Effect of virginiamycin on serum carotenoid levels and long, segmented, filamentous organisms in broiler chicks.

Virginiamycin (Stafac 20) was mixed with feed at three levels recommended for chickens--5.5, 11, and 22 mg/kg (respectively 5, 10 and 20 g/ton)--and fed to broiler chicks. When fed from 1 day through 2 weeks of age, the drug appeared to retard infection of the lower small intestine by long, segmented, filamentous organisms (LSFOs), and at 2 weeks of age serum carotenoids in treated chicks were significantly higher than levels found in unmedicated chicks. However, as chicks were grown out to 4 and 6 weeks of age, the drug did not completely prevent eventual LSFO infection, even at the highest dose, and mean serum carotenoid levels in treated chicks were not significantly different from levels in control chicks. However, chicks fed at the level of 22 mg/kg had fewer LSFOs. Withdrawal of virginiamycin from treated chicks at 4 weeks of age allowed LSFO infection to occur but did not significantly affect serum carotenoid levels. When the drug was fed for 2 weeks at 22 mg/kg to 2-week-old chicks already infected with LSFOs, the bacteria could no longer be detected, suggesting that virginiamycin may aid the natural decline in LSFO population. Coincident with this treatment, serum carotenoids were higher, but not significantly so. Virginiamycin did not significantly increase the mean body weights of chicks in any of these experiments.     

Dietary conjugated linoleic acid improves antioxidant capacity in broiler chicks

1. The influence of dietary conjugated linoleic acid (CLA) on the antioxidant status in the absence or presence of endotoxin exposure was studied with male broiler chicks. 2. In experiment 1, a total of 240 1-d-old broilers were allotted into 4 dietary groups (0, 2.5, 5.0 or 10.0 g pure CLA/kg) to study the influence of CLA on growth performance and antioxidant defence systems. The results showed that growth performance was not altered by 42 d of CLA consumption. Increased total superoxide dismutase (TSOD) activities in liver, serum and muscle were observed in chicks given 10.0 g CLA/kg diet. Dietary CLA at 10.0 g/kg also markedly elevated liver catalase (CAT) activity. Malondialdehyde (MDA), a marker of lipid peroxidation, decreased in liver, serum and muscle in chicks given 5.0 and 10.0 g CLA/kg diet. 3. In experiment 2, a total of 120 1-d-old broilers were fed on a control diet (without CLA) or 10.0 g CLA/kg diet. Half of the birds fed on each diet were injected intraperitoneally with 0.25 mg/kg body weight of Salmonella enteritidis lipopolysaccharide (LPS) at 16, 18 and 20 d of age. Decreased glutathione peroxidase (GSH-Px), TSOD activity and increased ceruloplasmin and MDA concentrations were seen in the challenged chicks. Dietary CLA prevented the loss of body weight gain and feed conversion ratio of chicks followed repeated endotoxin exposure. CLA partially inhibited the increase of serum ceruloplasmin and MDA at 17 and 21 d of age and notably suppressed the decrease of serum TSOD activity at 21 d of age. 4. These results suggested that dietary CLA enhances the activity of antioxidant enzymes including TSOD and CAT. Supplementation of CLA has been shown to ameliorate the antioxidant balance and performance of chicks during oxidative stress.     

Effect of feeding cassava (Manihot esculenta Crantz) root meal on growth performance,hydrocyanide intake and haematological parameters of broiler chicks

The effect of feeding cassava root meal on growth performance, hydrocyanide intake, haematological indices and serum thiocyanate concentration of broiler chicks was investigated using 300-day-old male broilers. There were five dietary treatments arranged in a 2?×?2?+?1 factorial arrangement of two processing methods of cassava root (peeled and unpeeled) included at two levels (100 and 200 g/kg) plus a control diet (maize-based diet, containing no cassava root). Each treatment was replicated six times with ten birds per replicate. The feeding trial lasted for 28 days. Control-fed birds had the highest overall (P?P?P?P?P?P?P?P?P?P?P?P?P?P?相似文献   

