Ali Reza Ghiasvand; Hassan Shirzadi; Hossein Ali Ghasemi; Kamran Taherpour; Shokoufeh Hasanvand; Ali Khatibjoo
Abstract
Objective: The aim of this study was to determine the optimal arginine level in the diet of Japanese quails (Coturnix coturnix japonica) and evaluate its effects on growth performance, feed efficiency, and carcass yield using broken-line and quadratic regression models.
Method: For this purpose, a total ...
Read More
Objective: The aim of this study was to determine the optimal arginine level in the diet of Japanese quails (Coturnix coturnix japonica) and evaluate its effects on growth performance, feed efficiency, and carcass yield using broken-line and quadratic regression models.
Method: For this purpose, a total of 600 twenty-one-day-old Japanese quail chicks were divided into five different treatments with digestible arginine levels of 0.75%, 1.00%, 1.25%, 1.50%, and 1.75%. Six replicates were used for each treatment, with 20 quails per replicate. The experimental diets were similar in all essential nutrients except for arginine. The experiment was conducted from day 21 to day 35, and during the experimental period, various performance parameters, including body weight gain, feed efficiency, and carcass yield, were measured. Additionally, the effects of different arginine levels on the chemical composition of breast and thigh meat were evaluated.
Results: The results indicated that increasing arginine levels had a significant impact on body weight gain and feed efficiency in the quails (P<0.05). Specifically, the 1.25% arginine treatment showed the greatest body weight gain and feed efficiency compared to the other treatments (P<0.05). This treatment showed a significant difference compared to the 0.75% and 1.00% treatments (P<0.05), with no significant difference compared to the 1.50% arginine treatment. No significant changes in feed intake were observed (P>0.05), indicating that greater arginine levels improved feed utilization efficiency due to increased body weight gain. To estimate the arginine requirement, both broken-line linear and quadratic regression models were employed. The broken-line linear model with a single slope identified breakpoints at 1.15% for body weight gain and 1.21% for feed efficiency. Additionally, the quadratic broken-line model predicted breakpoints at 1.30% for body weight gain and 1.29% for feed efficiency. The quadratic regression model showed that at 1.37% arginine, the greatest body weight gain was observed, and at 1.36%, the greatest feed efficiency was recorded. For carcass yield, the 1.25% arginine treatment showed the greatest carcass yield on day 35, with a significant difference compared to the 0.75% and 1.75% treatments. Both broken-line and quadratic regression models indicated that the optimal arginine level for the greatest carcass yield was approximately 1.12% and 1.26%, respectively. Additionally, the quadratic regression model predicted that the optimal level for carcass yield was 1.32% arginine. However, the chemical composition of breast and thigh meat was not affected by the arginine levels, and no significant changes in dry matter, organic matter, and ash content were observed.
Conclusions: The results of this study indicated that the use of broken-line linear and quadratic regression models are effective tools for accurately estimating the arginine requirement in the diet of Japanese quails. Based on the findings, it is recommended that the optimal arginine level for improving growth performance and carcass yield in Japanese quails was set between 1.15% and 1.37%. These findings can contribute to optimizing dietary formulations in the quail farming industry, improving production efficiency, and reducing feed costs.
Faezeh Khani; Ali Assadi-Alamouti; Behzad Khorrami
Abstract
Objective: Livestock producers in Iran face increasing challenges with forage supply due to progressively detrimental climatic changes. Due to nutrient losses during drying, and spoilage and mold during storage of fresh forage, ensiling is used to preserve and utilize forage when fresh produce is unavailable. ...
