Positive and Negative Impacts of Dietary Protein Levels in Laying Hens

Productive performance, lipid profile, immunity, and antioxidant parameters of quail breeders fed low protein diets supplemented with different zinc sources

The current study was conducted to study the impact of low-CP protein diets with different sources of zinc (zinc oxide-ZnO and zinc methionine-Zn-Met) on performance, lipid profile, immune and antioxidant parameters of quail breeders. A total number of 216 Japanese quail at 8 weeks of age were randomly distributed into nine (3 × 3) groups, with four replicates, each of six quails (four females and two males). Quails were fed three levels of CP (16, 18, and 20%) and three sources of Zn (0, 0.1 g ZnO, and 0.1 g Zn-Met/kg diets). No significant differences in daily feed intake (FI), feed conversion ratio (FCR), and egg mass are due to the main effect of protein levels or zinc sources at all ages. Dietary CP (16 and 20%) in growing quail diets increased SOD and GSH, while IgG levels were improved by 18%. Finally, it can be recommended that 16% CP and zinc source (Zn-Met or ZnO) can maintain egg mass, as well as lipid profile, immunological and antioxidant parameters in Japanese quails breeders. This level (16% CP) is enough during the production stage and a valuable way for mitigating ammonia pollution and reducing feeding costs.

In vivo performances, ileal digestibility, and physicochemical characterization of raw and boiled eggs as affected by Tenebrio molitor larvae meal at low inclusion rate in laying quail (Coturnix japonica) diet

A total of 120, twelve wk old female Japanese quails were divided into 4 groups (6 replicates of 5 birds each). The control group (CON) fed a corn-soybean diet; in the other 3 groups, Tenebrio molitor larvae meal (TML) replaced 5, 10, and 20% of the soybean protein (T5, T10, and T20). The laying performance and egg quality were studied for 54 d. The data were processed by a one-way ANOVA; the orthogonal contrast analysis was performed to test the linear, quadratic and cubic effects among the means. The laying rate and egg mass linearly decreased (P < 0.01) as the TML inclusion level in the diet increased. The egg weight and feed conversion ratio linearly increased from the control to T20 diet (P < 0.01) while the digestibility of dry matter, organic matter, and crude protein linearly decreased (P < 0.05). The albumen and yolk weight showed a linear increase (P < 0.01) due to dietary TML inclusion, while the eggshell weight showed the opposite (P < 0.05). The estimated activity of Δ9-desaturase (C16:0), Δ5+Δ6-desaturase on both polyunsaturated fatty acid n-6 and n-3 linearly increased (P < 0.05) as affected by dietary TML. The boiled yolk lightness (L*) showed higher values in T5 and T10 groups (quadratic contrast, P < 0.01). The yolk redness index (a*) showed lower values in T5 and T20 than control and T10 groups (cubic contrast, P < 0.01). The albumen L*, a*, and b* indexes showed a significant effect of the quadratic contrast (P < 0.05). In addition, the albumen b* index showed a significant effect of the cubic contrast (P < 0.01). The total lipids showed the highest values (cubic contrast, P < 0.05) in the T10 and T20 groups. The total monounsaturated fatty acids linearly increased (P < 0.05) according to the increase of dietary TML. The best inclusion level of defatted TML meal for laying quails seems to be 1.4% of diet, corresponding to the T5 diet.

Supplementation of different zinc sources to low-CP diets and its effect on performance, carcass traits, liver and kidney functions, immunological, and antioxidant parameters of quail chicks

The present study was performed to evaluate the influence of low crude protein (CP) levels, zinc sources (organic as zinc methionine-Zn-Met and inorganic as zinc oxide-ZnO) and their interactions on growth performance, carcass traits, and blood components of growing Japanese quail. A total of 450 one-wk-old Japanese quail with the same body weights were randomly distributed into 9 groups of 50 birds. The 9-diet treatments comprised 3 levels of CP (20, 22, and 24%) and 3 Zn source (0 g of Zn/kg diet, 0.1 g ZnO/kg diet, and 0.1 g Zn-Met/kg diet). The results obtained from this study showed that there were no significant differences among the groups, except for differences in body weight (BW) and body weight gain (BWG) at 3 to 5 – and 1 to 5 wk of age for quail supplemented with 24% and 20% CP. All the studied biochemical parameters were significantly influenced by different levels of CP and Zn, except urea and creatinine, which were affected by CP levels only. In conclusion, dietary protein level for growing Japanese quails could be reduced to 20% without negative effects on their performance, carcass traits, and blood metabolites.

