Influences of total sulfur amino acids and photoperiod on growth,carcass traits,blood parameters,meat quality and cecal microbial load of broilers

The current study aimed to discuss the impact of total sulfur amino acids (TSAA) %, photoperiod, and their interaction on growth performance, carcass and blood indices of broiler chicks. A total of 300 unsexed IR broiler chicks one-week old were used in a factorial arrangement (2 × 3), including two photoperiod systems (22 L: 2 D and 16 L: 8 D) and three experimental rations having three grades of Met + Cyst (TSAA) (70%, 85% and 100% of digestible lysine in starter and finisher diets). Results revealed that the higher LBW and BWG were noticed in birds given TSAA at grades of 1.1 or 0.90 % under 22L: 2D photoperiod at five weeks of age and the whole experimental period (1–5 weeks of age), respectively. The highest live body weight (LBW (and body weight gain (BWG) were recorded in birds received 1.1% TSAA under the long photoperiod compared to the control and the other groups. Birds fed 1.3% TSAA consumed more feed than the other groups. The opposite was found in birds fed 1.1% TSAA under the short photoperiod (16L: 8D). The best feed conversion (FCR) was detected by birds fed 1.1% and 0.90% TSAA diets during the whole experimental period. All carcass traits studied were significantly influenced by TSAA levels, except for the relative weights of abdominal fat and spleen. The interaction effect on was significant on all carcass traits except spleen %. In conclusion, the addition of TSAA at level 1.1 and 0.9 % to starter and finisher diets under a long photoperiod regime improved broiler’s performance, carcass traits, and blood parameters studied.     

Effect of different levels of rapeseed meal and sunflower meal and enzyme combination on the performance,digesta viscosity and carcass traits of broiler chickens fed wheat-based diets

The aim of the present experiment was to examine the effect of different levels of rapeseed meal (RSM) and sunflower meal (SFM) and enzyme combination (endoxylanase and β-glucanase) on the production performance, carcass quality, gizzard development and digesta viscosity of broiler chickens. The experimental design was a 3×2 factorial arrangement of treatments evaluating three diet types containing different levels of RSM and SFM (low (L), medium (M) and high (H)) and two levels of enzyme inclusion (0 or 100 g/tonne diet to provide 1220 U xylanase and 152 U β-glucanase per kg diet). Broiler starter and grower/finisher diets were formulated, based on wheat and soya bean meal and containing 50, 50 and 80 g/kg RSM and 0, 50 and 60 g/kg SFM for L, M and H treatments, respectively, during starter period and 80, 80 and 120 g/kg RSM and 0, 80 and 100 g/kg SFM for L, M and H, respectively, during grower/finisher period, and each diet was fed ad libitum to eight pens of 20 male broilers each. During the starter period (1 to 21 days), birds fed the H treatment had lower (P<0.05) BW gain (BWG) compared with those fed the L and M treatments. Diet type also influenced (P<0.05) feed intake (FI). Feeding the H treatment reduced (P<0.05) FI compared with the M treatment. Diet type and enzyme supplementation had no effect (P>0.05) on feed conversion ratio (FCR). During the grower/finisher phase (22 to 42 day) and over the entire period (1 to 42 day) birds fed the H treatment had lower (P<0.05) BWG and higher (P<0.05) FCR compared with those fed the L and M diets. Enzyme supplementation improved (P<0.05) FCR compared with the unsupplemented diets. No interactions (P>0.05) between RSM and SFM inclusion level and enzyme supplementation were observed for any of the measured parameters at any period. Diet type and enzyme supplementation had no effect (P>0.05) on carcass traits, abdominal fat pad, breast meat yield and jejunal digesta viscosity. Diet type influenced (P=0.05) relative empty gizzard weight, where the H treatment had higher relative empty gizzard weight compared with the L treatment. Enzyme supplementation tended (P=0.10) to increase relative empty gizzard weight. The present data suggest that high inclusion of SFM and RSM negatively influenced broiler performance. Enzyme supplementation improved FCR at all levels of RSM and SFM included in this study, but did not recover the reduction in weight gain caused by high inclusion of RSM and SFM.     

