Development of body temperature regulation in ostrich chicks

Information in the literature indicates that young ostrich chicks, despite being precocial, are poor thermoregulators and may take between 8 and 12 weeks to develop efficient homeothermy. We measured the body temperatures (Tb) of young ostrich chicks (1 to 10 d) at ambient temperatures between 13 degrees and 28 degrees C under controlled conditions in the laboratory and under typical farm-rearing conditions to assess their ability to thermoregulate. Even 1-d-old ostriches could maintain a Tb above 36 degrees C at temperatures of 20 degrees C and older chicks maintained typical adult Tb at ambient temperatures of 13 degrees C in a constant temperature room. Chicks from 2-d-old could maintain adult T(b)s outdoors under a wide range of ambient temperatures and weather conditions. We conclude that ostrich chicks have well developed homeothermy soon after hatching and that some of the higher rearing temperatures recommended in the literature are unnecessary. In appropriate climates, chicks can be allowed outdoors soon after hatching provided they are not exposed to unfavourable weather conditions. Thermoregulation is, however, energetically expensive and thermoregulatory behaviour such as huddling may compete with other important activities like feeding.     

The effect of cat Felis catus predation on three breeding Procellariidae species on Marion Island

Breeding success of Pterodroma macroptera, Procellaria aequinoctialis and Pachyptila vittata salvini in three cat-free and three control areas were used to evaluate the effects of cat Felis catus predation on the avifauna of Marion Island. Breeding success of all three species was significantly higher in the combined cat-free areas than in the combined control areas. However, breeding success in one cat-free area failed to show a significant difference from its particular control area, probably as a result of higher skua (Catharacta antarctica) predation inside the cat-free area. Chicks of P. macroptera and P. aequinoctialis were especially vulnerable to cat predation, since cats can enter their nesting burrows. P. macroptera was seriously affected by cat predation because it is the most abundant of only two winter-breeding petrels. Significant changes in the number of nest visits by these petrels during their breeding season followed hatching dates, which in turn were concomitant with, or were followed by significant differences in the combined breeding success between the cat-free and control areas. The cat-free areas show that an elimination of cat predation would still favour the recovery of the petrel population.     

Efficacy of adsorbents (bentonite and diatomaceous earth) and turmeric (Curcuma longa) in alleviating the toxic effects of aflatoxin in chicks

1. A study was conducted to determine the efficacy of bentonite clay (BC), diatomaceous earth (DE) and turmeric powder (TUM) in alleviating the toxic effects of aflatoxin B₁ (AFB₁).

2. A total of 250 Ross-308 d-old male broiler chicks were assigned to 10 dietary treatments (5 replicates of 5 chicks) from hatch to d 21. Dietary treatments were: basal diet; basal diet plus AFB₁ (2 mg) or BC (0.75%), or DE (0.75%), or TUM (200 mg/kg curcuminoids) and different combinations of AFB_1, BC, DE and TUM.

3. Feed intake (FI), body weight gain (BWG) and feed gain (FG) of the birds fed on BC or DE separately were not different from control birds. Birds fed on TUM only had similar FI and FG but lower BWG than control chicks.

4. Aflatoxin B₁ reduced FI, BWG and serum concentrations of glucose, albumin, total protein calcium, but increased FG and relative liver and kidney weights. Chicks fed on the combination of AFB₁ and BC had similar FI and FG to control chicks. Chicks fed on the combination of DE and AFB₁ had lower FI (23.1%) and BWG (28.6%) compared with control chicks.

5. Chicks fed on the combination of TUM and AFB₁ also had decreased FI (26.2 %) and BWG (31%) compared with control chicks. Chicks fed on the combination of AFB₁, BC and TUM consumed significantly higher amounts of feed compared with chicks fed on only AF, but gained less when compared with control diet chicks.

6. Chicks fed on the combination of AFB₁, DE and TUM diet had poorer growth performance than those fed on AFB₁ alone. None of the combination diets reduced the severity of liver lesions.

     

Food restriction and development of thermoregulation in Muscovy ducklings (Cairina moschata)

1. The interaction between the effects of food restriction and cold stress on the development of body temperature, homeothermy index, metabolic rate and body weight were studied in Muscovy ducklings from hatching to 21 d of age.

