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PubMedDate not supplied

Characterization of the toxicity of the mycotoxins aflatoxin, ochratoxin, and T-2 toxin in game birds. II. Ringneck pheasant.

Ringneck pheasants were fed diets containing 1.25, 2.5, or 5 ppm aflatoxin; 1, 2, or 4 ppm ochratoxin A (OA); or 4, 8, or 16 ppm T-2 toxin. Severe toxin-induced mortality was seen during the first to third weeks with 2.50 and 5.00 ppm aflatoxin (92.5% and 97.5%, respectively), compared with the mortality in control pheasants fed no toxin (0%). Slight mortality (less than or equal to 5%) was seen with OA and T-2 toxin. Body weights were significantly decreased by the lowest level (1.25 ppm) of aflatoxin by 2 weeks of age, by the two highest levels of aflatoxin by 1 week of age, and by 16 ppm T-2 toxin by 1 week of age. The feed-conversion ratio was increased by 2.50 and 5.00 ppm aflatoxin compared with the feed-conversion ratio in controls, although high mortality may have influenced the results. Aflatoxin had no effect on liver weight, but OA increased kidney weight in 3-week-old pheasants. Mouth lesions were seen in some of the pheasants fed T-2 toxin.

Aflatoxins↗
PubMed1991

Ascites in broilers. 1. Experimental factors evoking symptoms related to ascites.

Male broilers of two genetically related stocks with divergent growth rates and feed conversion ratios were used to study metabolic backgrounds on the occurrence of pulmonary hypertension, heart failure, hypoxemia, and ascites in poultry. An experiment with a 2 x 2 x 2 x 2 factorial split-plot arrangement of treatments with 96 groups of 12 broilers was performed. Effects of stock and environmental factors such as ambient temperature, dietary fat, and dietary energy on performance, energy metabolism, oxygen consumption, hematocrit values, and mortality were investigated in broilers from 1 to 5 wk of age. Dissimilar responses of the two stocks to environmental factors reflected genotype by environment interactions and revealed metabolic disorders related to heart failure and ascites. The results indicated that in the stock with the lower feed conversion ratio, a fast protein accretion was achieved together with a reduced ability to convert chemical energy to metabolic heat and to deposit body fat directly from ingested fat. Birds with a low feed conversion ratio show less flexibility in metabolic adaptation to a changing environment, which can account for the development of ascites.

Animal Feed↗
PubMed2005

Effect of daidzein on egg-laying performance in Shaoxing duck breeders during different stages of the egg production cycle.

The effect of a phyto-oestrogen, daidzein, on the laying performance of Shaoxing female ducks was examined in three experiments performed at different stages of the egg production cycle. Egg-laying rate, egg weight, egg composition, feed conversion ratio, hatchability characteristics of eggs and body weight, ovary and oviduct weight, as well as changes in serum concentrations of T3, T4 and E2 were recorded as response criteria. In the first experiment, 68 young ducks, 100 d of age, were given a basal diet (maize-soybean meal) with or without 3 mg of daidzein/kg diet for 42 d. Daidzein did not affect the onset of lay but apparently decreased egg-laying rate and mean egg weight as well as the feed conversion ratio. In the second experiment, 240 breeding ducks, 402 d of age, were allotted at random to three groups and given the basal diet containing daidzein at 0 (control), 3 (Da1) and 5mg/kg (Da2) for 35d. Egg-laying rate, mean egg weight and feed conversion ratio increased in both Da1 and Da2 groups. However, an adverse effect of daidzein on fertility and hatchability was observed. In the third experiment, 320 breeding ducks, 415 d of age, were fed on the basal diet with or without 5mg of daidzein/kg diet for 63 d. Egg-laying rate increased by 7.7%, average egg weight tended to increase, whereas yolk/albumen ratio decreased. Daidzein-treated ducks had higher body weight and oviduct weight compared with their controls. Elevated plasma T4 and E2 concentrations accompanied these phenotypic changes, but serum T3 was not affected. It is suggested that daidzein exerts divergent effects on the egg-laying performance of Shaoxing ducks under different physiological conditions and this action is dose-dependent. The changes in circulating E2 imply possible participation of endogenous oestrogen in the mechanism of daidzein action.

