Pelibuey Sheep Research Articles

Neural Network-Based Body Weight Prediction in Pelibuey Sheep through Biometric Measurements

This paper presents an intelligent system for the dynamic estimation of sheep body weight (BW). The methodology used to estimate body weight is based on measuring seven biometric parameters: height at withers, rump height, body length, body diagonal length, total body length, semicircumference of the abdomen, and semicircumference of the girth. A biometric parameter acquisition system was developed using a Kinect as a sensor. The results were contrasted with measurements obtained manually with a flexometer. The comparison gives an average root mean square error (RMSE) of 9.91 and a mean R2 of 0.81. Subsequently, the parameters were used as input in a back-propagation artificial neural network. Performance tests were performed with different combinations to make the best choice of architecture. In this way, an intelligent body weight estimation system was obtained from biometric parameters, with a 5.8% RMSE in the weight estimations for the best architecture. This approach represents an innovative, feasible, and economical alternative to contribute to decision-making in livestock production systems.

Haematological parameters of adult Pelibuey ewes under humid tropical conditions in Mexico

The aim of this study was to evaluate the haematological parameters of adult Pelibuey sheep under conditions of the humid tropics of Mexico. Erythrocytes (RBC, x106/µL), haemoglobin (HB, g/dL), haematocrit (HTO, %), mean corpuscular volume (MCV, fL), mean corpuscular haemoglobin (MCH, pg), and mean corpuscular haemoglobin concentration were analysed. (MCHC, g/dL), leukocyte count (WBC, x103/µL) and platelets (PLT, x103/µL) through descriptive statistics of 86 adult, non-pregnant, non-lactating sheep. The values were: RCB 10.35±1.08 x106/µL; HB 10.83 ±1.53 g/dL, HTO 33.97 ±3.79%, MCV 32.78 ±2.49 fL, MCH 10.63 ±1.16 pg, MCHC 32.55 ±3.35 g/dL, WBC 10.75 ±5.78 x103/µL, PLT 340±658 x103/µL. The haematological parameters obtained are within the average values of the species.

Investigating mutations in the genes GDF9 and BMP15 in Pelibuey sheep through the amplification-refractory mutation system with tetra-primers

Single Nucleotide Polymorphisms (SNP) or mutations are variations with a broad distribution in the genome and, as part of genetic studies, SNP allow the identification of allelic variants related to characteristics of economic importance in sheep production. However, the identification of SNP and their genotypes through sequencing is expensive, as it requires specialized materials and equipment. The objective of this study was to identify polymorphisms and their genotypes in the growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) genes in Pelibuey sheep using the tetra-primer amplification-refractory mutation system through polymerase chain reaction (T-ARMS-PCR). DNA extraction and amplification of BMP15 and GDF9 were conducted from blood samples contained in WhatmanTM FTATM cards from 60 multiparous Pelibuey ewes with reproductive records. The T-ARMS-PCR methodology allowed the identification of wild-type genotypes and mutated homozygous genotypes in polymorphisms G4 and G6 of GDF9, whereas mutations in the BMP15 gene were not found. These results were confirmed by sequencing. In conclusion, the T-ARMS-PCR methodology allowed the identification of mutated and wild-type genotypes in SNP G4 and G6 of GDF9, although no mutations were found in BMP15 in Pelibuey sheep. This technique was found to be reliable, rapid, and easily applied to identify polymorphic genotypes.

Effect of aqueous extract of Azadirachta indica leaves on gastrointestinal nematodes in ruminants: an in vitro study