The first insight into black soldier fly meal in brown trout nutrition as an environmentally sustainable fish meal replacement

Insect meals are considered among the most promising feed materials in fish nutrition due to their sustainability and possibility of fish meal replacement. The present study is the first application of full-fat black soldier fly larvae (BSFL) meal in brown trout (Salmo trutta m. fario) diets. Two experiments were performed on 240 brown trout fingerlings (average body mass 4.85 g) distributed into four groups (12 tanks for the growth performance experiment, 10 fish/tank; and 12 metabolic tanks for the digestibility test, 10 fish/tank). The experimental group design was conducted as follows: control diet, with no BSFL and 35% fish meal, and experimental diets: BSFL5 – with 5% BSFL full-fat meal and 32.5% fish meal; BSFL10 – with 10% BSFL full-fat meal and 30% fish meal; and BSFL20 – with 20% BSFL full-fat meal and 25% fish meal. No effects were recorded in the case of growth performance and feed utilization parameters. The environmental sustainability of the usage of insect meals in fish diets was proven – due to the lower fish meal inclusion, the fish-in-fish-out ratio decreased by 31% in BSFL20. In the case of the viscerosomatic index, increases in BSFL5 and BSFL20 were reported. In all experimental groups, decreases in hepatosomatic index values were observed. Crude protein digestibility decreased in BSFL5 and BSFL20, while crude fat digestibility decreased only in the BSFL20 group. The effect of including BSFL full-fat meal in a brown trout diet on serum biochemical parameters was reported. The aspartate transaminase concentration increased in BSFL10 and BSFL20, while the gamma-glutamyl transpeptidase values decreased in BSFL20. In the case of total cholesterol, higher values were observed in BSFL10 and BSFL20. The albumin content decreased in the BSFL20 group, while globulin showed the highest values in the control group. The microbiota composition was not affected by insect meal inclusion. In conclusion, the results of the present study showed the high potential of BSFL full-fat meal application of up to 20% in a brown trout diet.     

Effect of dietary incorporation of peanut and linseed meals with or without enzyme mixture on physiological performance of broilers

The present study aimed to evaluate the impact of feeding peanut meal and linseed meal (LSM) with or without enzyme mixture on growth, plasma metabolites, muscle amino acid (AA) profile, nutrient digestibility, and expression of nutrient absorption-related genes in broilers. A total of 560 one-day-old Cobb-500 male broiler chicks were distributed into eight experimental treatments (7 replications of 10 chicks each) as follows: This study was designed by using 560 one-day-old Cobb-500 male broiler chicks were distributed into eight experimental groups (7 replications of 10 chicks each) to evaluate the differences in body weight, body weight gain, feed intake, feed conversion rate, carcass parts, blood biochemical and mRNA expression genes. Group 1 (C) control fed the basal diet without supplements, Group 2 (C + E) is control group fed on 350 g/ton enzyme mixture, Group 3 (C + PNM100) is control group fed 100 kg/ton peanut meal, Group 4 (C + E + PNM100) is a control group fed on 350 g/ton enzyme mixture and 100 kg/ton peanut meal, Group 5 (C + LSM100) is a control group fed on 100 kg/ton linseed meal, Group 6 (C + E + LSM100) is a control group fed on 350 g/ton enzyme mixture and 100 kg/ton linseed meal, Group 7 (C + PNM50 + LSM50) is control group fed on 50 kg/ton peanut meal and 50 kg/ton linseed meal. Group 8 (C + E + PNM50 + LSM50) is the control group fed on 50 kg/ton peanut meal and 50 kg/ton linseed meal. Each gram of the enzyme mixture contains 11,000 U Xylanase, 6000 U Cellulase, 700 U β-Mannanase, 1500 U Phytase, 5 mg α-Amylase, and 2 mg Protease. No differences in Bodyweight, Bodyweight gain, Feed intake, and carcass parts were noticed among experimental groups, while abdominal fat (%) and FCR were reduced (P < 0.05) in PNM50 + LSM50 + E and LSM100 groups. Plasma metabolites were not altered except total cholesterol, triglyceride, and LDL, reduced (P < 0.01) in treated birds. Dietary inclusion of 100 kg PNM or LSM reduced (P < 0.05) methionine concentration in muscle, while all remaining AA and ammonia concentrations were unaffected. Hepatic MDA contents were reduced (P < 0.001) in treated groups. Nutrient digestibility was not altered among groups except for protein digestibility, which was elevated (P < 0.05) in PNM50 + LSM50 + E, E, and PNM100 + E groups. The highest mRNA expressions of PepT1, APN, SGLT1, HMGCR, GHr, and IGF-1 genes were noticed in PNM50 + LSM50 + E. Conclusively, PNM and LSM can efficiently substitute corn and soybean meal in broiler diets, particularly when fortified with exogenous enzymes, without negative impacts on broiler performance.     