Growth of broilers fed on diets containing dried poultry manure

Sixty 7‐d‐old male broiler chicks were housed in individual metabolism cages and offered one of six purified diets for 14 d. The diets were formulated to have the same ME contents but had different nitrogenous supplements: diet A, was the basal diet, containing PRG essential amino acid (EAA) mixture equivalent to 15 g N/kg; B, basal+12% glutamic acid (GA); C, basal plus EAA mixture equivalent to EAA content of 20.09% DPM; D, basal + EAA+12% GA; E, basal + 20.09% autoclaved DPM; F, basal + 20.09% unautoclaved DPM. The rank order of final body weights at 21 d of chicks fed on these diets were D(292 g) > B(258 g), (F254 g), E(253 g) > C(206 g) > A(180 g), (P<0.05). Chicks fed on diet C had better food conversion efficiencies (FCE) than those fed on diet A (0.449 and 0.374 respectively) and D was better than B (0.592 and 0.533 respectively).

In a second experiment, carried out under field trial conditions using commercial‐type diets formulated to contain DPM, 24 groups, each of about 40 male or female broiler chicks, were given diets containing 0% (P) or 5% (Q) DPM from 1 d of age for 4 weeks. From 4 to 8 weeks one of three diets with 0% (R), 5% (S) or 10% (T) DPM was fed according to a 2 (sexes) x 2 x 3 factorial design. Between o and 4 weeks feeding DPM had no significant effect on body weight or food consumption, but birds fed diet Q had an improved FCE (P<0.05). Between 4 and 8 weeks birds fed on S and T were heavier than the controls at 6 weeks, but this increase was not significant at 8 weeks (P> 0.05). Food consumption was not affected, but the FCE improved with increasing inclusion of DPM. At 8 weeks of age birds fed on Q, were heavier than birds fed on diet P.     

Vitamin A nutrition of growing cockatiel chicks (Nymphicus hollandicus)

The experiments examined the physiological response of growing cockatiel chicks to varying levels of dietary vitamin A (VA) or beta-carotene and the rate of liver VA uptake. Adult cockatiels breeding pairs (n=10 pairs) were fed a VA-deficient diet for approximately 90 days prior to onset of egg laying. Breeding pairs were then allowed to feed their chicks diets containing either 0 IU VA/kg, 4000 IU VA/kg, or 2.4 mg beta-carotene/kg. After 5 weeks, chicks fed 0 IU VA developed poor feathering, facial dermatitis and reduced body weight (p<0.05). Liver VA was higher in chicks fed 4,000 IU VA or 2.4 mg beta-carotene vs. those fed 0 IU VA (p<0.05). Duodenal beta-actin and 15,15'-dioxygenase mRNA expression was similar to that of growing chickens, and greatest for cockatiel chicks fed 0 IU VA (p<0.01). Chicks fed 0 IU VA had keratinization of the bursa and oral mucosa, and reduced bursa development and lymphocyte density (p<0.05). Finally, when chicks fed 0 IU VA were orally gavaged with 20 IU VA/g body weight, maximal liver retinol uptake occurred between 0 and 24 h and reached a plateau at 36 h. These data demonstrate that VA deficiency can be prevented with 4,000 IU VA/kg diet or 2.4 mg beta-carotene/kg diet, although beta-carotene conversion to VA may be lower in cockatiels than chickens.     

Comparison of the utilisation of palm kernel meal,brewers' dried grains and maize offal by broiler chicks

1. Palm kernel meal (PKM), brewers dried grains (BDG) and maize offal (MO) were included in broiler diets, each at 100, 150 or 200 g/kg; the diets were fed up to 35 d of age. 2. Overall food intake and weight gain decreased in the order BDG, PKM and MO. There were, however, significant interactions between the test ingredients and dietary concentrations in all the growth responses. Food intakes increased with the dietary concentrations of each test ingredient, but the increase was greater for BDG than PKM or MO. For weight gain, at 100 g/kg, the final body weights of the chicks fed on the diets with BDG and MO were similar, and those of chicks fed on the diet with PKM slightly lower. However, at 200 g/kg, growth rate of chicks fed on the BDG and PKM diets were similar while those of chicks fed on the MO diet was 7% lower. Efficiency of food utilisation was similar at 100 g/kg for all the ingredients and decreased as their concentrations increased; however, the decrease was considerably less for the PKM than for the MO and BDG diets. 3. Broilers fed on the BDG-based diets voided most excreta followed by those fed on the PKM and MO diets; excreta water content was highest from birds fed on the MO diets followed by the PKM and BDG diets. Apparent retention of dry matter was similar with all the test ingredients, but it decreased only significantly at 200 g/kg dietary concentration. The rate of passage was faster with the PKM diets followed by the MO and BDG diets; it was increased at 200 g/kg dietary concentration of the test ingredients.     