2. The control group (ad libitum fed) and the food restricted group (fed to zero growth rate for 9 d) both became homeothermic when they were 2 d old with moderate (10°C) cold stress. At severe cold stress (0°C) the control group was homeothermic 5 days after hatching. However the food restricted group did not reach homeothermy at 0°C and showed a large decrease (to hatching level) in homeothermy index at 10°C and 0°C after 9 d of food restriction.

3. Body temperature was lower in the food‐restricted group during restriction and increased by 1°C after 24 h of ad libitum feeding. During food restriction, resting metabolic rate did not increase with age and was lower than the basal and existence metabolic rate predicted by Aschoff and Pohl (1970) and Kendeigh (1970) respectively.

4. The ratio of metabolisable energy (ME) intake to resting metabolic rate was 3 times lower in the food‐restricted group than in the control group (0.09 and 0.27 respectively) on day 9. The availability of ME was more important than age for the development of thermoregulation in Muscovy ducklings. It is concluded that small improvements in the feeding regimen of young ducklings enhance the endurance and consequently reduce mortality from to environmental cold stress in a scavenger poultry system.     

Physiological adaptive indicators in fasted neonate broiler chicks in response to calcium gluconate injection

Four hundred and eighty mixed‐sex broiler chicks aged 3 h after hatching were allotted according to a completely random design in a 6 × 2 × 2 factorial schedule into two groups of 12 replications of 20 chicks each. The main experimental factors were fasting for 0, 6, 12, 24, 36 and 48 h after chick placement and calcium gluconate (Ca‐glu) injection (0 and 0.6 ml). Live body weight (BW) of chicks decreased linearly (Y = 43.36–0.109BW_0 h, r² = 0.876) as neonatal fasting extended. Injection of 0.6 ml Ca‐glu at 3 h post‐hatching did not affect weight loss of chicks. Yolk residuals (YR) utilized linearly (Y = 5.75–0.062YR, r² = 0.956) by 0.062 g/h in neonate fasted chicks up to 48 h, showing no effect of Ca‐glu injection. Neonatal fasting periods longer than 12 h increased liver weight (p < 0.05). The mean absolute and proportional (% of BW_0 h) breast and leg weight were reduced linearly as neonatal fasting extended (p < 0.05). Serum glucose concentration increased up to 6 h and then reduced linearly to 150 mg/dl after 48‐h fasting. The Ca‐glu treatment influenced serum glucose level for a short period up to 6 h of fasting. Serum Ca concentration sharply increased up to threefolds in the birds received Ca‐glu injection resulting in acute hypercalcemia, then decreased to the initial level after 24‐h feed withdrawal (p < 0.05). The mean serum level for creatinine, uric acid, cholesterol, HDL, albumins and total proteins significantly increased during the fasting periods of 6 to 48 h and significantly elevated in the birds receiving 0.6‐ml Ca‐glu injection compared with the non‐treated chicks (p < 0.05). It was concluded that subcutaneous administration of 0.6 ml Ca‐glu in the chick's neck did not suitably support the increased metabolic demands for glucose and calcium in feed‐deprived neonate chicks.     

Role of route of exposure, age, sex, and type of chicken on the pathogenicity of avian reovirus strain 81-176

Chickens were evaluated by age, sex, and type for susceptibility to reovirus strain 81-176 inoculated subcutaneously. Chicks were most susceptible to the lethal effects of reovirus infection at hatching, after which resistance increased rapidly. By 1 week of age, mortality was negligible, but chicks were still susceptible to the less lethal effects of the virus. Mortality rates of males and females were equal. Leghorn and broiler-type chicks did not differ appreciably in their response to viral inoculation. An effort was made to find a more "natural" means of exposure to reovirus than parenteral inoculation. Neither oral nor aerosol exposure was as effective as subcutaneous inoculation. Attempts to transmit reovirus to susceptible hatching chicks, starting when they were in ovo (19 days of incubation), also failed. Decreased weight gain proved to be a valid criterion for judging reovirus infection. Reovirus infection lowered the mean values of body weights, and the standard deviations were substantially greater, indicating an unevenness in size of the affected chickens.     