Effect of fat type and lysophosphatidylcholine addition to broiler diets on performance,apparent digestibility of fatty acids,and apparent metabolizable energy content

A completely randomized design study with a 3 × 2 factorial arrangement was conducted to evaluate the effects of three different fat sources (soybean oil, tallow, and poultry fat) with or without emulsifier supplementation on performance, coefficient of total tract apparent digestibility (CTTAD) of fatty acids, and apparent metabolizable energy (AME) content in broiler chickens. Two hundred and fifty-two one-day-old male Arbor Acres broiler chickens were randomly divided into 6 different treatments: (T1) basal diet containing soybean oil without lysophosphatidylcholine (LPC) supplementation, (T2) basal diet containing soybean oil with LPC supplementation, (T3) basal diet containing tallow without LPC supplementation, (T4) basal diet containing tallow with LPC supplementation, (T5) basal diet containing poultry fat without LPC supplementation, and (T6) basal diet containing poultry fat with LPC supplementation. Body weight gains from broiler chicks fed diets containing tallow were lower (P<0.05) than the body weight gains from chicks that were fed diets containing soybean oil or poultry fat in both the starter and grower periods. Birds fed diets containing tallow had the highest FCR (P<0.05), followed by the birds that were fed diets containing poultry fat, and soybean oil. The CTTAD of C16:0, C18:2, and C18:3n3 was greater (P<0.05) for broilers fed diets containing soybean oil than for those fed diets containing tallow or poultry fat in the starter period. The addition of LPC increased (P<0.05) body weight gain of broiler chickens in the starter period and the AME of the diets in the grower period, and tended to reduce FCR (P=0.072) in the starter period. LPC supplementation increased (P<0.05) the CTTAD of C16:0, C18:1n7 and C18:1n9 in the starter period, and of C18:2, and C18:3n3 in the grower period (P<0.05). There were no significant interactions between fat sources and the addition of LPC. These data indicated that LPC supplementation can improve body weight gain of broiler chickens in the starter period. This effect may be associated with an increase of CTTAD of FA due to LPC activity.     

Marine ash‐products influence growth and feed utilization when Atlantic cod Gadus morhua L. are fed plant‐based diets

Atlantic cod Gadus morhua L. were fed high plant protein diets added to either shrimp‐shell meal or crab‐shell meal. The aims were to investigate if diluting dietary energy would reduce the liver index (HSI) and if marine ash would add value to plant protein‐based diets. Two control diets were used: a high plant protein control diet (PP) with no marine ash addition, and a fishmeal‐based diet (FM) with no marine ash addition. All diets were evaluated in small cod (initial weight 79 ± 15g) and in market‐size cod (initial weight 1579 ± 20 g). Addition of crab‐shell meal up to 20% and shrimp‐shell meal up to 10% did not influence liver size in either small or market‐size cod. An addition of up to 20% crab‐shell meal and 10% shrimp‐shell meal improved growth compared to the PP control diet, and stimulated increased feed intake. However, 10% shrimp‐shell meal and 20% crab‐shell meal diets resulted in a similar intake of energy and protein as the control groups. Increasing shrimp‐shell meal to 20% resulted in reductions in feed intake, fat digestibility and growth, and in altered gut histology. All diets, except the 20% shrimp added diet, resulted in normal ranges of plasma nutrients and blood hematological values, showing good fish health with or without the marine ash addition.     

Improvement of nutritional quality of cultured sobaity sea bream,Sparidentex hasta (Valenciennes) muscle by preharvest feeding of finisher feeds

A 6‐month long study was conducted to improve the nutritional quality of the cultured sobaity bream, Sparidentex hasta by feeding them finisher feeds containing high docosahexaenoic acid (DHA) at the last two months of the grow‐out stage so that the muscle DHA level be increased at par to the wild. A grow‐out feed used from the beginning until the end of the trial was considered as the control (Diet 1). Experimental diets 2 and 3 were formulated to contain 9.0% DHA (e.g. 1.68 g DHA/100 g feed) and 10.5% DHA (2.20 g DHA/100 g feed), by incorporating high DHA tuna oil into a sea bream grow‐out diet. For comparison, a commercial finisher feed (Diet 4) from Skretting, Italy was also used. The results of this study demonstrated that fish fed DHA enriched finisher diets resulted in significantly (p < .05) better growth, feed utilization and higher muscle eicosapentaenoic acid (EPA) and DHA content compared to those fed grow‐out diet. The muscle DHA and EPA of fish fed finisher diets were also higher than those of the whole year average DHA and EPA content of wild sobaity. An organoleptic evaluation showed no significant (p > .05) differences between sensory attributes of muscle from cultured and wild sea bream. The results of the study demonstrated that feeding finisher feed enriched with DHA at the later part of the grow‐out operation, the n‐3 PUFA levels of cultured sobaity can cost‐effectively be increased at par to the wild.     

