Investigating the effect of sesame meal replacement for soybean meal in diets with different levels of calcium and phytase enzyme in broiler chickens.

BACKGROUND: As a major part of the cost of broiler farms is related to their feed, breeders are looking for diets at a reasonable price. One of these affordable ingredients is sesame meal (SM), which can be used to replace soybean meal (SBM) in diets. OBJECTIVES: This study aims to investigate the effect of replacing SBM with SM in diets with different levels of calcium (Ca) and phytase (Phy) during the grower (11-24 days), finisher (25-42 days) and whole phases (11-42 days) on the growth performance, carcass characteristics and blood serum parameters of broiler chickens. METHODS: A total of 600 1-day-old Ross 308 broiler male chicks were randomly dispensed to 12 dietary treatments with five replicates (10 birds per replicate) based on a completely randomized design in a factorial arrangement of 3 × 2 × 2 with 3 levels of SM (0%, 10% and 20%), 2 levels of Ca (standard (0.87% and 0.79% for grower and finisher phases, respectively) and 0.2% higher than the standard amount) and 2 levels of Phy (0 and 700 FTU/kg diet). RESULTS: During the study, the significant effects of SM, Ca and Phy on the daily average body weight gain (DAWG) and daily feed intake (DFI) were observed, whereas for the feed conversion ratio, only the effect of SM was significant (p < 0.05). During the finisher and whole phases, the SM and Ca levels influenced the DAWG and DFI, whereas the interaction between Phy and Ca was also significant for DAWG (p < 0.05). The main effects of SM and Ca on the relative weights of breast, heart and liver were significant (p < 0.05). Application of 20% of SM significantly reduced serum Ca concentration (p < 0.05). CONCLUSION: Generally, the inclusion of more than 10% of SM in the broilers diet is not recommended. In addition, the use of Phy and Ca levels 0.2% higher than standard in broilers diet could improve the birds' performance.

Some productive and reproductive performance, eggshell quality, serum metabolites and immune responses due to L-threonine supplementation in Japanese quail breeders' diet.

A dose-response experiment was conducted to evaluate the effects of graded levels of dietary digestible threonine (dThr) during the first laying cycle on productive and reproductive performance, egg quality and immune responses of Japanese quail breeders (Coturnix coturnix japonica). Also, dThr requirements were determined based on nutrient dose-response data. A total of 450 (360 females and 90 males) 11-week-old breeders were allocated to five increment (+0.03%) levels of dThr (0.49%, 0.52%, 0.55%, 0.58%, 0.61% and 0.64%) with five replicates per treatment and 15 (12 females and three males) birds each. The experiment lasted for 12 weeks. In response to increasing dietary dThr levels, egg production, egg mass, feed efficiency, egg specific gravity, eggshell relative weight, eggshell thickness, egg fertility (EF) and immune response against sheep red blood cell (SRBC) inoculation were improved with quadratic trends and egg hatchability as set eggs was improved with linear trends. Japanese quail breeders fed a diet with 0.58% dThr concentration (threonine/lysine ratio of 59%) showed the productive performance traits, EF, eggshell quality and immune response against SRBC inoculation in the highest values. However, feed intake, egg weight, egg albumen and yolk relative weight, egg shape index, haugh unit and egg composition were not affected by increasing dietary dThr level. Based on the broken-line regression model, the dThr requirements to optimize productive performance, eggshell quality, EF and immune response against SRBC inoculation were estimated at 159-188, 169-183, 175 and 178 mg/bird per day, respectively. It is concluded, in the Japanese quail breeders during the first laying phase a daily dThr intake of 188 mg/bird, dietary dThr concentration at 0.58% (threonine/lysine ratio of 59%) is adequate for optimized productive and reproductive performance, eggshell quality and immune responses. The estimated requirements depend on what production parameter is taken into considered for optimization.

Effect of dietary lysophospholipid supplementation on growth performance, serum lipids, small intestine morphology and caeca microflora in broiler chickens.

