Seyed Mohammad Ali Sheykholeslami; Ali Akbar Masoudi; Alireza Ehsani; Rasoul Vaez Torshizi
Abstract
Objective: Meta-analyses are conducted with the aim of systematically and reproducibly integrating diverse data reported in research articles. To date, such studies in Iranian sheep populations have been limited to estimating the heritability of a small number of traits. The primary objective of the ...
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Objective: Meta-analyses are conducted with the aim of systematically and reproducibly integrating diverse data reported in research articles. To date, such studies in Iranian sheep populations have been limited to estimating the heritability of a small number of traits. The primary objective of the present study was to compile and analyze information from published articles to calculate weighted means and genetic parameters for 23 production and reproductive traits, with the ultimate goal of supporting national breeding programs for indigenous Iranian sheep. Additional aims included providing an overall perspective on the range of genetic parameter estimates, identifying traits with greater potential for genetic improvement, and highlighting future research needs.Methods: A total of 279 research articles were collected from all available national and international databases to perform a meta-analysis of genetic parameters related to growth and reproductive traits in Iranian native sheep. Of these, 210 articles addressed growth traits and 69 addressed reproductive traits. Data heterogeneity was assessed using the I² statistic. Due to the high levels of heterogeneity observed among studies, a random-effects model was applied. The reliability of estimates was evaluated using the relative standard error (RSE) statistic.Results: For production traits, the highest and lowest coefficients of variation in weighted means were observed for average daily gain from weaning to 6 months of age (45.45%) and Kleiber ratio from birth to weaning (10.74%), respectively. Direct heritability estimates ranged from 0.101 for the Kleiber ratio from weaning to six months to 0.222 for body weight at six months of age. For reproductive traits, the highest and lowest coefficients of variation were recorded for total weaning weight per lambing (30.91%) and lamb survival rate to weaning (5.62%), respectively. Direct heritability for reproductive traits ranged from 0.040 for conception rate to 0.130 for total birth weight per lambing.Conclusions: In the present study, the heritability of production traits in Iranian native sheep was estimated to be low to moderate. Due to the substantial coefficient of variation observed in the phenotypic expression of growth traits, it is recommended that, in addition to implementing national breeding programs and phenotypic selection, breeders should also consider the crucial influence of environmental factors, such as breed, production system, nutritional management, and healthcare, in genetic improvement programs. Furthermore, the findings revealed that heritability estimates and coefficients of variation for the most important reproductive traits in Iranian sheep are significantly lower than the levels required for effective breeding programs based solely on phenotypic selection. Therefore, it is recommended that the improvement of reproductive traits in indigenous sheep populations be pursued through advanced methods, such as marker-assisted selection.
Ali Rezazadeh Vishkaei; Alireza Hasani Bafarani; Kian Pahlevan Afshar; Mehran Aboozari
Abstract
Objective: This study seeks to identify and systematically analyze key factors affecting the longevity of Holstein dairy cows in the herds, using advanced data mining algorithms. Understanding and predicting longevity is vital because it directly impacts productivity and profitability of dairy farm. ...
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Objective: This study seeks to identify and systematically analyze key factors affecting the longevity of Holstein dairy cows in the herds, using advanced data mining algorithms. Understanding and predicting longevity is vital because it directly impacts productivity and profitability of dairy farm. Longer-lasting cows tend to produce more calves and produce more milk, thereby increasing the overall economic efficiency of dairy operations. Furthermore, extended longevity is associated with reduced replacement costs.
Methods: In recent years, the integration of machine learning techniques into agricultural and livestock management has gained significant momentum. This study uses detailed phenotypic data collected from 37,009 female animals belonging to 664 sires in 82 separate herds, representing a comprehensive dataset spanning a decade. The data includes eight milk production records, along with other relevant variables such as animal age, sire number, shelf life in months, somatic cell count, days in milk, milk production (kg), protein and fat content, calving cycle length, milking frequency, geographic location (province), birth date, calving date, calving interval, herd code, and age at first calving. The data preparation phase included processing and organizing the dataset using Excel 2016, which ensured data quality and consistency. Subsequent data analyses were conducted using R software (version 4.3.3), and using the relevant specialized packages for machine learning and statistical modeling.