High rates of gastrointestinal parasite infestation lead to the frequent use of anthelmintics for their control, resulting in resistance in the main species of gastrointestinal nematodes. Natural plant extracts, particularly those from Azadirachta indica A. Juss leaves, have been described as having antiparasitic, antimicrobial, insecticidal, antioxidant, and anticorrosive activities, which are related to the diversity of their chemical composition. This research aimed to evaluate the effect of the aqueous extract of A. indica leaves on the control of gastrointestinal nematodes in ruminants. To achieve this, an in vitro test was performed using the larval development assay, with fecal samples obtained from Pelibuey sheep, Criolla goats in the development category, and Criolla calf cattle for the culture of gastrointestinal nematode larvae. Three concentrations (minimum, medium, and maximum) were evaluated for each animal species against Haemonchus placei and Cooperia sp larvae for cattle and Haemonchus contortus, Trichostrongylus sp, and Trichuris for sheep and goats. The survival percentage indicator was evaluated at 0, 24, 48, and 72 h. The research concluded that the minimum concentration was valid for sheep and goats but not for cattle, and the medium and maximum concentrations were effective against all three animal species, resulting in 100% larval mortality. Keywords: Azadirachta, drug effects, Ruminants, Trichostrongyloidea

Predictive biometrics of hair sheep through digital imaging

Direct collection of biometric measurements (BM) from sheep is an expensive and stressful procedure for animals; instead, indirect and novel methods have recently been used. The objective of this study was to use digital image analysis (DIA) to predict biometric measurements of Pelibuey sheep as a non-invasive approach under on-farm conditions. Withers height (WH), body length (BL), body diagonal length (BDL) and rib depth (RD) were predicted in Pelibuey ewes using DIA. Images were taken from the left flank from 65 non-pregnant and non-lactating Pelibuey ewes using a digital camera and analyzed by DIA. The BM determined from both in vivo and by DIA presented a positive and moderate (P <0.05) correlation coefficients (r) of 0.43, 0.66, 0.73 and 0.75 for BL, BDL, WH and RD, respectively. Regression equations from BM by DIA had a determination coefficient (R2) of 0.19, 0.44, 0.54 and 0.56 for BL, BDL, WH and RD, respectively. The equations developed were from low to moderate precision (R2 = 0.18 to 55), moderate to high accuracy (Cb > 0.69) and low to moderate reproducibility index (> 0.30). Overall, the use of DIA was able to predict the BM in Pelibuey ewes with low to moderate precision and accuracy. Factors affecting the accuracy and precision of this relationship should be further investigated.

Administración de lutropina (r-hLH) y su respuesta en la tasa ovulatoria y embriones viables en ovejas Pelibuey

Objective. To evaluate the influence of lutropin alfa (recombinant human LH, r-hLH) administered at 12 and 24 h post-progesterone device removal (CIDR) on the response of hours to the onset of estrus, ovulatory rate, unfertilized oocytes, transferable embryos and plasmatic levels of LH, in a multiple ovulation protocol based on FSHp in Pelibuey sheep. Materials and methods. Eighteen sheep of Pelibuey sheep were used, which were randomly distributed into three treatments (n=6): T1 (200 mg FSHp-Folltropin®); T2 (200 mg pFSH + 75 IU r-hLH at 12 h post-CIDR withdrawal) and T3 (200 mg pFSH + 75 IU r-hLH at 24 h post-CIDR withdrawal). Results. Hours from start to estrus and ovulatory rate (OR) no significant differences were found. In unfertilized oocytes (UO) it was higher (p<0.05) in T2 (5.0 ± 2.3) compared to T1 (0.8 ± 0.6) and T3 (1.3 ± 0.7). The number of Quality 1 Embryos (Q1E) was higher (p<0.05) in T3 (3.1 ± 1.1) compared to T1 (1.1 ± 0.3) and T2 (0.6 ± 0.5) and for Transferable Embryos (TE) it was higher (p< 0.05) for T3 (6.6 ± 0.9) in relation to T2 (2.0 ± 1) and T1 (4.0 ± 0.6). Conclusions. The application of r-hLH 24 h after removing the CIDR increases plasma levels of LH, in effect, the number of unfertilized oocytes is reduced, and the number and quality of transferable embryos in Pelibuey sheep are improved.

