Purine and pyrimidine utilisation by chicks fed nitrogen-limiting diets.

The responses of chicks to purine and pyrimidine supplementation of diets severely limiting in the dispensable amino acids have been measured in three experiments. In experiment 1, combined additions of adenine and uracil to a diet with a nitrogen (N) content of 19.84 g kg^?1 DM enhanced growth and dry matter intakes to levels similar to those attained by chicks receiving an equinitrogenous supplement of glutamic acid. Chicks in the latter group, however, had the best efficiencies of carcass N deposition. In experiment 2, growth, dry matter intakes and efficiency of food conversion of chicks fed a diet with 23.36 g N kg^?1 DM were improved markedly by combined supplements of adenine, uracil, guanine and cytosine. Equinitrogenous inclusions of guanine; guanine with thymine; uracil with thymine; or uracil with adenine were ineffective. Efficiency of carcass N deposition declined appreciably on supplementing the basal diet with purines and pyrimidines in different combinations, appreciable reductions occurring with additions of thymine; uracil with thymine and uracil with adenine. The low N efficiencies observed in the last two groups were improved by combined additions of adenine, uracil, guanine and cytosine. The highest efficiencies of N utilisation occurred in chicks fed a glutamic acid supplement. In experiment 3, the simultaneous addition of uracil, adenine and guanine was as effective in stimulating the growth performance of chicks fed a diet with 18.89 g N kg^?1 DM as a more complex mixture including cytosine. The best growth and efficiency of food conversion values were recorded in the group receiving supplementary glutamic acid.     

Nutritional evaluation of transgenic high‐methionine lupins (Lupinus angustifolius L) with broiler chickens

The nutritive value of transgenic lupin seeds (Lupinus angustifolius L) with higher contents of methionine was evaluated with broiler chickens. The crude protein, methionine and cysteine contents in the conventional and transgenic lupins were 322 and 324, 2.0 and 4.5, and 3.6 and 3.7 g kg^?1 dry matter respectively. In the feeding trial, conventional and transgenic lupins with hulls were incorporated into a maize–soyabean meal diet at 250 g kg^?1 level and the diets were fed to female broiler chicks from 6 to 20 days of age. All diets were balanced to contain similar levels of apparent metabolisable energy (AME), lysine and sulphur‐containing amino acids. The levels of free methionine added to the maize–soyabean meal control, conventional lupin and transgenic lupin diets were 2.2, 2.8 and 2.2 g kg^?1 respectively. Weight gain and feed intake were not influenced by dietary treatments, but feed/gain tended to be higher (P = 0.09) in birds fed lupin diets compared with those fed the control diet. Feed/gain of birds fed the conventional lupin diet was higher (1.82 vs 1.74) than for those fed the transgenic lupin diet. These results showed that the supplemental methionine required in poultry diets containing 250 g kg^?1 lupin can be lowered by 0.6 g kg^?1 diet by the use of high‐methionine lupins. The AME values of conventional and transgenic lupins were determined to be 9.42 and 10.18 MJ kg^?1 dry matter respectively. The higher AME value in transgenic lupins may be related to the lower content of soluble non‐starch polysaccharides (45.6 vs 60.7 g kg^?1 air‐dry basis). Data on ileal amino acid digestibility indicate that the amino acids in transgenic lupins are as digestible as those in conventional lupins. © 2002 Society of Chemical Industry     

Effects of methionine addition in soya bean or casein diets supplemented with carrageenan on weight gain and blood lipids in rats

Seven groups of 12 Wistar rats were fed during two experimental periods. During the first period of 4 weeks, rats were fed diets containing 100 g kg^?1 of casein or soya-protein. In the case of casein, diets contained casein, casein + 3.5 g kg^?1 of sodium carrageenan and casein + 3.5 g kg^?1 of sodium carrageenan + 1 g kg^?1 of DL-methionine. In the case of soya protein, diets contained soya protein, soya protein + 6.2 g kg^?1 of sodium carrageenan, soya protein + 6.2 g kg^?1 of sodium carrageenan + 1 g kg^?1 of DL-methionine and soya protein + 1 g kg^?1 of DL-methionine. During the second period of 8 weeks, all rats were fed laboratory pellets containing 170 g kg^?1 of standard protein mixture. Methionine supplementation of heated soya bean meal containing carrageenan prevented the decrease of growth observed with unsupplemented diet. Methionine supplementation of casein improved protein efficiency ratio and had no effect on long-term growth of rats because carrageenan did not cause growth retardation. At the end of second period, carrageenan ingested during the first period had no effect on plasma cholesterol. When carrageenans added to casein were ingested during the first period, plasma triglycerides were significantly lower after the second period. It would seem that carrageenans induce protein malnutrition by a lack of methionine when they are present in low protein diets with low methionine content, and that a sufficient content of methionine in diets prevents the carrageenan effect.     