Effect of high concentrations of dietary vitamin E during various age periods on performance, plasma vitamin E and meat stability of broiler chicks at 7 weeks of age.

1. The effect of high concentrations of vitamin E (alpha-tocopheryl acetate) fed during various age periods on the performance and the oxidative stability (thiobarbituric acid [TBA] values) of the drumstick meat of 7-week-old broiler chicks was determined. The basal diets (for the age periods 0 to 3, 3 to 6 and 6 to 7 weeks) contained 60 g soyabean oil and 24 mg vitamin E/kg. The following five treatments were evaluated: (1) the basal diets from 0 to 7 weeks of age (control); (2) vitamin E, 100 mg/kg diet from 0 to 7 weeks of age; (3) vitamin E, 150 mg/kg diet from 0 to 3 weeks of age; (4) vitamin E, 150 mg/kg diet from 0 to 3 weeks of age and 100 mg/kg diet from 6 to 7 weeks of age; (5) vitamin E, 100 mg/kg diet from 5 to 7 weeks of age. 2. Food intake, weight gain and food efficiency were not significantly (P greater than 0.05) affected by the vitamin E treatments. 3. Plasma alpha-tocopherol (AT) concentrations in treatments 2, 4 and 5 were similar, and markedly higher than those in treatments 1 and 3, while those of treatment 3 were significantly (P less than 0.001) higher than those of treatment 1. Plasma retinol concentrations were not significantly (P greater than 0.05) affected by the vitamin E treatments. 4. TBA values of the meat were very low and not significantly affected by the vitamin E treatments. However, after incubation the TBA values were highly significantly (P less than 0.01) negatively correlated with the amount of vitamin E consumed during the experiment. The stability of meat of birds fed the various combinations of vitamin E (treatments 3, 4 and 5) was significantly (P less than 0.05) higher than that of birds which did not receive additional vitamin E (treatment 1), but it was significantly (P less than 0.001) lower than that of birds which received vitamin E continuously (treatment 2). 5. It is concluded that a high concentration of vitamin E fed during 0 to 3 weeks of age may significantly improve AT status of the broiler chick up to 7 weeks of age.     

Effect of low protein diets for growing Leghorn pullets upon subsequent laying performance

An experiment was conducted with White Leghorn pullets to study the effect on laying performance of dietary protein content and amino acid supplementation during the growing period. From 0 to 6 weeks of age birds fed on diets containing either 149 g protein/kg supplemented with methionine and lysine or 182 g protein/kg grew faster than those fed on a diet containing 149 g protein/kg alone. However, only those fed on the supplemented diet utilised their food more efficiently. From 7 to 20 weeks of age neither body weight gain nor food utilisation was affected by the dietary protein content. Pullets fed the low protein diet supplemented with 2 g methionine/kg and 2.5 g lysine/kg during the period of 0 to 6 weeks of age had significantly better egg production than birds fed the low protein diet alone. The dietary protein content during 7 to 20 weeks of age did not influence subsequent egg production.     

Effect of early stages of fungal development on the nutritional value of diets for broiler chicks

During 65 d of storage a gradual increase in fungal activity (evaluated by CO2 production) was observed in a diet with its moisture content elevated to 136 g/kg. This activity was inhibited by supplementation of the wetted diets with either calcium propionate (3 g/kg) or Agrosil (2 g/kg). The fat content of the wetted untreated diet decreased between the 18th and the 45th d of storage from 38 to 29 g/kg. This change was prevented by the addition of either of the two fungistats. The weight gains of 7-d-old female broiler chicks fed on the wetted diets with or without the fungistats from the 18th d after their preparation for 27 d, did not differ significantly (P greater than 0.05) from those of birds fed on the unwetted diet. However, the food:gain ratio of chicks fed on the unwetted diet was significantly (P less than 0.05) better than that of chicks fed on the fungistat-free wetted diet. The results from birds fed on the fungistat-supplemented wetted diets were intermediate. It is concluded that the early stages of fungal activity (characterised by increased CO2 production, without changes or with only a slight decrease in fat content) have only a minor effect on the nutritional value of diets.     

