Effect of aflatoxin,ochratoxin and their combination on protein and energy utilisation in white leghorn laying hens

The effect of dietary aflatoxin B₁ (AF) at levels of 0.5, 1 and 2 mg kg^?1, ochratoxin A (OA) at levels of 1, 2 and 4 mg kg^?1 and their corresponding combinations on protein and energy utilisation as well as energy partitioning was studied in white leghorn laying hens. Protein retention was adversely affected at all levels of AF and OA either singly or in combination, though the effect was more evident with OA and AF + OA. Minimum protein retention was recorded in hens fed the combination of toxins at their highest levels (2 mg kg^?1 AF + 4 mg kg^?1 OA). Aflatoxin at 1 and 2 mg kg^?1 and OA and AF + OA at all levels caused a significant reduction in metabolisable energy (ME) value of the diets. The minimum ME value was recorded for the diet containing both toxins at their highest levels (2 mg kg^?1 AF + 4 mg kg^?1 OA). A significant depression in egg energy deposition was observed with dietary inclusion of 1 and 2 mg kg^?1 AF, 2 and 4 mg kg^?1 OA and all levels of AF + OA in period I. In period II the reduction in egg energy deposition was significant at all levels of toxins either singly or in combination. Body energy deposition was adversely affected in hens fed the highest levels of AF (2 mg kg^?1) and OA (4 mg kg^?1) and all levels of AF + OA in period I. However, in period II a significant decrease in body energy deposition was observed at all levels of toxins except 1 mg kg^?1 OA. A significant increase in maintenance energy (ME_m/W^0.75 day^?1) requirement was recorded in hens fed 2 mg kg^?1 AF, 4 mg kg^?1 OA and all levels of AF + OA. It is suggested that AF and OA either singly or in combination affect not only protein and energy utilisation in laying hens but also energy partitioning i.e. egg and body energy deposition and maintenance energy requirement. However, the combination of toxins (AF + OA) has more severe adverse effects on all parameters than the individual toxins because of their synergistic toxicity effect. Copyright © 2007 Society of Chemical Industry     

Nutrient utilisation and performance of broilers in response to processed flaxseed dietary levels and vitamin B6 supplementation

The objective of this study was to determine the effects of processing and dietary inclusion level of flaxseed on broiler performance and nutrient utilisation. Flaxseed was included in the diet fed to day‐old broilers for the first 3 weeks as whole seed, ground seed, autoclaved whole seed, ground autoclaved whole seed or whole seed pelleted with the other ingredients, at levels of 0, 100, 120 and 140 g kg^?1. Chicks fed the pelleted flaxseed‐containing diets had heavier body weights, consumed more feed and had better feed/gain ratios than those fed the other flaxseed‐containing diets during the 3 weeks period (P < 0.01). The flaxseed level in the diet also had very significant (P < 0.01) effects on body weight and feed/gain ratio at the end of weeks 1 and 3, with the diets containing 100 g kg^?1 flaxseed resulting in better performance than the other flaxseed‐containing diets. Among the flaxseed containing diets, the pelleted diets led to higher apparent ether extract digestibilities, with values of 778 and 770 g kg^?1 for the diets containing 100 and 140 g kg^?1 flaxseed respectively. This better utilisation of ether extract by young broilers may explain the significantly (P < 0.05) higher AME_n (apparent metabolisable energy) value of 2924 kcal kg^?1 for the pelleted 140 g kg^?1 flaxseed‐containing diet. This was 15.4–17.5% higher than for the diets with the same level of flaxseed but provided as raw or autoclaved whole seed. The pelleting of flaxseed allowed an inclusion rate of 100 g kg^?1 without any reduction in the performance and nutrient utilisation of broilers. Copyright © 2003 Society of Chemical Industry     

Optimising dietary energy and amino acid levels in the diets of naked neck broilers for growth,nutrient utilisation and immune response in a hot climate