Read More
Objective: Livestock producers in Iran face increasing challenges with forage supply due to progressively detrimental climatic changes. Due to nutrient losses during drying, and spoilage and mold during storage of fresh forage, ensiling is used to preserve and utilize forage when fresh produce is unavailable. Intercropping barley crop (Hordeum vulgare) with forage pea (Pisum arvense L.) can provide a substantial portion of the protein requirements for growing livestock and dairy cows, given its acceptable protein yield per hectare. Considering the advantages of legume-cereal forage intercropping and the widespread adoption of winter cropping for forage production nationwide, particularly in the Varamin region of Iran, optimizing the legume-cereal ratio in forage crop mixtures is essential to maximize agronomic performance, water-use efficiency, nutritional value, and suitability of the mix for animal feeding. Therefore, this study aimed to investigate the effects of different ratios of whole-crop barley to forage pea on silage fermentation quality and digestibility, and to determine the optimal mixing ratio.
Method: Whole crop barley and forage pea were harvested at specific growth stages (early dough stage for barley and mid-flowering to late flowering/early pod formation for forage pea). The experiment consisted of four treatments: 1) 100% barley silage, 2) 80% barley + 20% forage pea silage, 3) 70% barley + 30% forage pea silage, and 4) 60% barley + 40% forage pea silage, with three replicates in a completely randomized design. Ensiling was carried out in 10-liter plastic mini-silos. After 60 days of ensiling, the silos were opened and sampled for analysis of crude ash, ether extract (EE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent insoluble nitrogen (ADIN), lignin (ADL), water-soluble carbohydrates (WSC), ammonia N and volatile fatty acids. An in vitro gas production test was used to compare treatments for gas production kinetics, and estimated digestibility, metabolisable energy, and short-chain fatty acid concentrations.
Result: With the increase in the proportion of forage pea, the dry matter content decreased while pH increased. The inclusion of forage pea in the mixture tended to increase crude protein and crude ash contents (P < 0.10). However, the values of EE, ADF, NDF, ADL, and ADIN were not affected by the forage pea (P > 0.05). Furthermore, increasing the proportion of forage pea significantly elevated the concentration of ammonia-N in the silage (P<0.05). No significant differences were observed among silages in terms of acetic, propionic, and butyric acid concentrations, with the levels of these volatile fatty acids falling within the range typically found in well-fermented silages. The treated silage containing 20% forage pea exhibited higher gas production volume, organic matter digestibility, metabolizable energy, and short-chain fatty acids than forage barley silage as the sole crop (P < 0.05).
Conclusions: Overall, the results demonstrated that mixing forage pea with whole crop barley during ensiling improved its nutritional value by enhancing CP content and reducing fiber levels, while taking advantage of barley forage, such as higher dry matter and WSC. This approach could serve as a winter-cropping strategy in semi-arid climates, improving feed quality, reducing costs, and promoting environmental sustainability. The present study suggested a 20% forage pea inclusion level for mixing with barley forage in laboratory conditions. However, this proportion should be further studied in animal trials.
Mohammad Sedghi; zahra sarrami; Razie ghasemi; Mojtaba Abbasi; Ishmael Mohammadi
Abstract
Objective: In recent years, the poultry industry has shown increasing interest in low-protein diets due to their economic and environmental benefits, including reduced feed costs and lower nitrogen excretion. However, reducing dietary protein levels may lead to deficiencies in essential amino acids. ...
Read More
Objective: In recent years, the poultry industry has shown increasing interest in low-protein diets due to their economic and environmental benefits, including reduced feed costs and lower nitrogen excretion. However, reducing dietary protein levels may lead to deficiencies in essential amino acids. Therefore, extensive research over recent decades has focused on evaluating the relationships between dietary nutrients, production performance, and nutritional requirements of broiler chickens, particularly metabolizable energy, protein, and essential amino acids. The primary objective of these studies has been to provide more accurate estimations of nutritional requirements to maximize the genetic potential for growth and performance in poultry.