BACKGROUND: The digestibility of animal fats and oils is limited by a reduction in the production and secretion of lipase and bile salts in young chickens. The addition of a natural emulsifier (lysophospholipids [LPL]) in poultry diet may increase the emulsification of lipids and their digestibility. OBJECTIVES: An experiment was conducted to evaluate the effects of feed LPLs supplementation with different fat sources on performance, serum lipid composition, small intestine morphology and caeca microflora in broiler chickens. METHODS: A completely randomized factorial design (2 × 3 × 2) was used to evaluate the effect of LPL supplementation (0 and 0.25 g/kg) and three different fat sources (soybean oil, tallow and a 50:50 mixture of the two) in corn and soybean meal diets containing two levels of fat (1.5 and 3%), providing 12 isocaloric and isonitrogenous grower diets. Each experimental diet was fed to six replications of 10 birds from 15 to 28 days of age. Average growth performance during this period and small intestine morphology, serum lipid composition and caeca microflora were evaluated on day 28. RESULTS: The interaction effects of LPL supplementation, source and/or level of fats were not significant for the performance parameters measured during the 15 to 28 days. The treatment effects were significant for the villus width and crypt depth measured in the jejunum on day 28. The LPL supplementation significantly increased crypt depth. The interaction effect of fat source and level of fat were significant for villus width. The addition of a 3% blend of soybean oil/tallow (50/50) reduced the serum low-density lipoprotein (LDL) level. The Lactobacillus population was increased by the addition of LPL, or a 1.5% blend of soybean oil and tallow, to the diet. CONCLUSIONS: Our study showed that LPL supplementation of diet containing a 1.5% blend of soybean oil and tallow can improve serum lipid indices and caeca Lactobacillus populations in broiler chickens.

Effect of different levels of green tea (Camellia sinensis) and mulberry (Morus alba) leaves powder on performance, carcass characteristics, immune response and intestinal morphology of broiler chickens.

BACKGROUND: In recent years, the use of medicinal plants as an alternative to antibiotics has expanded. Plants containing medicines and antioxidants can improve the performance of poultry. OBJECTIVES: The purpose of this study was to achieve the appropriate levels of green tea leaf powder (GTP) and mulberry leaf powder (MLP) in the diet, which positively affects broilers' performance. METHODS: 648 one-day-old Ross 308 broiler chickens were allocated to nine dietary treatments with six replicates and each replicate containing 12 birds based on a completely randomised design (CRD) in a factorial arrangement of 3 × 3 with three levels of GTP, and three levels of MLP for 42 days. Treatments included: (1) no GTP + no MLP (control), (2) 1% GTP + no MLP, (3) 2% GTP + no MLP, (4) no GTP + 1% MLP, (5) 1% GTP + 1% MLP, (6) 2% GTP + 1% MLP, (7) no GTP + 2% MLP, (8) 1% GTP + 2% MLP and (9) 2% GTP + 2% MLP. RESULTS: The results revealed that the effect of added powders (2%) was significant and increased daily weight gain (DWG) and reduced feed conversion ratio (FCR) compared to the control group during the grower and whole phases (p < 0.05). On 35 days, the control and 2% GTP + 2% MLP treatment had the lowest and highest antibodies titre (total and immunoglobulin G [IgG]), respectively (p < 0.05). The groups fed with 1% GTP + 1% MLP showed higher villus height (VH) compared to the control, 2% GTP + 1% MLP, 1% GTP + 2% MLP, and 2% GTP + 2% MLP groups (p < 0.05). The ratio of the villus height to crypt depth (VH: CD) in treatments 1% GTP + no MLP, 2% GTP + no MLP and 1% GTP + 1% MLP was significantly higher than the control treatment (p < 0.05). CONCLUSIONS: It was concluded that the addition of 2% GTP or MLP could improve humoral immune response and performance, and the addition of 1% GTP without MLP increased VH: CD in broilers.

Effect of organic and inorganic manganese supplementation on performance and eggshell quality in aged laying hens.