Efficacy of virginiamycin and a commercially-available lactobacillus probiotic in swine diets

Eight feeding trials using 708 cross-bred pigs were conducted to evaluate the addition of virginiamycin and a commercially-available lactobacillus fermention product (probiotic) to starter, grower and finisher diets based on maize and soya bean meal. Virginiamycin was added at a level of 11 mg/kg of diet, and lactobacillus probiotic at 1 g/kg in starter diets and 500 mg/kg in grower and finisher diets. In the combined analysis of four starter trials, pigs fed on diets containing virginiamycin tended to eat more and grow faster than pigs fed on the control diet, but feed efficiency was not different. Furthermore, daily gain, daily feed intake and feed efficiency were not improved by the addition of lactobacillus probiotic to starter diets. In the combined analysis of a starter—grower—finisher and a grower—finisher trial, virginiamycin supplementation did not alter overall pig performance compared with control. Pigs fed on a positive control diet containing chlortetracycline, penicillin and sulfamethazine had a nonsignificantly greater daily gain and feed intake.Daily gain for the lactobacillus probiotic-fed pigs was lower (P < 0.05) than that of the negative controls, but daily feed intake and feed efficiency were not significantly different. In three growing—finishing trials in which virginiamycin and lactobacillus probiotic were compared in a 2 × 2 factorial arrangement of treatments, daily gain and feed intakes were greater (P < 0.01) for pigs given virginiamycin. The lactobacillus probiotic did not improve daily gain, feed intake or feed efficiency. Overall, no interaction between virginiamycin and lactobacillus probiotic occurred.     

Larval rearing of fringe-lipped carp,Labeo fimbriatus (Bloch) with low cost diets including green bottle fly Lucilia sericata (Meigen) larvae meal incorporated diet

A study was conducted with non-conventional ingredients to test their efficacy as fishmeal (FM) replacers in the diet of fringe- lipped carp. Labeo fimbriatus first feeding larvae and fry were reared for 30 and 60 days in indoor, 50 L, aerated, circular plastic tanks at 100 and 30 numbers tank⁻¹, respectively. In the first feeding larvae to fry rearing experiment (Exp. 1), the fish were fed with either of the following isonitrogenous and isocaloric diets – live plankton, FM diet, green bottle fly (Lucilia sericata) larvae meal (GBFLM) diet and silkworm pupa (SWP) diet. The fry to fingerling rearing (Exp. 2), was also conducted using the same diets described above except live plankton. All compounded diets were formulated to contain 40% crude protein for the experiment 1 and 35% for experiment 2 and were fed ad libitum. Triplicate tanks were maintained for each treatment in both the experiments. In Exp. 1, the mean final weight of fry was higher with plankton and FM diets, while no difference (p > .05) was observed between FM and GBFLM diets. Weight of fish fed SWP diets was not statistically different from those fed GBFLM diet. No difference (p > .05) in final length, survival and condition factor was recorded. Analysis of digestive enzyme activity of whole fish revealed lower (p < .05) activity of amylase in fish fed plankton. In Exp. 2, no difference (p > .05) was observed between the different diet groups in terms of mean final weight, length, survival and condition factor. Analysis of digestive enzyme activity of whole fish revealed no difference (p > .05) in the activity of digestive enzymes between the treatments except a lower (p < .05) activity of trypsin in FM diet and lipase in FM and GBFLM diets. Since the survival and condition factors of animals is the most important aspect during nursery rearing, similar (p > .05) values recorded in different treatments indicate the possibility of incorporation of these non-conventional protein sources in the diet of L. fimbriatus during first feeding larvae to fry and fry to fingerling rearing.     

Nutritional profile of soaked Cajanus cajan (L.) Millsp. and its utilization as partial replacement for soybean meal in the diet of Clarias gariepinus (Burchell, 1822) fingerlings