Effects of Dietary Inclusion Level of Microwave-Dried and Press-Defatted Black Soldier Fly (Hermetia illucens) Larvae Meal on Productive Performance, Cecal Volatile Fatty Acid Profile, and Egg Quality in Laying Hens

Simple Summary

The microwave drying method is convenient in terms of time efficiency, space, and low operational cost compared with the conventional air-drying method. For the same reasons, the microwave drying method has the potential for manufacturing insect meals that could be an alternative protein source in poultry. Therefore, we evaluated the productive performance, cecal volatile fatty acid (FA) profile, and egg quality in laying hens fed on microwave-dried Hermetia illucens larvae meal (HILM) at two different substitution levels (2% and 4%) of soybean meal. Similar productive performance with no negative effects on the nutritional and physical quality of eggs was observed from the study, indicating that microwave-dried HILM can be a potential ingredient in the diets of laying hens. However, further research is needed in improving the manufacturing process for better bioavailability of HILM and improved FA quality of eggs.

Abstract

Black soldier fly (Hermetia illucens) larvae meal (HILM) is a promising alternative to soybean meal (SBM). However, little information is available on the effect of microwave-dried HILM as a dietary protein source in the diets of laying hens. We studied the effect of dietary inclusion level of microwave-dried HILM on productive performance, cecal volatile fatty acid profile, egg quality, overall fatty acid profile, and heavy metal residues of the egg in laying hens. A total of 144 laying hens (25-week-old) were randomly assigned to three dietary groups (eight replicates and six birds/cage): a control diet, and two experimental diets in which SBM was replaced with 2% HILM (2HILM) and 4% HILM (4HILM). The laying hens that fed the HILM showed satisfactory results in productive performance and egg quality. Branched-chain fatty acid levels increased linearly (p < 0.001) with dietary treatment in the cecal digesta. Total monounsaturated fatty acid increased linearly (p < 0.01), while total polyunsaturated fatty acid decreased linearly (p < 0.01) in the eggs by dietary treatments. Heavy metals, magnesium, zinc, and aluminum were increased linearly with dietary treatment; however, undesirable heavy metals were under permissible levels. Thus, microwave-dried HILM could be a possible alternative to SBM in the diets of laying hens; however, improvements in fatty acid profile are needed.

Influence of Different Herbal-Mix Feed Additives on Serological Parameters, Tibia Bone Characteristics and Gut Morphology of Growing Pigs

A sixteen-week study was carried out in order to investigate the effects of different herbal-mix feed additives (Moringa, Basil and Neem) on serological parameters, tibia bone characteristics and gut morphology of growing pigs. Eighty-one Large White breed of pigs with a mean weight of 15.35 ± 1.07 were grouped on weight equalization basis into three treatments with 9 replicates per treatment and 3 pigs per replicate in a completely randomized design. Pigs on treatment 1 were fed a ration without integration of herbal-mix feed additives, those in treatments 2 and 3 were offered a diet that contained moringa-basil leaf meal and neem-basil leaf meal respectively. Blood samples were collected from the experimental pigs on the 12th week of the study for the determination of serum levels, while 1 pig from each replicate group whose weight was close to the mean replicate weight was chosen at the end of the study, fasted for 12 hours, sacrificed and the small intestine and left tibia bone were harvested and used for gut and bone morphology evaluation. These data generated from the study were subjected to a 1-way analysis of variance (ANOVA). The results indicated that herbal-mix feed additives influenced some of the serological parameters, i.e., globulin, glucose, total cholesterol, high- and low-density lipoproteins, and aspartate aminotransferase. These parameters decreased with integration of different herbal-mix in the pigs’ diets except high density lipoprotein that increased statistically. The tibia characteristics such as tibia breaking strength, medial thickness and lateral thickness were also positively impacted by the dietary inclusion of the herbal-mix. Likewise, the villus height of the jejunum was positively enhanced by dietary inclusion of the herbal-mix feed additives. This study concluded that herbal-mix feed additives can be utilized in pigs’ nutrition in enhancing some serological parameters, tibia bone and gut characteristics of growing pigs.

Consequences of varying dietary crude protein and metabolizable energy levels on growth performance, carcass characteristics and biochemical parameters of growing geese

This research aimed to investigate the effect of varying dietary crude protein (CP) and metabolizable energy (ME) quantity on growth, carcass characteristics, biochemical blood parameters and molecular aspects of growing geese. Overall, a total of 180 Egyptian goslings were used in a 2 × 3 factorial design. Two levels of CP (18% and 16%) and three levels of ME (3000, 2900 and 2800 kcal/kg diet) were employed. Growth traits showed no significant differences as a result of different CP or ME levels. Birds fed the higher CP level consumed more feed than the lower. Carcass, dressing, heart, spleen, abdominal fat and thigh percentages within the group fed 18% CP were higher than the other group. Compared with the other ME-based diet, geese fed a low-ME based diet had the highest heart percentage. Feeding growing geese on a 2900 Kcal/kg ME-based diet increased the serum content of total protein and globulin. Geese fed the high-ME diet showed the highest levels of ALP and C4 as compared with other ME levels. Regarding Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), different protein and energy levels did not affect the molecular weight of blood proteins of Egyptian geese during the growing phase. It could be concluded the levels of 16% CP and 2800 kcal/kg ME are enough to maintain the growth performance and the other physiological indices as well as molecular aspects.