Animals↗
PubMed1987

Interrelationships among lighting, ambient temperature, and dietary energy and broiler chicken performance.

A total of 4,800 broiler chickens of one commercial genotype were used to study the interrelated effects of two lighting treatments (green fluorescent vs. incandescent), three weekly rates of ambient temperature decline (4.5, 3.5, 2.0 C), and starter/finisher diets with four levels of dietary energy (3,100/3,300; 3,000/3,200; 2,900/3,100; and 2,800/3,000 kcal/kg metabolizable energy). Lighting and ambient temperature treatments had no significant (P greater than .05) effects on percentage mortality, feed conversion ratio, body weight, and monetary return. The highest dietary energy regimens resulted in the heaviest body weights, best feed conversion ratios, and the highest monetary returns. A lighting treatment x diet interaction occurred for female mortality to 42 days but was considered of minor importance. A lighting treatment x diet interaction for feed conversion provided evidence that low temperatures had a more pronounced depressing effect on broiler chickens fed low energy diets. A second order interaction for 42-day male body weights provides evidence that male broiler chickens may be less sensitive to lower ambient temperatures if fed higher energy diets under incandescent lighting compared with those fed lower energy diets under green fluorescent light.

Animal Nutritional Physiological Phenomena↗
PubMed2006

Experimental ochratoxicosis in broiler chickens.

This study describes the toxicity signs that developed when the diet of male broiler chickens was artificially contaminated with different levels of the mycotoxin ochratoxin A (OTA). Chicks were assigned randomly to three groups of 80 chicks that were fed a diet containing 0 parts per billion (ppb) (control, group 1), 400 ppb (group 2) or 800 ppb (group 3) OTA from day 1 to 5 weeks of age. Signs of ochratoxicosis were assessed on the basis of changes in the following criteria: body weight, relative weights of two representative internal organs (gizzard and thymus), feed consumption, feed conversion ratio, mortality, thyroid activity, blood profile, humoral and cell mediated immunity. Feeding OTA at levels of 400 and 800 ppb (groups 2 and 3) significantly decreased the body weight, thymus weight, feed consumption, feed conversion ratio and thyroxine concentration (P < 0.05). The OTA groups developed anaemia manifested by a significant decrease in the red blood cell count, packed cell volume percentage and haemoglobin concentration (P < 0.05). By the end of the experiment both groups that received OTA showed a 37% reduction in red blood cell count compared with the control group. Furthermore, a significant decrease in the white blood cell count, humoral immune response and cell-mediated immunity was found in both groups fed ochratoxin compared with the control group (P < 0.05). The reduction in the above parameters was more noticeable with time and was proportional to the level of OTA exposure. A significant increase in relative gizzard weight, cumulative mortality and triiodothyronine concentration was found in OTA-fed chicks (P < 0.05). These data provide a description of ochratoxicosis in broilers that should be useful in diagnosis and in improved understanding of the practical implications on broiler performance and health, a problem that can threaten the poultry industry.

Animals↗
PubMed1980

Anticoccidial activity of narasin in broiler chickens reared in floor pens.

The anticoccidial activity of the ionophore narasin was tested in 3 floor-pen experiments. Narasin was tested at levels of 40, 60, 80, 100, or 120 ppm and compared against feeding ration containing 80, 100, or 121 ppm monensin or no medication. Feeding at all levels of narasin significantly prevented coccidiosis-induced mortality and improved weight gains and feed conversion ratios compared with the same parameters in groups given unmedicated feed. Protection with narasin was equal to or slightly greater than the protection obtained with monensin. The reduction in intestinal lesion scores was greater with narasin medication than with monensin. Analysis of pooled data from these trials indicated that a level between 48 and 96 ppm narasin would provide the optimum, depending on whether maximum weight gain or optimum feed conversion ratio was desired. Testing for coccidial immunity using the immunity challenge technique indicated that, based on the parameters of weight gain and lesion scores, even levels as low as 40 ppm narasin had enough efficacy to significantly reduce the amount of immunity which developed in medicated birds compared with the level of immunity developed in birds receiving unmedicated feed.