The need for a critical amino acid (AA) profile for growth, immune response and N utilisation of naked neck broilers during summer was studied. Day‐old naked neck chicks (n = 198) from a single hatch were distributed into 24 groups (four dietary regimens (DRs) with six replicates each) having eight birds in each replicate. The first diet was based on crude protein (CP) and metabolisable energy (ME) (13.40 MJ) as per NRC recommendations (DR1). In the second diet, the CP content was reduced through supplementation of synthetic AAs to achieve critical AA contents as suggested by NRC with 13.40 MJ ME (DR2). In the third diet critical AAs were supplemented to achieve their level at 108% of NRC with 12.6 MJ ME (DR3), while in fourth diet critical AA concentration was reduced to 94% (DR4) of NRC with 12.6 MJ ME to match the ratio of ME to AA concentration as that of NRC (1994). Diets were formulated separately for starter (0–3 weeks) and finisher (3‐6 weeks) phases. A metabolism trial was conducted at the third week of age. At 3 and 6 weeks of age eight birds (four of each sex) per treatment were killed to study the growth of immune organs (Bursa of Fabricius, thymus and spleen). Immune response was studied at the fourth week of age. During the starting phase, the birds fed DR1 and DR2 having 13.40 MJ ME kg^?1 diet had higher body weight (P < 0.044) gain (P < 0.048) and better feed conversion ratio (FCR) (P < 0.001) as compared to DR3 and DR4 (12.6 MJ ME kg^?1 diets). However, better (P < 0.001) CP efficiency (CP intake kg^?1 gain) and lower feed cost kg^?1 gain (P < 0.001) was recorded in DR4. A similar trend was also observed during the finisher phase. Dietary regimens had no effect on dry matter (DM) metabolisability, N intake or output and N retention. There was no difference in the weight of immune organs (bursa, thymus and spleen) between dietary treatments at either 3 or 6 weeks of age. The cell mediated and humoral immune response was also not different between the NRC and modified NRC levels. Copyright © 2007 Society of Chemical Industry     

Nutritional response of mature rats to kidney bean (Phaseolus vulgaris) lectins

In a series of 10-day pair feeding experiments it was found that the nutritional value of diets containing beans was essentially the same for rats aged between 30 and 123 days. Thus net protein utilisation (NPU) values of 25–39 on diets containing Processor bean (35 g protein kg^?1) + egg albumin (65g protein kg^?1) were obtained. As food intakes were considerably reduced when rats were fed diets containing more than 35g protein kg^?1 of Processor bean, the measurement of protein utilisation became increasingly more difficult. The severe disruption of the brush borders of duodenal and jejunal enterocytes, originally observed when bean-containing diets were fed to young (30-day-old) rats was also found with rats up to the age of 120 days on similar diets. Similarly, the development of circulating anti-lectin antibodies in the animals showed no age dependence within the age limits investigated. It was also shown that oral immunisation did not protect the rats from the effects of toxicity and that the immune response was a result of continuous absorption of lectin throughout the feeding period. Thus the extent and the mechanism of toxicity of Phaseolus vulgaris bean lectins were found not to be dependent on the age or maturity of the animal.     

Growth performance,carcass characteristics,organs measurement and haematology of broiler chickens fed a high fibre diet supplemented with antibiotics or dried yeast

Four antibiotics, namely procaine penicillin, tylosin, streptomycin and neomycin-oxytetracycline each at 150 mg · kg^?1, and four levels of dried yeast, viz. 1.5, 3.0, 4.5 and 6.5 g · kg^?1 were incorporated into a basal high fibre diet containing 250 g · kg^?1 palm kernel meal. The unsupplemented diet was the control. The nine experimental diets were fed to broilers between 7 and 42 days of age to evaluate performance, carcass characteristics, organ weights and haematology in response to the supplements. The investigation revealed that broilers fed antibiotics or dried yeast supplemented diets attained heavier (P < 0.05) body weights, consumed greater (P < 0.05) quantities of feed except on penicillin and 6.0 g · kg^?1 dried yeast, converted the feed better (P < 0.05), and yielded heavier carcass and cut-parts than those fed the unsupplemented diet. Organ weights were similar in broilers on the treatments, except the greater (P < 0.05) hepatic, spleenic and gizzard weights and lengthier intestinal tracts in birds fed dried yeast. Haematological indices were superior (P < 0.05) in broilers fed supplemented diets to the basal group. The data suggest improvement in performance, carcass yield and haematology of broilers as a result of antibiotics or dried yeast supplementation of a high fibre diet.     