Effect of Guazuma ulmifolia tannins in the diet of Pelibuey lambs on animal performance and meat characteristics

The objective of this experiment was to evaluate the response of animal performance and meat characteristics of Pelibuey lambs to tannins of Guazuma ulmifolia Lam. in the diet. Twenty-eight male Pelibuey lambs (initial body weight of 23.6 ± 1.0 kg; 5 months old) were randomly assigned to one of four treatments (T): T1, control (base diet); T2, diet 1.5% tannins; T3, diet 2.5% tannins; and T4, diet 1000 IU vitamin E. Vitamin E was used as a positive control treatment. The variables evaluated were daily weight gain (DWG), dry matter intake (DMI), feed conversion, and carcass and meat characteristics. The experimental design was completely randomized, and treatments means were compared with Tukey test (P<0.05). None of the evaluated variables were different between treatments (P>0.05), except meat color (P<0.05), with higher values of L*(34.88), a*(11.49), and b*(2.28) when tannins were added to the diet of the lambs, without affecting the dry matter intake. Including Guazuma ulmifolia foliage in sheep feeding could be a feasible alternative.
 Keywords: Carcass dressing; Guazuma; Meat quality; Pelibuey sheep; Tannin

Relação entre o peso corporal e a circunferência escrotal em ovinos Pelibuey em crescimento criados em condições tropicais

ABSTRACT The body weight (BW) of an animal is a vital economic trait that might help in decision-making in the handling of animals. The objective of the present study was to develop equations for the prediction of BW in Pelibuey sheep using scrotal circumference (SC). The BW (23.40 ± 6.96 kg) and SC (20.25 ± 6.19 cm) have been recorded in 405 male Pelibuey at the Southeastern Center for Ovine Integration, Mexico. Linear, logarithmic, quadratic, exponential, cubic, and power regression models were used for data analysis. Pearson correlation (R), Coefficient of determination (R2), Adjusted coefficient of determination (Adj.R2) Root mean square error (RMSE), Akaike information criterion (AIC), and Bayesian information criterion (BIC) were used to select the best model. Power regression model showed the highest R (0.93), R2 (0.86), Adj.R2 (0.86) and lowest RMSE (0.02), AIC (-989.44) and BIC (-981.44). The current study suggests that SC might be used as the only predictor for BW of growing Pelibuey sheep raised under tropical conditions.

Relationships between body mass index, ultrasound measurements and, internal body fat depots in pelibuey sheep

The objective of this study was to evaluate the relationship between body mass index (BMI), ultrasound measurements (USM), and internal fat (IF) in hair sheep. The BMI and USM were determined 24 hours before laughter in 35 animals finished in intensive fattening. At slaughter, the IF (inner adipose tissue) was dissected, weighed, and grouped as mesenteric, omental, or perirenal fat; these three depots were summed to obtain their total weight. The relationship of the variables was evaluated through Pearson's correlation coefficient (r) using the CORR procedure and by regression models using the REG procedure of SAS ver. 9.3. The IF and BMI presented r= 0.75 (P <.0001), while the IF and USM presented an r that varied from 0.70 to 0.80 (P <.0001). Among the internal fat deposits, the perirenal was the one that presented minor correlation coefficients with BMI (r = 0.55), subcutaneous fat thickness (0.55), and thoracic Longissimus dorsi area) (r = 0.33), and for this, the last correlation was not significant (P>0.05). The regression equation between IF and BMI had a coefficient of determination (r2) of 0.67 (P <.0001). The inclusion of the subcutaneous fat thickness together with the BMI improved the r2 with a range of 0.77. The BMI and the subcutaneous fat thickness could be used to predict the weight of the internal fat in hair sheep.

Molecular markers for thermo-tolerance are associated with reproductive and physiological traits in Pelibuey ewes raised in a semiarid environment