Animals↗
PubMed2000

Rare earth elements--a new generation of growth promoters for pigs?

The present study which includes two feeding experiments was performed to investigate a possible performance enhancing effect of rare earth elements (REF) in piglets. This performance enhancing effect has been described in the Chinese literature for a long time, however, it was never tested under "western conditions". In the first feeding experiment 72 piglets at a mean BW of 7.3 kg were allotted to a control and to 4 REE groups at different levels of lanthanum chloride or an REE mixture containing mainly chlorides of lanthanum, cerium and praseodymium. The experimental period lasted 5 weeks. Positive effects of REE were found on body weight gain as well as on feed conversion ratio of the piglets. Compared to the control group, the daily weight gain was improved by 2 to 5% and feed conversion was better by up to 7%. These effects were, however, not significant. In the second feeding experiment, piglets (mean BW 17.3 kg) were fed for 8 weeks with a similar REE mixture. Significant positive effects of REE were found on both body weight gain and on feed conversion ratio by 19% and 10%, respectively. This is the first time that a performance enhancing effect of REE in pigs under western feeding conditions has been shown. Since the use of antibiotics as growth promoters in animal feed has been restricted in the European Union recently, rare earth elements might be of interest as new, safe and inexpensive alternative performance enhancers.

Animal Feed↗
PubMed1999

Studies on semduramicin and nutritional responses: 2. methionine levels.

Three experiments were conducted to determine whether feeding semduramicin at recommended levels would affect the broiler chicken's response to dietary methionine. In Experiment 1, three levels of methionine (0, 0.15, 0.30%) were fed to chicks in battery brooders. In Experiment 2, two levels of protein (18 and 22%) and three levels of methionine (0, 0.15, 0.30%) were fed to chicks in floor pens from 18 to 44 d. In Experiment 3, two methionine supplements were fed during each of the starter (0 and 0.21%, 0 to 18 d) and grower (0 and 0.10%, 18 to 35 d) periods to chicks in floor pens. In all experiments, male commercial broiler chicks were used, and all diets were fed with and without 25 mg/kg diet of semduramicin. The basal diets were based on corn, soybean meal, and poultry oil. In Experiment 1, there was a growth and feed conversion ratio response to methionine supplements, but there was no effect of semduramicin on growth nor any semduramicin by methionine supplement interaction. In Experiment 2, at 44 d, protein and methionine levels both influenced feed conversion ratios, but semduramicin did not. Feeding 22 vs 18% protein increased carcass and breast muscle yields and decreased abdominal fat pad weights. The results of Experiments 2 and 3 were very similar. Overall, the effects of semduramicin on growth and processing parameters were small and not significant, but considerable benefits in performance and carcass parameters could be realized by feeding the higher levels of protein or methionine.

Animals↗
PubMed1985

Response of growing-finishing pigs to decreasing floor space allowance and(or) virginiamycin in diet.

Five hundred forty crossbred pigs were utilized in four trials (10 replications) at two stations to determine the separate and interacting effects of decreasing floor space allowance with or without the addition of virginiamycin to the diet on performance of growing-finishing pigs. Pigs were allowed .37, .33 or .28 m2/pig during the growing phase (23 to 55 kg) and .74, .66, .56 m2/pig during the finishing phase (55 to 100 kg) and fed either a corn-soybean meal control diet or the control diet plus 11 mg of virginiamycin/kg of diet. Floor space allowances were achieved by varying pen size, so the number of pigs and feeder space per pig were constant for all pens. During the growing phase, daily gain (P less than .01) daily feed intake (P less than .05) and feed conversion ratio (P less than .05) decreased as floor space allowance decreased. During the finishing phase and for the total test period, daily gain (P less than .01) and feed conversion ratio (P less than .05) were reduced but daily feed intake was not affected (P greater than .05) by restricted floor space allowance. The addition of virginiamycin to the diet had no effect on pig performance. The virginiamycin X floor space allowance interaction was not significant, suggesting that pigs fed a diet with or without virginiamycin responded similarly to restricted floor space allowance. The data suggest that the addition of virginiamycin to the diet was ineffective in overcoming the decrease in performance of growing-finishing pigs caused by crowded conditions.