Protein nutrition of dairy cows receiving grass silage diets. Effects on silage intake and milk production of postruminal supplements of casein or soya-protein isolate and the effects of intravenous infusions of a mixture of methionine,phenylalanine and tryptophan

Milk production responses to protein supplementation of grass silage diets were investigated in two experiments with dairy cows. In Experiment 1. four cows received a basal diet of grass silage ad libitum plus a barley/soya supplement at 5 kg day^?1. The cows received the following treatments in a 4 × 4 Latin square design with 10-day periods: (1) basal diet, (2) basal diet plus 230 g casein day^?1 infused into the abomasum; (3) basal diet plus 225 g soya protein isolate (SPI) day^?1 into the abomasum; and (4) basal diet plus a dietary addition of 1.2 kg fishmeal-based product (AP) day^?1. All three supplements increased (P < 0.05) the yield of milk and milk protein relative to the basal diet, the values being 16.9. 535:18.8. 610; 19.5, 625; and 18.5 kg day^?1 and 582 g day^?1 for the basal. AP, casein and SPI treatments respectively. Responses to casein were greater (P < 0.05) than to SPI. Changes in the concentrations of amino acids in blood plasma suggested that methionine, tryptophan and phenylalanine were in shortest supply relative to demand, and their potential role as limiting amino acids was investigated in a second experiment. In Experiment 2, four dairy cows were used in a 4 × 4 Latin square design with 10-day periods. The four treatments were (1) a diet of grass silage ad libitum plus 5 kg day^?1 of a barley/soya supplement containing 176 g CP kg^?1 DM (LP); (2) LP plus an intravenous infusion of 5.0 g methionine, 9.1 g phenylalanine and 2.2 g tryptophan day^?1; (3) grass silage ad libitum plus 5 kg day^?1 of a barley/soya supplement containing 334 g CP kg^?1 DM (HP); and (4) HP plus the intravenous infusion of methionine, phenylalanine and tryptophan. The HP treatment produced a higher yield (P < 0.05) of milk protein than the LP treatment (722 vs. 667 g day^?1) but the amino acid infusion had no effect with either treatment. The elimination of methionine, phenylalanine and tryptophan (and, in previous experiments, methionine and lysine) as candidates for limiting amino acids on diets of grass silage plus soya-based supplements questions whether the differences in responses to casein and SPI can be explained in terms of their amino acid compositions. The role of factors such as peplides, producing during digestion, some of which may be biologically active, deserves investigation.     

Nutritional value of animal feed grade wheat as replacement for maize in lamb feeding for mutton production

