Small Ruminant Research最新文献

This study investigates the genotype and allele frequencies of three novel SNP loci (c.4218 T>G, c.2203 T>C, and c.7966 A>C) in the GHRHR gene within the Damascus goat breed and their associations with growth traits. The genotype frequencies for c.4218 T>G were 0.65 (TT), 0.15 (TG), and 0.20 (GG), with allele frequencies of 0.73 (T) and 0.27 (G), showing a significant deviation from Hardy-Weinberg equilibrium (HWE). The c.2203 T>C locus had genotype frequencies of 0.75 (TT) and 0.25 (CC), and the c.7966 A>C locus had 0.81 (AA) and 0.19 (CC), both consistent with HWE. Association analysis revealed significant correlations between the c.4218 T>G SNP and body weight and rump width, with the TT genotype showing the highest averages for both traits. The c.2203 T>C SNP was significantly associated with body weight and chest width, with the TT genotype again showing higher averages. The c.7966 A>C SNP was associated with chest depth and body length, with the AA genotype displaying lower averages for these traits. In silico predictions using multiple computational tools indicated that the identified missense SNP (p.31Ile>Ser) is novel and likely deleterious to the GHRHR protein's function and stability. Molecular docking demonstrated that the wild-type GHRHR binds more effectively with G protein alpha compared to the mutated form, predicting a mechanism through which this variant reduces the interactions of GHRHR with its cognate proteins. These findings provide valuable insights into the genetic factors influencing growth traits in Damascus goats and highlight the potential impact of the p.31Ile>Ser SNP on GHRHR functionality. This research underscores the importance of incorporating genetic markers in breeding programs to enhance growth traits and overall productivity.

Portable Accumulation Chambers (PAC) represent an important tool for quantifying greenhouse gases (GHG) in small ruminants. The objectives of the study were to evaluate to reduce the PAC time evaluation in sheep without compromising the GHG, methane (CH₄) and carbon dioxide (CO₂) measurements and to evaluate the PAC methodology, considering the variability of gaseous emissions in the day. Four times the animals spent in the PAC (10, 20, 30 and 40 minutes) and two collection times during the day (morning and afternoon) were tested for two consecutive days. The sheep used in the study came from a field experiment where they were subjected to different grazing feeding systems (only Italian ryegrass, Italian ryegrass in a mixture of legumes (Persian clover (Trifolium resupinatum L.) and White clover (Trifolium repens L.)) pasture and lambs grazing Italian ryegrass and consuming an energetic supplement (RyeG + Sup)). The gas samples collected at PAC were analyzed for CH₄ and CO₂ concentration on a gas chromatograph. There was no interaction in CH₄ and CO₂ measurements between times, shifts and grazing feeding systems (p > 0.05). CH₄ emission between times did not differ (p > 0.05), while CO₂ emissions were higher in the first 10 minutes of measurement and lower in the remaining times, fitting the non-linear regression model, with a reduction until 27.7 minutes. In relation to shifts, there was a difference for CH₄ (p < 0.01), and CO₂ (p = 0.01) with the highest emissions of CH₄ (21.7 ± 4.3 g/day) and CO₂ (1282 ± 332 g/day) found in the afternoon. The results of this study indicate that 27.7 minutes of sheep staying in the PAC is enough to evaluate CH₄ and CO₂ emissions and to improve the estimate of the gas emissions, evaluations should be carried out in the morning and afternoon.

In Ethiopia, enteric methane emissions from sheep contribute around 7 % to the national greenhouse gas (GHG) budget. This study examined the gross energy intake (GEI) and enteric methane emission factors (EFs) of sheep in smallholder systems in North Shewa, Ethiopia, using locally derived data via household surveys. The surveys encompassed two agroecological zones (AEZs) and analyzed various sheep classes across seasons. The study followed the Commonwealth Scientific Industrial Research Organization (CSIRO) Tier 2 methodology, which had previously been used in Kenya, and compared the results with those derived from the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (IPCC Tier 2) methodology. The EFs from the two Tier 2 methodologies were compared with IPCC default Tier 1 EF. The ranges of GEI and EF estimated for the different sheep classes showed similarity with larger variations observed for IPCC Tier 2 estimates. The estimated GEI for the various sheep classes ranged from 11.1 to 13.8 MJ day⁻¹ (‘CSIRO’ Tier 2) and 10.2–14.7 MJ day⁻¹ (IPCC Tier 2). The estimated EFs ranged from 4.8 to 5.9 kg CH₄ animal⁻¹ year⁻¹ (‘CSIRO’ Tier 2) and 4.5–6.5 kg CH₄ animal⁻¹ year⁻¹ (IPCC Tier 2). The flock-level EF was computed by aggregating the EFs of the different sheep categories. The flock level EF estimated by the IPCC Tier 2 (6.0 ± 0.1 kg CH₄ animal⁻¹ year⁻¹) was significantly higher compared to both the 'CSIRO' Tier 2 and IPCC Tier 1 methods. Based on the findings, we can say that variations in EF values emphasize the significance of taking different Tier 2 approaches into account when evaluating and comparing CH₄ emissions estimates in smallholder sheep farming systems. However, there is a need for further investigations to compare the two Tier 2 methodologies against actual intake and emission measurements to decide which methodology is better.