BACKGROUND: Manganese (Mn) is an important trace element for laying hen's nutrition, which is required in small amounts in the diet. Its deficiency results in lowered production performance and eggshell quality. OBJECTIVES: This experiment was conducted to investigate the influence of different sources and levels of Mn on egg production performance and eggshell quality in aged laying hens. METHODS: A total of 720, 83-week-old Hy-Line W-36 laying hens were fed a non-Mn supplemented basal diet for 4-week (to ime Mn-exhaustion of body) and then were allocated to a completely randomized design with 10 treatments, six replicates and 12 birds each. Concentration of Mn in the non-Mn supplemented basal diet was 10.34 mg/kg (treatment 1), the added doses of dietary Mn were included 30, 60, and 90 mg/kg of three different sources (Mn-oxide, Mn-sulphate, and Mn-organic) for treatments 2-10, respectively. The experiment lasted for 12 week. RESULTS: Dietary supplementation with either organic or inorganic Mn sources significantly enhanced egg production (EP), egg mass (EM), feed conversion ratio (FCR), and relative eggshell weight (RESW) compared with the non-Mn supplemented diet. However, the experimental diets did not influence feed intake (FI), egg weight, and other eggshell quality traits. Based on the broken line regression models, the performance traits were optimized at 30-40 mg/kg Mn concentration when supplemented by Mn-sulphate or Mn-organic. Although, it was 80-90 mg/kg when supplemented by Mn-oxide. The relative bio-efficacy of inorganic Mn sources include Mn-oxide and Mn-sulphate in compare with Mn-organic were estimated 45% and 87% (for EP trait), 30% and 94% (for EM trait), 36% and 99% (for FCR trait), and 37% and 78% (for RESW trait), respectively. CONCLUSIONS: In the aged laying hens, Mn requirement is higher than the NRC's recommendation. Sulphate and organic sources of Mn are more effective than Mn-oxide.

Effects of cold stress on growth performance, carcass traits and tibia attributes in broiler chickens with thiram-induced dyschondroplasia.

The objective of this study was to investigate the effect of cold stress (CS) on growth performance and tibia attributes in broiler chickens with thiram-induced dyschondroplasia (TD). Four hundred 10-day-old male broilers were randomly allocated into four groups including, NT0: normal temperature (NT) without thiram; NT50: NT + thiram; CS0: CS without thiram; and CS50: CS + thiram in a completely randomised. The birds in CS groups were placed at a constant temperature of 15 ± 1°C during 11-20 days. Thiram (50 mg/kg) was added to the diet during 11-14 days to induce TD. Results showed that main effects of CS and thiram significantly decreased body weight and daily weight gain during 11-42 days (p < 0.05). Feed intake in the thiram50 group was significantly lower than the group thiram0 during 25-42 days (p < 0.05). Feed conversion ratio in CS birds was significantly more than NT group during 25-42 days (p < 0.05). On day 16, tibia width (TW) and TW to tibia length (TL) ratio were significantly higher in CS chicks compared to the NT group. TW was significantly higher in thiram50 group than thiram0 group (p < 0.05). On day 19, TL in CS chicks was significantly shorter than NT (p < 0.05). On day 23, growth plate width (GPW) in thiram50 group was significantly higher than thiram0 birds. In general, thiram increased tibial GPW and CS decreased TD severity as well as decreased growth performance in broilers.

Apparent and standardized ileal amino acid digestibilities of corn, wheat, soybean meal, and corn gluten meal in quail chicks.

