Tropical Animal Science Journal

Genomic Signatures of Positive Selection and Local Adaptation in Ethiopian Sheep Populations

2025-05-10T00:49:51+07:00

Domestic sheep (Ovis aries) have adapted to diverse ecological regions and exhibit various phenotypic traits through long-term natural and artificial selection. Indigenous sheep populations, in particular, have developed valuable traits such as disease resistance, heat tolerance, and resilience to harsh environments. Understanding the genetic mechanisms underlying these adaptive traits is crucial for enhancing, sustainably utilizing, and conserving sheep genetic resources. In this study, we aimed to assess genomic selection among five Ethiopian indigenous sheep populations sampled from various ecological regions. Whole blood samples were randomly collected from 48 sheep representing two populations (Semien and Selale) from different ecological regions and genotyped using the Ovine 50K SNP BeadChip. Genotype data from three Ethiopian sheep populations was additionally included in the analyses. Fixation index (FST) and cross-population extended haplotype homozygosity (XPEHH) methods were used to detect signatures of positive selection. Functional analysis revealed genes related to plateau adaptation, immune response, and tail fat formation. Our study identified potential genes associated with alpine and sub-alpine adaptation, including GABRG3, SYT1, TGFBR3, ITPR2, KCNMB2, and ATP1A3. Candidate genes linked with wet highland adaptation, including GNB1, HDAC9, IGFBP6, JAKMIP1, PAK2, and EXOC4, were also detected as under selection. The BMP2 gene, known for its fundamental role in sheep adipose tissue, emerged as a positional candidate gene for tail fat formation. This study offers novel insight into genomic adaptation to alpine, sub-alpine, and wet highland ecological regions in sheep and provides a valuable resource for further investigation. Moreover, it contributes worthwhile information for sustainable conservation and utilization, and lays the groundwork for future research into the genetic mechanisms behind sheep adaptability to diverse ecological regions.

Impacts of Cryopreservation on Semen Quality and Sperm Protein Profiles of Pesisir Bulls

2025-05-10T00:49:50+07:00

This study aimed to evaluate the impacts of cryopreservation on semen quality and sperm protein profile in Pesisir bulls. Semen samples were collected from three bulls and analyzed in fresh and post-thaw conditions. The sperm motility and kinematic variables were assessed using Computer-Assisted Sperm Analysis (CASA), while sperm viability and plasma membrane integrity (PMI) were evaluated through eosin-nigrosin staining and the hypoosmotic swelling test (HOST), respectively. Subsequently, the total protein concentration (PC) and profile were examined using SDS-PAGE. The results showed that there was a significant decrease in semen quality after thawing, with sperm motility reducing from 81.10% to 70.22%, viability reducing fom 87.47% to 77.27%, and PMI reducing from 85.09% to 71.32% (p<0.05). Kinematic variables such as velocity, straightness, and beat cross frequency also decreased significantly. Protein analysis showed a reduction in total concentration from 1.78 mg/mL to 1.19 mg/mL and alterations in protein band distribution, with the loss of specific high- and low-molecular weight after freezing. These results suggested that cryopreservation negatively impacts semen quality and sperm protein integrity, potentially impairing fertility. Moreover, further studies were recommended to optimize cryopreservation protocols and mitigate adverse effects.

Sperm Quality, Kinematics, Membrane Integrity, and DNA Fragmentation of Frozen Sexed Semen in Holstein-Friesian Bulls

2025-05-10T00:49:49+07:00

Percoll density gradient centrifugation (PDGC) is a widely used method for sperm separation in Indonesia. This study evaluated sperm quality, membrane integrity, acrosome damage, and DNA fragmentation after PDGC-based sperm sexing and cryopreservation. This research was conducted as a laboratory experiment with six treatment groups: fresh semen (T1), post-sexing X-chromosome-bearing sperm (T2), post-sexing Y-chromosome-bearing sperm (T3), post-thawing unsexed semen (T4), post-thawing X-chromosome-bearing sperm (T5), and post-thawing Y-chromosome-bearing sperm (T6). The observed variables included individual motility (IM), viability, concentration, abnormality, total motile sperm (TMS), intact acrosome cap (IAC), membrane integrity (MI), DNA fragmentation, and sperm kinetic variables assessed using computer-assisted sperm analysis (CASA). The results showed that PDGC sexing significantly reduced IM, concentration, TMS, viability, MI, and IAC. Furthermore, the freezing of both unsexed and sexed semen further decreased IM, concentration, TMS, viability, MI, and IAC while increasing sperm abnormalities. DNA fragmentation increased post-sexing and freezing in unsexed semen, indicating potential DNA damage from these processes. Kinetic variable assessment using CASA showed that PDGC maintained sperm motility characteristics, whereas freezing led to a significant decline in sperm kinetics. In conclusion, PDGC is a viable method for sperm sexing in cattle, as it preserves sperm quality, membrane integrity, acrosome integrity, DNA integrity, and motility characteristics while being compatible with semen cryopreservation. These findings confirm that PDGC-processed semen is suitable for artificial insemination (AI).

