Small Ruminant Research最新文献

The study was designed as a randomized, prospective, blinded, clinical trial to compare the clinical effects of epidural lidocaine hydrochloride 2% (L2%) alone and in combination with dexmedetomidine (DL2%) in sheep. A total of 19 adult sheep, 14 females & 5 males were assigned to one of the two lumbosacral epidural treatments: L2% (4 mg kg ^–1) and DL2% (2.5 µg kg ^–1 + 4 mg kg ^–1) in a randomized order. The total volume of the drug combination was kept constant. Onset, analgesia, motor blockade, sedation and behaviour were determined before treatment, after effect of treatment and at recovery. Duration of epidural anesthesia and motor blockade were recorded. Heart rate, blood pressure, respiratory rate, rectal temperature and capillary refill time were recorded prior to treatments and every 15 minutes following epidural anesthesia for 60 minutes. Epidural anesthesia was produced with both the treatments effectively and was easily performed in all the studied animals. Both the treatments provided complete analgesia however no significant difference (p = 0.35) was recorded in onset time to analgesia. Duration of epidural anesthesia was significantly greater (p < 0.0001) with DL2% (239.56 ± 19.48 min) than L2% (69.30 ± 3.03 min). Significant extension (p < 0.0001) of motor blockade was recorded with DL2% (251.89 ± 22.18 min) than with L2% (88.30 ± 2.36 min) alone. The median analgesic scores were significantly higher in DL2% in comparison to the L2% alone. Rescue analgesia had to be given in 20% of L2% and 33.3% of DL2%.

The aim of this study is to determine how physiological changes occurring in the uterus during early pregnancy affect echotexture values by computer-assisted analysis of ultrasonographic images of the uterus in pregnant and non-pregnant ewes. It was also aimed to clarify the relationship between the echotextural parameters and progesterone (P₄) hormone in this period. A total of 40 Awassi ewes were used in the study, as Group 1 (n=20) not pregnant ewes, and Group 2 (n=20) pregnant ewes. Transrectal ultrasonography was applied on days 4, 7, 10, 13, 15, 16, and 17 after natural mating and the uterus tissue images were recorded. Blood samples were taken for the measurement of progesterone hormone. Measurements were taken on the uterus ultrasonographic images of the mean grayness value (MGV), homogeneity (HOM), and contrast (CON). In the statistical analyses of the data, two-way repeated measures ANOVA were examined with variance analysis and the Pearson test. It was found a time-related significant difference in the echotexture parameters within the groups of the pregnant and non-pregnant ewes in respect of the MGV, HOM, and CON values (P<0.05). The MGV and HOM values in all the days when measurements were taken after natural mating were significantly higher in the non-pregnant ewes compared to the pregnant group (P<0.001). The CON value was significantly higher in the pregnant ewes than the non-pregnant ewes in all days of measurement after natural mating (P<0.001). A time-related statistically significant difference was determined in the serum P₄ within the groups of pregnant and non-pregnant ewes (P<0.001) and it was higher in the pregnant ewes (P<0.001). A significant negative correlation was determined between P₄ and MGV, and between P₄ and HOM, and a significant positive correlation between P₄ and CON. In conclusion, it was found a significant difference between the pregnant and non-pregnant ewes in respect of the echotextural evaluation of the uterus and the measurement of P₄ hormone. In ewes farming, the early determination of pregnancy and early determination of ewes that are not pregnant gives the opportunity for repeat mating, and the evaluation of changes occurring in the uterus by computer-assisted image analysis can be used as an assistive method for providing additional nutrition in pregnant ewes.

Sesame, a polyunsaturated fatty acid (PUFA)-rich oilseed, can be a highly efficient animal feed to enriched ruminants’ milk with unsaturated fatty acids (UFAs). However, oils and oilseeds inclusion in ruminants’ diets can modify lipid metabolism in the mammary gland and affect milk chemical composition. Although the topic has been well-documented in cattle, a limited number of studies are available in small ruminants, particularly in goats. Given that, twenty-four goats (BW = 44.9 ± 5.4 kg) at 80 ± 10 days in milk were split up into three homogeneous groups (n = 8). The control (CON) group was fed a diet with a Forage/Concentrate ratio = 50/50 with no sesame seeds, while the groups S5 and S10 included whole sesame seeds at a level of 5 % and 10 % of concentrates, respectively, by partially substituting both soybean meal and corn grain. Mammary tissues were sampled on the 100th experimental day using a core needle biopsy. Significant increases (p < 0.05) in the gene expression of COX4I1 and AGPAT1 were observed in the S10 group, while none of the gene’s transcription was adversely affected by the whole sesame seed inclusion. In conclusion, sesame seed inclusion in goats’ diet (up to 10 % of concentrate) has a negligible effect on the transcription profile regulating lipid metabolism in the mammary gland.