Pelibuey sheep exhibit reproductive activity through the year, but warm weather lowers their fertility and demonstrates physiological limitations of environmental heat stress. Single nucleotide polymorphisms (SNPs) associated with heat stress tolerance in sheep have been reported previously. The objective was to validate the association of seven thermo-tolerance SNP markers with reproductive and physiological traits in Pelibuey ewes raised in a semiarid region. Pelibuey ewes were assigned to a cool (January 1st.– March 31st.; n = 101) or warm (April 1st.– August 31st.; n = 104) experimental group. All ewes were exposed to fertile rams and assessed for pregnancy diagnosis 90 days later; lambing day was reported at birth. These data served to calculate the reproductive traits of services per conception, prolificacy, days to estrus, days to conception, conception rate and lambing rate. Rectal temperature, rump/leg skin temperature and respiratory rate were measured and reported as physiological traits. Blood samples were collected and processed to extract DNA, which was genotyped using the TaqMan allelic discrimination method and qPCR. A mixed effects statistical model was used to validate associations between SNP genotypes and phenotypic traits. The SNPs rs421873172, rs417581105 and rs407804467 were confirmed as markers associated with reproductive and physiological traits (P < 0.05), and these SNPs were in the genes PAM, STAT1 and FBXO11, respectively. Interestingly, these SNP markers resulted as predictors for the evaluated traits but only in ewes from the warm group, which indicated their association with heat-stress tolerance. An additive SNP effect was confirmed with the highest contribution (P < 0.01) of the SNP rs417581105 for the evaluated traits. Reproductive performance improved (P < 0.05) and physiological parameters decreased in ewes carrying favorable SNP genotypes. In conclusion, three thermo-tolerance SNP markers were associated with improved reproductive and physiological traits in a prospective population of heat-stressed ewes raised in a semiarid environment.

Evaluation of Resistance and Susceptibility to Prion Diseases in Pelibuey Sheep from Mexico

Abstract Transmissible spongiform encephalopathies (TSEs) are a group of neurodegenerative diseases with a chronic and fatal course, which are caused by a misfolded form of the cellular prion protein that is encoded by the host. The purpose of this work was to evaluate the resistance and genetic susceptibility to prion diseases in Pelibuey sheep from Mexico. The sequences of 99 Pelibuey sheep from the central and southwestern regions of Mexico were analyzed to determine the polymorphisms related to resistance and genetic susceptibility to scrapie, the Hardy-Weinberg equilibrium test and the D-Tajima test was used to identify the effect of evolutionary forces on the PRNP gene. Twelve non-synonymous polymorphisms Q101R, M112T, A116P, G127A, A136V, M137T, L141F, H143R, R154H, Q171R, Q171H, N176K were detected, in addition two synonymous substitutions 231R (agg/cgg) and 237L (ctc/ctg) were found. As a result of the sequence analysis, the ARR allele was not under the Hardy-Weinberg equilibrium, indicating that there is an evolutionary force at work, and the D-Tajima suggest the existence of purifying genetic selection. In conclusion, Pelibuey sheep exhibit genotypes for the PRNP gene that make them resistant to developing classic scrapie; at least 98% of the population is a carrier of an allele related to scrapie resistance; while for atypical scrapie there is a very high probability that an outbreak occurred in the herds, since the ARQ allele in combination with the L substitution at codon 141 confers susceptibility to carrier sheep.

A novel model for estimating the body weight of Pelibuey sheep through Gray Wolf Optimizer algorithm

ABSTRACT Weight prediction in live animals remains challenging. Several studies have been carried out trying to predict the body weight in livestock through morphometric measurements, the Schaeffer's model is one of them. However, the fit of those studies in small ruminants is not well covered. Therefore, a novel model to predict the weight of Pelibuey sheep through morphometric measurements and the Gray Wolf Optimizer algorithm is presented. The model involves calculating the volume of the specimen through a truncated cone and leaving density as an estimation parameter of the algorithm. Also, two alternative models were made where the original Schaeffer's model was optimized. The modified models from the original Schaeffer's formula showed improvements up to 22.61% in R-squared and decreases up to 33.48% in RMSE. However, the truncated cone model had the best estimates, with an RMSE of 2.57, R-squared of 89.02%, and the lowest AIC. This represented a 25.13% improvement in R-squared and a 38.31% reduction in the RMSE. The model is expected to improve its efficiency if the cattle sample is larger, and it is also intended to be implemented in animals of other proportions.