The utilization of abundantly available animal feed grade wheat (AFW) as a replacement for conventional and costly cereal supplement in lamb feeding to lower the cost of mutton production was explored. Thirty‐five growing lambs divided into five equal groups and were fed diets containing 0, 118, 235, 353 or 470 g kg^?1 AFW replacing equal quantity of maize. The diets were fed in the form of composite feed mixture, which had a roughage (Prosopis cineraria leaves) to concentrate ratio of 25:75. Dry matter intake (DMI) was not different in these groups, ranging from 35 to 42 g kg^?1 body weight, while AFW inclusion linearly (P < 0.05) reduced DMI. The digestibility coefficients of dry matter (DM), organic matter (OM), crude protein (CP) and cellulose were not affected by AFW addition, whereas neutral detergent fibre and acid detergent fibre digestibility coefficients were reduced (P < 0.05). The digestible CP content (142.7–162.7 g kg^?1 diet) increased (P < 0.01) linearly with increased AFW inclusion levels. However, AFW additions did not affect metabolizable energy (ME) value of diet (10.2–10.5 MJ kg^?1 diet DM). Digestible CP intake was similar but digestible DM and OM intake tended to decrease (P < 0.05) linearly when expressed in terms of g kg^?1 W^0.75. ME intake (MJ d^?1) was not different among the diets but showed linear (P = 0.041) reducing trends with increasing AFW levels in diet. The efficiency of ME and N utilization for unit gain was also not affected by AFW incorporation. N retained as g d^?1, percentage of intake and percentage of absorbed ranged from 15.4 to 19.5 g, 49.7% to 60.3% and 62.6% to 74.6%, respectively. Intake and utilization of dietary N was not affected but urinary N excretion reduced (P < 0.05) linearly by AFW. Daily microbial N (MN) flow estimated by urinary purine derivative excretion was significantly (P < 0.01) higher for lambs fed a diet with AFW 235 g kg^?1 (3.05 g MN) and 353 g kg^?1 (2.51 g MN) compared to without AFW diet (1.31 g MN). MN when expressed as g kg^?1digestible organic matter intake (DOMI) and microbial protein g kg^?1 digestible organic matter apparently fermented in rumen (DOMR) followed a similar trend. During the growth trial, lambs fed diets containing AFW (353 g kg^?1), which replaced 75% maize had higher total gain (14 kg, P < 0.05) and average daily gain (ADG 154 g, P < 0.05). However, feed efficiency (feed consumed kg^?1 live weight gain) was not different. Rumen pH and microbial enzyme activities studied 4 h post feeding revealed that AFW did not affect rumen pH, which ranged from 5.95 to 6.30. Similarly, carboxymethyl cellulase and β‐xylosidase enzyme activities were not different among treatments, but AFW inclusion linearly (P = 003) increased carboxymethyl cellulase enzyme activities. The α‐amylase enzyme activity differed significantly (P < 0.05) and was highest (22.6 IU) in groups where AFW replaced maize completely. It was concluded that, in lambs reared under intensive system for mutton production on high concentrate diets, conventional and costly energy supplements like maize can be replaced up to 75% with a low‐cost animal feed grade wheat to economize on cost of production. However, more studies are required to confirm these inclusion levels for greater economic returns. Copyright © 2007 Society of Chemical Industry     

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     

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.     

Chemical composition and nutritive value of peach palm (Bactris gasipaes Kunth) in rats

The peach palm (Bactris gasipaes Kunth) is the starchy fruit of a palm tree widely cultivated in Central and South America. The present study aimed at determining its chemical composition and its nutritive value in rats. The average chemical composition of 17 samples was as follows: 410 g kg^?1 water and, in g kg^?1 of dry matter (DM), 54 g crude protein, 114 g oil, 39 g neutral detergent fibre, 716 g starch, 21 g sugars and 18 g ash. The main variability was observed for the oil (60–180 g kg^?1 DM) and starch (590–780 g DM) contents. The proteins contained, on average, in g kg^?1 of proteins, 49 g lysine, 13 g methionine, 19 g cysteine, 39 g threonine and 7 g tryptophan. The mineral fraction contained, per kg DM: 1.0 g Ca, 0.8 g P, 0.6 g Mg, 0.3 g Na, 44 mg Fe, 4 mg Cu and 10 mg Zn. The digestibility of four peach palm genotypes was determined in rats fed a diet composed of 350 g kg^?1 of peach palm and 650 g of a control diet based on maize and soybean meal. The digestibility of DM, energy, starch and protein of peach palm alone reached, on average 91, 87, 96 and 95%, respectively. No difference was observed between varieties, except for starch (p < 0.05). On average, peach palm contained 51 g of truly digestible protein kg^?1 DM and 3.691 kcal digestible energy kg^?1 DM. A growth trial was also carried out for 1 month on rats (initial weight: 78 g) fed a diet containing 0, 200, 400, 600 or 800 g peach palm kg^?1, at the expense of a diet composed of maize starch and casein. The growth rate of the rats decreased (p < 0.05) as the peach palm concentration increased. The growth decrease was due to a decrease (p < 0.05) in DM intake and to the lower quality of the peach palm protein. It is concluded that peach palm is mainly an energy source for humans and animals. It is poor in protein and minerals but can be consumed in large amounts. Copyright © 2005 Society of Chemical Industry     