Two experiments were conducted to measure the apparent and standardized ileal digestibilities (AID and SID) of amino acid (AA) of corn, wheat, soybean meal (SBM), and corn gluten meal (CGM) in growing Japanese quail from 14 to 18 (Exp. 1) and 28 to 32 (Exp. 2) d of age. The basal endogenous losses of amino acids were measured by the use of N-free diet. The birds were fed on standard diet before the use of experimental diets. The experimental diets (four ingredients) and N-free diet were randomly assigned to 5 replicate pens (30 birds per pen) and fed for 5 consecutive days. The ileal digesta were collected on d 18 and 32 for the Exp. 1 and Exp. 2, respectively. AID of lysine (Lys) in corn (P = 0.047), SBM (P < 0.001), and CGM (P < 0.001); AID of threonine (Thr) in corn (P < 0.001), SBM (P < 0.001), and CGM (P = 0.075); and AID of isoleucine (Ile) in wheat (P < 0.001), SBM (P = 0.002), and CGM (P < 0.001) were increased as the birds aged. However, AID of methionine (Met) in corn (P < 0.001) and CGM (P < 0.001), AID of arginine (Arg; P < 0.001) and valine (Val; P < 0.001) in CGM were lower in younger quails. Among indispensable amino acids, the basal endogenous losses of Thr, Val, and Arg decreased by age (P < 0.001). The average of SID of Lys, Ile, Met, Val, Thr, Arg, leucine (Leu), and histidine (His) for corn, wheat, SBM, and CGM were estimated as 83, ND, 89.4, 89.4, 92.1, 90.2, 91.9, and 90.8%; 92.7, ND, 89.1, 93.9, 87.4, 90.2, 89.8, and 88.1%; 90.3, 91.8, 94.3, 90.4, 86.5, 94.0, 84.3, and 95.0%; 82.6, ND, 74.1, 79.6, 84.4, 90.6, 85.2, and 82.4%, respectively. Based on the present study, the AID and SID coefficients of indispensable AA should be adjusted for age classes in Japanese quail during the growing period.

Effect of Supplemental Zinc on Performance, Nutrient Digestibility, Jejunum Architecture, and Immune Response in Broiler chickens Fed Wheat-Soy Diets.

The present study was conducted to evaluate the effect of dietary zinc (Zn) levels on growth performance, carcass characteristic, nutrient digestibility, jejunum architecture and immune responses in broiler chickens fed wheat-soy diets. In addition the Zn requirement to optimize responses were estimated through regression models. A total, of 250 day-old male Ross-308 broiler chicks were randomly allocated to a completely randomized design experiment with five dietary treatments of five replicates of 10 birds each. Birds were fed diets containing 30, 70, 110, 150, and 190 mg/kg Zn from 1 to 35 days of age. A Zn level of 70 mg/kg diet was adequate to acquire typical growth performance, the nutrient digestibility, and carcass yield. First antibody titres response to sheep red blood cell inoculation, cutaneous basophil hypersensitivity elicited by phytohemagglutinin-P intradermal injection increased linearly by the increase in dietary Zn level. The Zn requirement estimated by the quadratic and linear broken-line models was varied between 63-70 mg/kg to optimize growth performance criteria. It is concluded the basal Zn concentration in wheat-soy diet is inadequate to fulfill the broiler chickens genetic potential in growth and a minimum of 70 mg/kg dietary Zn concentration is suggested to optimize broiler chickens performance.

Dietary sources and levels of selenium supplements affect growth performance, carcass yield, meat quality and tissue selenium deposition in broilers.

This study examined the effects of sources and levels of selenium (Se) on performance, carcass parts yield, meat quality and tissue Se concentration in broilers. A total of 960 one-day-old male broilers were divided into 8 treatments in a 4 × 2 factorial arrangement. Chicks were penned in groups of 20 with 6 pens per group. Selenium sources were sodium selenite (SS), Se enriched yeast (SY), DL-selenomethionine (SM) and nano-selenium (NS) and dietary supplemental Se levels were 0.1 and 0.3 mg/kg diet. The average daily gain (ADG), average daily feed intake (ADFI), feed:gain ratio, mortality, and carcass parts yield were not affected by dietary treatments. The level of 0.3 mg/kg Se decreased lightness and increased yellowness of the breast and thighs (P < 0.001). Nano-selenium improved yellowness, redness and meat quality (P < 0.05). The interactive effects of sources and the levels of Se affected Se retention (P < 0.001). Inorganic Se showed poor retention compared to other sources of Se; and NS showed equal retention with the organic sources. With consideration to meat quality responses, NS had a more significant positive effect compared to SS as an inorganic source of Se. Overall, NS and organic sources of Se resulted in better meat quality compared with the inorganic source. Moreover, the highest Se retention percentage was achieved by supplementation of NS followed by organic sources at 0.1 mg/kg compared to SS.