Method: To investigate the effects of dietary metabolizable energy, protein, methionine +cysteine, and lysine levels on performance and physiological responses of Arian broiler chickens, a total of 2,160 one-day-old chicks (mixed sex) were used in a 4 × 4 × 4 × 4 factorial experiment with 16 treatments, 5 replicates per treatment, and 27 birds per replicate. Nutrient levels were formulated at 97, 100, 103, and 106% of the recommended requirements according to the Arian catalog. Performance parameters, including body weight gain, feed intake, and feed conversion ratio, were recorded. At 35 days of age, blood samples were collected from one bird per replicate to evaluate serum biochemical parameters (cholesterol, triglycerides, HDL, LDL, albumin, globulin, ALP, AST, and ALT). Antibody titers against sheep red blood cells (SRBC) were measured at 28 and 35 days of age. At the end of the experimental period, five birds per treatment were slaughtered to determine carcass, liver, and lymphoid organ weights. Additionally, intestinal tissue samples were collected from one bird per replicate to evaluate micromorphological traits, including villus height and width, crypt depth, villus height to crypt depth ratio, and muscular layer thickness.
Results: Statistical analysis revealed that the optimal nutrient levels for maximizing daily weight gain over the entire rearing period were 103% of energy and lysine requirements, 106% of protein requirements, and the standard level of methionine +cysteine. Standard levels of energy and protein, 97% of methionine +cysteine requirements, and 103% of lysine requirements were optimal for feed intake. Increasing dietary energy and protein levels improved the feed conversion ratio and the European production efficiency index. Serum cholesterol and triglyceride concentrations increased with increasing dietary energy levels. Higher dietary energy combined with lower protein levels led to increased HDL concentrations. Elevated energy and protein levels increased serum total protein, globulin, and the activities of AST and ALT enzymes. Moreover, villus height and surface area increased with increasing dietary lysine levels.
Conclusion: Overall, the results of the present study suggest that increasing dietary metabolizable energy beyond 103% of the recommended requirement may negatively affect performance and feed intake. Increasing dietary protein up to 106% of the requirement improved performance; however, considering the similar performance observed at 103 and 106% protein levels, a protein level of 103% is economically recommended. Additionally, the standard level of methionine +cysteine and 103% of lysine requirements are recommended for optimal performance in Arian broiler chickens.
Milad Rostami; Arash Kheradmand; Majid Masoudi Fard
Abstract
Objective: Due to the economic losses caused by mammary gland diseases in ruminants, rapid and accurate diagnosis of these diseases is important. For this reason, it is necessary to use new, precise and rapid techniques such as ultrasonography. The main advantage of ultrasonography is the non-invasiveness ...
Read More
Objective: Due to the economic losses caused by mammary gland diseases in ruminants, rapid and accurate diagnosis of these diseases is important. For this reason, it is necessary to use new, precise and rapid techniques such as ultrasonography. The main advantage of ultrasonography is the non-invasiveness and the ability to study of various structures of the mammary gland. Using of "Water bath" and dipping of udder within the water is the primary ultrasonic mothod with high resolution in order to diagnostic study of different structures of udder and teat. This method causes the teat to be without any under pressure and therefor prevents teat deformity upon examination. Thus the teat stand in its normal form and acquired ultrasonographic images during this procedure will be depicted most clear with resoulative quality.
Methods: The present study was conducted to compare udder and teat in pregnant and non-pregnant native goats, as well as comparison of right and left quarter in each udder. For this purpose, a total of 50 native goats slaughtered in Golshan slaughterhouse of Khorramabad were examined and selected. The udder samples were selectedbased on the presence of the embryo in the uterus, and two were divided into pregnant and non-pregnant udder (25 samples in each group) were isolated from each group. For ultrasonography of udder and teat, water bath and linear probe with frequency of 7.5 MHz were used. With this method, all of the samples were examined and the two groups of specimens were measured using the instrument's ruler option. Udder cistern diameter, teat end width, teat cistern depth, teat wall thickness and teat canal length were compared statistically using student t test.
Results: The findings of this study showed that the measured parameters of the teat cistern depth and teat end width in pregnant goats were significantly different from that of non-pregnant goats (P<0.05), but the Teat wall thickness parameter showed no significant difference between pregnant and non-pregnant goats (P>0.05). There were no significant differences between the teat canal length and the udder cistern diameter in the comparison of the quarter leaves of pregnant and non-pregnant goats (P<0.05) and in the comparison of right quarter (P>0.05), although they were close to the level of significance. Also, the results showed that there was no significant difference between left quarter and right quarter in any of the measured parameters in both pregnant goats and non-pregnant goats.