Chemical composition,nutritive value and voluntary intake of tropical tree foliage and cocoyam in pigs

The composition of the leaves of cocoyam (Xanthosoma sagittifolium) and of two trees (Trichanthera gigantea and mulberry, Morus alba), their nutritive value in pigs and voluntary intake by pigs were determined. The average protein content ranged from 170 to 240 g kg^?1 dry matter (DM) and that of neutral detergent fibres from 218 to 398 g kg^?1 DM. The leaves are interesting sources of calcium (up to 69 g kg^?1 DM), potassium, iron and manganese. The proteins are well balanced in essential amino acids, with lysine ranging from 43 to 57 g kg^?1 proteins. The apparent faecal digestibility was determined by difference in 35 kg pigs fed a diet containing 35% leaf meal. The digestibility coefficients of DM, N and energy were, respectively, 47–57, 33–36 and 51–53%. The digestible energy value ranged from 1.674 to 2.037 kcal kg^?1 DM. The voluntary intake of Trichanthera and Xanthosoma was measured in sows weighing 100 kg on average. The intake reached 3.4 kg fresh leaves day^?1 (0.51 kg DM) and 1.0–1.1 kg dry leaf meal/day. It is concluded that low energy density is the main limiting factor of tree foliage for pig nutrition but that they are good sources of minerals and well‐balanced proteins. Copyright © 2005 Society of Chemical Industry     

Evaluation of castor (Ricinus communis) seed cake in the total mixed ration for sheep

BACKGROUND: Castor (Ricinus communis) seed cake (CSC), a byproduct of the vegetable‐oil industry, contains fairly good amounts of protein (crude protein, 290–390 g kg^?1) which could be a suitable substitute of conventional oil cakes like soybean meal (SBM) in livestock diets but for the presence of a toxic glycoprotein, ricin. Efforts were, therefore, made to determine the feasibility of feeding CSC as such or after detoxification with lime (4%, wt/wt) by incorporating it into a total mixed ration (TMR) containing 65 and 35 parts ragi (Eleucine coracana) straw and concentrate mixture, respectively, with 11 g kg^?1 CP and 50 g kg^?1 TDN in which the SBM of a control diet was isonitrogenously replaced with either raw or lime‐treated CSC in test diets. The control and two test TMRs were fed to 24 sheep, respectively, divided at random into three dietary groups having equal number of animals for 150 days. RESULTS: Although lime treatment had a positive effect in reducing ricin by 58%, no adverse effect could be noticed by feeding raw or lime‐treated CSC in terms of body weight changes, macro‐ and micro‐nutrient utilisation, blood biochemical and mineral profile, rumen fermentation pattern, carcass traits, except the level of plasma immunoglobulins which was significantly (P < 0.05) higher in sheep fed CSC diets. No pathological lesions could be noticed in the tissues of visceral organs due to feeding the raw or treated CSC. CONCLUSIONS: The findings suggest no adverse effect in the nutritional performance of adult sheep due to feeding the raw or treated CSC when incorporated into TMRs, probably due to a dilution of the ricin concentration or the development of immunity to the glycoprotein ricin, warranting long‐term growth‐cum‐production studies. Copyright © 2008 Society of Chemical Industry     