Reduction of enteric methane production with palm oil: Responses in dry matter intake, rumen fermentation and apparent digestibility in sheep

The aim of the trial was to assess the effect of palm oil (PO; Elaeis guineensis Jacq.) in a basal ration of low-quality Pennisetum purpureum grass on DMI, enteric CH4 emissions, rumen fermentation and apparent digestibility in hair sheep. Eight non-castrated male Pelibuey sheep with an average live weight (LW) of 28 ± 1.1 kg housed in metabolic crates inside respiration chambers, were used in a replicated 4 × 4 Latin square design. Each period lasted 18 days (13 days for adaptation to handling and rations, and 5 days for measurements of response variables). A control (CON) ration and three PO levels were evaluated: 20, 40 and 60 g/kg as a percentage of dry matter (DM) in the ration. The basal ration had a 70:30 forage:concentrate ratio (DM basis). Individual DMI was measured daily. Measurement of apparent digestibilities of nutrients was carried out by total collection of feces. Samples of rumen liquor were taken postprandial from sheep, subsequently, the molar proportion of VFA was determined. Enteric CH4 production (L/d) was measured using head boxes. Average intakes of DM per day (855 g/d), DM/kgW0.75 (64 g/d), organic matter (OM; 809 g/d) and crude protein (CP; 106 g/d) were not affected by treatment (P > 0.05). Neutral detergent fiber (NDF) and crude fat (CF) intake were reduced linearly (P < 0.05) as the percentage of PO in the ration was increased. Apparent digestibilities of DM, OM and NDF were not affected by the inclusion of PO (P > 0.05). Molar proportion of propionic acid in the rumen increased linearly as the level of PO inclusion in the ration was augmented (P < 0.05). The acetic:propionic acid ratio decreased linearly (P < 0.01) from 2.02 for the control ration to 1.66 for the ration with 60 g/kg PO. Enteric CH4 emissions decreased with increasing levels of PO in the ration (P < 0.01). Energy loss (MJ/d) as CH4 was reduced (P < 0.01), as well as methane energy loss as a proportion of gross energy intake (Ym; P < 0.01) and CH4 emission per year (EF; P < 0.01). Results demonstrate that PO is a promising by-product for mitigating CH4 emissions in hair sheep fed low-quality tropical grasses, with reductions of up to 14.1 %, without negative effects on DMI, nutrient intake and ration digestibility.

Comparison of mathematical models to estimate live weight through heart girth in growing Pelibuey sheep

Background: Assessment of animal growth based on live weight (LW) in traditional sheep production systems is limited by the high cost of purchase and maintenance of livestock scales. Objective: To develop and evaluate equations for LW prediction using heart girth (HG) in growing Pelibuey sheep. Methods: A dataset (n=415) of clinically healthy male Pelibuey sheep from two months to one year of age, with an average LW of 25.96 ± 10.25 kg and HG of 68.31 ± 10.53 cm, were used. Three equations were evaluated: LW (kg) = −37.70 + 0.93 × HG (Eq. 1); LW (kg) = −1.74 + 0.19 × HG + 0.008 × HG2 (Eq. 2); and LW (kg) = 0.003 × HG2.68 (Eq. 3). Results: The correlation coefficient between LW and HG was r = 0.94 (p&lt;0.001). The three equations showed a high concordance correlation coefficient (CCCs≥0.97). However, the random error was the main component of the mean square partition of the prediction error (≥82.78%) only for Eqs. 1 and 2. The test for parameter identity (intercept=0; slope=1) was accepted only for Eq. 2 (p&gt;0.05). On the other hand, for Eqs. 1 and 3 the intercept was different from zero and the slope was different from one (p&lt;0.05). Conclusion: The second-degree equation accurately and precisely estimated body weight of growing Pelibuey sheep using the HG as a sole predictor variable.