Studies on the toxic effects of crambe meal and two of its constituents, 1‐cyano‐2‐hydroxy‐3‐butene (GHB) and epiprogoitrin,in broiler chick diets

1. Studies were undertaken to determine a safe inclusion rate for crambe (Crambe abyssinica) meal in broiler chick diets, and to determine the mechanism for adverse effects by investigating its constituents; l‐cyano‐2‐hydroxy‐3‐butene (CHB) and 3‐butenyl glucosinolate (epi‐progoitrin, E‐PG).

2. Crambe meals were prepared to differ in E‐PG (19, 36 and 40 g/kg) and CHB contents (0.1, 0.7 and 1.9 g/kg), and with either active or inactive thioglucosidase.

3. Meals were fed to 7‐d‐old broiler chicks at 50 or 100 g/kg of the diet for 12 or 13 d. In separate studies, isolated E‐PG or CHB were mixed into the diet or administered by gavage to 7‐d‐old broiler chicks in amounts equivalent to 50 or 100 g/kg crambe meal diets for 10 and 12 d, respectively.

4. Weight gain decreased (P<0.05) in chicks fed on the high glucosinolate crambe diets or isolated E‐PG. Food consumption decreased (P<0.05) in chicks fed on the diet containing the high E‐PG meal with active enzyme.

5. Mild liver lesions and increased serum aspartate aminotransferase were found in chicks fed on the diet containing the high glucosinolate meal with active enzyme. Other organs, including thyroids, were normal.

6. Commercially‐processed crambe meal appeared safe at an inclusion rate of 50 or 100 g/kg diet, but could not be recommended at this point for long term feeding.     

Influence of dietary conjugated linoleic acid isomers on early inflammatory responses in male broiler chickens

1. The influence of dietary conjugated linoleic acid isomer (CLA, 0 and 10 g/kg) on the metabolic and physiological responses to immune stimulation induced by a single injection of Salmonella enteritidis lipopolysaccharide (LPS) or repeated injections of LPS and Sephadex G-50 was determined in male broiler chicks. 2. In experiment 1, 10-d-old chicks were fed on experimental diets for 14 d and half of the birds fed on each diet were injected intraperitoneally with LPS (1.5 mg/kg body weight). In experiment 2,7-d-old chicks were fed on experimental diets for 18 d. Immune stimulation was started at 19 d old and continued for 5 d. Half of the birds fed on each diet were injected intraperitoneally with 0.25 mg/kg body weight of LPS at 19, 21 and 23 d of age, and with 250 mg/kg body weight of Sephadex at 20 and 22 d of age to stimulate the immune system. 3. In experiment 1, giving CLA prevented an increase in blood heterophil to lymphocyte ratio 7 h after a single injection of LPS, and increases in plasma ceruloplasmin and alpha 1 acid glycoprotein (AGP) 24 h after the injection, but not 7 h after the injection. CLA also prevented a decrease in food intake for 24 h after LPS injection. 4. In experiment 2, the CLA diet partially prevented reductions in body weight gain and weight gain to feed intake ratio caused by repeated injections of LPS and Sephadex. Feeding CLA prevented increases in plasma ceruloplasmin and AGP at 24 d of age caused by repeated injections of LPS and Sephadex, but not at 20 d of age. 5. These results suggest that feeding CLA alleviates some undesirable metabolic and physiological changes induced by immunological stimulation in male broiler chicks.     

Studies on the action of pectin in depressing the growth of chicks

1. Citrus pectin (40 g/kg diet) significantly depressed weight gain and food utilisation when fed to young chicks. This effect was not associated with pathological manifestations or signs of deficiency.