Conclusion: Regarding to the results of this study, it seems that ultrasonography of udder and teat can be used as a novel and applied method for diagnosis imaging of udder and teat healthy status and/or probable pathological disorders such as obstruction of lactiferous ducts in the native goats within the farm or research investigations.
Vahid Kalantar; Hamed Najafi Alamdarloo; Seyed Habibollah Mosavi
Abstract
Objective: Protein-rich foods are primary dietary sources, and chicken meat constitutes a major protein component in Iranian household consumption. This study aims to identify and quantify the determinants of chicken meat supply and demand across Iran’s provinces, emphasizing both economic and spatial ...
Read More
Objective: Protein-rich foods are primary dietary sources, and chicken meat constitutes a major protein component in Iranian household consumption. This study aims to identify and quantify the determinants of chicken meat supply and demand across Iran’s provinces, emphasizing both economic and spatial interactions, to inform regionally sensitive policy design. The analysis covers the period 2002–2024 in the Iranian calendar.
Methods: Using provincial panel data, the study estimates supply and demand functions through conventional panel econometric models and spatial panel models. After performing necessary specification and diagnostic tests, fixed-effects panel estimation was selected. Key explanatory variables include live-chicken prices (supply-side), consumer chicken prices (demand-side), input costs, exchange rates, household income, and red meat prices as a substitute. The analysis also computes historical price elasticities to assess changes in consumer responsiveness over time.
Results: After conducting the necessary statistical tests, the results indicated that a fixed effects panel model is more suitable for analyzing the supply and demand data of chicken meat. The analysis revealed that the price of live poultry has a significant positive impact on chicken meat supply. Additionally, the price of chicken meat negatively affects demand, while the price of red meat positively influences the demand for chicken meat. Furthermore, spatial analysis demonstrated that spatial factors significantly affect the supply and demand of chicken meat at the provincial level. The presence of positive spatial autocorrelation in supply and negative spatial autocorrelation in demand indicates different spatial distribution patterns for these two variables.
Conclusions: This study employed spatial econometric analyses to explore how regional factors interact to shape Iran’s chicken meat market. The findings reveal that both the supply and demand of chicken meat are influenced not only by internal provincial economic factors but also by the conditions of neighboring provinces, indicating significant spatial interdependence. The estimated supply equation demonstrates that the price of live chickens has a positive effect on supply, whereas higher input costs and exchange rate fluctuations negatively influence production. On the demand side, household income and the price of red meat considered a substitute good positively affect chicken consumption, while the price of chicken meat itself exerts a negative influence. Compared with earlier studies that estimated chicken meat’s price elasticity at approximately −0.93, this study finds a lower elasticity of about −0.25. This suggests that chicken meat has become a necessity in the Iranian household food basket, with consumers showing reduced responsiveness to price changes. Consequently, any price adjustment in this market may face inflexibility from consumers. The observed substitution effect between chicken and red meat implies that as red meat prices rise, households tend to shift their consumption toward chicken. Spatial analysis further indicates the presence of spatial convergence in supply, meaning that production levels in one province tend to influence those in neighboring provinces. The spatial models confirm that economic variables such as input prices, exchange rates, and household income significantly shape both supply and demand patterns. Overall, the study highlights the need for regionally tailored policies that consider spatial dependencies rather than uniform national interventions. Despite data and modeling limitations, the research underscores the critical role of spatial factors in developing more effective and balanced policies for the chicken meat market.
Mahdi Nasrabadi; Khalil zaboli
Abstract
Objective: One of the major challenges in the livestock industry is the health and proper growth of suckling calves, which are prone to digestive and respiratory diseases because of their immature immune system and are more susceptible to increased mortality. This study evaluated the nutritional strategy ...