Pre-cecal phosphorus digestibility for corn, wheat, soybean meal, and corn gluten meal in growing Japanese quails from 28 to 32 d of age.

The optimization of dietary phosphorus (P) depends on precise details of the P availability in feed ingredients to avoid excess or deficient P in a mixed diet. This study was carried out to measure the apparent ileal digestibility of P for corn, wheat, soybean meal, and corn gluten meal in growing Japanese quails from 28 to 32 d posthatch. A total of 400 quail chicks were randomly distributed across 5 treatments with 4 replicates and 20 birds in each floor pen. The P-free diet (PFD) was formulated based on cornstarch to measure the basal endogenous P losses (EPL). Digestibility coefficients were determined by ileal digesta sampling using TiO2 as an indigestible marker. The EPL was estimated at 384 mg/kg DMI. The apparent ileal P digestibility (AIPD) for corn, soybean meal, wheat, and corn gluten meal were determined to be 0.38, 0.53, 0.38, and 0.78, respectively. The corresponding values for true ileal P digestibility (TIPD) were 0.48, 0.61, 0.50, and 0.83, respectively. The t-test analysis showed that the difference of AIPD and TIPD values for corn (P = 0.031) and wheat (P = 0.015) were statistically significant, however, no significant differences were observed for corn gluten meal (P = 0.318) and soybean meal (P = 0.104). In conclusion, the correction of AIPD coefficients for EPL in low-P ingredients such as corn and wheat may be much more important than that in high-P feedstuffs such as corn gluten meal and soybean meal in growing quails.

Effects of dietary supplemental methionine source and betaine replacement on the growth performance and activity of mitochondrial respiratory chain enzymes in normal and heat-stressed broiler chickens.

This study aimed to evaluate the effects of dietary supplemental methionine (Met) source and betaine (Bet) replacement for Met on performance and activity of mitochondrial respiratory chain enzymes (MRCEs) in normal and heat-stressed broiler chickens. Total of 1,200-day-old Ross 308 chicks were allocated to two houses, each consisted of 12 treatments, five replicates of 10 birds each with 2 × 2×3 × 2 (temperature × Met source × Met level × Bet, respectively) split-plot factorial arrangement. Met level in the basal diets was 70% requirements (Req) that was increased to the requirement or 130% by supplemental dl- or l-Met. Bet was or was not substituted at the rate of 30% supplemental dl- or l-Met. Feed conversion ratio (FCR) in chicks fed 70% l-Met was lower than those fed 70% dl-Met diet during 1-10 days (p = 0.04). Broilers fed diets containing requirement or 130% Met, regardless of its source, showed higher weight gain (WG) than those received 70% Met diet during 11-42 days (p < 0.001). Feed intake (FI) of broilers fed 130% Met diet was decreased compared to other two groups during 11-42 days (p < 0.05). One hundred thirty percent Met requirement diet resulted in lower FCR comparing to other two groups during 11-42 days (p < 0.001). Heat-stressed birds grew less than those under normal condition (p < 0.05). Broilers fed Req Met diet under normal temperature exhibited higher activities of complexes (Cox) I and III (p < 0.05). Cox I activity in heat-stressed birds fed Bet + diet was similar to those fed Bet-diet under normal temperature (p = 0.046). It is concluded that performance and the activities of Cox I and III were increased as the level of Met increased. Bet replacement for 30% supplemental Met resulted in similar consequences comparing to non-Bet replacement diets on performance, but increased the activity of Cox III. l-Met was effective than dl-Met at the cellular level. High ambient temperature depressed performance and MRCE activity.

Effect of plant extracts derived from thyme on male broiler performance.