Biological response of broiler chickens fed peas (Pisum sativum L.) expressing the bean (Phaseolus vulgaris L.) α‐amylase inhibitor transgene

The nutritive value of transgenic peas expressing an α‐amylase inhibitor (α‐Ai1) was evaluated with broiler chickens. The effects of feeding transgenic peas on the development of visceral organs associated with digestion and nutrient absorption were also examined. The chemical composition of the conventional and the transgenic peas used in this study were similar. In the two feeding trials, that were conducted normal and transgenic peas were incorporated into a maize–soybean diet at concentrations up to 500 g kg^?1. The diets were balanced to contain similar levels of apparent metabolisable energy (AME) and amino acids. In the first trial, the birds were fed the diets from 3 to 17 days post‐hatching and with levels of transgenic peas at 250 g kg^?1 or greater there was a significant reduction in body weight but an increase in feed intake resulting in deceased feed conversion efficiency. In the second trial, in which the birds were fed diets containing 300 g kg^?1 transgenic peas until 40 days of age, growth performance was significantly reduced. It was also demonstrated that the ileal starch digestibility coefficient (0.80 vs 0.42) was significantly reduced in the birds fed transgenic peas. Determination of AME and ileal digestibility of amino acids in 5‐week‐old broilers demonstrated a significant reduction in AME (12.12 vs 5.08 MJ kg^?1 DM) in the birds fed the transgenic peas. The AME value recorded for transgenic peas reflected the lower starch digestibility of this line. Ileal digestion of protein and amino acids was unaffected by treatment. Expression of α‐Ai1 in peas did not appear to affect bird health or the utilisation of dietary protein. However, the significant reduction in ileal digestion of starch in transgenic peas does reduce the utility of this feedstuff in monogastric diets where efficient energy utilisation is required. Copyright © 2006 Society of Chemical Industry     

Riboflavin content in lupine seeds and blood plasma riboflavin status in broilers fed diets containing high levels of lupine seeds

BACKGROUND: The potential of lupine as a source of protein and other nutrients in poultry has attracted considerable attention in countries dependent on imports of soybean meal (SBM), as well as in organic farming. Nutritional aspects of riboflavin in lupines are poorly understood. This work evaluated riboflavin content in whole and dehulled seeds of three lupines (L. albus, L. angustifolius, L. luteus) and riboflavin status in broiler fed diets containing high levels of lupine seeds in comparison to SBM. RESULTS: Riboflavin is concentrated mainly in lupine cotyledons, predominantly as flavin mononucleotide. Its content in whole seeds ranged from 2.07 to 2.70 mg kg^?1, and was comparable to content in SBM (2.35 mg kg^?1). In comparison to the SBM‐fed group, broilers fed lupine diets showed higher plasma riboflavin (P < 0.05), but their growth rate and feed intake parameters were significantly lower (P < 0.05). CONCLUSION: Lupine seeds contain moderate to high levels of riboflavin. Feeding diets containing high levels of lupine seeds did not have adverse effects on plasma riboflavin status in broilers. Poor performance of broilers fed lupine diets is not associated with inadequacy of riboflavin. Copyright © 2008 Society of Chemical Industry     

Effect of temperature and dietary energy on live performance blood chemistry and organ proportions in broiler chickens

Two thousand commercial broiler chickens of both sexes were used to study the effect of temperature (21°C constant (LT) vs 21 to 30 to 21°C cycling (HT)), and dietary energy (13.0 MJ ME kg^?1 (LE) vs 13.8 MJ ME kg^?1 (HE)) on the live performance, blood pH, Pco₂, Po₂ and HCO₃ and on heart, liver, gizzard and abdominal fat weights as proportions of body weight. Weights and analytical samples were taken at 34 and 54 days. Daily gain was depressed by HT (P < 0.05) but HE overcame this depression in female broilers. The HT treatment reduced (P < 0.05) blood pH and Po₂, but increased (P < 0.01) Pco₂ and HCO₃ levels especially when LE diets were fed. Heart, liver and abdominal fat proportions were all reduced (P < 0.05) by HT in male broilers. Female broilers on HT had reduced heart proportions whereas liver and abdominal fat proportions were increased (P<0.001) especially in those fed HE diets. Gizzard proportions were increased (P<0.05) by HT, and reduced (P<0.05) in birds fed HE diets. Up to 34 days, for both sexes, a combination of LT × LE was superior to all the other combinations. By 54 days, LT × HE and HT × HE were advantageous for males and females, respectively.     