Rumen modifiers play a crucial role in minimizing dietary energy loss for finishing lambs. This study endeavors to assess nutrient digestibility, in vitro gas production, productive performance, and carcass characteristics in finishing lambs through the incorporation of three rumen fermentation modifiers (monensin sodium, calcium malate, and essential oils). Thirty-five four-months-old Pelibuey lambs of 23.6 kg ± 3.2 were assigned to a completely randomized block design to evaluate five diets: control (CON, without rumen modifier), monensin sodium (MON, 25 g/t); calcium malate (MAL, 2.5 kg/t), essential oils (EO, 150 g/t); and EO (150 g/t) plus MON (25 g/t). Daily feed intake, average daily weight gain, feed conversion ratio, dorsal fat thickness, rib eye area, ruminal pH, and chewing time did not differ among the diets. Notably, feed efficiency trend to be superior (P = 0.07) in the EO lambs, showing a 15.31 % and 17.28 % increase versus CON and MON diets, respectively. Dry matter intake in g/kg^0.75 was highest (P < 0.05) in MAL lambs by 23 % higher than lambs fed on diets added with EO and MON. The control diet (i.e., CON) exhibited the lowest (P < 0.05) in vivo dry matter digestibility compared to all other diets. Additionally, there was a trend (P = 0.056) towards reduced crude protein digestibility in CON diet. The inclusion of EO led to a higher (P < 0.05) proportion of ruminal acetic acid and a decrease (P < 0.05) in propionic acid versus the CON diet. The observed effects can be attributed to the antimicrobial activity of EO, specifically their secondary metabolites, which demonstrate antimicrobial properties. This underscores their potential in addressing concerns related to antibiotic use. Compared to MON, dietary inclusion with EO improves feed efficiency, with no notable effects on average daily gain, final weight, or the investigated carcass characteristics. The EO supplementation emerges as a practical alternative to antibiotic ionophore monensin for enhancing feed efficiency in finishing feedlot lambs.

Ram semen cryopreservation is not so widely used compared to bull semen. This study was carried out to explore the potential of methanolic chia seed extract (MCSE) in ram semen extender on kinematics, acrosome, apoptosis, antioxidant capacity, genes-related antioxidants, and caspase-3 in post-thawing ram semen. Semen from Rahmani rams (n=5) was collected, pooled, and diluted with Tris-extender (15 % egg yolk, 1 % soybean lecithin and 5 % glycerol) supplemented with MCSE (0, 125, 250, 375, and 500 µg/mL). MCSE had 67.5 % linolenic acid, 17.99 % linoleic acid, total phenolic, and flavonoid compounds. MCSE had higher antioxidant activity by DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) and FRAP (Ferric-reducing antioxidant power) assays. MCSE (500 µg/mL) significantly improved sperm motility (43.6 vs. 30.0 %), vitality (44.0 vs. 30.7 %), and membrane integrity (43.1 vs. 31.3 %) as well as sperm velocity parameters and acrosome integrity (53.4 vs. 36.2 %) after thawing. MCSE at a level of 500 µg/mL increased viability, total antioxidant capacity level, and decreased apoptotic spermatozoa and malondialdehyde levels in post-thawed semen. MCSE at levels of 250, 375, and 500 µg/mL decreased caspase-3 level to 42.8, 35.6, and 30.0 % compared to control (54.6 %) after thawing, and resulted in a clear up-regulation of antioxidant-related genes of superoxide dismutase 1, catalase, glutathione peroxidase 1, and GA-binding protein transcription factor subunit beta-1 (GAPP1). The highest impact was observed for MCSE on GAPP1 as compared to other profiles as well as for MCSE at 500 µg/mL as compared to with other levels. All MCSE levels decreased Caspase-3 mRNA by about 44, 51, 61, and 61 %, respectively. In conclusion, MCSE had higher anti-oxidative activity. Tris-soya bean lecithin extender supplemented with MCSE at a level of 500 µg/mL, as a natural antioxidant, has a vital role in maintaining the freezing ability of ram spermatozoa after cryopreservation.

Optimization of cryopreservation media to attenuate oxidative damage on post-thaw spermatozoa is crucial. This study aimed to assess the antioxidant functionality of curcumin-loaded niosomal nanocarriers (CurLNN) on the quality of cryopreserved ram spermatozoa. Semen samples (n=16) of four Dalagh rams were extended with different concentrations (10 or 20 μL) of curcumin (Cur) or CurLNN and then cryopreserved using a standard protocol. The findings indicated that sperm cells exposed to curcumin, specifically CurLNN at a concentration of 20 μL, displayed increased levels of total and progressive motility, greater lateral head displacement and linearity values, improved plasma membrane function, and reduced abnormality (P < 0.05). Viability and plasma membrane functionality increased by supplementing cryopreservation medium with Cur20 and CurLNN (P < 0.05). A significant decline (P < 0.05) in malondialdehyde (MDA) and reactive oxygen species (ROS) concentrations was observed by supplementing cryopreservation medium with both curcumin and its nano-sized. There was a significant (P < 0.05) increase in the percentage of spermatozoa with mitochondrial activity when the cryopreservation medium was incorporated with CurLNN. Spermatozoa treated with CurLNN demonstrated higher viability and lower late apoptosis (P < 0.05) compared with other groups. There were no differences among groups in terms of the percentage of necrotic and early apoptotic spermatozoa. In conclusion, the results of this study demonstrated that nano-sized curcumin, particularly at a 20 µL concentration, had a higher antioxidant potential, leading to improved sperm functional quality by mitigating oxidative damage during cryopreservation.