This study aimed to investigate the efficacy of soaking as a cheap processing method in improving the nutritional utilization of Cajanus cajan for partial replacement of soybean meal in formulated diets of the African catfish Clarias gariepinus (Burchell, 1822). The nutrient profile of soaked C. cajan revealed a significant reduction (≤50%) in all anti‐nutritional factors. Proximate and amino acids were also affected by this processing method. Six practical diets (35 g/kg crude protein, 19.1 KJ/g diet) containing substitution levels of 0, 10, 20, 30, 40 and 50% C. cajan for soybean protein (included at 578 g/kg) were then formulated and fed to triplicate groups (n = 50 in each group) of C. gariepinus fingerlings (1.41 ± 0.06 g) in a hapa pond system (1 × 1 × 1 m³) for 56 days (mean temperature 25.3 ± 0.6). The results revealed that fish survival was not significantly affected until a 40% substitution of soybean was reached. However, beyond 20% soybean substitution, growth was significantly reduced (≥7%; p ≤ .05). Fish fed the highest substitution of soaked C. cajan meal (50% soybean replacement) had the poorest performance. The cost of the compound diets was substantially reduced with the inclusion of soaked C. cajan. Production costs of 1 kg fish using the diet with an inclusion of up to 20% soaked C. cajan meal replacement were comparable to using the control diet. It was concluded that soaking C. cajan seed for 24 hr improved the nutritional profile of the ingredients to replace 20% of the soybean (included at 57.8%) protein in the diet of C. gariepinus with no negative effect on growth and nutrient utilization.     

Simultaneous inclusion of sorghum and cottonseed meal or millet in broiler diets: effects on performance and nutrient digestibility

Two experiments were conducted to investigate the use of sorghum, cottonseed meal and millet in broiler diets and their interaction when they are used simultaneously. In Experiment 1, a corn-soybean meal control diet was compared with eight experimental treatments based on low tannin sorghum (S30, S45 and S60), cottonseed meal (CM15, CM40) or both ingredients included in the same diet (S30/CM40, S45/CM25 and S60CM15). Results showed that BW gain was not affected by the inclusion of sorghum or cottonseed meal. However, feed intake tended to be affected by the cereal type with the highest values with sorghum-based diets. Feed conversion ratio increased (P<0.001) with sorghum-based diets compared with the control diet, whereas a combination of cottonseed meal and sorghum in the same diet did not affect the feed conversion ratio. Significant differences (P<0.001) were observed in apparent ileal digestibility (%) of protein and energy with the cottonseed meal and sorghum/cottonseed meal-based diets having lower protein and energy digestibility compared with corn-based diets. In Experiment 2, a control diet was compared with six diets in which corn was substituted at 60%, 80% or 100% by either sorghum or millet and other three diets with simultaneous inclusion of these two ingredients (S30/M30, S40/M40, S50/M50). Single or combined inclusion of sorghum and millet resulted in similar feed intake and growth performance as the control diet. Apparent ileal digestibility of protein and energy was higher with millet-based diets (P<0.001). Total tract digestibility of protein in sorghum and millet-based diets tended to decrease linearly with the increasing level of substitution. Sorghum-based diets resulted in lower total tract digestibility of fat compared with millet and sorghum/millet-based diets (P<0.001). Higher total tract digestibility of starch were obtained with the control diet and millet-based diets compared with the sorghum-based treatments. Results of the two experiments suggest that broiler growth performance was not affected by the dietary level of sorghum, millet or cottonseed meal. Nutrient digestion can, however, be affected by these feed ingredients.     

Proportion of insoluble fibre in the diet affects behaviour and hunger in broiler breeders growing at similar rates

With a view to alleviate the feeling of hunger in broiler breeders, different types of fibre sources were used in high-fibre diets to increase feed quantity while limiting growth to industry recommended levels. Using scatter feeding, three diets (C1: commercial control diet, 1 × fibre content, 80% insoluble fibre (ISF); H2: 2 × fibre content, 89% ISF; and L2: 2 × fibre content, 71% ISF) were each fed to 10 groups of 16 broiler breeder chickens. Similar growth rates were obtained on different quantities of food with all birds reaching commercial target weight at 15 weeks of age. In a hunger test, birds fed C1 ate significantly faster and showed a higher compensatory feed intake than birds on diets H2 and L2, indicating that the two high-fibre diets did reduce the level of hunger experienced by the birds. Behavioural observations carried out at 14 weeks of age showed high levels of tail pecking in birds fed C1 and almost none in birds fed L2, whereas birds fed H2 were intermediate. Stereotypic pecking at fixtures was seen twice as frequently in birds fed C1. Birds on diet L2 displayed behavioural signs indicative of discomfort, and the high water usage on this diet created problems with litter quality. Birds on diet H2 continued to show foraging behaviour throughout the day, and were more frequently engaged in dust bathing and other comfort behaviour. This experiment indicates that high-fibre diets can alleviate the feeling of hunger currently experienced by broiler breeders, and a high ratio of ISF may improve the well-being of the birds.     