Silage Quality, Rumen Fermentation Characteristics, and Nutrient Digestibility of Sorghum bicolor cv. Samurai 1 Harvested at Different Maturity Stages Treated with Fibrolytic Enzyme

2025-05-10T00:49:49+07:00

The Samurai 1 variety is a genetically mutated strain with superior agronomic characteristics and enhanced nutrient content. This study aimed to evaluate the effect of harvest maturity stages and fibrolytic enzyme (Sunsonzyme) treatment on the nutrient value, fermentative quality, and nutrient digestibility of Sorghum bicolor cv. Samurai 1 silage. The silage quality was assessed using a completely randomized design with a 3 x 3 factorial arrangement. Sorghum was harvested at three different maturity stages, namely 85, 90, and 95 days, with fibrolytic enzyme added at 0%, 0.025%, and 0.05% of the dry matter. In vitro fermentability and digestibility were evaluated using a randomized block factorial design, which was also based on the same three harvest stages and enzyme levels. Observed variables included the nutrient composition of the sorghum, physical characteristics and nutrient content of the silage, as well as in vitro fermentability and digestibility. The results showed a significant interaction between harvest maturity and enzyme level on lactic acid production and total volatile fatty acid (VFA). Harvest age significantly affected (p<0.05) all variables, while the treatment of fibrolytic enzyme significantly increased ammonia (NH₃) and total VFA concentrations, as well as reduced the fiber fraction of the silage (p<0.05). The harvest age of 90 days showed the best quality in terms of nutrients, silage, and rumen fermentability. The addition of enzyme levels up to 0.05% improved the fermentative quality of silage, reduced fiber fractions, and enhanced rumen fermentability.

Calcareous Algae (Lithothamnium calcareum) as an Alternative Source of Calcium in Commercial Layer Diets

2025-05-10T00:49:48+07:00

Calcareous algae (CA) are an alternative renewable source of organic minerals that are used in poultry feed. However, the optimal CA concentration that can be included in poultry diets and its effect on egg production requires further investigation. The aim of this study was to determine the effects of diets containing varying CA (Lithothamnium calcareum) levels and particle sizes on the performance, mineral balance, quality, and composition of the eggs of commercial laying hens. A completely randomized experimental design with a 3 × 2 factorial arrangement (CA level × particle size) was employed in this study. A total of 210 Dekalb White laying hens were distributed to the following experimental units, with six birds each and five replicates per unit: the control (diet without CA addition) and treatment groups, which were fed with diets containing varying CA levels (1%, 2%, and 3%) and particle sizes (0.128 and 1.114 mm). Productive performance, external egg quality, and percentage of non-viable eggs were not affected by the inclusion of CA in the diets. The inclusion of 2% fine-particle CA reduced (p<0.05) calcium excretion (%) and, consequently, improved calcium retention. Similarly, the inclusion of 2% fine-particle CA decreased phosphorus excretion (p<0.05). The inclusion of 2% and 3% fine-particle CA increased mineral matter retention (p<0.05). Therefore, the inclusion of CA in the diets of lightweight laying hens did not affect productive variables or egg quality. However, 2% fine-particle CA reduced calcium and phosphorus excretion, thereby improving the retention of these minerals.