Influence of hatching order and brood size on growth in jackass penguins

Jackass penguins Spheniscus demersus hatch two different-sized eggs asynchronously: the second-hatched chick, being, on average, 59% of the weight of the first-hatched chick on hatching. We examined the effect of hatching order on growth rates of mass, culmen length and culmen depth by comparing: (i) growth rates of first-and second-hatched chicks, and (ii) chicks from experimentally synchronized broods to chicks from normal asynchronous broods. Only growth rates in mass showed significant variation. Within a brood, B chicks grew more slowly than A chicks. The effect of synchronizing a brood was to lower the growth rate of both chicks to that of a B chick, suggesting that equal-sized siblings feed less efficiently. Chicks hatching from larger A eggs, that had been synchronized for age and size with chiçks from B eggs, did not grow faster, indicating that chicks hatching from A and B eggs do not have intrinsically different growth rates. Single-chick nests result usually from egg infertility. Singletons showed only a non-significant trend towards faster growth in mass than offspring in two-chick broods, even though food availability in one-chick nests should be better than in two-chick nests. Overall, hatching order had more impact on growth rates of mass than did brood size or egg dimensions.     

The effect of incubation temperature on pre- and post-hatching development in chickens

Chicks hatched from eggs incubated at two temperatures (36.8 °C, 37.8 °C) but similar humidities (30 mmHg during the first 18 d and 40 mmHg thereafter) were reared for 12 weeks in groups of six at 22 °C and in a relative humidity of 45 to 55%.

The lower incubation temperature resulted in a longer incubation period. Female embryos utilised the energy of the egg better than males.

A possible difference in the relationship between the post‐hatching development of males and females and pre‐hatching environmental conditions was indicated by a higher viability at 14 d and a higher body weight after 12 weeks of cocks incubated at 36.8 °C. There were significant effects of sex on food conversion efficiency. Results suggest that pre‐hatching temperatures may influence post‐hatching energy utilisation.     

Sound exposure and its beneficial effects on embryonic growth and hatching of broiler chicks

ABSTRACT

1. The physical factors that involve artificial incubation determine embryonic growth and hatching of broiler chicks, and have important implications for the poultry production chain and chick welfare. This study explored the effects of sound exposure on incubation responses (hatching, embryonic development and chick quality).

2. A 2 × 2 factorial experiment with the factors ‘sound pressure level’ (at 70 and 90 dB) and ‘species-specific vocalisations’ (at 75dB - 85dB) was performed in four experimental incubators (loaded with 90 eggs each) for eight consecutive cycles of incubation, totalling 2880 Cobb-500® broiler breeder eggs.

3. Embryonic growth was not influenced by any experimental factor, but the highest sound pressure level (90 dB) led to earlier hatching, higher hatchability, better chick quality and lower weight at hatching. Additional effects of species-specific vocalisations were found at 70 dB noise, which caused early hatching and better chick quality.

4. It was concluded that the loud noise found in commercial hatcheries (at 90 dB) can be beneficial. Furthermore, the presence of species-specific vocalisations could improve the hatching time and chick quality from experimental incubators (at 70 dB). However, this would not provide additional benefits in commercial hatcheries, due to the machinery noise masking them.     

Brooding temperatures for chicks acclimated to heat during incubation: effects on post-hatch intestinal development and body weight under heat stress

1.?The objective was to evaluate the effects of brooding temperature on intestinal development, oxidative organ damage, and performance of chicks acclimated to high temperature during incubation. The effects of acclimation and brooding temperatures on slaughter weights of broilers under heat stress were also investigated.

2.?Eggs were incubated at either 37?8°C (INC_Cont) or heat-acclimated at 39?5°C for 6 h daily from d 10 to d 18 of incubation (INC_H). Brooding temperatures at floor level were set at 32, 33?5 and 35°C (Bt₃₂, Bt_33?5, Bt₃₅, respectively) for the first 5 d. The temperature was reduced gradually to 30°C from d 6 to d 10. From 21 to 42 d, broilers from INC_Cont Bt₃₂ and INC_H Bt₃₂ and Bt₃₅ were divided into two groups; half from each group was exposed to daily cyclic higher ambient temperatures, while the other half was reared at control temperature.

3.?INC_H chicks had lower jejunum, but greater liver and residual yolk sac weights than INC_Cont chicks on the day of hatching. Although INC_H chicks from Bt_33?5 and Bt₃₅ had lighter body weights than Bt₃₂ on d 5, no significant differences were observed in the body weight of broilers among treatments at 10 and 21 d.

4.?Similar jejunum protein, alkaline phosphatase, maltase, glutathione, and malondialdehyde contents of chicks from INC_Cont and INC_H suggested that heat acclimation during incubation has no effect on jejunum enzyme activity or oxidative status of chicks.