Dietary inclusion of mussel meal enhances performance and improves feed and protein utilization in common sole (Solea solea,Linnaeus, 1758) juveniles

The present study was carried out to test different mussel meal (MM) dietary levels in combination with fishmeal (FM) on the growth performance, fatty acid composition and liver histology of common sole, Solea solea juveniles to highlight the growth potential of this species. Four isoproteic (53%) and isolipidic (11%) pelletized diets were formulated to contain graded levels of mussel meal, MM0 (0%), MM25 (25%), MM50 (50%) and MM75 (75%), up to 75%. Sole juveniles (initial individual mean body weight 13.1 ± 2.3 g, n = 840) were fed to satiation for 91 days. Seventy fish per tank (500‐L, 0.64 m² bottom surface) were reared in 12 tanks (3 tanks per treatment) at 20 ± 1°C. Diets containing MM (MM25, MM50 and MM75) gave a significantly higher specific growth rate (SGR, 1.27 ± 0.01, 1.38 ± 0.06 and 1.40 ± 0.05, respectively), higher feed intake and lower feed conversion rate (FCR, 1.09 ± 0.01, 1.00 ± 0.04 and 0.98 ± 0.02, respectively) when compared to the FM‐based diet (MM0, SGR, 0.98 ± 0.11, FCR, 1.52 ± 0.13). Carcass proximate composition was not influenced by dietary treatments, with the exception of the significantly lower lipid content in the MM75 group. Protein efficiency ratio (PER) and gross protein efficiency (GPE) were significantly improved by the mussel meal inclusion (PER, 1.29 ± 0.12, 1.76 ± 0.01, 1.89 ± 0.06, 1.95 ± 0.08; GPE, 25.29 ± 1.85, 33.38 ± 0.89, 35.96 ± 1.36, 36.59 ± 1.05 in MM0, MM25, MM50 and MM75, respectively). A significant decrease in the viscerosomatic index was observed in fish fed with MM50 and MM75 in comparison to MM0. The hepatosomatic index of fish fed with MM0 and MM25 was higher than that of fish fed with MM75, although the histological examination of liver parenchyma in all experimental groups showed a uniformly abundant accumulation of lipid droplets. Carcass fatty acid composition was significantly affected by dietary treatments, reflecting the dietary fatty acid profile. According to these results, the inclusion of MM in experimental FM‐based diets improved the performance and feed utilization of common sole juveniles. The inclusion of MM in the present trial allowed a higher SGR than that registered in previous growth trials on common sole. This study could provide useful information to detect effective ingredients for practical diets in Solea solea. It also seems advisable to consider an inclusion of at least 25% MM in the experimental reference diet to be used for further application towards the development of specific diets for this species.     

Relationship between the amino acid release kinetics of feed proteins and nitrogen balance in finishing pigs

In current nutrition requirements of swine, although the protein diets are formulated based on the ileal digestibility of protein and amino acid (AA), there is a difference in nitrogen utilisation among various protein diets, which might be related to the AA release kinetics. To evaluate the relationship between AA release kinetics of feed proteins and nitrogen balance in finishing pigs, pigs were fed diets based on casein (CAS) or corn gluten meal (CGM) at normal or low-protein concentrations, and the AA release patterns were assessed. A 2 × 2 full factorial experimental design was used. 24 pigs (Duroc × Landrace × Yorkshire) with an initial weight of 67.0 ± 1.8 kg were randomly assigned to consume a normal-protein casein-based diet (N.CAS, 10% CP), normal-protein corn gluten meal-based diet (N.CGM, 10% CP), low-protein casein-based diet (L.CAS, 8.5% CP), or low-protein corn gluten meal-based diet (L.CGM, 8.5% CP) for 14 days (n = 6 per group; pigs housed and fed separately). The low-protein diets were associated with a more rapid release of AAs in the early stages of gastric digestion than the normal-protein diets. The N.CAS and L.CAS diets were associated with a peak AA release at approximately 4 h during trypsin digestion, whereas N.CGM and L.CGM were at approximately 16 h. The N.CAS diet was associated with the least dispersed release curves and lowest synchronisation indexes, implying that it was associated with the best AA release synchronism, whereas the L.CGM diet was on the contrary. The nitrogen intake (NI), faecal nitrogen, urine nitrogen (UN), total nitrogen, net protein utilisation and apparent biological value (ABV) of protein of pigs fed the L.CAS or L.CGM diets were lower than those fed the N.CAS or N.CGM diets (P < 0.05). Notably, there was a difference in NI (P < 0.05) and trends with respect to UN and ABV (0.05 < P < 0.1), but no differences in retained nitrogen or apparent nitrogen digestibility between pigs fed the N.CAS or L.CAS diets and those fed the N.CGM or L.CGM diets. Pigs fed the N.CAS or N.CGM diets had higher serum concentrations of UN than pigs fed the L.CAS or L.CGM diets (P < 0.05), but there were no differences in serum total protein, albumin, triglyceride, glucose, alanine transaminase, or aspartate aminotransferase between the groups. In addition, there was an interaction between protein level and protein source on serum globulin (P < 0.05). Therefore, the diet with a better AA release synchronism can improve protein utilisation efficiency in finishing pigs and to reduce environmental pollution.     