Runs of Homozygosity and Gene Identification in Pelibuey Sheep Using Genomic Data

The runs of homozygosity (ROHs), the inbreeding coefficient, and the effective population size (Ne) in Pelibuey sheep were analyzed in 24 Pelibuey ewes from two lambs at parturition and 24 ewes that gave birth to a single lamb using the Ilumina OvineSNP50 BeadChip. The Ne decreased from 535 to 192 in the first ten generations. A total of 2194 ROHs were identified on the basis of single nucleotide polymorphisms (SNPs), were identified in the prolific group and 2185 SNPs in ROH in the non-prolific group. The distribution of the lengths of the ROH, considering both groups, were found to be: 4065 less than 6 Mb, 213 between 6 and 12 Mb, 72 between 12 and 24 Mb, twenty between 24 and 48 Mb and 8 greater than 48 Mb. In prolific sheep, the ROH associated with prolificacy were identified near the LINGO2, FLRT2, ADGRB3 genes, related to “positive regulation of synapse assembly”; and the DGKG, DGKE, DGKB and DGKI genes, related to “protein kinase C-activating G-protein coupled receptor signaling pathway”. The present work present genes that can function as signal mediators or have activity in embryonic development, which is relevant to the economic activity of this species.

Estimation of milk yield based on udder measures of Pelibuey sheep using artificial neural networks

Udder measures have been used to assess milk yield of sheep through classical methods of estimation. Artificial neural networks (ANN) can deal with complex non-linear relationships between input and output variables. In the current study, ANN were applied to udder measures from Pelibuey ewes to estimate their milk yield and this was compared with linear regression. A total of 357 milk yield records with its corresponding udder measures were used. A supervised learning was used to train and teach the network using a two-layer ANN with seven hidden structures. The globally convergent algorithm based on the resilient backpropagation was used to calculate ANN. Goodness of fit was evaluated using the mean square prediction error (MSPE), root MSPE (RMSPE), correlation coefficient (r), Bayesian’s Information Criterion (BIC), Akaike’s Information Criterion (AIC) and accuracy. The 15–15 ANN architecture showed that the best predictive milk yield performance achieved an accuracy of 97.9% and the highest values of r2 (0.93), and the lowest values of MSPE (0.0023), RMSPE (0.04), AIC (− 2088.81) and BIC (− 2069.56). The study revealed that ANN is a powerful tool to estimate milk yield when udder measures are used as input variables and showed better goodness of fit in comparison with classical regression methods.

Effect of short-term radiation stress on physiological and hematological parameters in Pelibuey sheep in Cuba

Projections of warming temperatures as a consequence of climate change will have impacts on food production globally. This heat stress coupled with increased solar radiation, will affect the well-being of livestock. In many regions of the world, local breeds are reared as they demonstrate improved tolerance to local conditions resulting in minimal effects on production when compared with commercial breeds. However, it is still critical to assess the consequences of increased heat and radiation stress on local breeds to ensure that on-farm productivity is not adversely affected. This short communication describes the effects of radiation intensity during daylight on Pelibuey sheep (intact male calves). Three treatments were tested: control (no shade; ≈ 50 lux at 14:00 h), one layer of shade mesh (≈ 35 lux at 14:00 h), and two layers of shade mesh (≈ 15 lux at 14:00 h). Increasing radiation resulted in a decline in sheep body weight from 18 kg to 16 kg. Only animals exposed to 15 lux were capable of gaining in body weight. Exposure to elevated radiation increased the respiratory rate of animals from 130 respirations per min at the lowest exposure level to a maximum of 170 respirations per min in animals kept at 50 lux. The rectal temperature of animals remained consistent (approximately 40 °C) irrespective of the level of radiation. In contrast, the temperature measured at the head, back and thigh were all similarly affected by radiation. In terms of the hematological parameters measured, radiation stress did not affect the concentrations of hemoglobin or hematocrit. There was a non-significant decrease in the concentration of lymphocytes from 58% to 52%. However, neutrophils showed an increasing trend from 42% in animals at the lowest radiation level to a maximum of 51% in animals exposed to the highest stress level. The concentrations of leukocytes were similar in animals kept at 15 and 35 lux and were significantly elevated in those at 50 lux. Serum proteins and CAT concentrations were not affected by the different levels of radiation tested. However, SOD specific activity significantly declined from 11 to 8 U mg−1 protein in animals exposed to 15 and 50 lux respectively. To the best of our knowledge, this is the first report on the response of Pelibuey sheep to short-term radiation stress under Cuban conditions.