5.?Taking into account INC_H Bt₃₅ chicks having lower T₃ levels on d 5, lower heterophil/lymphocyte (H/L) ratios and similar weights at 42 d under heat stress compared with control broilers, the results suggested that although higher brooding temperatures had no effect on body weights of INC_H chicks during the brooding period, those broilers may able to cope better with heat stress.     

Activity of the Namib Desert dune ant,Camponotus detritus

The activity of the ant Camponotus detritus was studied in the dunes of the central Namib Desert. Activity was divided into two components: transit activity and honeydew collection. Temperature governed both forms, but light controlled the initiation and termination of transit activity, which was bimodal in warm conditions and unimodal in cool conditions. No transit activity occurred at night. Ants were active over a surface temperature range of 10-55°C. Owing to a steep thermal gradient above the sand surface during the day in summer, the temperatures which the ants bodies experienced at 5 mm above the sand were 10-15°C lower than surface temperatures; well within the ants' physiological limits. Winds of about 16 km h^-1 inhibited activity which ceased when wind speeds reached about 25 km h^-1. In summer, the number of ants collecting honeydew was negatively correlated with air temperature while in winter it was positively correlated.     

Soil carbon dioxide effluxes from different vegetation environments in semi-arid Eastern Cape,South Africa

Though important, CO₂ effluxes from non-agricultural ecosystems are poorly characterised. Given that thicket vegetation is prevalent in Eastern Cape, South Africa, we monitored soil CO₂ effluxes from an intact thicket, degraded thicket (DT) and grassland (G) over 10 months, as affected by temperature, moisture and penetration resistance (PR). High soil moisture (16%) reduced PR (4?kg cm^?2), which raised winter effluxes (1.2 µmol m^?2 s^?1), while low moisture (2%) resulted in hard dry soil (14?kg cm^?2) that suppressed spring effluxes (0.2 µmol m^?2 s^?1). There was good interaction between PR and moisture (r = ?0.53), with seasonal effluxes increasing with increasing moisture (r = 0.9, p = 0.0001) and decreasing PR (r = ?0.66, p = 0.02). Temperature effects were significant under unlimited moisture supply. Thus high summer temperature (40 °C) gave lower effluxes in DT and G (<1 µmol m^?2 s^?1) due to limited moisture (<10%), whereas high autumn temperature (48 °C) and good moisture (16%) accelerated CO₂ emissions (averaging 2 µmol m^?2 s^?1) from all covers. Although semi-arid ecosystems are limited by low moisture and sandy soils, they contribute to CO₂ emissions under high moisture and increasing temperature. Keywords: Eastern Cape, grassland, soil carbon dioxide effluxes, soil organic carbon, thicket     

Metabolism and thermoregulation of individual and clustered long-fingered bats,Miniopterus schreibersii,and the implications for roosting

Oxygen consumption of individual long-fingered bats, Miniopterus schreibersii, was measured at air temperatures (T_r) between 2 and 42°C and that of clusters of four and six bats between 5 and 30°C. BMR of individuals was estimated to be 2.29 ml O₂ g ¹ h^-1 between 34 and about 38°C. M. schreibersii showed two different responses to T_a, either maintaining body temperature (T_b) by increasing metabolic rate, or allowing T_b to fall close to ambient temperature and conserving energy (torpor). Euthermic clusters of four and six bats had lower rates of mass-specific oxygen consumption and lower thermal conductances than individuals at equivalent temperatures and torpid clusters maintained a greater temperature differential between T_b and T_a. Lowest rates of metabolism were measured for euthermic bats at air temperatures higher than those available to them in their natural roost in summer, so typical roost temperatures result in metabolic rates that are about 2 4–3.1 times estimated BMR. Roost temperatures of M. schreibersii in South Africa are substantially higher in winter than are generally accepted as being suitable for hibernation but these do not substantially affect torpid metabolic rates, which are low and independent of ambient temperature below 22°C. Clearly at least some species of insectivorous bats are capable of hibernating at temperatures generally considered to be too warm for this activity.     

