Elmutaz Atta Awad

Amino Acids Fortification of Low-Protein Diet for Broilers Under Tropical Climate: Ideal Essential Amino Acids Profile

A three-week trial was conducted to determine the effect of lowering dietary protein level (DPL) with optimal amino acid (AA) profile on growth performance, blood metabolites, and relative weights of abdominal fat and internal organs in broiler chickens raised under tropical hot and humid environment. Five isocaloric (3023 metabolisable energy/kg) starter (1-21 days) experimental diets were formulated in a gradual crude protein (CP) decline from 22.2 (control) to 16.2% by 1.5% interval. All diets were meeting or exceeding National Research Council recommendations except CP and metabolisable energy. The formulations were also adjusted to contain 1.1 digestible Lys to meet the ideal AA ratios concept. Body weights (BW), weight gains (WG), feed intake and feed conversion ratio of groups with 19.2, 20.7 and 22.2% DPL were not significantly different. However, BW and WG suppressed (P<0.05) with 16.2 and 17.7% DPL. Feeding the 16.2% CP diet significantly reduced serum total protein and uric acid, but increased serum triglyceride (P<0.05). Moreover, relative heart weights increased (P<0.05) but no changes occurred in liver and abdominal fat weights in chicks with 16.2% DPL. In summary, CP of broilers starter (1-21 days) diet can be reduced till 19.2% with essential AA fortification and without any adverse effect on growth performance under the hot, humid tropics.

Amino Acids Fortification of Low-protein Diet for Broilers Under Tropical Climate. 2. Nonessential Amino Acids and Increasing Essential Amino Acids

A three-week trial was carried out to evaluate the effect of nonessential amino acids (NEAA) supplementation to a low-crude protein (CP) diet with adequate essential amino acids (EAA) level on growth performance, blood metabolites, and relative weights of abdominal fat, breast yield, and internal organs in broiler chickens raised under tropical hot and humid environment. Five isocaloric (3000 metabolisable energy/kg) corn-soybean diets were administered (1 to 21 days) to 5 groups of broilers (60 birds/group) as follows: i) 22.2% CP (positive control; PC); ii) 16.2% CP+all EAA to meet or exceed the National Research Council (1994) recommendations (negative control; NC); iii) NC+further EAA to equal the levels in the PC diet; iv) NC+NEAA to equal the levels in the PC; v) NC+EAA and NEAA to equal the amino acids levels in the PC diet. The results showed that the fortification of EAA alone, only improved feed intake (FI), whereas, addition of NEAA or EAA+NEAA significantly enhanced body weight, daily weight gain, and FI and decreased the feed conversion ratio to the same levels as in PC. Serum uric acid was significantly reduced and serum triglyceride increased in NC group. Dietary treatments had no significant effect on relative weights of heart, liver, abdominal fat, breast meat yield, serum albumin, and serum total protein. In conclusion, these results suggest that NEAA fortification may improve the growth performance of broilers fed an excessive low-CP diet under tropical hot and humid condition.

Effect of Solid State Fermentation on Nutrient Content and Ileal Amino Acids Digestibility of Canola Meal in Broiler Chickens

The aim of the current study was to investigate the potential of Lactobacillus salivarius solid state fermentation for reduction of glucosinolate content in canola meal (CM) as well as the improvement of its nutrient digestibility for broiler chickens. Canola meal was treated with the L. salivarius in solid state fermentation for 30 days. Nutrients ileal digestibility was tested using 42-day-old broilers fed by either CM or fermented CM (FCM) as the sole source of energy and protein. The results showed that fermentation of CM using L. salivarius reduced glucosinolate content of CM by 38%. The digestibility coefficient was improved significantly for crude protein, Met, Cys, Arg, Asp, Glu, and Ser in FCM compared to CM. However, apparent metabolisable energy of CM was not affected by fermentation. It appears that fermentation treatment of CM using L. salivarius may improve the overall nutritive value of CM for broiler chickens, reducing its total glucosinolate and crude fibre content by 38 and 16%, respectively.