The effect of dietary thyme-oil extract (TOE) supplementation on immune functions of broilers were assessed by feeding graded levels (50, 100, 200, or 400 ppm) of TOE to male broiler chicks during a 42-d feeding trial compared with negative- or positive-control diets. Dietary control treatments included a negative-control diet with no feed-additive supplementation and 2 positive-control groups supplemented with either virginiamycin or zinc bacitracin. In total, 300 1-day-old Ross × Ross male broilers were randomly assigned to 6 dietary treatments that consisted of 5 replicates of 10 birds each. On d 21 and 42, 2 birds from each replicate were killed by cervical cutting to measure the relative weights of spleen and bursa of Fabricius. At 25 d of age, chicks were injected with 0.5 mL of 10% SRBC suspension. Broilers fed with 200 ppm of TOE had heavier weights of bursa of Fabricius than those fed other dietary treatments at d 42 of age. Furthermore, dietary inclusion of 100 ppm of TOE resulted in higher (P < 0.05) total immunoglobulin response in primary antibody titer against sheep erythrocytes compared with other dietary treatments. On the other hand, diet modifications had no significant effect on blood leukocyte subpopulations and heterophil-to-lymphocyte ratio. These results suggest that dietary supplementation with TOE, especially at the level of 100 ppm, can improve immunological responses of broiler chicks.

Manipulation of broiler chickens sex differentiation by in ovo injection of aromatase inhibitors, and garlic and tomato extracts.

The influence of in ovo administration of aromatase inhibitors, clomiphen citrate, tomoxifen, and garlic and tomato extracts on sex differentiation in broiler chickens were investigated in 2 experiments. Five hundred, and 1,000 fertile eggs from Ross 308 strain were used in experiments 1 and 2, respectively. In both experiments, eggs were divided into 5 groups: control group (DW, 0.1 mL/egg), tomoxifen (0.05 mg/egg), clomiphene citrate (0.05 mg/egg), garlic and tomato extracts (0.1 mL/egg). Eggs were sanitized and prepared for incubation in a regular automatic hatchery. Experimental preparations were injected into eggs at day 5 of the incubation period. Injection sites on the eggs were cleaned with 70% ethylic alcohol, bored by a needle, and aromatase inhibitors were injected into the white from the thin end of the eggs by insulin syringe and then sealed by melted paraffin. In experiment 1, hatched one-day-old chicks (mixed-sex) were raised till 42 days of age in 25 floor pens with a completely randomized design. Experiment 2 was designed to investigate the effects of sex and treatments on the feed-to-gain ratio of broiler chicks. In experiment 2, hatched one-day-old chicks were feather sexed and raised till 42 days of age in 50 floor pens. A completely randomized design with a 2 × 5 factorial arrangement of treatments (sex×treatment) was used. Gonads of the chicks were checked to determine their sex on day 42 by optic microscope to make sure feather sexing was correct. At the end of both experiments, on day 42, one bird from each pen was slaughtered for carcass analysis. In experiment 1, hatchability and the one-day-old weight of chicks showed no significant differences among treatments (P > 0.05). However, in ovo administration of garlic and tomato extracts caused the highest percentage of male chicks (P < 0.05). Also, the percentage of thighs and wings of the males were significantly higher than those of females (P < 0.05). In experiment 2, feed-to-gain ratio of male and female broiler chicks showed no significant differences among treatments (P > 0.05).

Effects of sterol regulatory element-binding protein (SREBP) in chickens.

Sterol regulatory element binding protein- 1 and -2 (SREBP-1 and -2) are key transcription factors involved in the biosynthesis of cholesterol and fatty acids. The SREBP have mostly been studied in rodents in which lipogenesis is regulated in both liver and adipose tissue. There is, though, a paucity of information on birds, in which lipogenesis occurs essentially in the liver as in humans. Since a prelude to the investigation of the role of SREBP in lipid metabolism regulation in chicken, we review Size and Tissue expression Pattern of SREBP and role of this protein in chickens.