出雏时间与雏鸡性别比例关系的研究

以尼克红商品蛋鸡鸡胚和出壳雏鸡为材料，分析了不同出雏时间雏鸡性比例的变化，旨在探讨出雏时间与雏鸡性别的关系及鸡胚在孵化期不同性别生长发育的规律，为精细调控孵化条件和制定鸡苗销售计划提供依据。结果表明，不同时间出壳的雏鸡，性比例存在明显差异(P<0.05或P<0.01),并呈现出明显的规律性。在20d12h之前出壳的母雏比公雏多，20d时母雏比例最高(公母性比值为0.268±0.054)；其后公雏比例增加，到21d时公雏比例最高(公母性比值为2．184±0．090）；此后，母雏比例又逐渐增加。到21d16h时公母比例降低到1.453±0.099;但接近出雏结束时，公雏比例又有所回升，至出雏结束时，公母比例上升为1.75±0.057。     

Minimum infusion rates and recovery times from different durations of continuous infusion of fospropofol, a prodrug of propofol, in rabbits: a comparison with propofol emulsion

ObjectiveTo explore, in rabbits, the minimum infusion rates (MIR) required and recovery time from long duration (≤8 hours) continuous infusion of fospropofol disodium, a novel water-soluble prodrug of propofol, and compare it with propofol.Study designProspective, randomized, blinded experimental trial.AnimalsNinety-six adult laboratory rabbits, mean ± SD weight 2.20 ± 0.15 kg.MethodsStage 1. 16 rabbits were assigned to receive fospropofol disodium or propofol to measure MIR, using an up-and-down method with response to tail-clamping stimulus (TCS). Stage 2. Eighty rabbits were allocated to group F (fospropofol disodium) or group P (propofol), and further subdivided (n = 10 in each subgroup) according to infusion time (2, 4, 6 or 8 hours), to groups F_2h, F_4h, F_6h, F_8h and P_2h, P_4h, P_6h, P_8h. Fospropofol or propofol were infused, and tail clamping applied to maintain the same depth of anaesthesia until infusion was completed. Times to recover righting reflex (RR), to respond to TCS, and total recovery to different durations of continuous infusion of two anaesthetic drugs were noted. Respiratory and pulse rates and oxygen saturation were analyzed. The plasma concentrations of fospropofol disodium, the active metabolite propofol (propofol_F) and propofol emulsion were measured with respect to loss and recovery of RR and TCS.ResultsMIR of fospropofol disodium was 2.0 mg kg^?1 minute^?1, and MIR of propofol was 0.9 mg kg^?1 minute^?1. Times in minutes to total recovery from anaesthesia in groups F and P were as follows, F_2h 15 ± 3; F_4h 26 ± 4; F_6h 52 ± 6; F_8h 84 ± 10; and P_2h 10 ± 1; P_4h 19 ± 7; P_6h 36 ± 7; P_8h 48 ± 5.Conclusions and clinical relevanceAfter continuous intravenous infusion in rabbits (≤8 hours), fospropofol disodium and propofol both show an extension of recovery time with increasing infusion time, fospropofol disodium showing a significantly greater prolongation compared to propofol emulsion when infusion time increases to 6 and 8 hours.     

Food of Canis Mesomelas in South Africa

Data from five jackass penguin chicks (mean mass 201 g) showed that even young chicks can increase their oxygen consumption from 0,76± 0,16 ml 0¹/gxhr at 35°C to 2,09± 0,21 ml 0, at 20 °C. Close parental attendance may therefore be interpreted not only as protection against aerial predators but also as creating a microclimate which could favour a decrease in maintenance requirements and thus channel a substantial part of the available energy into growth. A decrease in rectal temperature, despite the increase in heat production, is interpreted as indicative of poor insulative properties of the down. Preliminary data on the ontogeny of thermoregulation indicate that penguin chicks may attain mature thermoregulatory abilities at a mass of approximately 400g.     

Higher levels of CO2 during late incubation alter the hatch time of chicken embryos

1. It has been reported that the increasing CO₂ tension triggers the embryo to pip the air cell and emerge from the egg. However, the mechanism by which higher CO₂ concentrations during the last few days of incubation affect chick physiology and the hatching process is unclear. This study investigated the effect of CO₂ concentrations up to 1% during pipping, on the onset and length of the hatch window (HW) and chick quality.

2. Four batches of Ross 308 broiler eggs (600 eggs per batch) were incubated in two small-scale custom-built incubators (Petersime NV). During the final 3 d of incubation, control eggs were exposed to a lower CO₂ concentration (0.3%), while the test eggs experienced a higher CO₂ concentration programme (peak of 1%).

3. There were no significant differences in blood values, organ weight and body weight. There was also no difference in hatchability between control and test groups. However, a small increase in the chick weight and the percentage of first class chicks was found in the test groups. Furthermore, plasma corticosterone profiles during hatching were altered in embryos exposed to higher CO_2; however, they dropped to normal levels at d 21 of incubation. Importantly, the hatching process was delayed and synchronised in the test group, resulting in a narrowed HW which was 2.7 h shorter and 5.3 h later than the control group.