Protein and energy requirements for starting and finishing broiler guineafowl (Numida meleagris) in the tropics

Two experiments were conducted to determine the optimum protein and energy levels for starting and finishing guineafowls. Eighty one-day-old guinea-fowl keets were tested in groups of 20 on four starter rations (made up of four protein contents 28, 26, 24, and 22% (w/w) with corresponding energy levels 13.8, 13.4, 13.0, and 12.6MJ kg^?1 diet), for a period of 6 weeks and later changed to four finisher rations. The finisher rations were made up of four protein levels (24, 20, 16 and 12% w/w) and four corresponding energy levels (12.6, 12.2, 11.7, 11.3MJ kg^?1 diet). These were fed from 7 to 12 weeks. The result of this study indicated that the optimum protein and energy levels for starting guineafowl in the tropics were 22% (w/w) crude protein and 12.6 MJ kg^?1 ME diet while that of finishing guineafowl 16% (w/w) crude protein and 11.7MJ kg^?1 ME diet.     

Effects of enzymes in diets with varying energy levels on growth and egg production performance of Japanese quail

The present study was conducted to evaluate the effect of feed‐grade enzyme supplementation in diets with varying levels of energy on the performance of growing and laying Japanese quails. Day‐old Japanese quails, 504 in number, were subjected to six dietary treatments with six replicates at each treatment. Each replicate had 14 chicks. The dietary treatments consisted of three energy levels ie 12.15 MJ (2900 kcal), 11.30 MJ (2700 kcal) and 10.48 MJ (2500 kcal) ME kg^?1 diet and two enzyme levels (0 and 0.5 g kg^?1 diet). A metabolism trial was conducted at the fourth week of age. At the end of week 5, 10 quails (five of each sex) per treatment were sacrificed for carcass characteristics and 20 female quails from each of the six dietary groups were housed in individual laying cages and fed respective layer diet to study the laying performance and egg quality up to 20 weeks of age. Body weight gains of quails fed 12.15 MJ or 11.30 MJ ME kg^?1 diets were significantly higher (p < 0.01) than those fed diets with 10.46 MJ ME kg^?1 diet. Feed intake was significantly lower (p < 0.01) in birds that received diet with 12.15 MJ ME kg^?1 than in birds that diets containing either 11.30 or 10.46 MJ ME kg^?1 diet. Feed conversion ratio (p < 0.01) was best at 12.15, followed by 11.30 and 10.46 MJ ME kg^?1 diet. Enzyme supplementation did not improve the growth performance, feed intake or feed conversion efficiency of quails. Enzyme addition also did not influence nitrogen retention or energy or dry matter metabolizability. The carcass characteristics did not differ because of energy or enzyme supplementation. Feed intake increased significantly (p < 0.01) as the dietary energy level decreased. The egg production and quality characteristics remained almost similar in all the dietary treatments. It was concluded that the optimum dietary energy level for quail was 12.15 MJ (2900 kcal) ME kg^?1 during the growing phase and 11.30 MJ (2700 kcal) ME kg^?1 during the laying phase. Addition of feed enzymes to conventional diets containing varying levels of maize, soyabean meal, fish meal and deoiled rice bran was not beneficial to improve growth, carcass traits, egg production performance or nutrient utilization. Copyright © 2004 Society of Chemical Industry     

Vitamin E levels,thiobarbituric acid test and sensory evaluation of breast muscles from broilers fed α‐tocopheryl acetate‐ and β‐carotene‐supplemented diets

The objective of this study was to investigate the effect of dietary α‐tocopheryl acetate and β‐carotene supplementation on lipid oxidation of breast meat from broilers fed lard as the fat source. Supplementation of broilers with 100 mg kg^?1 α‐tocopheryl acetate increased the vitamin E levels in raw breast samples significantly (p < 0.05), whereas the presence of 1.5 mg kg^?1 dietary β‐carotene tended to decrease vitamin E deposition. The presence of vitamin E delayed lipid oxidation significantly, but thiobarbituric acid values of samples from broilers fed the β‐carotene‐supplemented diet did not differ from those of control samples. Vitamin E reduced sensory meat rancidity, whilst vitamin E, β‐carotene and their combination modified meat texture. The results show the effectiveness of dietary α‐tocopheryl acetate supplementation in protecting broiler meat against lipid oxidation. Copyright © 2004 Society of Chemical Industry     

Responses of broilers fed guineacorn/palm kernel meal based ration to supplemental biotin