Results: The results showed that, the Support Vector Machine has the best accuracy (0.987). Random Forest was the second most efficient algorithm. The accuracy of the Gradient Boosting Machine was slightly lower than that of the Random Forest, but it still showed good performance. The Decision Tree provided the least accuracy among these algorithms. The Decision Tree and Support Vector Machine achieved this performance with fewer input variables compared to Gradient Boosting Machine and Random Forest.
Conclusion: The results showed that none of the algorithms used for survival classification, despite acceptable accuracy, are error-free, but on the other hand, it was shown that the decision tree is simpler and less expensive. The most important features of these methods are the lack of statistical assumptions and requirements that linear regression and interpolation methods require, the lack of normality assumptions, robustness against missing values and the ability to detect complex nonlinear relationships between variables and prediction targets, which makes them suitable for various applications in the livestock industry. Accurate data recording protocols as well as precise algorithm settings are essential for accurate prediction.
Parviz Azizi; Hossein Moradi Shahrbabak; Mohammad Moradi Shahrbabak; Sara Nezhadi
Abstract
Objective: Leptin is a peptide hormone secreted by adipose tissue and also associated with feed intake, growth, and lipid metabolism. The aim of this study was to investigate the polymorphism of the 271 base pair locus, including the entire exon 2 and part of intron 2 of the leptin gene in two sheep ...
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Objective: Leptin is a peptide hormone secreted by adipose tissue and also associated with feed intake, growth, and lipid metabolism. The aim of this study was to investigate the polymorphism of the 271 base pair locus, including the entire exon 2 and part of intron 2 of the leptin gene in two sheep breeds, Lori-Bakhtiari and Zel-Atabay crossbreds, and to determine the relationship of this locus with carcass traits and identify desirable genotypes for these traits in the studied sheep.
Methods: In the present study blood samples were collected from 114 sheep, including 74 Lori-Bakhtiari lambs from the industrial slaughterhouse in Farsan County and 40 Zel-Atabay crossbred sheep from the industrial slaughterhouse in Gorgan County. DNA extraction was performed using an optimized salt method. Polymerase chain reaction (PCR) was performed to amplify a 271 base pair fragment encompassing exon 2 and part of intron 2 of the leptin gene. Examination of this fragment using the single-strand conformation polymorphism (SSCP) method revealed nine banding patterns. Following sequencing of the observed banding patterns, comparison with the reference sequence identified six genotypes. To investigate the association between genotypes and the studied traits, genotype effect was included as an independent variable in the models.
Results: Sequencing identified three mutations in this region: the (A/G) 1416 mutation observed in Iranian breeds, another mutation in the coding region where a cytosine base is inserted (+C 1328), resulting in a truncated protein, and the third mutation in intron 2, where thymine is replaced by guanine at nucleotide 1566. Allele frequencies in Lori-Bakhtiari and Zel-Atabay crossbred sheep were 0.552 and 0.788 for the first mutation (+C 1328), 0.359 and 0.00 for the second mutation (A/G 1416), and 0.179 and 0.121 for the third mutation (T/C 1566), respectively. Comparison of the obtained sequences with NCBI database sequences identified six genotypes. Evaluations in this study showed significant relationships between the identified genotypes in Lori-Bakhtiari sheep and traits such as chest circumference, animal height, upper and middle tail circumference, upper and middle tail width, and blood triglyceride levels. In Zel-Atabay crossbreds, significant relationships were observed between the identified genotypes and traits such as carcass weight and lower tail circumference.
Conclusions: The findings demonstrate that the leptin gene polymorphisms at the 271-bp locus, particularly the +C1328 and A/G1416 mutations, can serve as effective molecular markers in sheep breeding programs to improve carcass traits (such as increased carcass weight and optimized fat distribution). These results highlight the importance of targeting this genomic region for superior animal selection in breeding and herd management.
MH Heidary Far; Mohammad Ali Norouzian; Behzad Khorrami
Abstract
Objective: This study aimed to investigate the chemical composition, dry matter (DM) and crude protein (CP) degradability, and gas production parameters of Lemna minor (duckweed) in ruminant nutrition.
Methods: In the first phase, the chemical composition and mineral content, gas production parameters, ...
