, was similar for the diet supplied and that consumed, irrespective of the type of diet. The diets had no systematic effect on plasma lipid concentrations. There were marked differences in plasma cholesterol concentrations between parrot species. When the diet with the low ALA content was fed (0.8% ALA of total fatty acids consumed, 1.1 g ALA/kg of diet consumed), the plasma CE and TG did not contain detectable ALA amounts. When the diet with the high ALA content was fed (4.2% ALA of total fatty acids consumed, 6.1 g ALA/kg of diet consumed), the plasma CE and TG contained about 1% ALA of total fatty acids. It is suggested that the content of ALA in plasma CE and TG might be used as an indicator of ALA intake.     

Serum concentrations and analgesic effects of liposome-encapsulated and standard butorphanol tartrate in parrots

OBJECTIVE: To compare serum concentrations of liposome-encapsulated butorphanol tartrate (LEBT) and standard butorphanol tartrate (STDBT) following SC and IM administration, respectively, and to evaluate analgesic effects of LEBT and STDBT after parenteral administration to Hispaniolan parrots. ANIMALS: 11 adult Hispaniolan parrots. PROCEDURE: The ability of LEBT to prolong the duration of analgesia in an avian species was tested. Blood samples were collected at serial time points after SC administration of LEBT (10 mg/kg or 15 mg/kg) or IM administration of STDBT (5 mg/kg). Serum concentrations of butorphanol tartrate were determined by use of a commercial immunoassay that measured parent drug and metabolites. Analgesic efficacy was evaluated in parrots exposed to electrical and thermal stimuli. Foot withdrawal thresholds were recorded at baseline and at serial time points after LEBT (15 mg/kg), liposome vehicle, STDBT (2 mg/kg), or physiologic saline (0.9% NaCl) solution administration. RESULTS: LEBT had a prolonged in vivo release for up to 5 days. Negligible serum butorphanol and butorphanol metabolite concentrations were obtained at 24 hours after IM administration of STDBT. Analgesic efficacy of LEBT as measured by foot withdrawal threshold to noxious thermal and electrical stimuli persisted for 3 to 5 days following SC administration of LEBT. CONCLUSIONS AND CLINICAL RELEVANCE: SC administration of LEBT provided analgesia and detectable serum butorphanol concentrations in Hispaniolan parrots for up to 5 days. The use of LEBT may allow for substantial improvement in long-term pain relief without subjecting birds to the stress of handling and multiple daily injections.     

Sunflower seed meal as a substitute for soybean meal in commercial broiler chicken diets

1. An experiment was conducted to study the possibility of replacing soybean meal (SBM) with sunflower seed meal (SFM) in broiler chick diets. The SBM in broiler starter (317.9 g/kg) and finisher (275.4 g/kg) diets was replaced with SFM at 33, 67 and 100% on an iso-caloric and iso-nitrogenous basis using sunflower oil to balance the energy content of the diets. The metabolisable energy levels used in the diet were considerably less than the recommended levels for broilers. Each experimental diet was fed ad libitum from 2 to 42 d of age to 8 replicates of 5 birds. Parameters studied included amino acid and apparent metabolisable energy contents in food ingredients, body weight, food intake, food efficiency, leg abnormality score, dry matter digestibility, carcase traits, relative weight and length of intestine, fat and protein content in liver and serum biochemical profile. 2. SFM had higher concentrations of calcium, phosphorus, methionine and cystine and lower energy content than SBM. 3. Replacement of SBM with SFM up to 67% in starter and 100% in finisher diets did not affect weight gain. Total and 67% replacement of SBM with SFM depressed food efficiency at 21 and 42 d of age, respectively. Food intake was significantly higher in SFM-based diets than in the SBM reference diet at 21 and 42 d of age, except in groups given SFM100 at 21 d of age. In the latter group, the food intake was similar to that on the SBM reference diet. The digestibility of dry matter decreased with increased levels of SFM in the diet. 4. The relative weights of giblet, liver and abdominal fat, length of intestine, activity of alkaline phosphatase, concentrations of calcium and inorganic phosphorus in serum were not influenced by incorporation of SFM in the broiler diet. 5. The ready to cook yield and liver fat content decreased, while the relative weights of gizzard and intestine and protein content in liver increased, with increasing levels of SFM in the diet. 6. The concentration of HDL cholesterol increased while the concentration of LDL cholesterol decreased with increasing content of SFM (> or =67% of SBM) in diet. The serum protein concentration decreased progressively with increase in dietary SFM. The concentrations of protein and triglycerides in serum were lowest in groups receiving SFM100. 7. Body weight gain was not affected by total replacement of SBM with SFM at 42 d of age. However, considering food efficiency, carcase yields, serum lipid profile and level of supplemental fat in diet, it is concluded that SFM can replace up to two-thirds of soybean, corresponding to inclusion of 345 and 296 g SFM per kg for starter and finisher phases, respectively.     