Seven duplicate floor pens with 20 day-old commercial broiler chicks each were fed a practical type broiler diet formulated with guineacorn/palm kernel meal and supplemented with graded levels of biotin (0.00, 0.04, 0.08, 0.12, 0.16, 0.20 and 0.24 mg kg^?1 feed) for a period of 6 weeks. Significantly poorer feed utilisation and carcass characteristics, higher blood lipid, lower blood glucose, lower pyruvate carboxylase activity in the liver, higher liver and kidney weights (% live weight), more lipid deposition in these organs coupled with more frequent incidences of foot dermatitis, higher mortality due to fatty liver and kidney syndrome (FLKS) and abnormal development of leg bone in broilers maintained on the diet without biotin supplementation indicated that they suffered vitamin deficiency. However, the responses of experimental birds indicated that a dietary supplement of 0.20 mg biotin kg^?1 feed was adequate for the promotion of good performance and prevention of dermal lesions, FLKS mortality and leg deformities.     

Natural occurrence of zearalenone and trichothecene toxins in maize-based animal feeds in zambia

A year-long collection of maize-based animal feed samples from the National Milling Company and mouldy maize collected from farmers fields near Lusaka were analysed for Fusarium mycotoxins. In the survey, 148 samples were tested for zearalenone, deoxynivalenol and nivalenol, and 60 samples for T-2 toxin and diacetoxyscirpenol. Zearalenone was present up to 0.6 mg kg^?1 in 17% of the feed samples, and deoxynivalenol was found at I-0 mg kg^?1 in 1.4 % of these samples. This is the first report of these toxins in animal feeds in Zambia. Zearalenone was also found in 57.6 % of the 33 mouldy maize samples collected at levels ranging from 0.08 to 6.0 mg kg^?1 (mean concentration 1.11 mg kg^?1), and 49.5% of these samples contained deoxynivalenol at levels ranging from 0.5 to 16.0 mg kg^?1 (mean concentration 5.56 mg kg ^?1). T-2 toxin and diacetoxyscirpenol were not detected.     

Residues of ethoxyquin in poultry tissues and eggs

Tissues of broilers raised experimentally on diets containing the feed antioxidant ethoxyquin (6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline) contained very low levels of this compound (<0.005 mg kg^?1) both raw and after roasting. Residues were higher in liver (up to 0.063 mg kg^?1) and highest in what appeared to be the major deposition site, the body fat (0.215 mg kg^?1). The body fat of commercial broiler samples showed much lower levels (0.015-0.051 mg kg^?1). Leg and breast muscles from laying hens after 30 weeks on the experimental diets had low ethoxyquin levels (< 0.005 mg kg^?1) with a higher liver content (0.048 mg kg^?1) and again the highest level in the body fat (0.238 mg kg^?1). Eggs from these hens contained 0.031 mg kg^?1 ethoxyquin, probably all in the yolk. Market samples of eggs from five major producers gave an average value of 0.011 mg kg^?1. A rapid and considerable loss of ethoxyquin occurred in the feed troughs, the concentration dropping from 125 mg kg^?1 to 90 mg kg^?1 in four hours.     

The nutritional quality of two types of fish silage for broiler chickens

Fish waste was ensiled either by acidification with formic acid or by fermentation with a bacterial starter culture and molasses. The resulting liquids were mixed with wheat bran (85:15 w/w liquid: bran) and dried (70°C) to produce acid silage meal (ASM) and fermented silage meal (FSM). ASM and FSM were incorporated into wheat-based diets at 25, 50 and 100 g kg^?1 at the expense of soya bean meal. There were two control diets, one which contained soya bean meal as the predominant protein supplement and a second in which fish meal (50 g kg^?1) was added at the expense of some of the soya bean meal. Starter diets (13.25 MJ ME kg^?1, 12 g kg^?1 lysine) were fed from 1-day-old to 21-days-old and finisher diets (13.25 MJ ME kg^?1, 9.5 g kg^?1 lysine) were fed from 22 to 42-days-old to six replicates each of five birds. Birds were reared in raised-wire cages, and feed intake, liveweight and mortality were recorded. There were no significant effects of dietary inclusion of either ASM and FSM on the performance of broiler chickens relative to those fed on control diets. FSM contained less crude protein and amino acids than ASM. The recovery of amino acids relative to the total crude protein content from FSM was only 78.7%, presumably as a result of formation of Maillard reaction products during drying.     