Thyme Plant Powder (Thymus vulgaris) Improves the Production Performance of Laying Hens by Affecting Ovarian Follicles

2025-05-10T00:49:48+07:00

The present experiment investigated the effects of different levels of thyme powder on performance, blood biochemical parameters, reproductive system morphometry, and egg quality traits at different storage temperatures in old laying hens. For this purpose, in a completely randomized design, 144 laying hens (Hy-line-W36) aged 65 weeks were assigned to 3 treatments, 6 replications, and 8 birds each. Experimental diets were corn-soy based, including 0%, 0.25%, and 0.5% thyme powder (TP). At the end of the experimental period (8th week of the experiment), 6 eggs were selected from each replicate and kept at temperatures of 4 and 25 °C for 30 days to determine the internal quality. The results showed that the egg weight of birds fed with diets containing 0.25% and 0.5% TP was significantly higher than control ones (p<0.05), but egg mass and feed conversion ratio were higher in the 0.5% group. Triglycerides and cholesterol decreased in the egg yolk and blood serum of birds fed 0.5% TP comparing control birds (p<0.05). At a temperature of 25 °C, the use of 0.5% TP compared to the control treatment increased the Haugh unit but decreased the albumin pH compared to the control treatment and 0.25% TP (p<0.05). Laying hens fed a diet containing 0.5% TP had larger white follicle numbers than birds fed a control diet and 0.25% TP groups (p<0.05). In conclusion, 0.5% TP supplement in the diet of laying hens can increase performance and the number of large white follicles and decrease the level of triglycerides and cholesterol in egg yolk and blood serum.

Sex and Tomato Flour Supplementation Influence Hepatic Function, Intestinal Morphometry, and Performance in Broilers

2025-05-10T00:49:47+07:00

Plant-derived supplements, such as tomato flour (TF), may enhance organ function and improve productive performance in poultry, but their effects under tropical conditions and between sexes remain unclear. This study assessed the effects of TF supplementation and sex on productive performance, hepatic function, and intestinal morphometry in broilers reared under tropical conditions. A total of 300 28-day-old Cobb-500 broilers were randomly allocated to six treatments: males and females fed a conventional diet or diets supplemented with 1% or 2% TF (T1-T6). Body weight, feed intake, and feed conversion ratio (FCR) were recorded weekly to evaluate productive performance. Intestinal morphometry (duodenum, jejunum, ileum), hepatic fatty infiltration (HFI), and liver function were analyzed. Supplementation with 1% TF improved final weight and FCR in male broilers (p<0.05). Supplementation with 2% TF reduced HFI in both sexes (p= 0.01) and lowered the albumin-to-globulin (A/G) ratio in males (p= 0.015). However, 2% TF impaired villus height and villus-to-crypt ratio in females, particularly in the duodenum and jejunum (p<0.05), while males were less affected. These findings indicate that TF enhances hepatic function and productive performance while reducing HFI in tropical-reared broilers. Its effects on intestinal morphometry are dose- and sex-dependent, with females being more negatively affected at higher doses, warranting further research into sex-specific dietary strategies.

Optimizing Apparent Metabolizable Energy and Digestible Amino Acids of Layer Feed by Response Surface Methodology

2025-05-10T00:49:47+07:00

Optimizing dietary energy and amino acid levels is essential for enhancing the performance and cost-efficiency of laying hens. The primary goals were to identify the optimal apparent metabolizable energy (AMEn) and digestible lysine (dLys) levels that maximize hen-day production (HDP) and egg weight (EW) while minimizing feed conversion ratio (FCR) and FC. A total of 150 cages, each housing five hens, were used. Hens with 24 weeks of age were assigned to ten dietary treatments following a central composite design (CCD), with AMEn levels ranging from 2,400 to 2,733 kcal/kg and dLys from 0.42% to 1.02%. The experiment was carried out during peak production (24 to 38 weeks of age). Response surface methodology (RSM) combined with CCD effectively optimized AMEn and dAA levels, providing practical insights for formulating cost-effective diets for commercial laying hens. Dietary dLys significantly influenced HDP and EW, while AMEn affected feed intake (FI). The optimal conditions, determined by the desirability function (DF), were AMEn of 2,660 kcal/kg and dLys of 0.81%, maximizing HDP and EW with minimal FCR and FC. Excluding EW from DF optimization, the best results were achieved at AMEn of 2,623 kcal/kg and dLys of 0.78%.