Influence of low-protein diet with different levels of amino acids on laying hen performance, quality and egg composition

The present study aimed to investigate the consequences of dietary levels of crude protein (CP) and total sulfur amino acids (TSAA, Met+Cys) on productive performance, egg quality and egg components for Lohmann Brown laying hens through 18-34 weeks of age. A 2×3 factorial design experiment was conducted using two levels of CP (16 and 18 %) and three levels of Met+ Cys (0.67, 0.72 and 0.77 %). A total of 144 Lohmann Brown laying hens at 18 weeks of age were randomly divided into 6 treatment groups. The best values of final body weight and body weight change were recorded by the hens fed 18 % CP diet. Increasing dietary CP up to 18 % accompanied with the best (P> 0.01) feed conversion, egg weight and egg mass. The combination between low-CP diet (16 %) and 0.72 % Met+ Cys gave the best percentage of egg production. The majority of egg quality traits were not significantly altered by dietary treatments. The interaction between CP and Met+Cys levels had a statistical (P>0.01) impact on egg content of moisture and total solids only. It could be concluded that the best production criteria could be obtained by using 0.72% Met+Cys. Moreover, dietary level of 16 or 18 % CP with 0.72% Met+Cys is recommended for feeding Lohmann hens.

Effect of Dietary Protein and Tsaa Levels on Performance, Carcass Traits, Meat Composition and Some Blood Components of Egyptian Geese During the Rearing Period

The present study was performed to investigate the effect of dietary levels of protein, total sulfur amino acids (TSAA), methionine and cystine (M + C) and their interaction on the performance, carcass characteristics, blood components and meat quality of Egyptian geese. A total number of 144 geese at twelve weeks of age were randomly divided into 9 groups (16 birds/each group), each group of birds was sub-divided into 4 replicates, each of 4 birds. There was a significant increase in the bodyweight of geese due to protein and M + C levels (p < 0.01). The studied levels of M + C affected significantly on weight gain of growing geese at the early period of 12-18 wk of age. Feed intake was increased with high dietary levels of CP % or M + C (p < 0.05). There was a significant (p < 0.01) increase in percentages of carcass, liver, dressing, breast and wing with high dietary protein level as compared to a moderate or low level. A high level of dietary protein led to increase in concentrations of total protein and albumin, while total lipids, cholesterol, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were decreased with increasing level of protein (p < 0.01). Fat percentage of breast muscle was significantly (p < 0.01) decreased with increasing M + C levels. Protein % of breast muscle was increased with increasing protein levels. Finally, it can be concluded that the consumption of diets with high levels of protein or M + C can improve the bodyweight, feed conversion ratio, carcass and meat composition of Egyptian geese during the rearing period (12-24 wk of age).

Effect of low- or high-CP diet with cold-pressed oil supplementation on growth, immunity and antioxidant indices of growing quail

This study was to investigate the effect of dietary protein levels and supplementation with two cold-pressed oils on the performance, immunity and antioxidant indices of growing Japanese quails. A 3 × 4 factorial experiment, using 3 dietary crude protein (CP) levels (22%, 24% and 26%) and 4 supplemental herbal oils levels: control without additives, 250 mg marjoram (Mar), 250 mg thyme (Thy) and 125 mg Mar + 125 mg Thy per kg diet. A total of 720 unsexed, 7-day-old quail chicks were randomly distributed into twelve treatment groups (4 replicates per group of 15 chicks in each). The live body weight (LBW) on 42 days and body weight gain (BWG) from 7 to 42 days were significantly improved (p < 0.01 and 0.05) in chicks fed 24% or 26% CP compared with those of the 22% CP group. The groups fed diets supplemented with Mar or in combination with Thy oil exhibited significantly better LBW, BWG and feed conversion ratio (FCR) than the control at all periods except BWG from 21 to 42 days and FCR from 7 to 21 days were not significant. Feed intake was gradually decreased with increasing dietary CP level or adding herbal oils during the periods 21-42 and 7-42 days of age. Plasma triglycerides, cholesterol, total lipids and malondialdehyde were decreased by cold-pressed oils supplementation, but the activity of reduced glutathione and superoxide dismutase was increased (p < 0.01) compared with the control. In conclusion, quails fed a diet containing 24% or 26% CP or diets supplemented with Mar or Thy oils or both exhibited improvement in the performance, lipid profile, immunity and antioxidant capacity without any detrimental impacts on the other studied parameters.