Effect of papaya (Carica papaya) leaf extract as dietary growth promoter supplement in red hybrid tilapia (Oreochromis mossambicus × Oreochromis niloticus) diet

The purpose of this experiment was to examine the potential use of Carica papaya leaf extract as a supplement to promote growth and improve feed utilization in red hybrid tilapia. Five diets were formulated containing isolipidic (80 g/kg) and isonitrogenic (350 g/kg) levels. All feeds contained similar types and amounts of raw materials but differed in the inclusion of papaya leaf extract (0, 5, 10, 20 and 40 g/kg feed). The initial size of fish used was 2.3 ± 0.01 g. Each diet was performed in triplicate tanks, and the feeding period was 12 weeks. Fish fed diet containing 2% papaya leaf extract (PLE) had the highest final weight, 31.14 ± 1.47 g, followed by 1% PLE (27.27 ± 1.75 g). These two diets (1% and 2%) were also showed significant improvements of weight gain, SGR, and feed efficiency of the red hybrid tilapia (p < 0.05). However, papaya leaf extract did not affect the HSI, VSI, PER, digestive enzymes activity, blood composition, and survival rate. Supplementing the diets with papaya leaf extract lowered serum urea. Findings of this research suggest that adding papaya leaf extract to the diet of red hybrid tilapia improves growth and feed efficiency without adversely affecting blood parameters. Therefore, an inclusion level between 1% and 2% of the papaya leaf extract is recommended as a feed additive to promote red hybrid tilapia fry growth.     

Effects of feeding crambe meal upon intake,gain, health and meat quality of broiler chicks

True metabolizable energy of crambe meal was determined with adult cecectomized turkeys to be 11.8 kJ(2.8 kcal)g⁻¹. Amino acid digestibilities were 90% or greater, indicating that protein quality of crambe meal was high. Growing broilers were fed diets containing 0, 50, 100 or 150 (g crambe meal) kg⁻¹ diet (control, 50C, 100C and 150C, respectively) for 56 days. Feed intake for the 150C birds was lower than the other treatments initially; at the end of the experiment, intake of the 150C birds compensated and was similar to the control birds. Weight gain patterns were similar to intake responses. Birds on the 150C treatment had reduced tibial ash content and locomotor difficulties in the first half of the experiment; these effects were absent in the second half of the experiment. Meat quality and serum chemistries were unaffected by feeding crambe meal. Broilers fed the 150C diet had increased liver and kidney weights. Broilers can be fed diets containing up to 50 (g crambe meal) kg⁻¹ diet with no adverse effects on gain and health and up to 100 g kg⁻¹ diet with minimal adverse effects on gain and health.     

Investigations on Genetically Modified Maize (Bt-Maize) in Pig Nutrition: Fattening Performance and Slaughtering Results

A grower finisher performance trial with forty-eight pigs was designed to compare the growth performance of pigs fed diets containing either genetically modified (GM) Bt-maize (NX6262) or its parental maize (Prelude) line. During the experiment, the pigs were fed with a grower and a finisher diet both containing 70% maize investigated in a previously study which showed that they contained similar ME values and digestibility of crude nutrients. The pigs with an initial live weight of 23.9 ± 3.0kg were allotted to single boxes. During a 91 days growing period the pigs of both groups recorded equal performance in daily weight gain ( j W) 815 ± 93 vs. 804 ± 64g/d depending on equal amounts of feed intake 1.95 ± 0.15 vs . 1.94 ± 0.15kg/d (parental vs. transgenic). The results confirm equal performance among growing-finishing pigs fed parental or genetically modified maize containing diets. For slaughtering the pigs were divided into 4 groups with a different duration of the finishing period. After slaughtering the carcass characteristic were registered.     