Residual Feed Intake and Rumen Metabolism in Growing Pelibuey Sheep.

This study was carried out to evaluate the residual feed intake (RFI), volatile fatty acid (VFA) production and enteric methane (CH4) from growing Pelibuey sheep. In this case, 12 non-castrated Pelibuey with an initial average live weight (LW) of 21.17 ± 3.87 kg and an age of 3 months, were housed in individual pens and fed a basal diet with 16% of crude protein and 11 MJ ME for 45 days. Dry matter intake (DMI) was measured and the daily weight gain (DWG) was calculated using a linear regression between the LW and experimental period. Mean metabolic live weight (LW0.75) was calculated. RFI was determined by linear regression with DWG and LW0.75 as independent variables. Lambs were classified as low, medium, and high RFI. Feed efficiency was determined as DWG/DMI. For determining rumen pH, ammonia nitrogen concentration NH3-N), and VFA, ruminal fluid was obtained using an esophageal probe on day 40. Feed intake of low RFI lambs was approximately 16% lower (p &lt; 0.05) while growth rate was not significantly different. Their average energy loss, expressed as CH4 production per kilogram of metabolic weight, was 17% lower (p &lt; 0.05).

MOLECULAR ANALYSIS OF FECGH GENE IN HAMDANI SHEEP BREED IN IRAQI KURDISTAN REGION

The objective of this study was to investigate association between FecGH-GDF-9 gene polymorphism and litter size in Hamdani fat-tailed sheep. The genomic DNA was extracted from eighty-seven blood samples of Hamdani ewes. The FecGH-GDF-9 locus was detected by PCRs, and identified DNA genotyped by DNA sequencing. The evaluate several parameters included fertility (%), conception (%), letter size at birth, twining rate (%), triple rate (%), barrenness (%) and productivity (%) were measured and arrived 91.95, 95.40, 1.825, 150, 11.25, 8.05 and 159.77, respectively. The blast tree view results in NCBI blast show Hamdani sheep is more closely to Norway white face sheep, Han sheep and Pelibuey Sheep breeds which have high litter sizes than the Iranian Ghezel sheep. Hamdani ewe’s genome have three changed nucleotides point at 1273 bp (C to G) changed Alanine to Arginine, 1281 bp (A to T) changed lysine to Isoleucine and 1344 bp (C to A) changed Proline to Glutamine. Also three nucleotides deletion were detected at 1279 bp (C), 1283 (T) and 1376 bp (G) position with two inserted nucleotides at 1319 bp (T) and 1357 bp (G) position. The 5'….C/TNAG…3' sequence cite of mutated FecGH locus was detected by Ddel restriction enzyme which have significant effect on litter size in sheep breeds.

Impacts of short-term water restriction on Pelibuey sheep: physiological and blood parameters

One of the projected effects of climate change is a reduction in rainfall in certain regions of the world. Hence, the agricultural and livestock sectors will have to cope with increasing incidences of water shortage while still maintaining productivity levels to feed an ever increasing global population. This short communication reports on the effect of a 2-week water stress on Pelibuey sheep in Cuba. Three treatments were compared, viz. supply of water ad libitum, water supplied once every 3 or 6 days. Following exposure to the water stress, the results showed no changes in sheep body weight or rectal temperature. However, respiration frequency was affected with water stress causing a reduction from 23.3 to 13.3 respirations per min in control and water-deprived animals, respectively. Furthermore, there was evidence for hemoconcentration in response to water stress (levels of hemoglobin increased from 9.2 to 13.1 g L-1 and hematocrits from 27.6 to 39.3% in the control group and animals restricted to water once every 6 days. The imposed water stress was also evident in the reduction of lymphocytes (from ±63 to 43%), and in increase of neutrophils (from approximately 38 to 54%) and leukocytes (from 3133 to 4933 per mm3). The results indicated a decline in the levels of antioxidants, i.e., SOD from approximately 13 to 10 U mg-1 protein and CAT activity from 23 to 9 U mg-1 protein. To the best of our knowledge, this is the first report on the response of Pelibuey sheep to short-term water shortage stress under Cuban environmental conditions.