Animal Feed↗
PubMed2003

Effect of dietary supplementation with oregano essential oil on performance of broilers after experimental infection with Eimeria tenella.

A study was carried out to examine the effect of dietary supplementation of oregano essential oil on performance of broiler chickens experimentally infected with Eimeria tenella at 14 days of age. A total of 120 day-old Cobb-500 chicks separated into 4 equal groups with three replicates each, were used in this study. Two groups, one infected with 5 x 10(4) sporulated oocysts of E. tenella and the other not, were given a basal diet and served as controls. The other two groups also infected with E. tenella were administered diets supplemented with oregano essential oil at a level of 300 mg/kg, or with the anticoccidial lasalocid at 75 mg/kg. Following this infection, survival rate, bloody diarrhoea and oocysts excretion as well as lesion score were determined. Throughout the experimental period of 42 days, body weight gain and feed intake were recorded weekly, and feed conversion ratios were calculated. Two weeks after the infection with E. tenella supplementation with dietary oregano oil resulted in body weight gains and feed conversion ratios not differing from the non-infected group, but higher than those of the infected control group and lower than those of the lasalocid group. These parameters correspond with the extent of bloody diarrhoea, survival rate, lesion score and oocyst numbers and indicated that oregano essential oil exerted an anticoccidial effect against E. tenella, which was, however, lower than that exhibited by lasalocid.

Animals↗
PubMed2004

Testing the efficacy of fermented wheat germ extract against Mycoplasma gallisepticum infection of chickens.

The effect of fermented wheat germ extract (FWGE, Immunovet-HBM) was studied in chickens challenged with Mycoplasma gallisepticum. Ninety M. gallisepticum- and M. synoviae-free 3-wk-old chickens were exposed to aerosol infection of M. gallisepticum. One group (30 birds) was treated with FWGE, a second group with tiamulin, and a third group was untreated. The fourth group was exposed to PBS aerosol as a negative control. On d 9, all chickens were slaughtered and examined for the presence of gross and histological lesions, the presence of the challenge strain in the organs and specific antibodies in the serum. Body weight gains and feed conversion rates were recorded. In the groups treated with FWGE and with tiamulin, the chickens remained clinically healthy: their BW gains were 441.7 g and 446.8 g, respectively. Feed conversion ratios were 1.72 and 1.71 for FWGE- and tiamulin-treated birds, respectively. Control birds had BW gain of 480.8 g, and feed conversion ratio of 1.78. The numbers of birds with gross lesions (15 and 11, respectively) and lesion scores (25 and 25, respectively) of the FWGE- and tiamulin-treated groups were significantly lower than in the infected untreated group (25 birds, lesion score of 190). No mycoplasma was reisolated from brain, liver, spleen, heart, or kidneys of the FWGE-treated birds, and the number of mycoplasma isolations from the respiratory tract samples was less frequent (10) than from the infected untreated group (64). In addition, 35 samples from other internal organs were also positive. Twenty percent of the birds treated with FWGE showed serological response with a 5.0% reaction score, whereas in the infected untreated group, 83.3% of birds were reactors, with a 62.5% reaction score.

Animals↗
PubMed1997

Pathogenicity of three strains of Serpulina pilosicoli in pigs with a naturally acquired intestinal flora.