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Objective: This study aimed to investigate the chemical composition, dry matter (DM) and crude protein (CP) degradability, and gas production parameters of Lemna minor (duckweed) in ruminant nutrition.
Methods: In the first phase, the chemical composition and mineral content, gas production parameters, and degradability of DM and CP of Lemna minor (collected from two regions: Rasht and Varamin) as well as alfalfa forage were determined using standard analytical methods. In the second phase, based on the CP content of Lemna minor, the fermentative value of gas production was measured for experimental diets consisting of a control group (60% concentrate and 40% alfalfa) and treatments in which alfalfa was replaced with Lemna minor at levels of 25%, 50%, 75%, and 100%.
Results: The CP content in whole Lemna minor from Varamin was significantly higher than that of whole Lemna minor from Rasht and alfalfa forage (P<0.05). The neutral detergent fiber content of whole Lemna minor from both Rasht and Varamin was higher than that of alfalfa (P<0.05). Crude ash content in whole Lemna minor from Varamin was higher than in the Rasht sample and alfalfa (P<0.05). The concentrations of macro-minerals (calcium, phosphorus, magnesium, and potassium) and micro-minerals (copper, zinc, iron, and manganese) differed between the two Lemna minor samples. Across all incubation times, gas production was significantly greater in alfalfa than in Lemna minor (P<0.05). Similarly, the potential and rate of gas production, metabolizable energy (ME) content, and organic matter digestibility were all higher in alfalfa compared with Lemna minor (P<0.05). Methane gas production from Lemna minor was also lower than from alfalfa (P<0.05). The rapidly degradable fraction of DM and CP in Lemna minor (32.3% and 27.0%, respectively) was significantly higher than that in alfalfa (22.6% and 25.9%, respectively; P<0.05). However, the slowly degradable fraction, the degradation rate constant, and the effective degradability at passage rates of 0.02, 0.04, and 0.06 per hour for both DM and CP were higher in alfalfa than in Lemna minor from Rasht (P<0.05). Replacing alfalfa with Lemna minor in the experimental diets significantly reduced gas production at various incubation times, particularly at higher replacement levels (P<0.05). Moreover, the gas production potential parameter (b) and ME content were highest in the control group without Lemna minor and lowest in the treatment where alfalfa was completely replaced by Lemna minor (P<0.05).
Conclusion: Considering its crude protein content, mineral concentrations, and degradability characteristics, Lemna minor has potential as a valuable feed ingredient in ruminant diets. Nevertheless, further studies, especially under practical farm conditions, are recommended before its widespread application.
Parvaneh Hashemi; Leila Taherabadi; Farokh Kafilzadeh
Abstract
Objective: Ensilage is one of the methods of preserving forage plants for livestock feeding. The use of carbohydrate sources in silage preparation can improve the quality of anaerobic fermentation by increasing the concentration of lactic acid. Aerobic stability of silage after exposure to air ...
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Objective: Ensilage is one of the methods of preserving forage plants for livestock feeding. The use of carbohydrate sources in silage preparation can improve the quality of anaerobic fermentation by increasing the concentration of lactic acid. Aerobic stability of silage after exposure to air is one of the quality parameters of silages. Heterofermentative lactic acid bacteria are among the additives that have been used to improve the aerobic stability of silages. However, there is no information on the use of the Lactobacillus fermentum on the aerobic stability of Napier grass silage with or without the use of carbohydrate sources. Therefore, this research was conducted to study the effect of Lactobacillus fermentum 92069 and molasses on fermentation properties, aerobic stability and in vitro digestibility of Napier grass silage as a new forage source (introduced for the first time) in the country.
Methods: Napier grass was cultivated in the research farm of the Faculty of Agriculture, Razi University on May 2021. To prepare silage, the forage was harvested, chopped and treated with 0, 3 or 6 percent molasses with or without 0, 1× 106 cfu or 2×106 cfu of Lactobacillus Fermentum 92069 per gram of fresh forage and then ensiled in laboratory silos with four replicates. After 90 days of ensiling, the chemical composition and fermentation products of the silages such as lactic acid, butyric acid, acetic acid, ammonia nitrogen and in vitro digestibility were determined. The fungal population of the silages including yeast and mold was also determined. During the aerobic fermentation process, aerobic stability of the silages and changes in pH and the population of fungal in the silages were also measured.