Comparison of the nutrient analysis and caloric density of 30 commercial seed mixtures (in toto and dehulled) with 27 commercial diets for parrots

In this paper, an overview is given of the composition of 30 commercially available parrot seed mixtures. As parrots dehull the seeds, the analysis of the total seed mixture tends to differ from that of the ingested feed. Statistical evaluation and comparison of the dehulled seeds vs. the whole seeds indicates that most parrot species are fed a diet rich in fat (31.7 +/- 13.1% crude fat) and energy (22.4 +/- 2.9 MJ ME/kg). As the analysis of the total seed mixtures underestimates fat and energy content of the ingested feed, it is suggested that researchers, bird nutritionists and bird food producers should calculate diets based on the analysis of the dehulled seeds. Finally, the calculated data were compared with the composition of formulated pelleted/extruded diets on the market. These data indicate that the energy density of most diets (15.6 +/- 1.4 MJ ME/kg) is far below the energy density of common seed mixtures.     

Effects of UVB radiation on calcium metabolism in psittacine birds

The effects of providing ultraviolet (uv) radiation (285 to 315 nm, ultraviolet B) on calcium metabolism in two groups of 20 healthy grey parrots (Psittacus e erithacus) fed either a seed or pellet-based diet were investigated. There was a significant increase in the concentration of ionised calcium in the plasma of both groups, independent of the calcium and vitamin D(3) content of the diets fed, and a significant increase in the plasma concentration of 25-hydroxycholecalciferol in only the seed-fed group. In a separate study there were no significant increases in plasma ionised calcium or 25-hydroxycholecalciferol between March and August in a group of 28 South American parrots (Pionus species) exposed to unfiltered natural sunlight.     

Conversion of α‐linolenic acid to long‐chain omega‐3 fatty acid derivatives and alterations of HDL density subfractions and plasma lipids with dietary polyunsaturated fatty acids in Monk parrots (Myiopsitta monachus)

The effect of α‐linolenic acid from a flaxseed (FLX)‐enriched diet on plasma lipid and fatty acid metabolism and possible atherosclerosis risk factors was studied in Monk parrots (Myiopsitta monachus). Twenty‐four Monk parrots were randomly assigned to diets containing either 10% ground SUNs or 10% ground FLXs. Feed intake was calculated daily. Blood samples, body condition scores and body weights were obtained at ?5 weeks, day 0, 7, 14, 28, 42 and 70. Plasma samples were analysed for total cholesterol, free cholesterol, triacylglycerols and lipoproteins. Phospholipid subfraction fatty acid profiles were determined. By day 70, the FLX group had significantly higher plasma phospholipid fatty acids including 18:3n‐3 (α‐linolenic acid), 20:5n‐3 (eicosapentaenoic acid) and 22:6n‐3 (docosahexaenoic acid). The sunflower group had significantly higher plasma phospholipid levels of 20:4n‐6 (arachidonic acid). By day 70, the high‐density lipoprotein (HDL) peak shifted resulting in significantly different HDL peak densities between the two experimental groups (1.097 g/ml FLX group and 1.095 g/ml SUN group, p = 0.028). The plasma fatty acid results indicate that Monk parrots can readily convert α‐linolenic acid to the long‐chain omega‐3 derivatives including docosahexaenoic acid and reduce 20:4n‐6 accumulation in plasma phospholipids. The reason for a shift in the HDL peak density is unknown at this time.     