Serpulina pilosicoli is an anaerobic spirochete which has been isolated from the colons of pigs with enteric disease. The clinical and pathologic features of experimental infections of conventional pigs (born by normal farrowing with a naturally acquired intestinal flora) with three strains of S. pilosicoli were determined in order to confirm the enteropathogenicity of this species. Strains were derived from the colons of British pigs with colitis and passaged 8 to 10 times during expansion and purification in vitro. Eighteen ten-week-old Large White-Landrace cross pigs were each inoculated once orally with 0.7 x 10(9) to 1.6 x 10(9) of one of three strains of S. pilosicoli. Six pigs were challenged with each strain. Control pigs were dosed with uninfected broth medium or with 1.8 x 10(7) cells of the nonpathogenic Serpulina innocens. Eight pigs (two to four per S. pilosicoli challenge group) developed soft or diarrheic feces (fecal dry matter < 24%) between 3 and 8 days after challenge, which persisted for 7 to 8 days or until necropsy at 14 days after challenge. Average weight gains in two of the three groups challenged with S. pilosicoli were significantly less than controls. The feed conversion ratios of all the groups challenged with S. pilosicoli were impaired compared to controls. The mean values for daily liveweight gain (and feed conversion ratio) for the three groups challenged with S. pilosicoli were 0.799 (2.13), 0.783 (2.05), and 0.844 kg (2.10), respectively, while that of the uninoculated controls was 0.944 kg (1.70). Gross lesions with slight mucosal thickening, congestion, and multifocal erosions were evident in seven of eight diarrheic pigs. The relative weights of the large intestines of pigs challenged with S. pilosicoli were significantly less than controls. Histologic lesions with an increase in mucosal height, infiltration of the lamina propria with mononuclear cells, mucosal erosion with mixed inflammatory cell infiltration, and goblet cell hyperplasia in colonic glands were evident in 15 of the 18 challenged pigs. S. pilosicoli was recovered on bacterial culture of the colon from all except one of the pigs with these histologic lesions. Serpulina sp. was clearly visible within the colonic glands of these affected pigs in silver-stained sections of the gut. Clinical and pathologic findings in control pigs were unremarkable, with no diarrhea or colonic lesions evident. The results provide further evidence that S. pilosicoli is a specific enteric pathogen for conventional pigs. It is capable of colonizing the large intestine and causing mucosal damage, which although mild is sufficient to result in significant adverse effects on growth.

Animals↗
PubMed2004

Performance of rabbits and oxidative stability of muscle tissues as affected by dietary supplementation with oregano essential oil.

The effect of dietary supplementation with oregano essential oil on the performance of rabbits, and the susceptibility of the produced raw and thermally treated muscle tissue to lipid oxidation during refrigerated storage, were investigated. A total of 96 weaned rabbits were separated into four equal groups with three subgroups each. One group was given the basal diet and served as control, two groups were administered diets supplemented with oregano essential oil at levels of 100 and 200 mg/kg diet, whereas the remaining group was given a diet supplemented with alpha-tocopheryl acetate at 200 mg/kg. During the 42-day experimental period, body weight and feed intake were recorded weekly and the feed conversion ratio was calculated. Feeding the experimental diets to rabbits, performance parameters were not affected. Therefore, dietary oregano essential oil exerted no growth-promoting effect on rabbits. With increased supplementation of oregano essential oil, malondialdehyde values decreased in both raw and thermally treated muscles during refrigerated storage. This finding suggests that dietary oregano essential oil exerted a significant antioxidant effect. Dietary supplementation of oregano essential oil at the level of 200 mg/kg was more effective in delaying lipid oxidation compared with the level of 100 mg/kg, but inferior to dietary supplementation of 200 mg alpha-tocopheryl acetate per kg. This study indirectly provides evidence that antioxidant compounds occurring in oregano essential oil were absorbed by the rabbit and increased the antioxidative capacity of tissues.

Animals↗
PubMed2006

Effects of humic acid on broiler chickens.