2. Feeding pectin at 40 g/kg diet did not affect the retention of energy, nitrogen, lipids or calcium, but decreased serum and liver total cholesterol and altered the glucose tolerance of chicks by retarding clearance of ingested glucose from blood.

3. Supplementation of the pectin‐containing diet with penicillin (70 mg/ kg), with selected essential elements and vitamins, or increasing the energy density of the diet had no ameliorating effect on the depressed growth.

4. Pair‐feeding showed that pectin depressed food intake, reduced carcase lipid content and increased carcase moisture content.

     

Responses of broiler chicks to dietary copra cake of high lipid content

1. Broiler chicks fed on a diet containing 500 g/kg expeller copra cake of high residual oil content not only retained less dry matter and gained less weight than those fed on a control diet with no copra, they also experienced difficulty in achieving similar food intakes. 2. Chicks given the 500 g/kg copra ration initially displayed an excited behaviour pattern, which may have developed out of frustration as they could neither derive adequate nourishment from their food nor increase food intakes sufficiently to allow them to achieve their genetic potential for growth. 3. Chicks however showed considerable adaptation in that efficiency of food utilisation and intakes were increased gradually; the latter appeared to be partly regulated by an increased intake of water that was associated with copra feeding. The surface area of the intestines was also increased in order to facilitate the absorption of nutrients, and greater proportions of the nutrients absorbed were converted into body weight. 4. There were no significant differences in 7-week body weights of chicks fed the control, 125 g/kg and 250 g/kg copra diets. Although weight gains at the 500 g/kg inclusion rate were lower, the carcases of these chicks had less abdominal fat and were consequently leaner.     

Effects of different rates of drying cassava root on its toxicity to broiler chicks.

1. The effects of drying cassava root at different rates on its composition and toxicity to broiler chicks were examined. Unpeeled roots from a high-cyanide cultivar of cassava were chipped and dried at 25 degrees C to a moisture content of below 100 g/kg over 24 h for fast-dried meal (FD) or 72 h for slow-dried meal (SD). The meals were incorporated at 250 and 500 g/kg into semi-synthetic diets which were fed to day-old broiler chicks as mash or pellets in separate experiments. 2. The two drying rates produced meals with similar concentrations of polyphenols, but different concentrations of cyanogens, the latter being 38 and 482 mg total cyanide/kg for SD and FD, respectively. The linamarin, acetonecyanohydrin or total cyanide content measurements of pelleted diets were highly correlated. 3. Growth rates of chicks fed on SD-based diets were significantly higher than those of chicks fed on FD-based diets. Compared with a control diet, weight gain of chicks fed on the 500 g FD/kg diet (containing 258 mg total cyanide/kg) was 77% lower, although performance also appeared to be reduced at 142 mg total cyanide/kg. 4. The ratio of water:food intake of chicks was higher in FD than in SD groups, and this was reflected in the high water content of excreta. There was increased bile excretion, the chloretic effect increasing with the cyanogen content of diet. Pancreas weights were lower in FD than in SD groups in experiment 1 (mash diets), but not in experiment 2 (pelleted diets), while there was a significant interaction between drying method and cassava inclusion rate on liver weight in experiment 2, but not in experiment 1. There were no effects on the mortality rate. 5. Pelleting of diets generated high temperatures, but did not significantly alter the cyanogen concentration or the growth of the chicks. 6. Thus, slower rates of drying cassava roots produce meals with lower cyanogen concentration that are, consequently, less toxic to broiler chicks. Cassava root meal of less than 40 mg total cyanide/kg can be fed to broiler chicks at 500 g/kg without any adverse effects.     