Effects of feeding male and female broiler chickens on low-protein diets fortified with different dietary glycine levels under the hot and humid tropical climate

Abstract This study was conducted to evaluate the effect of sex and level of glycine (Gly) fortification to low-protein diets on growth performance, selected serum metabolites, carcass yield and litter characteristics in broiler chickens under tropical climate. Day-old male (n = 400) and female (n = 400) broiler chicks were assigned to five isocaloric diets (positive control, PC; negative control, NC; and more three diets obtained by fortifying NC diet with higher Gly concentrations). No significant diet × sex interaction was observed for all the parameters measured. Comapered to NC group, weight gain (WG) significantly increased (p<.0001) by feeding Gly fortified low-CP diets throughout the experiment; however, WG and feed intake (FI) of birds fed NC or NC + Gly diets were significantly lower (p<.0001) compared to PC group. During the overall period, fortification of NC diet with Gly significantly improved (p<.0001) the feed conversion ratio (FCR) compared to NC group, and resulted in FCR similar to those birds fed the PC diet. Diet effect was significant (p<.0001) for performance parameters, proportional liver and abdominal fat weights, serum triglycerides (TG) and uric acid (UA) and litter moisture and nitrogen contents; with no Gly level effect (linear and quadratic, p > .05). The sex effect was significant for performance parameters, abdominal fat, and litters’ moisture and nitrogen contents. In conclusion, it is likely that additional Gly fortification to low-CP diets under tropical climate may have a better effect on broiler chickens after the starter phase. Moreover, feeding Gly fortified low-CP diets may improve the FCR and reduce the nitrogen excretion.

Individual non-essential amino acids fortification of a low-protein diet for broilers under the hot and humid tropical climate

A study was conducted to investigate the effects of feeding low-protein diets fortified with individual non-essential amino acids (NEAA) on growth performance, serum metabolites (uric acid, UA; triglycerides, TG; total protein, TP; and albumin, Alb), organ weight, breast yield, and abdominal fat weight in broiler chicks raised under the hot and humid tropical climate. Eight isocaloric (3,017 kcal/kg) experimental diets were formulated and fed to male broiler chicks from d 1-21 as follows: 1) 22.2% crude protein (CP) (positive control; PC); 2) 16.2% CP + mixture essential amino acids (EAA) to meet or exceed the National Research Council (1994) recommendations (negative control; NC); 3) NC + glycine (Gly) to equal the total glycine + serine level in the PC; diets 4 through 7 were obtained by supplementing NC diet with individual glutamic acid, proline, alanine, or aspartic acid (Glu, Pro, Ala, or Asp, respectively); 8) NC + NEAA (Gly + Glu + Pro + Ala + Asp) to equal the total level of these NEAA in the PC. Fortifying NC diet with mixture NEAA resulted in a similar growth performance as PC. However, fortification of low-CP diet with individual NEAA failed to improve body weight (BW) (P < 0.0001), feed intake (FI) (P = 0.0001), and feed conversion ratio (FCR) (P = 0.0001). Serum uric acid (UA) was lower (P = 0.0356) in NC birds and NC diet supplemented with individual NEAA birds, whereas serum triglyceride (TG) (P = 0.007) and relative weight of abdominal fat (P = 0.001) were higher in these birds. In conclusion, no single NEAA fortification may compensate the depressed growth performance attributed to a low-CP diet. However, fortification with Gly may improve FCR. There is a possibility that broilers raised under the hot and humid climate require higher Gly fortification than the level used in this study.

Growth performance, duodenal morphology and the caecal microbial population in female broiler chickens fed glycine-fortified low protein diets under heat stress conditions