Evaluation of triticale for use in diets for meat-type chickens

Cultivar variation in the nutritional quality of triticale grain was examined with respect to apparent metabolisable energy (AME), ileal digestibility of dry matter (DM), nitrogen (N) and amino acids, and growth, in male broiler chickens. Eight triticale cultivars and two wheat cultivars were grown in an agronomic trial at a single experimental site to collect grain samples. Mean (±SD) AME was 13.54 (±0.64) MJ kg^?1 DM, with a range of 12.57 to 14.25 MJ kg^?1 DM. There were significant (P<0.05) differences between the grain cultivars in their DM, N and amino acid digestibility at the terminal ileum. Apparent lysine digestibility coefficients varied between 0.85 and 0.97. There was a significant (P<0.01) relationship between nutrient digestibility at the terminal ileum and acid-detergent fibre (ADF) in the cereal grains. Three triticale cultivars (Towan, Grow-quick and Ningadhu) had a lower N and lysine digestibility than the other triticales or wheat cultivars, but this was related to their higher ADF content. Trypsin inhibitor level in the cereal grain did not influence either nutrient digestibility or growth rate. Growth rate of broiler chickens from 1 to 21 days of age fed balanced diets which contained 50% cereal grain was significantly affected by cultivar. Birds fed one of the wheat cultivars (Warigal) had a higher (P<0.05) feed conversion ratio (g feed g^?1 liveweight gain) than those birds fed diets containing triticale. Feeding birds diets which contained the triticale cultivar Ningadhu and the maize resulted in greater (P<0.05) liveweight gain than did the other cereal grains tested.     

Carcass characteristics and meat quality of broilers fed periwinkle flesh (Pachymelania aurita), palm kernel cake and oil‐based rations

The effect of supplementation of palm kernel oil in periwinkle flesh and palm kernel cake‐based diets on carcass characteristics and meat quality of broilers was evaluated. Birds were assigned to five dietary treatments in a completely randomized design. The first diet, which was the control, contained 20 mg kg^?1 fishmeal but it did not contain palm kernel cake and periwinkle flesh. The second diet contained 20 mg kg^?1 fishmeal, 250 mg kg^?1 palm kernel cake but no periwinkle flesh. The third diet contained 60 mg kg^?1 periwinkle flesh, 250 mg kg^?1 palm kernel cake and no fishmeal. Present in the fourth diet were 250 mg kg^?1 palm kernel cake, 30 mg kg^?1 periwinkle flesh, no fishmeal and 20 mg kg^?1 palm kernel oil. Similarly, the fifth diet contained 250 mg kg^?1 palm kernel cake, 30 mg kg^?1 periwinkle flesh, no fishmeal and 40 mg kg^?1 palm kernel oil. Carcass measures and cuts were significantly influenced (P < 0.05) by dietary treatments. Diets 2, 3 and 5 gave significantly higher plucked dressed weights, total edible meat and total bone weights, respectively. Also carcass cuts were significantly increased (P < 0.05) in birds on periwinkle and palm kernel oil diets, with abdominal fat being highest in diet 5 having 40 mg kg^?1 palm kernel oil. However, proximate composition, physical and sensory properties were not significantly (P < 0.05) influenced by dietary treatment. Results showed that carcass characteristics improved as compared to the control group. Copyright © 2005 Society of Chemical Industry     

Cassava leaf meal as a replacement for coconut oil meal in pig diet

Two feeding trials were conducted to evaluate cassava leaf meal (CLM) as a replacement for coconut oil meal (COM) in tropical pig diets. In each trial, 36 pigs (initial weight, 14.5 kg) were limit fed diets containing 0, 133, 267 and 400 g kg^?1 CLM substituted for equal amounts (w/w) of COM in a 179 g kg^?1 protein basal diet. An extra-period Latin-square changeover design with 2-week periods was used. Average daily gain and feed efficiency were improved when diets containing 133 g kg^?1 CLM were fed, which may be attributed to the higher lysine content of CLM. Daily gain and feed efficiency of pigs fed diets containing 267 g kg^?1 CLM were similar to those on the basal diet. Poor performance of pigs fed the 400 g kg^?1 CLM diets may be explained by the low energy content and the presence of anti-nutritional factors, such as cyanide and tannin, in CLM. Two balance trials were conducted using 16 barrows (castrated male pigs, initial weight, 37.2 kg). Apparent digestibility coefficients for dry matter, energy, protein, cell contents, cell wall and hemicellulose were depressed, whereas those for ash and lignin were improved as CLM was substituted for COM. The data indicate that cassava leaf protein is utilised efficiently, although other nutrients in CLM are not as digestible as those in COM.     