The growth in demand and demand for quality in the sheep chain has generated the need for automation techniques in the meat industry and the need to obtain responses with greater speed and standardization. The research aimed to predict tissue characteristics of the carcass and commercial cuts based on measurements obtained by VIA – see oimage analysis, carried out on cold carcasses of hairless lambs, using machine learning employing regressive techniques for variable selection. Information from 72 carcasses of castrated male lambs, aged between 8 and 11 months, with an average cold carcass weight of 16.13 ± 3.98 kg, was used. Images of the right side of the carcasses were captured from the dorsal and lateral views using a digital camera. From the ImageJ2 software, VIA data, measurements and shape descriptors (areas, perimeters, widths, lengths, convexities, solidities) were obtained, combined with cold carcass weight and used to generate four sets of data, called descriptor sets (DSs). Obtaining DS1, DS1’, DS2, DS2’, DS3, DS3’, DS4 AND DS4’. To generate these sets, a database was formed and divided into a training bank (with 70% of the observations) and a test bank (30% of the observations). Multiple linear regression models were developed using Stepwise, LASSO, and Elastic Net regression methods, combined with k-fold cross-validation, to evaluate the performance of the models. The accuracy of the estimates was based on RMSE, R², Pearson correlation and bias metrics. For the variables tested in this study, the proposed shape descriptors were mostly efficient in predicting tissue and weight variables. DS1' with the LASSO technique presented the best adjustments for variables total muscle and fat followed by shoulder, loin and rib cuts. The descriptors tested by this study were able to predict with quality the vast majority of the characteristics tested, the variable cold carcass weight (CCW), introduced as additional predictor, promoted a consistent improvement in the fits of all models. DS1 presented greater constancy for the twenty-three predicted characteristics and Stepwise presented the worst predictive performance, in relation to LASSO and Elastic Net. Despite close adjustments between the generated models, in general, Elastic Net presented lower performance than LASSO.

The aim of this study was to compare the efficacy of two doses (700 and 1000 IU) of the native eCG (N-eCG) and a synthetic eCG like glycoprotein (S-eCG) on ovarian superstimulation and embryo production in llamas. Females were examined daily by transrectal ultrasonography until a follicle ≥ 7 mm was observed and a GnRH analogue was injected (i.v.) (Day 0). On Day 3, transrectal ultrasonography was performed to confirm the absence of follicles > 5 mm and animals were randomly divided into four groups (n=10/group): N-eCG700, N-eCG1000, S-eCG700 and S-eCG1000 which received 700 or 1000 IU (i.m.) of N-eCG or S-eCG, accordingly. On Day 7, 112.5 μg of cloprostenol (i.m.) was injected in all llamas. On Day 10, the number of follicles ≥7 mm, mean diameter and their vascularization were determined by ultrasonography. Then, llamas were injected with a GnRH analogue and mated. Natural mating was repeated 24 h later. On Day 18, the number of corpora lutea (CL), their diameter and vascularization were assessed and embryo recovery was performed by uterine flushing. On Day 10, there were no significant differences in the number of follicles ≥ 7 mm, neither in their diameter or vascularization between groups. Similarly, no significant differences were observed in the number of CL on Day 18, neither in their diameter or vascularization between groups. In conclusion, the results of the present study indicate that S-eCG produced by recombinant technology has the same biological activity as N-eCG in llamas.