Influences of dietary crude protein and stocking density on growth performance and body measurements of ostrich chicks

Thirty-six African Black ostrich chicks were used to investigate the effects of dietary crude protein (CP) levels (180, 210 and 240 g/kg), stocking density (4.5 and 3 m2/bird) and their interactions. A factorial arrangement was used to examine the impact of treatments on growth performance and body measurements of ostrich chicks during 2 to 10 weeks of the age. Results indicated that factors studied did not change growth performance traits. The highest value of protein efficiency ratio was observed in ostrich chicks fed diet contained 240 g/kg diet. Birds fed diet contained 240 g CP /kg diet and kept at stocking density of 3 m2 per bird had numerically the highest protein efficiency ratio. Shank girth and tibiotarsus length decreased with increasing dietary CP level. Stocking density did not change values of body measurements, except tibiotarsus length at 6 weeks of age, which increased in birds kept at the lower density than the higher. Body height at 10 weeks of age was significantly affected by the interactions between dietary CP and stocking density. In conclusion, results affirmed that ostrich chicks can grow on diets containing low levels of CP (180-210 g/kg). Our results provide a comprehensive set of morphometric data for ostrich chicks as affected by the factors studied.

Influence of low-protein and low-amino acid diets with different sources of protease on performance, carcasses and nitrogen retention of broiler chickens

A 42-day experiment was conducted with 625 1-day-old male Hubbard chickens to evaluate the performance, carcass traits, nitrogen retention and economics of broiler chickens fed low protein and amino acid diets supplemented with different protease sources. Treatments included positive (PC) and negative (NC) controls (PC at 19.3% protein vs NC at 18.8% protein), with NC containing 7% less digestible amino acids. The other three treatment groups were based on the NC diet supplemented with 0.05% Cibenza® DP100 (CB), 0.02% Ronozyme® (RZ) or 0.02% Winzyme pro plus (WZ). Birds fed the PC, CB and WZ diets achieved the heaviest bodyweight compared with those fed the NC diet at end of the experiment. Total feed intake of birds fed the PC diet was higher (P < 0.05) than that of birds fed the NC diet. Feed conversion ratio was numerically significantly (P = 0.005) improved with all tested groups in comparison with NC throughout the experiment. European production index was similar (P > 0.05) among birds fed the PC, NC, RZ or WZ diets. All carcass parameters studied, including dressing, heart, gizzard, giblets, chest meat, thigh meat and abdominal fat percentages, were not significantly (P > 0.05) affected by feeding on the different sources of protease. Broilers fed the PC diet or diets formulated with all protease sources had higher (P < 0.05) nitrogen retention than did birds fed the NC diet. The supplementation of protease to low-protein and low-amino acid diets resulted in higher profit margin in broilers. It is concluded that supplementing exogenous protease to broiler diets containing low protein and amino acids improved the growth performance, feed utilisation, carcass traits, nitrogen retention and net returns of broiler chickens.

Individual and combined effects of crude protein, methionine, and probiotic levels on laying hen productive performance and nitrogen pollution in the manure

The present study aimed to investigate the effect of the dietary levels of protein, methionine (Met), as well as probiotic on productive performance, feed utilization, and environmental pollution by N in Lohmann Brown laying hens. A total number of 160 Lohmann Brown laying hens at 20 weeks of age were randomly divided into 8 treatment groups using a 2 × 2 × 2 factorial design experiment. The experiment involved two levels of crude protein (16 and 18 %), two levels of Met (0.45 and 0.50 %), and two concentrations of probiotic (0 or 1 g/kg diet, with a concentration of 10¹⁰ CFU/g of Lactobacillus acidophilus) within 20-42 weeks of age. Results revealed that egg production parameters were significantly (P < 0.01) improved for hens fed diets of 18 % CP comparing with that of 16 % protein within the period from 26 to 30 weeks of age. Protein utilization and feed efficiency values were enhanced with 0.67 and 0.72 % Met during the period of 26-30 weeks of the age. For the N pollution, results showed that increasing crude protein in the diet from 16 to 18 % caused significant (P < 0.01) increase in the excreted N from 0.349 to 0.492 g/d. The methionine level of 0.72 % recorded the highest values of total consumed N being 3.98 g/d and excreted N being 0.527 g/d comparing with the other levels. It could be concluded that the best productive performance could be given by using 0.72 % total sulfur amino acids (TSAA). Furthermore, the dietary level of 18 % CP with 0.72 % Met is preferred in feeding laying hens through the whole experimental period. Ecologically, reducing the level of crude protein in layer diets to be 16 % along with the supplementation of Met can play an important role in minimizing the pollution with N from poultry excretion.