Chemical composition,digestibility and protein quality of 12 sunflower (Helianthus annuus L) cultivars

Twelve sunflower (Helianthus annuus L) cultivars grown in Spain were analysed and tested in experiments with rats. The dehulled seeds contained an average of 32.2 MJ kg⁻¹ dry matter (DM) gross energy, 653 g kg⁻¹ DM fat, 60 g kg⁻¹ DM total non-starch polysaccharides (NSP) and 6 g kg⁻¹ DM Klason lignin. The sunflower seed hulls contained 20.2 MJ kg⁻¹ DM gross energy, 53 g kg⁻¹ DM fat, 562 g kg⁻¹ DM total NSPs and 239 g kg⁻¹ DM Klason lignin. The sunflower samples were dehulled and partially defatted (to ∼17% fat) and included in diets for rats. The dehulled, partially defatted samples contained on average 74.6 g nitrogen kg⁻¹ DM and 1.409 mg g⁻¹ phenolic compounds (chlorogenic acid + caffeic acid + derivative 1 + derivative 2) varying from 0.677 to 2.847 mg g⁻¹. Groups of five growing rats were fed diets (9.38% crude protein) containing one of the sunflower cultivars as the only source of protein. Apparent ileal and faecal digestibilities were determined by using an indigestible marker (Cr₂O₃) and faecal digestibility based on total faecal collections. Apparent ileal, caecal and faecal digestibilities of organic matter were 81.2–91.5% (P = 0.05), 95.8–97.1% (P = 0.005) and 94.7–95.3% (P = 0.94) respectively. The apparent faecal digestibilities of DM, energy and protein (N × 6.25) were 93.2–93.8%, 93.5–94.3% and 81.6–84.3% respectively with no differences among cultivars. Biological value (BV) ranged between 63.8 and 73.2% (P = 0.0001) and net protein utilisation (NPU) between 59.9 and 69.5% (P = 0.0001). BV and NPU were positively correlated with lysine and threonine contents, but no correlation with the analysed phenolic compounds was detected. © 1999 Society of Chemical Industry     

Microbial protein synthesis, nitrogen capture efficiency and nutrient utilisation in sheep fed on finger millet straw (Eleucine coracana)-based diet with different rumen-degradable nitrogen levels

BACKGROUND: Microbial protein synthesised in the rumen is a very important protein source for ruminants. It is essential to provide an adequate amount of rumen‐degradable nitrogen (RDN) for optimum microbial protein synthesis in the rumen on straw‐based diets. The objective of this study was to determine the RDN requirement for optimum microbial protein synthesis (MPS), nitrogen capture efficiency (NCE) and nutrient utilisation in Nellore rams fed on a finger millet straw (FMS)‐based diet. RESULTS: Thirty‐six Nellore sheep were randomly divided into four groups of nine animals each using a balanced, completely randomised design. The animals in group 1 (RDN0) were fed with ad libitum FMS. Those in groups 2, 3 and 4 (RDN1, RDN2 and RDN3) were supplemented with groundnut cake to provide RDN levels of 14, 18 and 23 g RDN kg^?1 digestible organic matter intake (DOMI) or 21, 27 and 35 g RDN kg^?1 digestible organic matter apparently digested in the rumen (DOMR) respectively along with FMS. The digestibility coefficients of all nutrients and MPS increased (P < 0.05) quadratically with increasing level of RDN supplementation. NCE decreased linearly (P < 0.05) as the level of RDN increased. CONCLUSION: The results suggest that 12 g RDN kg^?1 DOMI or 19 g RDN kg^?1 DOMR may be adequate for optimum MPS, NCE and digestibility of nutrients in sheep fed on an FMS‐based diet. Copyright © 2011 Society of Chemical Industry     

Validating the current amino acid and energy requirements of coloured broiler chickens