Dairy goats adjust their meal patterns to the fibre content of the diet

Few studies have investigated how meal patterns of ruminants are affected by diet fibre content. Dairy goats (N = 32) in late lactation and early gestation were housed in eight groups of four goats, with all combinations of breed (Alpine and Saanen) and lactation number (1 and 2) represented in each group. Each goat had access to its own individual feed trough placed on a weigh scale with data logged automatically. All goats were fed the same total mixed ration (TMR; 30% concentrate and 44.6% NDF in DM) ad libitum for a control period of 22 days. Using the same feed ingredients, half of the groups were then offered a High fibre diet (20% concentrate; 47.3% NDF), and the other half a Low fibre diet (40% concentrate; 41.5% NDF) for a treatment period of 16 days. Daily meal patterns (meal frequency, duration and size, feeding rate, daily feed intake and daily feeding time) were computed for each animal using a meal criterion of 8 min. The last 10 days for each period (control and treatment) were used to calculate individual period means and individual differences between the two periods. During the control period, the goats ate on average 12.1 ± 0.49 meals/day, consuming 4.2 ± 0.10 kg fresh TMR daily. When the ration changed, all measures of feeding behaviour except meal size changed asymmetrically for the goats on the two diets. Goats fed the High fibre diet reduced their meal frequency by 10%, and the first meal after feed distribution lasted 11% longer, leading to a 9% reduction in feeding rate and no significant changes in daily feed intake and daily feeding time. Goats on the Low fibre diet did not significantly change their meal frequency or meal size, but the combined changes nevertheless led to a 9% increase in daily feed intake. On the Low fibre diet, goats were able to increase their feeding rate by a third, leading to a reduction in meal durations, thus reducing daily feeding time by 13%. Goats adapt their feeding behaviour to the fibre proportion of the offered diet, with more changes when fibre content is lowered, which needs to be taken into account when comparing phenotypes and adaptability of small ruminants to different diets.     

Dietary inclusion of mealworm (Tenebrio molitor) meal as an alternative protein source in practical diets for juvenile rockfish (Sebastes schlegeli)

An 8‐week feeding trial was designed to evaluate the potential of yellow mealworm (Tenebrio molitor) as a locally available nutrient‐rich feedstuff for juvenile rockfish (Sebastes schlegeli). Experimental diets containing elevated levels of mealworm meal (WM) supplemented with synthetic methionine were formulated to be isonitrogenous, isolipidic and isoenergetic to a WM‐free fishmeal (FM) based control diet (designated as WM0, WM8, WM16, WM24 and WM32, respectively). To determine the necessity of dietary methionine supplementation at the highest inclusion of WM, a diet was prepared to contain 32% WM without methionine supplementation (WM32‐AA). Triplicate groups of rockfish juveniles (Mean ± S.E.; 3.11 ± 0.01 g) were fed one of the experimental diets to apparent satiation twice daily for 8 weeks. Fish growth performance in terms of weight gain and specific growth rate increased with increasing dietary inclusion of WM from 0 to 16% and then tended to decrease with further increase in dietary WM levels to 32%. Protein retention (PR) values followed the same trend as growth rates with the highest values found in fish offered WM16 diet. Although fish fed WM32‐AA diet showed significantly lower growth rate and PR values compared to those fed WM16 diet, their performance was still comparable to that of the WM‐free control group. Plasma triglyceride level was negatively affected by dietary WM inclusion and the lowest values were observed in the WM32‐AA group. Whole‐body and fillet proximate and essential amino acid compositions were not altered by dietary treatment and these values were comparable to those of the WM0 group. These findings suggested that WM might prove to be a promising alternative to FM in practical diets for juvenile rockfish and could be used at an inclusion level of up to 32% without having any adverse consequences for the health and performance of the fish. Although the diet containing 32% WM seemed to support a performance similar to that of the control diet, the recommended dietary inclusion level was no more than 16% of the diet dry matter.     

Evaluation of safflower meal as a protein source in diets of rainbow trout [Oncorhynchus mykiss,Walbaum, 1792)]*

The effects of different levels of safflower meal (a residue of the plant oil extraction process) in diets of rainbow trout (Oncorhynchus mykiss) on growth performance, nutrient digestibility and body composition were investigated. Four different diets containing 0% (Control group), 10% (Diet 1), 15% (Diet 2) and 20% (Diet 3) safflower meal were formulated for the fish with a mean weight of 132.70 ± 0.75 g fed for 70 days. At the end of the experiment, there were no significant differences among dietary treatments for weight gain, specific growth rate and feed conversion ratio (P > 0.05). There were also no differences in the digestibility of crude protein and crude lipid between groups (P > 0.05). Supplementation of safflower meal in the diets also had no adverse effects on body composition. The results indicate that safflower meal is a promising feed ingredient and can be used up to a concentration of 20% in the rainbow trout diet with no adverse effects on growth performance, nutrient digestibility or body composition.