ABSTRACT 1. This study was undertaken to examine the effect of feeding glycine (Gly)-fortified low protein (LP) diets on the growth performance, duodenal morphology and caecal microbial populations of broiler chickens raised under unheated, cyclic or constant heat stress environmental conditions. 2. From d 1 to 21 (starter phase), an equivalent number of birds were fed either a normal protein (NP) diet or a LP diet fortified with Gly. From d 22 to 42 (grower phase), an equivalent number of birds from each starter diet were distributed to one of the following dietary groups: (i) an NP diet during the starter and grower phases (NPNP), (ii) an NP diet during the starter phase and a LP diet during the grower phase (NPLP), (iii) an LP diet during the starter phase and an NP diet during the grower phase (LPNP) or (iv) LP diets during both phases (LPLP). 3. Commencing from d 22, an equivalent number of birds from each dietary group were exposed to (i) 23 ± 1°C throughout (unheated), (ii) 34 ± 1°C for 7 h each day from 10:00 to 17:00 (cyclic heat) or (iii) 34 ± 1°C throughout (constant heat). 4. Feeding the LP diet during the starter phase resulted in feed intake (FI), weight gain (WG), feed conversion ratios (FCR) and energy efficiency ratios (EER) similar to those for the NP diet. The birds fed the LP diet had a significantly higher protein efficiency ratio (PER) compared with the birds fed the NP diet. 5. During the grower phase, there were significant diet × temperature interactions for F, WG, FCR, PER, EER, villus height, crypt depth and caecal Clostridia. The birds fed the NPLP and LPLP diets had lower FI, WG and EER, higher FCR, shorter villus height and crypt depth and higher caecal Clostridia compared with the birds fed LPNP and NPNP diets under constant heat stress. However, feeding birds the NPLP and LPLP diets resulted in FI, WG, EER, FCR, morphology parameters and caecal Clostridia equivalent to the birds fed LPNP and NPNP diets, as well as improved PER, under unheated and cyclic heat stress conditions. 6. In conclusion, our results indicate that Gly-fortified LP diets can be fed to broilers under normal and acute heat stress environmental conditions without any adverse effects on performance. However, the use of such LP diets can be detrimental to broilers under chronic heat stress conditions.

Effects of Ultrasound Assisted Extraction in Conjugation with Aid of Actinidin on the Molecular and Physicochemical Properties of Bovine Hide Gelatin

Actinidin was used to pretreat the bovine hide and ultrasonic wave (53 kHz and 500 W) was used for the time durations of 2, 4 and 6 h at 60 °C to extract gelatin samples (UA2, UA4 and UA6, respectively). Control (UAC) gelatin was extracted using ultrasound for 6 h at 60 °C without enzyme pretreatment. There was significant (p < 0.05) increase in gelatin yield as the time duration of ultrasound treatment increased with UA6 giving the highest yield of 19.65%. Gel strength and viscosity of UAC and UA6 extracted gelatin samples were 627.53 and 502.16 g and 16.33 and 15.60 mPa.s, respectively. Longer duration of ultrasound treatment increased amino acids content of the extracted gelatin and UAC exhibited the highest content of amino acids. Progressive degradation of polypeptide chains was observed in the protein pattern of the extracted gelatin as the time duration of ultrasound extraction increased. Fourier transform infrared (FTIR) spectroscopy depicted loss of molecular order and degradation in UA6. Scanning electron microscopy (SEM) revealed protein aggregation and network formation in the gelatin samples with increasing time of ultrasound treatment. The study indicated that ultrasound assisted gelatin extraction using actinidin exhibited high yield with good quality gelatin.

Effects of low-protein diets on acute phase proteins and heat shock protein 70 responses, and growth performance in broiler chickens under heat stress condition