Results: Increasing the level of molasses was associated with an increase in dry matter and soluble carbohydrates in silage. The lowest pH values (3.90 to 3.97) with higher production of lactic acid concentration (47.9 to 53.3 g/kg dry matter) were observed in silages containing the high level of molasses with or without bacterial inoculant. The addition of Lactobacillus fermentum increased acetic acid production, but had no effect on the aerobic stability of the silage. There was no difference in the fungi population of silages among treatments. Dry matter and organic matter digestibility, as well as metabolizable energy, were higher in silages containing molasses with or without bacterial inoculants.
Conclusion: The results of the present study showed that Napier grass silage without additives was of good quality. However, the use of molasses resulted in improved anaerobic fermentation and digestibility. The aerobic stability of Napier grass silages in spite of an increase in acetic acid was not affected by the addition of the Lactobacillus fermentum up to 2 ×106 cfu/ g fresh forage.
Ayub Mohammadi; Farhang Fatehi; Kamran Reza-yazdi; Farhad Parnian-khajehdizaj; Ali sadeghi-sefidmazgi
Abstract
Objective: One of the most important goals in dairy cattle farming is to increase milk production and quality. This important goal is achieved when high-quality feed with high nutrient concentration is used in dairy cows, especially high-producing cows. However, understanding the importance of starch ...
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Objective: One of the most important goals in dairy cattle farming is to increase milk production and quality. This important goal is achieved when high-quality feed with high nutrient concentration is used in dairy cows, especially high-producing cows. However, understanding the importance of starch in cattle feed is vital for maximizing their performance and ensuring their health and welfare, from increasing energy levels for milk production to affecting rumen health and digestive tract efficiency. Therefore, increasing the amount of concentrate consumed has reached its maximum, and consequently, increasing nutrient digestion and reducing nutrient waste through feces in dairy cattle herds is of particular importance, which requires better herd management. Thus, the objective of the present study was to investigate the relationship between total mixed ration (TMR) nutrient compositions and their effects on fecal starch excretion, as one of the most widely used nutrients in high-producing Holstein cows across the country's herds.
Methods: This study was conducted on 76 Holstein dairy herds. In each herd, one pen of high-producing Holstein cows was selected as the index pen based on average milk production, average days in milk (DIM), and average parity. From each pen, 10 cows with body condition score of 3±0.25, DIM of 80±10, milk production of 47±2.5, and parity of 2.5±0.5 were selected. Samples were collected from TMR, feed ingredients, and cow feces for three consecutive days. Finally, data such as dry matter intake (DMI), forage-to-concentrate ratio, and amounts and ratios of dietary starch, crude protein (CP), neutral detergent fiber (NDF), crude fat, non-fiber carbohydrates, and organic matter in TMR were measured. The resulting data were used to estimate fecal starch excretion using single and multiple linear regression models. The prioritization criterion for the effects of each parameter was determined using the coefficient of determination.
Results: Based on univariate prioritization, the results showed that in addition to the amount and percentage of dietary starch (coefficient of determination of 0.56 and 0.43, respectively), the amount of NDF, amount of CP intake, dietary protein percentage, DMI, and dietary NDF percentage with coefficients of determination of 0.42, 0.36, 0.36, 0.34, and 0.33, respectively, had significant effects on fecal starch excretion (P-value ≤0.01) and had the greatest impact on fecal starch excretion in that order. Additionally, based on the multivariate model, it was determined that including two factors - dietary starch percentage and dietary protein percentage - in the model equation provided the highest estimation of fecal starch percentage with a coefficient of determination of 0.73. It should be noted that the next priorities were for DMI, dietary starch percentage, and dietary protein percentage (R² = 0.68), as well as DMI, protein percentage, and dietary NDF percentage (R² = 0.65).
Conclusions: This study showed that fecal starch concentration in the country's high-producing cows is significantly high (average 11.5% based on fecal dry matter). Also, based on univariate prioritization, it was shown that increases in dietary starch amounts and percentages, dietary CP, and daily DMI (in kilograms) lead to increased fecal starch excretion, while increases in dietary NDF amount and percentage resulted in decreased fecal starch excretion. Furthermore, based on multivariate prioritization, the best estimation of fecal starch excretion was achieved using a model including dietary starch percentage and dietary protein percentage variables, which could predict fecal starch concentration with a coefficient of determination of 0.73.