Chlortetracycline supplementation of yearling dairy heifers

Chlortetracycline is an antibiotic that is used to increase weight gain, efficiency of gain, carcass grade, and conception rates. The objective of this experiment was to evaluate the effects of supplementation of 350 mg/d of chlortetracycline on ADG, G:F, BCS, thyroxine, and systemic glucose concentrations in yearling dairy heifers. Forty 12-mo-old Holstein heifers (initial BW = 363 +/- 21 kg) were housed in a free-stall barn with ad libitum access to feed and water for 104 d. A transition period was begun 14 d before the age of 12 mo to acclimate the heifers to the diet. The chlortetracycline-fed group (n = 20) consumed 328 +/- 8.2 mg of chlortetracycline/heifer daily. Measurements for BW, withers and hip heights, BCS, and health score were recorded weekly. Dry matter intake was measured daily. Blood was sampled every 4 d to determine plasma thyroxine and glucose concentrations and every 2 d to determine progesterone concentrations. Heifers were artificially inseminated on the first observed standing heat after 13 mo of age. There were no effects of chlortetracycline on ADG, G:F, withers and hip heights, BCS, blood glucose concentrations, peak progesterone concentrations, health, or conception rate. There was an interaction between treatment and time for chlortetracycline on serum thyroxine concentration. In the beginning of the experiment, serum thyroxine concentration was lower in heifers supplemented with chlortetracycline. There was no difference between treatments in thyroxine concentration at the end of the experiment. Chlortetracycline supplementation was not beneficial for yearling dairy heifers.     

Supplementation with sunflower seeds in beef cattle did not impact on oocyte and in vitro embryo production

Supplementation with compounds rich in linoleic acid, including sunflower seed supplementation, promotes increase in conception rates in cows. We aimed to evaluate whether the sunflower seed (linoleic acid source) supplementation in beef donor females alters the plasma concentrations of cholesterol, triglycerides, HDL and LDL, increases the number and quality of oocytes, increases the cleavage rates and determines an improvement in number and quality of in vitro produced blastocysts. Thus, Nelore females were divided into two groups of 15 animals to receive supplementation with or without sunflower seed for 57 days. Females underwent follicular aspiration and the oocytes were subjected to in vitro embryo production. There was no difference (p > .1) between control group and group supplemented with sunflower seed on the number of displayed follicles; number of aspired oocytes; recovery rate; cleavage rate; number of embryos; number of blastocysts; embryos number of grades I and II; plasma concentrations of total cholesterol, triglycerides; HDL and LDL. Therefore, sunflower seed supplementation in oocyte donors did not increase the number and quality of oocytes, cleavage rates and the number and quality of blastocysts produced in vitro.     

Effect of enzyme supplementation on the metabolisable energy content of solvent-extracted rapeseed and sunflower seed meals for chicken, guinea fowl and quail

(1) The nitrogen-corrected apparent metabolisable energy (AME(N)) content of solvent-extracted rapeseed and sunflower seed (un-decorticated) meals in relation to species (chicken, guinea fowl and quail) and dietary addition of feed enzymes (0 or 0.5 g/kg diet) was evaluated by a diet replacement method in a 3 x 2 factorial design. (2) The metabolism trial was conducted at two substitution levels (200 and 400 g/kg diet) of each meal with or without supplementation of commercial enzyme preparation in 6 individuals or 6 groups of cockerels, guinea fowls and quails. (3) The experimental diets were fed for a period of 12 d followed by a 3-d collection period during which total feed consumed and droppings output were quantitatively recorded. (4) The AME(N) values of rapeseed meal for cockerels, guinea fowls and quails were 8.4, 8.7 and 8.8 MJ/kg, respectively, while the corresponding values for sunflower seed meal were 6.1, 6.1 and 6.2 MJ/kg dry matter, without enzyme supplementation. (5) The AME(N) value of rapeseed meal did not improve with enzyme supplementation. However, AME(N) values of sunflower seed meal significantly increased with enzyme supplementation, from 6.1 to 6.5 MJ/kg dry matter. (6) Since AME(N) values of rapeseed meal and sunflower seed meal were similar in chicken, guinea fowl and quail, values reported for chicken could, therefore, be used for guinea fowl and Japanese quail.     

Canola and sunflower meal in beef cattle diets.