Preservation of High-Moisture Sorghum Silage Using Combination of Biological and Chemical Additives in the Tropical Region

2025-05-10T00:49:46+07:00

This study aimed to investigate the effect of the biological and chemical additives on fermentation characteristics, aerobic stability, and ruminal digestibility of high-moisture sorghum silage. A mixture of Lactiplantibacillus plantarum FNCC 0020 (LP) and Limosilactobacillus fermentum BN21 (LF) was used as a biological additive and potassium sorbate as a chemical additive. At the milk ripening stage (26.8% of DM), sorghum was harvested, chopped to 3-5 cm length, and ensiled into 20 L silo (5 kg) for 100 days. Subsequently, various additives were added, including a control group without additives (CON), LF + LP with a ratio of 1:1 at 1 x 105 cfu/g fresh weight (INO), potassium sorbate at 1 g/kg fresh weight (PS), and INO + PS (MIX). Each treatment used 5 silos as replication. The results showed that INO silage had the lowest (p<0.05) pH with the highest (p<0.05) contents of lactate and acetate, as well as lactic acid bacteria (LAB) count. PS silage produced the minimum contents of lactate and acetate but had lower yeast compared to CON silage. MIX silage had lower (p<0.05) lactate and acetate contents than CON silage, with a similar effect on yeast inhibition to PS silage. Furthermore, PS and MIX silages had higher (p<0.05) aerobic stability and in vitro digestibility of dry matter and organic matter than CON and INO. These results showed that combining biological and chemical additives was more effective in improving fermentation, aerobic stability, and ruminal digestibility of high-moisture sorghum silage.

Adding Multiple Enzymes to Diets Containing Wheat Distillers Dried Grains with Solubles Improves Broiler Performance by Reducing Viscosity

2025-05-10T00:49:46+07:00

This study aimed to investigate the effects of adding the multienzyme Apsazyme (glucanase, xylanase, galactosidase, mannanase) to diets containing different levels of wheat distiller’s dried grains with solubles (WDDGS) on performance, ileal bacteria, intestinal viscosity, pH, and blood variables of broiler chickens. For this purpose, 300 one-day-old male and female broilers of the Ross 308 strain were used. The experimental diets included three levels of WDDGS (0%, 10%, and 20%) with and without multienzyme (125 g/ton). Data analysis was done using SAS statistical software as a factorial design. The use of 20% WDDGS reduced feed intake (FI) in the finisher period and total period compared to the control treatment (p<0.05). The use of 20% WDDGS level reduced body weight gain (BWG) compared to 10% WDDGS treatment (p<0.05). The feed conversion ratio (FCR) was significantly reduced in birds fed with 125 g/ton of multienzyme diet (p<0.05). The number of aerobes bacteria and coliform was higher in broiler chickens fed with 10% and 20% WDDGS diet compared to the control treatment (p<0.05). Also, the use of multienzyme increased the number of lactic acid bacteria in the ileum. Multienzyme supplementation significantly reduced the increase in intestinal viscosity and pH caused by the 20% WDDGS level (p<0.05). Using 20% WDDGS in the diet increased the serum albumin concentration compared to 10% and 0% WDDGS (p<0.05). Finally, it can be concluded that the use of multienzymes compensates for the negative effects of diets containing 20% WDDGS on performance by reducing intestinal viscosity and modulating the gut microbial population. Therefore, it is recommended to add a multienzyme to the diet when using a 20% WDDGS level.

Front-matter

2025-05-10T00:49:45+07:00

DOI: https://doi.org/10.5398/tasj.2025.48.3.fm.i

Back-matter

2025-05-10T00:49:44+07:00

DOI: https://doi.org/10.5398/tasj.2025.48.3.bm.i

Correction to: Supplementation of Zinc Palm Oil Soap Improves Feed Fermentability and Unsaturated Fatty Acid Profile in Rumen Liquid

2025-05-10T00:49:45+07:00

Correction to: Tropical Animal Science Journal, 47(3), 371-380. https://doi.org/10.5398/tasj.2024.47.3.371

An error occurred on Page 373, Table 1, on “Note” under the table. The previous version was written: 1Total digestible nutrients (TDN) were calculated using TDN (%DM). TDN = -17.2649 + 1.2120(PK) + 0.8352(BETN) + 2.4637(LK) + 0.4475(SK), according to Wardeh (1981). The correct version should be: 1Total digestible nutrients (TDN) were calculated using TDN (%DM). TDN = -17.2649 + 1.2120(CP) + 0.8352(NFE) + 2.4637(EE) + 0.4475(CF), according to Wardeh (1981).