Mahdi Nasrabadi; Zahra Ghanbarian
Abstract
Objective: Limited access to high-quality forages such as alfalfa is a major challenge in improving production effeciency in Iran's livestock industry. Despite efforts in recent years to identify and replace cost-effective plant species, no suitable and reliable alternative plant has been introduced ...
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Objective: Limited access to high-quality forages such as alfalfa is a major challenge in improving production effeciency in Iran's livestock industry. Despite efforts in recent years to identify and replace cost-effective plant species, no suitable and reliable alternative plant has been introduced so far. This study was designed and conducted to evaluate the potential of Moringa oleifera leaves (MOL) as an alternative forage source. For this purpose, the chemical composition of MOL was determined, and the effect of including different levels of this plant in the diet on in vitro digestibility and fermentation parameters was investigated.
Methods: The chemical composition of MOL and alfalfa hay (Medicago sativa) was determined using standard methods. Subsequently, the experimental diets were formulated with four levels of MOL inclusion (0, 15, 30, and 45% of dietary DM) to meet the requirements of growing sheep, balanced with a 55:45 forage to concentrate ratio. Dry matter and organic matter digestibility were measured using the two-stage procedure of Tilley and Terry method, and other parameters such as gas production, microbial biomass production, ammonia-N and volatile fatty acids (VFA) concentrations, antioxidant capacity, and protozoa population were evaluated using the gas production technique.
Results: The results indicated that MOL had higher crude protein (CP), ash, ether extract (EE), calcium, and phosphorus, and lower cell NDF, ADF, and lignin compared to alfalfa hay (P<0.05), so that the CP, ash, and EE of MOL were 48.3%, 25.8%, and 33.3% higher than those of alfalfa, respectively. The amounts of non-fibrous carbohydrates and metabolizable energy (ME) of the two plants did not differ. In diets containing MOL, digestibility, ME, gas production volume, truly degraded substrate, and microbial biomass production increased linearly (P<0.05), while partitioning factor and microbial biomass production efficiency did not change. Also, the use of MOL in the diet significantly increased the concentration of ruminal VFA and antioxidant capacity and reduced the concentration of rumen ammonia-N (P<0.05), while the mentioned plant had no effect on pH and the ratio of VFA. On the other hand, the inclusion of MOL in the diet caused a significant reduction in the total population and subfamilies of protozoa (P<0.05).
Conclusions: Based on the obtained results, Moringa oleifera leaves can be considered as a potential alternative for the forage part of the diet and can be recommended up to 45% of the diet, with the aim of meeting livestock nutritional requirements, improve ruminal fermentation and antioxidant status. However, in vivo studies are needed to further explore the performance effects of Moringa oleifera leaves.
Abdollah Heydar Shaker Al-Mousavi; Soudabeh Moradi; Mehran Torki; Ali Khatibjoo; Reza Abdollahi
Abstract
Objective: This experiment was conducted to evaluate the effect of different phosphorus sources and phytase supplementation on performance, egg quality, and the digestibility coefficients of P in mono and dicalcium phosphate and meat and bone meal in commercial laying hens.
Methods: A total of ...
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Objective: This experiment was conducted to evaluate the effect of different phosphorus sources and phytase supplementation on performance, egg quality, and the digestibility coefficients of P in mono and dicalcium phosphate and meat and bone meal in commercial laying hens.
Methods: A total of 288 lohmann laying hens (LSL-Lite) was used in a completely randomized design with 3×2 factorial arrangements with 6 treatments, 8 replicates and 6 birds in each from 50 to 62 wk of age. Experimental treatments included: three sources of P including mono- and di calcium phosphate (MCP and DCP) and meat and bone meal (MBM) with and without phytase enzyme (400 FTU/kg). Apparent and true ileal digestibility (AIDP and TIDP), as well as apparent retention of P (TTDP), were measures using semi-purified corn-based diets.