This study evaluated the effect of including slow-release urea (SRU) coated from the low-trans vegetable fat (LTFV) microspheres in the diet of lambs on fatty acids intake, carcass traits, meat quality, and fatty acid composition of meat. Thirty-two non-castrated Santa Inês lambs (17.98 ± 2.01 kg of initial weight) were used in a randomized complete block design. Experimental treatments included a control which contained 5 g/kg urea (U_0.5%) and three other treatments in which SRU (60% LTFV and 40% urea) was incorporated at 1.25% (SRU_1.25%); 2% (SRU_2.0%) and 3% (SRU_3.0%) of total diet dry matter (DM). The inclusion of SRU in lamb diets increased linearly (P < 0.05) the intake of ether extract, metabolizable energy, and fatty acids. Carcass traits and physical-chemical composition of the Longissimus muscle were not changed by protected urea addition in lamb diet (P > 0.05). The addition of the protected urea in lamb diet linearly increased proportions of CLA and the 18:1 isomer (cis-12, cis-15, and cis-16) compared to U_0.5%. There was a linear increase in branched-chain fatty acid (BCFA) content (P = 0.048) in Longissimus muscle due SRU inclusion. There were a quadratic increases for the sums of trans-MUFA (P = 0.003) and n-6 PUFA (P = 0.046) and total PUFA (P = 0.037) as SRU was added to lambs diet. Adding urea coated into low-trans vegetable fat microspheres increased the lamb intake of most FA and energy dietary, however, without affecting carcass traits and meat physicochemical composition. The inclusion of protected urea (SRU) in the lamb diet quadratically increases trans-MUFA, n-6 PUFA, and total PUFA concentrations in meat, and lambs fed with SRU at level 1.25% in DM total diet presented greater CLA and trans-MUFA concentrations compared free urea (U_0.5%), which is beneficial from the point of view of the lipid quality of the meat and its relationship with consumer health.

Iranian goat breeds, including Markhoz, Adani, and Najdi, are considered as endangered populations because of the downward trend of breeding goats and flocks, habitat loss, using other breeds in reproduction, and the presence of survival-threatening factors. This research aims to investigate the current status and provide the necessary information to conserve these three endangered populations. For this purpose, the census data and the required parameters were collected from the available resources and flocks during the years of the project implementation. Then, two scenarios, the past and future dynamics of the population assuming continuing existing conditions, were simulated using the population viability analysis (PVA) method. Finally, the sensitivity analyses of parameters affecting the viability criteria were done. PVA was conducted using the Vortex simulation program version 10.5.6. The past dynamics simulation of the population showed that the biological parameters and assumptions used in the model have valid and reliable values and frequencies, and they can be used in the simulation of different management scenarios. Based on this scenario, the inbreeding rates (∆F) for the Markhoz and Adani populations have reached above the critical level of 0.5%. The future dynamics simulation of the population showed that the process of increasing inbreeding and decreasing genetic diversity would accelerate, and the breeds' extinction probability would start in 2026, 2033, and 2031 for Markhoz, Adani, and Najdi, respectively. The mean time to the first extinction was also 15.4 ± 2.53, 26.68 ± 3.75, and 13.96 ±1.78 years, respectively. The sensitivity analyses indicated that adult does overharvest, the frequency of feed limitation, and competition with other breeds had the highest effect on the population viability criteria of the investigated breeds. Markhoz, Najdi, and Adani goats need urgent conservation measures. The results obtained in this research may prepare a suitable framework for providing conservation programs.