It is apparent from the limited research that sunflower meal is a biologically and economically useful protein source for growing and finishing cattle. Similarly, beef cows can be provided supplemental protein effectively with sunflower meal. Sunflower meal may be especially useful in diets where degradable protein is required, such as lower quality forage or high corn finishing rations. The increased bulk of this relatively high fiber meal may affect logistics, but ruminants are positioned to be more tolerant of high fiber levels than other species. Additional research is warranted to evaluate practical and economic aspects of using sunflower meal in beef cattle diets.     

Effects of feeding supplemental fat to beef cows on cold tolerance in newborn calves

Our objectives were to examine the effects of added fat in late-gestation cow diets on neonatal response to cold. In Exp. 1, pregnant fall-calving heifers received control (n = 5), safflower seed (n = 5), or whole cottonseed (n = 5) diets. The hay-based, isonitrogenous, and isocaloric diets, fed for 47 d prepartum, contained 1.5, 4.0, and 5.0% fat for control, safflower, and whole cottonseed diets, respectively. At calving, calf BW and vigor score, as well as fat, lactose, and IgG in colostrum were not affected (P > 0.30) by diet. Heifers fed the safflower diet tended to have greater colostral solids (P < 0.10) than heifers fed the control or whole cottonseed diets. At 6.5 h of age, calves were placed in a 5 degrees C cold room for 90 min. Calf vigor, shivering, body temperature, and blood samples were taken every 15 min. During cold stress, calf body temperature decreased 0.7 degrees C (P < 0.03). Across all diets, shivering and serum glucose concentrations increased (P < 0.05), whereas calf vigor and cortisol concentrations decreased (P < 0.02) during cold exposure. In Exp. 2, pregnant spring-calving cows (n = 98) received a control (n = 47) or whole cottonseed (n = 51) supplement. Hay-based diets fed for 68 d prepartum contained 2.0 and 5.0% fat for control and whole cottonseed diets, respectively. Calf BW, vigor, shivering, dystocia score, time to stand, time to nurse, serum glucose concentrations, and serum IgG were not affected (P > 0.50) by diet. Between 30 and 180 min, body temperature of calves from dams fed the whole cottonseed supplement decreased (P < 0.05) more than calves from dams fed the control supplement. Serum glucose concentrations in calves were not affected by diet (P > 0.30). Serum cortisol concentrations tended (P < 0.09) to be greater for calves from dams fed whole cottonseed than control calves. When ambient temperature was < 6 degrees C, calves born to dams fed whole cottonseed had greater (P < 0.05) BW, tended (P < 0.1) to stand earlier, and had greater serum IgG concentrations. We conclude that calves from dams fed high-fat diets containing safflower or whole cottonseed respond similarly to cold stress, but these responses may not be consistent with greater cold resistance. In addition, high-fat dietary supplementation of late-gestation cows may only be beneficial during calving seasons with prolonged cold weather.     

Comparison of biochemical values in serum and plasma, fresh and frozen plasma, and hemolyzed samples from orange-winged Amazon parrots (Amazona amazonica)

BACKGROUND: To the authors' knowledge, on the basis of sample type, storage condition, or hemolysis, differences in serum and plasma biochemical values have not been evaluated in orange-winged Amazon parrots (Amazona amazonica). OBJECTIVES: The purpose of this study was to compare values for biochemical analytes in serum vs plasma, fresh vs frozen plasma, and nonhemolyzed vs hemolyzed samples in orange-winged Amazon parrots. We also compared differences in serum and plasma yield from whole-blood aliquots. METHODS: Fifteen biochemical analytes were evaluated in paired serum and plasma, fresh and frozen plasma, nonhemolyzed and hemolyzed serum and plasma samples from orange-winged Amazon parrots (n = 10) using a wet reagent analyzer. Hemolysis was assessed qualitatively (visually) and quantitatively (hemoglobin [Hgb] measured spectrophotometrically). Serum and plasma yields from 500-microl whole-blood aliquots were determined from centrifuged samples. RESULTS: Analyte values significantly differed among sample groups, but were still within published reference intervals, with the exception of increases in potassium concentration in markedly hemolyzed serum and plasma samples. Clinically important changes in hemolyzed serum and plasma samples included increases in potassium, phosphorus, and albumin concentrations and lactate dehydrogenase activity. The degree of hemolysis assigned qualitatively did not correlate with quantitative Hgb concentration. A significantly greater yield of plasma (288 +/- 13 microL) than serum (241 +/- 44 microL) was obtained. CONCLUSIONS: Significant differences may occur in different sample types, however, only changes in potassium, phosphorus, albumin, and lactate dehydrogenase values in hemolyzed samples were considered clinically relevant. Lack of agreement between qualitative and quantitative Hgb concentration indicates the unreliability of visual estimation. Based on higher sample yield, and lack of clinically relevant differences from serum, plasma is a better sample choice for clinical chemistry analysis in birds.     