Responses of intake,digestibility and nitrogen utilisation in goats fed low‐quality roughages supplemented with tree foliages

BACKGROUND: A meta‐analysis of data containing 127 different dietary treatments with 593 goats from 30 published studies was performed to explain the effects of foliage supplementation to low‐quality roughages on intake, digestibility and N utilisation in goats. RESULTS: Basal dry matter (DM) intake decreased linearly with increasing foliage level (FL) in diets and foliage crude protein (CP) intake, whereas total DM intake increased linearly with increasing FL and CP intake from foliages and quadratically with increasing concentration of neutral detergent fibre (NDF) in foliages. The digestibility of DM and CP increased linearly with increasing FL and CP concentration in basal roughages and foliage CP intake. The greater concentration of NDF in foliages and roughages decreased CP digestibility linearly. Intakes of digestible DM and CP increased quadratically with increasing FL, with plateau levels of 36.4 and 5.52 g kg^?1 (body weight)^0.75 in response to 490 and 740 g kg^?1 FL respectively. Faecal N, urinary N and N retention increased linearly with increasing FL and foliage CP intake. CONCLUSION: Responses of goats fed basal roughages supplemented with foliages are influenced by the quality and quantity of foliages and quality of roughages. Up to 490 g kg^?1 FL can be incorporated in diets for better feed utilisation and animal performance, beyond which nutrient utilisation may be adversely affected. Copyright © 2009 Society of Chemical Industry     

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     

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     

Estimates of basal ileal endogenous losses of amino acids by regression analysis and determination of standardised ileal amino acid digestibilities from casein in newly weaned pigs

BACKGROUND: This study was carried out to estimate basal ileal endogenous crude protein (CP) and amino acid (AA) losses (IAAL_B) in newly weaned pigs by regression analysis from apparent ileal digestible and the corresponding total dietary contents of CP and AA in order to obtain standardised ileal digestibilities (SID) of CP and AA originating from casein. A total of fourteen 3‐week‐old barrows were fitted with simple T cannulas at the distal ileum and were fed six diets with two pigs per diet in 4 weekly repeated measurements. Corn starch‐based diets containing six graded levels of CP from casein with 90, 155, 220, 285, 350 and 415 g kg^?1 CP (as‐fed basis) were formulated. RESULTS: Linear relationships (P < 0.001) between apparent ileal digestible and total dietary contents of CP and AA (g kg^?1 dry matter intake (DMI)) exist for CP and all AA in the range of 90–220 g kg^?1 CP content in the diet. The IAAL_B extrapolated from the range of 90–220 g kg^?1 CP content are different from zero (P < 0.001 to P = 0.019) except for tryptophan (P = 0.220). Based on regression analysis in the range of 90–220 g kg^?1 CP, estimates of IAAL_B, expressed as g kg^?1 DMI, and SID of CP and AA in casein (in parentheses, %) were as follows: CP 9.3 (98.0); arginine 0.4 (98.9); histidine 0.2 (98.5); isoleucine 0.2 (98.1); leucine 0.5 (99.2); lysine 0.4 (99.0); methionine 0.1 (99.1); phenylalanine 0.4 (99.9); threonine 0.6 (97.8); tryptophan 0.1 (96.2); valine 0.4 (98.5). CONCLUSION: The IAAL_B and SID of CP and AA originating from casein in newly weaned pigs are in close agreement with values obtained in grower finisher pigs. Copyright © 2007 Society of Chemical Industry     

Fermentation characteristics of corn‐, triticale‐, and wheat‐based dried distillers' grains with solubles in barley‐based diets determined using continuous and batch culture systems

BACKGROUND: Dried distillers' grains with solubles (DDGS) are becoming increasingly available and popular as an alternative livestock feed. This study used continuous and batch culture techniques to compare the in vitro fermentation characteristics of diets containing corn‐, triticale‐ or wheat‐based DDGS at 200 g kg^?1 diet dry matter (DM) against a barley grain‐based control diet. RESULTS: In continuous fermentation of wheat DDGS diet, total volatile fatty acid (VFA) concentration was decreased by 15.7% across sampling times and NH₃ concentration was quadrupled compared with control, whereas fermentations of corn‐ and triticale‐DDGS diets were similar to the barley‐based control. In batch cultures, corn DDGS differed from control only in increased culture pH. Compared with control diet, triticale DDGS yielded lower total gas production (140.94 versus 148.78 mL g^?1 DM) and in vitro DM digestibility (IVDMD; 0.509 versus 0.535). Wheat DDGS diet yielded decreased total gas production (123.49 mL g^?1 DM) and IVDMD (0.468), as well as total VFA production (105.84 versus 134.20 mmol L^?1) and substantially increased ammonia concentration (151.61 versus 58.34 mg L^?1) and acetate:propionate ratio (2.94 versus 1.11). CONCLUSION: Corn‐ and triticale‐ DDGS diets exhibited fermentation characteristics similar to the barley based control diet, consistent with in vivo findings that these diets yielded no adverse effects on production. In vitro ruminal fermentation of wheat DDGS diet differed significantly from control in several aspects including 2.6 to 6X higher ammonia concentrations. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd     