Background: Coloured broilers are gaining popularity in the Indian subcontinent. However, very scanty reports are available on their dietary requirements for amino acid (AA) and energy. An experiment was conducted involving three levels of amino acids (115, 100 and 85% AA level of the NRC), at three levels of energy (13.40, 12.55 and 11.72 MJ kg^?1 diet) for 0–28 days of age. Results: Body weight gain and feed conversion ratio (FCR) in the 115% AA group was better than those fed diets with 100 and 85% AA. Dietary energy levels did not influence body weight gain up to 14 days of age but thereafter it was higher (P < 0.01) in birds offered the 13.40 MJ ME kg^?1 diet. The exponential regression equation had better curve fitting for daily body weight gain over daily AA intake and the power regression model for FCR. Nitrogen retention was higher in birds offered the diets with 115 and 100% AA than 85% AA, although nitrogen retention was not affected by dietary energy level. Thymus weight (P < 0.036) and in vivo response to PHA‐P (P < 0.006) was significantly higher in birds offered the 85% AA diet. Dietary energy levels had no effect on the immune response of the birds. Weight of gizzard, proven‐triculus and small intestine was higher in birds offered the 85% AA diet. Conclusion: Body weight of coloured broilers may be optimised by feeding higher level of AA and immune response can be optimised by feeding 12.55 kJ ME kg^?1 diet and 15% lower level of AA as suggested by the US National Research Council. Copyright © 2007 Society of Chemical Industry     

Lipophilic toxin profiles detected in farmed and benthic mussels populations from the most relevant production zones in Southern Chile

Lipophilic toxins associated with diarrhoeic toxins were found in Mytilus chilensis (Blue mussels) and Aulacomya ater (Ribbed mussels). These shellfish samples were collected from Chiloe Island, Southern Chile. The samples were tested by liquid chromatography–tandem mass spectrometry (LC-MS/MS). After the analysis, four toxins were found: DTX-1, DTX-3, YTX and PTX. All toxins were identified by comparing their HPLC retention times with those of analytical standards and confirmed by LC-MS/MS. Dinophysistoxin-1 (DTX-1) and dinophysistoxin-3 (DTX-3) toxins were the major components within the mussel extracts. Nevertheless, the percentages of these toxins differed depending on the area they were collected from and/or the sampling date. The levels detected in Butacheuques Island for okadaic acid (OA) was 267?±?3.5?µg OA?eq?kg^?1 (p?<?0.05) and for DTX-3 was 183.4?±?7.5?µg?kg^?1 in ribbed mussels. Pectenotoxin (PTX) and yessotoxin (YTX) were the toxins detected in minor proportions in the toxic profile of the bivalves. The maximum concentration of YTX detected in ribbed mussels was 85.2?±?2.8?µg?kg^?1 in Mechuque Island, whereas the PTX-2 level in ribbed mussels was 82.0?±?2.4?µg?kg^?1 in Cailin Island. Analogues of YTX and PTX-2 were not detected in any of the analysed mussels, which did not support the supposed presence of isomers of toxins as a result of the enzymatic metabolism of bivalves. This study found evidence proving co-occurrence of lipophilic toxins – like PTX and YTX – with diarrhoeic toxin in samples collected in Southern Chile, which is, to date, the more complex mix of lipophilic toxins ever found in mussels samples from Southern Chile.     

Response of growing Japanese quails to dietary concentration of L‐threonine

The influence of dietary levels of L ‐threonine (Thr) on growth and immune response was investigated in growing (0–5 weeks of age) Japanese quails (n = 288). Three dietary treatments were formulated using three levels of Thr [9.6, 10.2 and 11.2 kg^?1 diet dry matter (DM)] at a fixed protein level of 233 g kg^?1 and an energy level of 12.15 MJ (2900 kcal) metabolizable energy (ME) kg^?1 feed dry matter. A metabolism trial with a 3‐day collection period was conducted at the third week of age employing all the birds. The cell‐mediated (using PHA‐P) and humoral (SRBC response) immune responses were measured at the fourth week of age. Carcass traits were assessed at the end of fifth week of age. Body weight gain was lower (P < 0.01) in birds received 9.6 g Thr kg^?1 DM than in groups fed 10.2 g or 11.2 g kg^?1 DM in the diet, but there was no significant difference in gain between the groups fed 10.2 or 11.2 g Thr kg^?1 DM in the diet. Feed intake differed significantly owing to Thr levels being lowest (P < 0.05) at 9.6 g Thr kg^?1 DM in the diet. Feed conversion ratio (FCR), protein efficiency and energy efficiency improved at the 11.2 g kg^?1 level from 0 to 3 weeks of age; however, from 3 to 5 weeks of age, better FCR emanated from a diet with 9.6 g Thr kg^?1 DM. The nitrogen balance did not differ (P > 0.05) with Thr level. Carcass traits, relative weight of immune organs and cell‐mediated (PHA‐P) and humoral (SRBC response) immune responses did not differ significantly (P > 0.05) as a result of the dietary treatments. Copyright © 2006 Society of Chemical Industry