In view of the alleged effect of humic acid (HA) on growth plate arthrosis in humans, we sought to find if poultry tibial dyschondroplasia (TD) is caused by HA that can occur as a ground water contaminant. In 2 separate trials, broiler chickens were fed different concentrations of HA added to their diet for 4 and 5 wk. The effects of these treatments were measured by general health indices such as growth, feed conversion ratio, relative organ weights, blood differential count, serum chemistry, TD index, and bone biomechanical strength. Humic acid treatment decreased BW but appeared to improve feed conversion ratio. There was no effect on TD index or bone biomechanical strength in HA-treated birds compared with controls. There was no toxic effect of HA that was evident by the absence of any dramatic change in relative organ weights or other telltale signs of serum clinical chemistry that would suggest liver, muscle, or kidney dysfunction. Red blood cell, white blood cell, monocyte, and hematocrit values were not affected, but there was a decrease in blood heterophil counts and heterophil to lymphocyte ratio, which was significant in 4-wk HA-treated birds. Overall these results show that HA slows down growth, but it does not have any adverse health effects on chickens.

Animals↗
PubMed2005

Genetics of efficient feed utilization and national cattle evaluation: a review.

Selection for the wide range of traits for which most beef breed associations calculate expected progeny differences focus on increasing the outputs of the production system, thereby increasing the genetic potential of cattle for reproductive rates, weights, growth rates, and end-product yield. Feed costs, however, represent a large proportion of the variable cost of beef production and genetic improvement programs for reducing input costs should include traits related to feed utilization. Feed conversion ratio, defined as feed inputs per unit output, is a traditional measure of efficiency that has significant phenotypic and genetic correlations with feed intake, growth rate, and mature size. One limitation is that favorable decreases in feed to gain either directly or due to correlated response to increasing growth rate do not necessarily relate to improvement in efficiency of feed utilization. Residual feed intake is defined as the difference between actual feed intake and that predicted on the basis of requirements for maintenance of body weight and production. Phenotypic independence of residual feed intake with growth rate, body weight, and other energy depots can be forced. However, genetic associations may remain when a phenotypic prediction approach is used. Heritability estimates for phenotypic residual feed intake have been moderate, ranging from 0.26 to 0.43. Genetic correlations of phenotypic residual feed intake with feed intake have been large and positive, suggesting that improvement would produce a correlated response of decreased feed intake. Residual feed intake estimated by genetic regression results in a zero genetic correlation with its predictors, which reduces concerns over long-term antagonistic responses such as increased mature size and maintenance requirements. The genetic regression approach requires knowledge of genetic covariances of feed intake with weight and production traits. Cost of individual feed intake measurements on potential replacements must be considered in implementation of national cattle evaluations for efficiency of feed utilization. These costs need to be compared to expected, and, if possible, realized rates of genetic change and the associated reduction in feed input requirements.

Animal Feed↗
PubMed2004

Dietary self-selection for organic acids by the piglet.

Two feeding trials using 48 weaned crossbred piglets each were carried out to determine the effect of acidifying diets with potassium diformate (K-diformate), formic or sorbic acid on dietary preferences in piglets. In Exp. 1 two reference groups were fed either an unacidified diet or a diet containing 2.4% of K-diformate with no choice for selection. Furthermore, piglets in choice group 1 and 2 had the choice between an unacidified diet and a diet supplemented with 1.2 and 2.4% K-diformate, respectively. In Exp. 2, animals of three reference groups received exclusively an unacidified diet or diets supplemented with 1.2% formic acid or 1.2% sorbic acid, respectively. The animals of the choice groups had the choice between an unacidified diet and diets with 1.2% formic acid or 1.2% sorbic acid, respectively. In Exp. 1 average daily feed intake, daily gain and feed conversion ratio were 751 g, 458 g and 1.64 kg/kg, respectively, with no significant differences between treatments. In both choice feeding groups animals chose the diets on offer at random (each around 50%). In Exp. 2 growth and feed intake were not affected by the treatment, but feed conversion ratio was enhanced due to the 1.2% formic acid supplementation. Animals of both organic acid choice groups showed a significant preference for the unacidified diets in each experimental week. The formic acid and sorbic acid diets represented on average only 13.5% and 23.5% of the total feed intake. The present results demonstrate that the inclusion of 1.2% sorbic or formic acid or 2.4% of K-diformate in piglet diets has no negative impact on feed intake, but in a situation of choice feeding, piglets will refuse diets acidified with 1.2% formic or sorbic acid, presumably because of negative taste cues. Acidifying the diets with varying amounts of a K-diformate had no effect on dietary preferences of piglets.