Effect of dietary inclusion of fermented pigeon pea (Cajanus cajan) meal on growth, apparent nutrient digestibility and blood parameters of cockerel chicks

The effect of dietary inclusion of fermented pigeon pea meal (FPPM) on growth response, apparent nutrient digestibility, haematological indices and serum biochemistry of cockerel chicks was studied using 240-day-old cockerel chicks allotted to four dietary treatments consisting of 60 birds each. Four experimental diets were formulated to include FPPM at 0, 50, 100 and 150?g/kg inclusion levels, respectively. Each of the diets was fed to 60 birds replicated six times with ten birds per replicate. The feeding trial lasted for 56?days. Results indicated that final live weight (linear (L). quadratic (Q): P??0.05) by the inclusion of FPPM. Haemoglobin and serum uric acid concentrations were also reduced (P?相似文献   

Dietary conjugated linoleic acids alleviate early inflammatory response caused by lipopolysaccharide injection in male broiler chicks

An experiment was undertaken to determine if dietary conjugated linoleic acid (CLA) influences the early stage of the inflammatory response caused by a single injection of Salmonella enteritidisi lipopolysaccharide (LPS) in male broiler chicks. Chicks (7 days old) were fed either 0 or 10 g CLA/kg in their diet for 21 days. At 28 days old, birds were injected intraperitoneally with 1.5 mg LPS/kg body weight after 12 h fasting. Changes in feed intake, rectal temperature and plasma α‐1 acid glycoprotein and ceruloplasmin concentrations were measured during 24 h after LPS injection. Chicks fed the CLA diet were fed more feed for 24 h, had a lower rectal temperature at 9 and 24 h and a lower plasma α‐1 acid glycoprotein concentration at 24 h after LPS injection than chicks fed the basal diet. Plasma ceruloplasmin concentration tended to be lower in chicks fed the CLA diet than in chicks fed the basal diet. The results suggest that dietary CLA alleviate undesirable early inflammatory response due to LPS injection in male broiler chicks.     

Vitamin D3 requirement of young chicks receiving diets varying in calcium and available phosphorus

1. Three battery experiments were conducted with broiler chicks during the 2nd and 3rd week of life. Graded amounts of cholecalciferol (D3) were added to maize-soyabean meal diets that were designed to be (a) severely deficient in available phosphorus (P), (b) marginally deficient in calcium (Ca) or (c) adequate in both available P and Ca. 2. With diets containing 1.0 g available P and 6.3 g Ca/kg (assay 1), graded doses of D3 between 0 and 37.5 mu/kg produced linear (P 0.05) positive responses in both weight gain and tibia ash. With a D3 concentration of 1250 mug/kg, 250 times the requirement recommended by the NRC, bone ash was increased (P 0.05) over that of birds fed 37.5 mug/kg, and neither weight gain nor food intake were reduced. 3. With a P- adequate diet (4.5 g available P/kg) containing 8.5 g Ca/kg (assay 2), weight gain and bone ash increased linearly (P 0.05) upon supplementing the basal diet with 0, 2.5 and 5.0 mug D3/kg. Higher doses of D3 did not elicit further responses, and chicks fed on a diet containing 1250 mug D3/kg gained as fast and had bone ash values that did not differ from those of chicks receiving 5, 10, 20 or 40 mug D3/kg. 4. When the maize-soyabean meal basal diet was fortified with Ca and P to achieve adequate amounts of Ca (10.1 g/kg) and P (4.5 g available P/kg) in assay 3, dietary additions produced results similar to those obtained in assay 2 where P was adequate and Ca was slightly deficient. Again, chicks receiving a surfeit of D3 (1250 mug/kg) exhibited weight gains and bone ash values that were as great as those of chicks receiving 5, 10, 15 or 30 mug D3/kg. 5. It is apparent that young chicks have a high tolerance for excess D3, and chicks fed on diets that are severely deficient in available P continue to respond to D3 in excess of 37.5 mug/kg.     

葡多酚对肉鸡生产性能和免疫机能的影响

试验旨在探讨日粮中葡多酚对肉鸡生产性能和免疫机能的影响。选用1日龄健康爱拔益加(AA)肉仔鸡公雏鸡240只,随机分配到对照组及试验Ⅰ、Ⅱ、Ⅲ组4个处理组中,空白对照组饲喂基础日粮(不含葡多酚),试验Ⅰ、Ⅱ、Ⅲ组分别在基础日粮中添加葡多酚7.5、15、22.5 mg/kg,试验期42 d。结果表明,在0~3周龄,试验Ⅲ组采食量最高,生长速度较快;在3~6和0~6周龄,试验Ⅰ组日增重和饲料效率最佳,而试验Ⅱ组略低于对照组。葡多酚对肉仔鸡的免疫器官发育无显著影响,7.5 mg/kg葡多酚有增加肉仔鸡外周血中CD3⁺、CD8⁺、αβ和γδ T细胞数量的潜力。因此,肉仔鸡日粮中添加适量葡多酚可促进生长,调节免疫机能。     

Energy and nitrogen metabolism of diseased chickens: aflatoxicosis.