4. These results showed that exposing chicks to 1% CO₂ concentration during pipping did not have negative impacts on physiological status of newly hatched chicks. In addition, it may have a significant impact on the physiological mechanisms controlling hatching and have benefits for the health and welfare of chickens by reducing the waiting time after hatching.     

Factors related to high levels of ostrich chick mortality from hatching to 90 days of age in an intensive rearing system

Ostrich chick mortality was studied in 2522 chicks that were hatched artificially during the 1999/2000 breeding season. High levels of mortality were observed, with 1978 (78.4 %) of these chicks dying before 90 days after hatching. A total of 46.7 % (1,177) of these chicks died before 28 days of age, and a further 30.7% (801) died between 28 and 90 days post-hatching. Chick mortality to 28 days of age could not be conclusively related to sex, day of external pipping or breeder diet. Mortality rates were higher (P< 0.05) at the beginning and end of the breeding season than in the middle months. Differences in mortality levels of chicks incubated in different incubators could be related to the time of the breeding season during which the incubator was mostly used. The regression of chick mortality to 28 days of age on day-old chick mass followed a 2nd-degree polynomial. Chicks with day-old masses below 762.5 g were particularly at risk of dying before 28 days after hatching. Chicks hatching from eggs where excessive water loss to 35 days of incubation (>18%) was recorded were also at risk of succumbing before 28 days of age. Chick mortality percentages for the period from 28 to 90 days of age exceeded 80 % in chicks weighing an average of 1.050 g at 28 days. Mortality percentages declined sharply at higher live masses, to between 20 and 30 % in chicks weighing > or = 1,950 g. This 'core' level of mortality remained throughout, even in the heaviest chicks. It was concluded that the high levels of chick mortality could be related to stress in chicks, resulting from an inability to adapt to the rearing environment. The high subsequent mortality percentages of low live mass chicks that survived to 28 days after hatching could probably be attributed to residual setbacks suffered earlier. Abetter understanding of the underlying principles involved in ostrich chick mortality in intensive rearing environments is required for progress in this field, resulting in more predictable survival rates under these conditions.     

Stressor effects of adrenaline on the immature fowl

Chicks were injected with L-adrenaline (500 microgram/kg) thrice weekly from hatching for one, two or three weeks. The growth rate of treated chicks was depressed, particularly in the first week. When four-week-old chicks were given nine injections of adrenaline over a three-week period, growth rate was also depressed but less severely. The greater sensitivity of the younger chicks is thought to result from an immature blood-brain barrier. Relative adrenal mass (mg/kg) was generally increased but adrenal cholesterol depletion occurred only in three-week-old birds treated with adrenaline throughout. Plasma glucose and cholesterole concentrations were within the normal range after three weeks of treatment but there was a significant hypolipacidaemia in the younger birds treated for two or three weeks.     

Effect of butyrate,clopidol and their combination on the performance of broilers infected with Eimeria maxima

1. The effect of butyric acid glycerides (BAGs) with and without clopidol (CLP) on Eimeria maxima on growth and associated biochemical variables was investigated in broiler chickens.

2. One-day-old chicks were divided into 6 equal groups (Gps) of 30 chicks each; each group was subdivided into 6 equal subgroups. Gp 1 was not infected and not treated. Chicks in Gp 2 were not infected and fed on a ration mixed with 4 g BAGs/kg for 6 successive weeks. Chicks of the other groups were directly inoculated intra-crop with 1 × 10⁴ sporulated oocysts of E. maxima at 14 d of age. Gp 3 was infected and not treated. Chicks in the remaining three groups were given diets mixed with the tested drugs for 6 successive weeks. Gp 4 was fed on a diet mixed with CLP (125 g/kg). Gp 5 was given a diet mixed with BAGs (4 g/kg diet). Gp 6 was fed on a diet mixed with both BAGs (4 g/kg diet) and CLP (125 g/kg).

3. Birds in Gps 5 and 6 showed a reduction in the mean oocyst count, lesion scores and developmental stages in the lamina propria and improved growth and biochemical variables. BAG supplementation enhanced growth and production of healthy broilers.

4. It was concluded that BAGs were a useful supplement in broiler diets as an alternative to growth promoters and antimicrobial drugs.