Read More
Objective: One of the major challenges in the livestock industry is the health and proper growth of suckling calves, which are prone to digestive and respiratory diseases because of their immature immune system and are more susceptible to increased mortality. This study evaluated the nutritional strategy to improve performance by adding feed additives such as probiotic and biochar to the diet of Holstein suckling calves.
Methods: A total of 28 female newborn Holstein calves (41.2 ± 3.8 kg) were used as a 2×2 factorial arrangement within a completely randomized design over a 70‑day experimental period. The experimental treatments consisted of 1- basal diet without additive (control diet), 2- basal diet with 2 g/day of probiotic, 3- basal diet with 1% biochar and 4- basal diet with 2 g/day of probiotic plus 1% biochar. The basal diet was formulated with a forage-to-concentrate ratio of 10:90 to fulfill nutrient requirements. Water and starter feed were provided ad libitum during the experiment. Feed intake was recorded daily, while body weight and skeletal growth changes were assessed every two weeks. Blood samples were collected on days 0 (birth time), 35 and 70, and fecal samples were collected to evaluate diet digestibility in the last week of the experiment from all calves. All calves were observed for three days at the end of the experiment to record their feeding behaviors (standing, lying, eating, and ruminating) and non-feeding behaviors (licking, sucking, and chewing on environmental objects).
Results: The results indicated that calves receiving dietary biochar had significantly greater starter feed intake and weaning body weight compared with non‑biochar groups (P<0.05). Biochar supplementation also increased wither height, hip height and abdominal circumference of the calves (P<0.05). Moreover, concurrent supplementation with probiotic and biochar (treatment 4) further enhanced wither height and hip height (P<0.05). Dietary supplementation of probiotic and biochar improved the apparent digestibility of organic matter and crude protein, respectively (P<0.05), whereas the digestibility of other nutrients was not affected by experimental treatments. Blood glucose concentration was also increased by biochar supplementation (P<0.05). None of the feeding behaviors were significantly affected by dietary treatments. The interaction effect of probiotic and biochar was not significant on any of the parameters measured in this study.
Conclusions: Overall, dietary supplementation with biochar, alone or in combination with probiotic, positively enhanced performance, skeletal growth indices, and digestibility of nutrients in suckling calves, highlighting its potential as a functional feed additive to support early‑life health and productivity.
Pooria pezeshknejad; mohammad asadi; shoheil mirhabibi
Abstract
Objective: Golestan Province, possessing valuable rangelands, faces challenges from climate change and human activities, leading to reduced productivity and disrupted ecosystem function. Since soil is the primary substrate for supplying mineral elements to the soil-plant-livestock food chain, assessing ...
Read More
Objective: Golestan Province, possessing valuable rangelands, faces challenges from climate change and human activities, leading to reduced productivity and disrupted ecosystem function. Since soil is the primary substrate for supplying mineral elements to the soil-plant-livestock food chain, assessing the status of macro and micro-elements within this system is of particular importance. Recent field studies indicate the occurrence of metabolic disorders in the region's sheep, likely stemming from mineral deficiencies at various levels of this food chain. This research was conducted to investigate the correlation between the minerals present in the soil and forage of Golestan Province's rangelands and the serum element levels in lactating Dall lambs. A secondary objective was to examine the correlative relationships between the levels of these elements across different matrices and to analyze the impact of environmental variables on their bioavailability.
Material and Methods: The present study was conducted in June 2024 in Golestan Province. Fifty soil samples were collected from five distinct areas of the province (Maraveh Tappeh, Incheh Borun, Ghaleh Miran, Chahar Bagh, and Gomishan). Fifty samples of mature rangeland forage, each comprising a uniform mixture of forage species from the area with a dry weight of 50 grams, were harvested, packaged, and transferred to the laboratory for measurement of the target elements. To investigate serum element concentrations in sheep, blood samples were collected from 50 heads of Dalagh sheep in the study areas (10 per area) and transported to the laboratory. Data obtained from laboratory analyses were statistically evaluated in a completely randomized design with 5 treatments and 10 replications using SAS 9 software (Tukey; P<0.05). Pearson correlation analysis was performed using R software.