The effect of methanal (formaldehyde) treatment of casein on its digestion in vivo and in vitro

The effect of methanal (HCHO) treatment of casein on its in vitro and in vivo digestion was investigated. As the quantity of HCHO bound to casein increased, the in vitro rumen degradability decreased but no further reduction occurred above 10.6 g HCHO kg^?1 treated casein DM. The proportion of the original HCHO (25.4 g HCHO kg^?1 treated casein DM) remaining bound to casein at pH values 3.0 to 6.0 was approximately 0.5; the proportion remaining bound at pH 2.0 was significantly less (0.39). N solubility and in vitro digestion of casein by pepsin/HCl and/or intestinal proteolytic enzymes was significantly reduced by treatment with HCHO (10.6 g HCHO kg^?1 treated casein DM). When fed to rats the dry matter (DM) and true N digestibilities decreased significantly as the ratio HCHO;casein increased; the digestibility of the N-free component of the diet remained unchanged. The quantity of available lysine in the diets and their true biological value (BV) decreased as the level of bound HCHO increased; there was significant linear relationship between BV and available lysine. The apparent disappearances of amino acids from the small intestine of sheep, when untreated or HCHO treated caseins (12.3 g HCHO kg^?1 DM) were infused into the duodenum, were not affected by the pH of the infusate (pH 2.5 or 6.8) but were significantly reduced by HCHO treatment. It is concluded that exposure of HCHO-treated casein to low pH values does not completely release bound HCHO from casein and that the intestinal digestion of casein to which HCHO remains bound is reduced when compared to untreated casein. All amino acids determined showed similarly reduced apparent intestinal absorptions due to HCHO treatment. It is suggested that the lower BV of HCHO-treated caseins was due to reduced metabolic availability of lysine.     

Beneficial effect of yam on the amyloid β‐protein,monoamine oxidase B and cognitive deficit in mice with accelerated senescence

This study was designed to evaluate the effect of yam tuber material [Dioscorea alata L. var. purpurea (M.) Pouch.] on the amyloid β‐protein (Aβ) accumulation, monoamine oxidase (MAO) activity, cognitive ability and antioxidative defense system in senescence‐accelerated mice (SAMP8). Three‐month‐old male mice were fed with four different diets for 12 weeks: a casein diet (control group) and a casein diet supplemented with either 100, 200 or 400 g kg^?1 lyophilized yam. The results of the active shuttle avoidance test showed that the mice fed with the yam‐containing diets had significantly better learning and memory ability than the control group. All yam‐containing diet groups had lower Aβ levels and MAO B activities than the control, whereas the MAO A activity did not differ among the four diet groups. At the 400 g kg^?1 level, the yam‐containing diet group showed significantly lower concentration of thiobarbituric acid‐reactive substances (TBARS), higher total thiol level and superoxide dismutase (SOD) activity in the hippocampus than the control, but these values were not altered by the 100 and 200 g kg^?1 yam‐containing diet groups. The addition of 200 or 400 g kg^?1 yam also lowered the triglyceride levels but not the total cholesterol concentration. These results indicate that lyophilized yam could reduce brain Aβ accumulation, MAO B activity and cognitive deficits and promote the antioxidative defense system in SAMP8 mice. The improvements were in a dose‐dependent manner, possibly because the 400 g kg^?1 yam‐containing diet might contain more antioxidative phytochemicals. Copyright © 2006 Society of Chemical Industry