1. New Hampshire chicks were fed on diets containing 0 (control), 0-7 (A), or 1-1 (B) ppm of aflatoxin B1. In two trials 1-d-old chicks were offered ad libitum the three diets for 14 d. The gaseous exchange of five chickens from each group was measured for 3 or 4 d, the same diets being fed, at 2, 3, 4 and 5 weeks of age in two series of experiments. The controls were fed at the lower intake of the two other groups. Following each series of experiments at the various ages, birds were starved for 24 h and their heat production was re-measured over the next 24 h. 2. Mortality was highest and growth and food conversion poorest where the diet with the highest aflatoxin concentration was fed. Mortality was confined to the first 2 weeks. 3. Performance of birds in the chambers was improved in the second series due to differences in food intake. It also improved with age suggesting some resistance to the toxin. 4. Mean respiratory quotient was 0-97 for fed chickens on diet B. This was significantly different from 0-92 for the two other groups. Similarly, during starvation the RQ was 0-76 compared with 0-73. 5. birds fed on diet B generally grew better, retained more nitrogen and had a better energy balance in the respiration chambers than the other two groups. Metabolisability of dietary energy was less (68.5%) for all groups at 2 to 3 weeks than when older (70%) but availability of ME was the same (71%) for all groups. 6. Heat production (kJ/kg0-75) of starved birds on diet B was significantly lower than the other two groups, while endogenous nitrogen excretion was higher. 7. Water consumption (ml/g food and g/100 g body weight) was greatest for birds on diet B. 8. Although aflatoxin in the diet substantially reduced intake there was no indication that at these reduced levels of intake, nitrogen or energy metabolism were measurably impaired.     

Xanthophylls increased HDLC level and nuclear factor PPARγ, RXRγ and RARα expression in hens and chicks

This study was designed to investigate effects of xanthophylls on serum lipid profile (triglyceride, TG; cholesterol, CHO; high‐density lipoprotein cholesterol, HDLC; and low‐density lipoprotein cholesterol, LDLC) and nuclear factor (peroxisome proliferator‐activated receptor gamma, PPARγ; PPAR gamma coactivator 1 alpha, PGC1α; retinoid X receptor gamma, RXRγ; and retinoic acid receptor alpha, RARα) gene expression of breeding hens and chicks. In experiment 1, 432 hens were divided into three groups and fed diets supplemented with 0 (as control group), 20 or 40 mg/kg xanthophylls. Blood was sampled at 7, 14, 21, 28 and 35 days of trial. Liver, duodenum, jejunum and ileum were sampled at 35 days of trial. Results showed that serum HDLC level of hens was increased after dietary 40 mg/kg xanthophyll addition for 21, 28 and 35 days, while serum TG, CHO and LDLC were not affected. Xanthophyll addition also increased PPARγ expression in jejunum, RXRγ expression in duodenum and jejunum, and RARα expression in liver and duodenum. Experiment 2 was a 2 × 2 factorial design. Male chicks hatched from 0 or 40 mg/kg xanthophyll diet of hens were fed diet containing either 0 or 40 mg/kg xanthophylls. Liver, duodenum, jejunum and ileum were sampled at 0, 7, 14 and 21 days after hatching. Blood samples were also collected at 21 days. Results showed that in ovo xanthophylls elevated PPARγ in duodenum and jejunum, and RXRγ and RARα in liver of chicks mainly within 1 week after hatching, while dietary xanthophylls increased serum HDLC level and PPARγ and RXRγ in liver from 2 weeks onwards. In conclusion, our research suggested xanthophylls can regulate serum lipid profile and nuclear factor expression in hens and chicks.