Results and Discussion: Based on soil analysis results, the macro-elements, including calcium, magnesium, potassium, and sulfur, showed significant differences among rangelands, indicating greater sensitivity of these elements to the ecological and soil characteristics of different regions. Forage analysis revealed that only phosphorus concentration differed significantly among rangelands, while the concentrations of other macro and micro-elements were within a similar range and showed no significant regional differences. The concentration of elements in animal blood serum followed a similar pattern, with only calcium and phosphorus showing significant differences among rangelands. Correlation analysis results indicated that the pattern of association between mineral elements in the soil-forage-animal serum chain was not uniform and was dependent on the element type. The metallic micronutrients include iron, zinc, copper, and manganese exhibited stronger and more consistent correlation coefficients among soil, plant, and animal blood serum compared to macro-elements. In contrast, correlations for macro-elements within this chain were generally weaker and more variable.
Conclusion: Considering the totality of mineral elements examined in this study, differences in the nutritional status of grazing animals were observed among the studied rangelands. Based on the overall pattern of elements in soil, forage, and blood serum, the Ghaleh Miran and Gomishan rangelands demonstrated greater stability and harmony in mineral concentration throughout the soil-forage-serum chain compared to other areas. In contrast, the Chahar Bagh rangeland, despite the availability of some elements in soil and forage, showed signs of macro-element imbalance, particularly in the calcium-to-phosphorus ratio, at the serum level in animals, likely due to absorption or homeostatic regulation of these elements in the livestock. Overall, the Ghaleh Miran and Gomishan rangelands exhibited more favorable conditions. In contrast, the Maraveh Tappeh and Incheh Borun rangelands showed greater fluctuations and a less stable pattern in the concentration of certain elements, and the Chahar Bagh rangeland displayed a different pattern regarding mineral balance at the animal serum level.
Hossein Khoshroo; Hossein Naeemipour; Seyed Homayon Farhangfar; Hadi Sarir
Abstract
Objective: There are a few research considering the relationship between birth weight (BW) of Holstein cows and their productive and reproductive traits. As matter of fact, BW is expected to be associated with some of productive and reproductive traits. Based on this, the objective of this research was ...
Read More
Objective: There are a few research considering the relationship between birth weight (BW) of Holstein cows and their productive and reproductive traits. As matter of fact, BW is expected to be associated with some of productive and reproductive traits. Based on this, the objective of this research was to conduct a genetic analysis of BW and its association with some future productive and reproductive traits of Holstein cows in Isfahan province.
Methods: A total of 51,427 records from dairy cows in 82 herds of Isfahan province collected during the calving years from 2001 to 2023 were used. The traits under consideration were BW, 305-day milk yield (MY), 305-day fat yield (FY), 305-day protein yield (PY), days to first service (DFS), days open (DO), number of services per conception (NSPC), and age at first calving (AFC). Genetic analysis was performed using a series of bivariate animal models. Fixed effects of herd, calving year, calving season, and age at first calving, along with the random additive genetic effect were included in the model. The model was fitted to the data using DMU software.
Results: Mean BW (± standard deviation) of female calves was 39.05 ± 4.52 kg. The mean values for MY, FY, and PY traits were 11432 ± 1731, 324.09 ± 90.63, and 301.26 ± 68.74 kg, respectively. The mean values for reproductive traits, including DO, DFS, AFC, and NSPC were 122.8 ± 45.35, 68.55 ± 21.09, 726 ± 59.19 day, and 1.64 ± 0.95, respectively. Heritability estimates for BW female calves, MY, FY, and PY were 0.24, 0.26, 0.36, and 0.39, respectively while the estimates for AFC, NSPC, DFS , and DO were 0.15, 0.08, 0.08, 0.02, and 0.02, respectively. Phenotypic and genetic correlations between the BW of calves and their future productive and reproductive traits were generally low. Phenotypic and genetic trends for BW were -0.26 ± 0.03 kg per year and 0.024 ± 0.005 kg per year, respectively, which were statistically significant (P < 0.01). The findings of the present research indicated that one kilogram increase in BW of Holstein calves is connected to an increase of 33.77 kg, 0.79 kg, and 0.814 kg for MY, FT, and PY, respectively. Additionally, DFS, DO, AFC, and NSPC in the first lactation period increased by 0.151, 0.115, 0.992 day, and 0.155, respectively.