Results: The true ileal digestibility coefficients of P in MCP, DCP and MBM were 43.4, 44.0, and 40.7 % respectively, in laying hens at 62 weeks of age, and the AIDP, and TIDP of MCP and DCP was greater than that of MBM. AIDP and TIDP for DCP and MCP were greter than that of MBM, and phytase supplementation increased P digestibility (P < 0.05), however, TTDP in 62-week-old laying hens in MBM was numerically higher than those of DCP and MCP. The interaction of P source and phytase on egg production, egg weight, egg mass and feed intake were significant. The greatest percentage of egg production was observed in hens fed with DCP plus phytase and MBM plus phytase, which was significantly more than those of DCP and MCP plus phytase treatments (P<0.05). Phytase supplementation in DCP containing diets increased egg production rate and egg weight (P<0.05). Compared to other groups, the greatest feed intake was observed in the birds fed MCP diets without and with phytase (P<0.01). The best egg weight was observed in birds fed MCP, which was significantly different from those of DCP and MBM diets (P<0.05). The egg mass in birds fed MCP and DCP with phytase was lower than in other experimental treatments (P<0.05). Compared to a diet without phytase, the addition of phytase and MBM, the inclusion of DCP and MCP in thr diet improved yolk color (P<0.05).
Conclusions: Inconclusion, using DCP and MCP was more effective than MBM and phytase inclusion has impact on P digestibility and egg production in DCP and MBM containing diets.
Seyedeh Fatemeh Mousavi; Mohammad Reza Rezvani; Mohammad Javad Agah; Alidad Boostani; Mohammad Dadpasand
Abstract
Objective: The poultry industry plays a vital role in providing high-quality dietary protein and addressing global food shortages. Ensuring the safety of poultry products for human consumption while minimizing environmental impact has become a key priority in modern production systems. In the past, antibiotics ...
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Objective: The poultry industry plays a vital role in providing high-quality dietary protein and addressing global food shortages. Ensuring the safety of poultry products for human consumption while minimizing environmental impact has become a key priority in modern production systems. In the past, antibiotics were widely used to enhance growth performance and prevent diseases in poultry. However, concerns over the development of antibiotic-resistant pathogens and the associated risks to public health have led to increasing restrictions on their use. The reduction or withdrawal of antibiotic use has, in some cases, contributed to the resurgence of infectious diseases and economic losses within the poultry sector. Consequently, there has been growing interest in natural alternatives that can support health and productivity. Among these alternatives, dietary immunomodulators have emerged as promising candidates. Substances such as nano-copper and propolis are recognized for their potential to act as natural growth promoters and immune enhancers in poultry production systems-
Methods: In this research, 240 chickens of Ross 308 strain were used with five treatments and four replicates in a completely randomized design. The experimental treatments included the control diet, 0.05% Oxytetracycline antibiotic, 100 mg/kg Nano-copper, 125 mg/kg Propolis, and the simultaneous use of 100 mg/kg Nano-copper and 125 mg/kg Propolis. The experimental data were statistically analyzed using SAS software (version 9.4) and one-way analysis of variance, and the least squares mean of the treatments was examined at a significance level of five percent.
Results: The findings of this study demonstrated that the use of propolis had significant effects on growth performance, nutrient digestibility, and certain physiological parameters of broiler chickens. During the finisher phase and over the entire rearing period, birds receiving diets supplemented with nano-copper or a combination of nano-copper and propolis consumed significantly less feed than the control group. In terms of body weight gain over the entire period, the antibiotic-supplemented group showed superior performance relative to the control group, while the propolis-treated group exhibited similar results to the antibiotic group. However, no significant differences were observed among the treatments in terms of feed conversion ratio. In terms of digestibility, the control and propolis treatments had the highest apparent digestibility of crude protein and ash. However, nano-copper supplementation, especially in combination with propolis, resulted in reduced nutrient digestibility, which may be attributed to the potential negative effects of nano-copper on intestinal function. Although some previous studies have reported positive impacts of nano-copper on protein synthesis, these effects appear to be highly dose-dependent and influenced by environmental and management conditions. Additionally, the presence of enzymes and antioxidant compounds in propolis may contribute to improved digestibility. Regarding carcass traits, no significant difference was observed among treatments in the relative weight of internal organs, indicating the relative safety of these additives at the inclusion levels used in this study.
Conclusions: Considering the improvement of protein and ash digestibility by ethanolic extract of Propolis and the lack of significant difference in performance with Oxytetracycline, this supplement can be used as an alternative to antibiotics.