Reproductive management of captive parrots.

Studies of the behavior of Amazon parrots throughout a reproductive trial indicate that activities such as food gathering, which may occupy large fractions of the activity budget of wild parrots, occupy little time in captivity. This may be one factor contributing to the large percentage of time during which Amazon parrots are generally inactive in typical captive conditions. The extent of inactivity in captive Amazons creates an open time niche wherein enrichment devices might play a role in improving their well being. Studies of the reproductive endocrinology and the behavior of parrots suggest that hand rearing may impair adult fertility and nest box use. Hand rearing may also cause adult Cockatiels to lay eggs on cage floors rather than in nest boxes. However, the use of nest boxes with oversized nest entrances can be very effective in alleviating chronic floor laying in Cockatiels. Another egg-laying problem in Cockatiels, unwanted egg laying, can be prevented by the use of long-acting formulations of the superactive GnRH agonist, leuprolide acetate, which presumably [figure: see text] acts in birds, as in mammals, by down-regulating pituitary GnRH receptors. Manipulations to limit the increases in prolactin normally seen during incubation in poultry can significantly increase egg production. As clutch size in Cockatiels may also be limited by rising prolactin levels, such manipulations may be effective in stimulating egg production in parrots. An alternative approach for increasing flock egg production is to place foster eggs in nests of Cockatiel pairs that are slow to lay. This technique stimulates males to increase their nest-oriented behavior and, subsequently, may stimulate egg laying in some females that might not otherwise have laid eggs. The parental phases of reproduction in Amazon parrots are often a time of heightened aggressiveness towards humans, but low levels of serum testosterone in males during that time suggest that this particular interspecies aggressiveness may not be dependent on elevated testosterone levels. Occasional human handling during the nestling stage may produce a degree of tameness comparable with hand-reared chicks, yet not impair adult reproductive performance. Such handling may also alter the immune status of captive parrots, and possibly reduce the serum corticosterone response to handling. If so, occasional human handling during the nestling stage could improve the adaptation of parrots to captivity.     

Pharmacokinetics of voriconazole after oral administration of single and multiple doses in African grey parrots (Psittacus erithacus timneh)

OBJECTIVE: To determine the pharmacokinetics and safety of orally administered voriconazole in African grey parrots. ANIMALS: 20 clinically normal Timneh African grey parrots (Psittacus erithacus timneh). PROCEDURES: In single-dose trials, 12 parrots were each administered 6, 12, and 18 mg of voriconazole/kg orally and plasma concentrations of voriconazole were determined via high-pressure liquid chromatography. In a multiple-dose trial, voriconazole (18 mg/kg) was administered orally to 6 birds every 12 hours for 9 days; a control group (2 birds) received tap water. Treatment effects were assessed via observation, clinicopathologic analyses (3 assessments), and measurement of trough plasma voriconazole concentrations (2 assessments). RESULTS: Voriconazole's elimination half-life was short (1.1 to 1.6 hours). Higher doses resulted in disproportional increases in the maximum plasma voriconazole concentration and area under the curve. Trough plasma voriconazole concentrations achieved in the multiple-dose trial were lower than those achieved after administration of single doses. Polyuria (the only adverse treatment effect) developed in treated and control birds but was more severe in the treatment group. CONCLUSIONS AND CLINICAL RELEVANCE: In African grey parrots, voriconazole has dose-dependent pharmacokinetics and may induce its own metabolism. Oral administration of 12 to 18 mg of voriconazole/kg twice daily is a rational starting dose for treatment of African grey parrots infected with Aspergillus or other fungal organisms that have a minimal inhibitory concentration for voriconazole < or = 0.4 microg/mL. Higher doses may be needed to maintain plasma voriconazole concentrations during long-term treatment. Safety and efficacy of various voriconazole treatment regimens in this species require investigation.