ABSTRACT A study with a 4 × 2 factorial arrangement was conducted to investigate the effects of 4 dietary protein levels and 2 environmental conditions on acute phase proteins (APP), brain heat shock protein (HSP) 70 density, and growth performance of broiler chickens. Day‐old broiler chicks (Cobb 500) were fed isocaloric diets but with various levels of crude protein (CP), namely, (1) 21.0 and 19.0% CP in starter and finisher diets, respectively (control), (2) 19.5 and 17.5% CP in starter and finisher diets, respectively (Diet A), (3) 18.0 and 16.0% CP in starter and finisher diets, respectively (Diet B), and (4) 16.5 and 14.5% CP in starter and finisher diets, respectively (Diet C). Equal numbers of birds from each diet were subjected to either 23±1°C throughout or 33±1°C for 6 h per d from 22 to 35 d of age. From d 1 to 21, feed intake (FI) and weight gain (WG) decreased linearly (P = 0.021 and P = 0.009, respectively), as CP level was reduced. During the heat treatment period (d 22 to 35), there were significant (P = 0.04) diet × heat treatment interactions for FCR. Diet had no effect on FCR among the unheated birds, but the ratio increased linearly (P = 0.007) as dietary CP level decreased. Irrespective of ambient temperature, there was a significant linear decrease in FI (P = 0.032) and WG (P < 0.001) as dietary CP level decreased. Low‐CP diets improved the survivability of heat‐stressed broilers when compared to those fed control diets. Low‐CP diets linearly decreased (P < 0.01) APP (ovotransferrin and alpha‐acid glycoprotein) responses. Both APP and HSP 70 reactions were elevated following heat treatment. In conclusion, feeding broilers with low‐CP diets adversely affect the growth performance of broilers under heat stress condition. However, low‐CP diets were beneficial in improving the survivability. Because APP are involved in the restoration of homeostasis, the adverse effect of low‐CP diet on the synthesis of these proteins could be of concern.

Autolysis of bovine skin, its endogenous proteases, protease inhibitors and their effects on quality characteristics of extracted gelatin

The autolysis of pretreated bovine skin (PBS) (treated with 0.1 M NaOH and 1% HCl), its endogenous proteases, inhibitors and their effects on quality attributes of gelatin were examined. PBS was subjected to different temperatures (20-90 °C) and pH (2-9) and treated with different protease inhibitors. Maximum autolytic activity of PBS was observed at 40 °C and pH 5. Ethylene-bis (oxyethylenenitrilo) tetraacetic acid (EGTA) was the most effective in impeding the degradation of γ-, β- and α- chains of PBS protein indicating that metallocollagenases were the predominant endogenous proteases in bovine skin. Gelatin was extracted in the absence (GAE) and presence (GPE) of EGTA, and EGTA with papain enzyme (GPEP). GPEP had a higher yield and lower gel strength than GEA and GPE. Metallocollagenases partook in the degradation of gelatin thereby affecting its functional properties. Pretreating PBS with or without EGTA, and papain influenced the quality attributes of gelatin.

Effects of method and duration of restraint on stress hormones and meat quality in broiler chickens with different body weights

Objective The study was designed to investigate the effects of restraint method, restraint duration, and body weight on stress-linked hormones (corticosterone, adrenaline, and noradrenaline), blood biochemical (namely glucose and lactate), and the meat quality in broiler chickens. Methods A total of 120 male broiler chickens (Cobb 500) were assigned to a 2×3×2 factorial arrangement in a completely randomized design using two restraint methods (shackle and cone), three durations of restraint (10, 30, and 60 s), and two categories of live body weight (1.8±0.1 kg as lightweight and 2.8±0.1 kg as heavyweight). Results Irrespective of the duration of restraint and body weight, the coned chickens were found to have lower plasma corticosterone (p<0.01), lactate (p<0.001), lower meat drip loss (p<0.01), cooking loss (p<0.05), and higher blood loss (p<0.05) compared with their shackled counterparts. The duration of restraint had significant effects on the meat initial pH (p<0.05), ultimate pH (p<0.05), and yellowness (p<0.01). The lightweight broilers exhibited higher (p< 0.001) blood loss and lower (p<0.05) cooking loss compared to the heavyweight broilers, regardless of the restraint method used and the duration of restraint. However, the interaction between the restraint method, duration of restraint, and body weight contributed to differences in pre-slaughter stress and meat quality. Therefore, the interaction between the restraint method and the duration of restraint affected the meat shear force, lightness (L*) and redness (a*). Conclusion The duration of restraint and body weight undoubtedly affect stress responses and meat quality of broiler chickens. Regardless of the duration of restraint and body weight, the cone restraint resulted in notably lower stress, lower meat water loss, and higher blood loss compared to shackling. Overall, the findings of this study showed that restraint method, duration of restraint, and body weight may affect the stress response and meat quality parameters in broilers and should be considered independently or interactively in future studies.