Animal Feed↗
PubMed2004

Effects of cottonseed cake-based diets supplemented with blood meal, alone or with lysine, on the growth of pigs.

An experiment was carried out to establish the effect on the growth of pigs of including blood meal or lysine in diets containing gossypol from cottonseed cake. Forty Landrace x Large White pigs (20 of each sex) were randomly allocated to 5 treatments of 8 pigs each in a 2 x 2 factorial design with two levels of lysine or two levels of blood meal in the diets plus a control diet. The pigs were fed different diets and slaughtered at 75.0 +/- 2.0 kg live weight for carcase analysis. Supplementing the diets with blood meal resulted in higher live weight gains (p<0.001) and improved feed conversion ratios (p<0.001) than supplementing with lysine. Pigs fed the higher level of cottonseed cake showed a significant (p<0.001) depression in live weight gain and feed conversion ratio compared to those fed a low level of the cake. There was no significant difference (p>0.05) in intake in the pigs fed diets with cottonseed cake including blood meal or synthetic lysine. The kidney and liver weights of the pigs fed the diets with a higher level of cottonseed cake were significantly greater (p<0.001) than in those fed the lower level, but when the diets containing cottonseed cake were supplemented with blood meal or lysine at the same level there was no significant difference (p>0.05) in the weights of these organs. Lysine or other factors derived from blood meal appear to be more efficient than synthetic lysine in reducing the adverse effects of gossypol.

Animal Feed↗
PubMedDate not supplied

Comparison of two formaldehyde administration methods of in ovo-injected eggs.

Formaldehyde administration in the hatchery can be very useful in decreasing microbial numbers. However, its use is controversial because of the adverse effects that can occur to chicks and people. This study was designed to look at alternative methods of application of formaldehyde in the hatchery. In addition, the study compared the effects of these methods of application on in ovo-and non-in ovo-injected eggs. All in ovo-injected eggs were given diluent only with no vaccine or antibiotic added. In hatchers containing both in ovo-injected eggs and non-in ovo-injected eggs, formaldehyde was administered two ways, dose (DOSE) and constant rate infusion (CRI). In the DOSE hatcher, 12 ml of formaldehyde was administered at one time every 12 hr, whereas in the CRI hatcher, the same volume was administered at a rate of 1 ml/hr over a 12-hr period. A control (CONT) hatcher received 12 ml of distilled water at the same time that the DOSE hatcher was given formaldehyde. In the DOSE hatcher, a peak concentration of formaldehyde of 102 ppm was reached. The CRI was maintained at approximately 20 ppm of formaldehyde. At pipping, the aerosol bacterial load in the hatchers receiving formaldehyde (DOSE, 130 colony-forming units [CFU]/m3; CRI, 82.5 CFU/m3) was significantly less than in the CONT hatcher (235 CFU/m3). At hatch, the CRI (337.5 CFU/m3) was not able to control bacterial levels and only the DOSE hatcher (150 CFU/m3) had a significantly lower aerosol bacterial count. The CRI non-in ovo-injected eggs (93.39%) had a significantly higher percentage of hatch of fertile compared with non-in ovo-injected eggs exposed to water (84.27%). In ovo-injected eggs in CONT and DOSE treatment groups contained significantly higher percentages of visual contamination than non-in on-injected eggs in the same hatchers. This difference had numerical significance only in the treatment groups within the CRI hatcher. The chicks were then placed into replicate treatment groups and grown for 14 days. Chicks from the CRI in ovo-injected eggs had a statistically significant improvement in feed conversion ratio (1.24) at 14 days when compared with chicks from CONT non-in ovo-injected eggs (1.29). All formaldehyde-exposed chicks had numerically lower feed conversion ratios compared with the CONT exposed chicks.

Animals↗