Conclusion: The results of this research revealed that any increase in BW is expected to lead an increment of productive and reproductive traits in dairy cows. The positive genetic trend for BW indicates that BW genetically increased over the time of period suggesting that this trait has been successfully been selected directly or indirectly in the herds. With respect to the moderate heritability estimate of BW, it could be concluded that rapid change of BW could influence productive and reproductive traits. Therefore, a multiple trait selection index is needed to be developed and applied for having a balanced breeding programs in terms of economic traits.
vahid mohammadi; Shokoofeh Ghazanfari; Abdullah Mohammadi Sang-Cheshmeh
Abstract
Abstract
Objective: Trace element, particularly zinc (Zn), play a pivotal role in the normal metabolism and growth of broiler chickens. The application of novel technologies facilitates the synthesis of new Zn complexes designed for more efficient nutrient delivery. This study was conducted to evaluate ...
Read More
Abstract
Objective: Trace element, particularly zinc (Zn), play a pivotal role in the normal metabolism and growth of broiler chickens. The application of novel technologies facilitates the synthesis of new Zn complexes designed for more efficient nutrient delivery. This study was conducted to evaluate the effects of various dietary Zn sources on the performance, carcass characteristics, immunological parameters, and lipid oxidation of broiler meat.
Methods: Two hundred one-day-old Ross 308 broiler chicks were randomly assigned to five experimental treatments, with four replicates per treatment. The dietary treatments consisted of: (1) a basal corn-soybean meal diet (Control), (2) basal diet supplemented with Zn-sulfate, (3) Zn methionine, (4) Zn nano sulfate, and (5) Zn nano methionine, all supplemented at a level of 40 mg/kg of diet. Birds were provided ad libitum access to feed and water. Environmental conditions (temperature and relative humidity) were maintained within optimal ranges. Parameters assessed included growth performance, carcass traits, blood hematology, and thigh meat quality. The Zn nano complexes were designed based on nano-chelate technology.
Results: At the end of the starter period, the lowest feed intake (FI) was observed in birds fed the Zn nano sulfate supplement (40 mg/kg) (P<0.05). Lower FI in this group resulted in reduced bird growth during this period, showing a significant difference compared to other groups (P<0.05). Over the entire experimental period (1 to 42 days), a statistically significant numerical trend toward increased body weight gain (BWG) was noted among treatments (P=0.06). The best feed conversion ratio (FCR) was recorded in the Zn nano methionine group, which significantly differed from the Control and Zn nano sulfate groups (P<0.05). Carcass yield was significantly affected by the experimental treatments (P<0.05), with the lowest yield observed in birds fed Zn nano- sulfate and the Control diet. Abdominal fat pad relative weight was significantly higher in the Control and Zn nano sulfate groups compared to the other treatments (P<0.05). Furthermore, dietary Zn sources significantly impacted serum lymphocyte percentages (P<0.05); the best cell-mediated immune response was observed in birds fed zinc nano methionine and Zn methionine. The extent of oxidative spoilage in thigh meat of the Control group was significantly higher at 50, 100, and 150 minutes’ post-mortem compared to the other treatment groups (P<0.05).
Conclusion: Overall, the results of the present study indicate that incorporating 40 mg/kg of various Zn sources in nano scale (Zn nano sulfate and Zn nano methionine) in the diet elicits variable effects on growth performance, certain immune parameters, and meat quality in broiler chickens.