In small ruminants, photoperiod synchronizes reproductive seasonality, and this environmental factor has been used to stimulate the sexual activity of males and females in months of seasonal sexual rest. However, socio-sexual interactions between males and females can also be used to stimulate the sexual activity of females in the seasonal anestrus. In this review, we describe how photoperiodic treatments can stimulate the sexual activity of bucks and rams in the months of sexual rest. In addition, we describe how sexually active males can be used to stimulate reproduction in goats and sheep in seasonal anestrus or to prevent seasonal anovulation through the classic “short-term male effect”, and or through the newly discovered so-called “long-term male effect”. We conclude with a description of the very recently documented “male-to-male effect”. The “male-effect” is a socio-sexual stimuli caused by the sudden introduction of males and close contact with anestrous females in sheep and goats. After introduction of the male, the levels of pituitary luteinizing hormone (LH) in the blood of females increase quickly (< 10 min), and remain high for at least 4 h. That stimulus triggers the resumption of ovulatory activity in females, which occurs within 48 h. Prior separation of male and females, the intensity of anestrus, and the age, diet, and body condition of females can affect the response of the females to the male introduction. The long-term “male effect” phenomenon consists of a permanent contact of females with males that had been made sexually hyperactive in the usual period of sexual rest by light treatments applied in winter. This stimulation causes strong activity of the hypothalamic-pituitary axis, which releases the gonadotropic hormone LH at a frequency that allows a succession of ovulatory cycles during the anoestrous period as it does in the usual estrous period. The introduction of a male into a group of males in sexual rest stimulates the secretion of LH and testosterone, and their sexual behavior; this has been called the "male-to-male effect" ("buck-to-buck effect" or "ram-to-ram effect"). The intensity of sexual behavior displayed by the stimulatory males influences the responses of bucks and rams in sexual rest to the "male-to-male effect". Moreover, bucks that had been stimulated by the "buck-to-buck effect" are as effective in inducing high ovulatory and estrous activities in females as bucks that had been made sexually hyperactive by the photoperiodic treatment. In conclusion, these effects illustrate the power of socio-sexual relationships in controlling seasonal reproduction in sheep and goats, and shifts their importance in the final control of seasonal reproduction throughout the year compared with photoperiod.

Strongylosis poses a significant threat to goat populations, particularly in humid tropical regions like Kerala, a southern peninsular state in India. This study aimed to compare breed differences in host resistance and resilience to natural strongyle infection between Attappady Black and Malabari goats reared under semi-intensive systems. Additionally, we analyzed the association of a potential single nucleotide polymorphism (SNP) in the Serine Proteinase Inhibitor Clade G member 1 (SERPING1) gene with these traits. Faecal egg count (FEC) and volume of packed red cells (VPRC) were employed as indicators of host resistance and resilience, respectively. Over the course of one year, fortnightly phenotypic data on FEC and VPRC were collected from 109 native goats, including 58 Malabari and 51 Attappady Black goats. The Malabari goats exhibited greater resistance and resilience to strongylosis, evidenced by significantly lower FEC (p≤0.01) and higher VPRC (p≤0.05) compared to Attappady Black goats. Pearson correlation analysis revealed a highly significant negative correlation between FEC and VPRC (r= −0.41, p<0.01). Genotyping of the −312-C>T SNP in SERPING1 gene was conducted using modified bidirectional PCR amplification of specific alleles (Bi-PASA). While the association between SERPING1 genotypes and FEC was not significant, a significant association was observed between SERPING1 genotypes and VPRC (p<0.05). These findings underscore the importance of breed-specific differences in goat resilience to strongyle infection and highlight the potential role of SERPING1 gene polymorphism in modulating host resilience traits.

The alpine grassland ecosystem is characterized by high-altitude, hypoxia, harsh cold and strong radiation conditions, and the unique growth performance and stress resistance of indigenous domestic animals. Maduo sheep, a newly discovered Tibetan sheep breed living in the source area of the Yellow River, is famous for its high-quality wool and meat production. However, its genome and genetic features still need to be deciphered. The genomes of 12 Maduo sheep were sequenced on a genome-wide scale and compared with those of 6 other Tibetan sheep breeds. Population structure analyses revealed that Maduo sheep were distinctly separated from other Tibetan sheep breeds with a higher genetic diversity. Strong selective signatures were detected by the F_ST and XP-CLR results, identifying MREG, RXFP2 and SYNDIG1 in Maduo sheep. To explore the molecular regulation of Maduo sheep adaptability to the high-altitude environment, the muscle tissues of 3 Tibetan sheep populations living at different altitudes (1500 m, 2500 m and 4200 m) were sampled for RNA sequencing. We found 132, 269 and 149 specific transcripts from 1500 m, 2500 m and 4200 m groups respectively. A total of 327 differentially expressed transcripts were found in both 2500 m vs. 1500 m and 4200 m vs. 1500 m comparisons, which were closely related to stem cell differentiation, p38-MAPK cascade, skeletal system morphogenesis, etc. On the other hand, 122 differentially expressed transcripts were found in both 4200 m vs. 1500 m and 4200 m vs. 2500 m comparisons, which should be responsible for adaptive immune response, cytoskeleton, apoptotic regulation and so on. This study provides important genomic insights into the genetic resources of Maduo sheep and could be helpful for understanding the mechanisms of hypoxic adaptability.