A study on the genetic and phenotypic factors affecting specific ewe productivity traits in Sangsari sheep.

The study's objectives were to assess the genetic parameters of reproductive characteristics in Sangsari sheep. A data set of reproductive information with pedigree details from 1995 to 2016 was used. Studied traits were litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB), litter mean weight per lamb weaned (LMWLW), total litter weight at birth (TLWB) and total litter weight at weaning (TLWW). Test significance of the environmental factors to be included in the model was conducted using the general linear model procedure of the SAS program. All traits were significantly affected by the year of lambing and ewe age at lambing (P < 0.01). The AI-REML procedure of the Wombat program was used to evaluate genetic parameters. A series of bivariate animal models were employed to calculate genetic (rg) and phenotypic (rp) correlations between traits. The total least square means ± standard error of LSB and LSW were 1.04 ± 0.05 and 0.96 ± 0.03, while LMWLB, LMWLW, TLWB, and TLWW were 3.12 ± 0.08, 15.40 ± 0.13, 3.28 ± 0.04, and 19.31 ± 0.16 kg, respectively. The estimates of h2 were relatively low (P < 0.01) and ranged from 0.063 ± 0.028 for LSW to 0.181 ± 0.063 for TLWW. Repeatability estimates varied from 0.101 for LSW to 0.241 for TLWW. The sire service effects for LMWLB, TLWB, and TLWW were 0.012 ± 0.004, 0.023 ± 0.006, and 0.039 ± 0.009, respectively. The traits studied showed a greater magnitude of genetic correlation than phenotypic correlation, with values ranging from - 0.59 (LSB-LMWLB) to 0.87 (LMWLB-TLWB). It appears that focusing on TLWW for selection could result in more significant improvements in the reproductive performance of Sangsari ewes.

The effect of Vachellia eriolaba leaf meal inclusion on growth performance, blood parameters and methane gas emission in lambs fed diets containing ammoniated maize stover.

The study evaluated the effect of Vachellia erioloba leaf meal in diets containing ammoniated maize stove on growth performance, methane emission and heath of growing lambs. Thirty-two female lambs were allocated to the following four dietary treatments: total mixed ration (TMR, control), 20% inclusion of untreated maize stover (UMS), 20% inclusion of ammoniated maize stover (AMS), and combined inclusion of 10% ammoniated maize stover and 10% Vachellia erioloba leaves (AMSVL). Each treatment was replicated 8 times and a lamb in an individual pen was regarded as an experimental unit in a completely randomized design. Feed intake was higher (P < 0.05) in lambs fed the AMS and AMSVL diets compared to those fed UMS. Final body weights were higher in lambs fed the AMS and AMSVL diets. Both average daily gain (ADG) and feed convention ratio (FCR) were not affected by diet. In comparison with the AMS and AMSVL diets, the lambs fed the UMS diet had the highest (P < 0.05) methane emission. Overall, lambs fed the control diets had the lowest (P < 0.05) methane gas emission. Blood hematological values were affected by diet with the AMSVL fed lambs having the highest (P < 0.05) mean platelet volume (MPV) and procalcitonin (PCT) values. Furthermore, total albumin, amylase and total bilirubin were the highest (P < 0.05) in lambs fed on the AMSVL diet. Lambs fed on AMS diet had the highest (P < 0.05) serum urea levels. It can be concluded that combined inclusion of ammoniated maize stover and Vachellia leaves improved feed value and lamb performance when compared to the individual inclusion of both UMS and AMS.

Determination of the nutritional potential and valorization of saffron (Crocus sativus L.) wastes as an antioxidant agent in ruminant feeding: in vitro and in vivo studies.

Saffron (Crocus sativus L.) is a plant known for its diverse medicinal and nutritional properties, which has adapted well to arid and semi-arid regions of the world, particularly in the Middle East. Research on saffron wastes (SW) as a dietary additive for small ruminants is limited. Therefore, two primary experiments were designed to evaluate the nutritional potential of SW. In the first trial, the nutritional value of SW collected from various regions in northeast Iran was assessed through proximate analysis and in vitro procedures. In the second trial, the effects of incorporating SW (a 1: 1 mixture from all regions, w: w) at two levels (30 and 60 g/day) into the diets of Afshari male lambs were investigated in comparison to a control diet. Except for dry matter and ether extract contents, other chemical and mineral compounds varied among the SW collected from different regions. The samples displayed diversity in potential gas production and estimated dry matter intake (DMI). In the in vivo experiment, DMI, nutrient digestibility, and most blood metabolites were not significantly affected by the addition of SW; however, malondialdehyde, total antioxidant capacity, and cholesterol levels were respectively decreased, increased, and decreased in lambs fed 60 g SW/day compared to the control group. Overall, SW collected from various regions demonstrated different nutritional values. Although the dietary inclusion of SW at the level of 60 g/day did not adversely effect on DMI, nutrient digestibility, or certain blood metabolites, it is suggested for its potential improvement in lambs' health indicators. Long-term studies are recommended for future SW evaluation in vivo.

Selenium efficiency in protecting sperm quality and testicular parameters of South African indigenous Zulu rams exposed to heat stress.

The study investigated selenium's (Se) efficiency in preserving South African Zulu rams' sperm quality and testicular parameters when they were exposed to heat stress. Indigenous Zulu rams (20) between 2 and 5 years old were allocated into four groups, namely the Se, testicular heat stress (THS), selenium plus testicular heat stress (SeTHS), and control. Each group comprised five rams; the groups were balanced according to the rams' body weight and scrotal circumference. The Se and SeTHS groups received sodium selenite orally bi-weekly for 5 months. To induce heat stress, testicular heat insulation bags were wrapped around the testes of the rams receiving the THS and SeTHS treatments for 49 days. Semen was collected from the rams weekly from the third month onward; the first two months were for Se & THS acclimatization. In addition, testicular measurements were taken bi-weekly. Analysis of variance was used to analyze the sperm quality data. Duncan's multiple range test was used to compare the groups' data for significant differences. The results showed that the Se-supplemented rams' scrotal circumference was smaller (p < 0.05) compared with the other groups. The Se, SeTHS, and control groups demonstrated similar total sperm motility; in contrast, the THS and SeTHS groups recorded low and high total sperm motility, respectively, compared with other treatment groups (p < 0.05). The semen from the rams that received THS without Se displayed a significantly higher number of immotile sperm cells (p < 0.05) and poor sperm quality, including total and progressive motility, and kinematic parameters when compared with other treatments, suggesting that Se protects sperm against THS. We concluded that selenium protected some sperm parameters (TSM, PSM, MV, VCL, VSL) of THS- treated rams while others did not improve (RV, NSM, C, STR).

Shrinkage and tree-based regression methods for the prediction of the live weight of Akkaraman sheep using morphological traits.

The prediction of live weight (LW) is of critical importance to farmers in a range of applications, including breeding and monitoring animal growth. In this context, Ridge, Least Absolute Shrinkage and Selection Operator (LASSO), and Elastic Net as shrinkage methods, and Classification and Regression Trees (CART) and Random Forest (RF) as tree-based regression methods were used in this study to predict LW of Akkaraman Sheep at 6-month age using sex, birth weight (BW) and some morphological traits such as withers height (WH), chest depth (CD), body length (BL), chest width (CW), rump height (RH), and chest circumference (CC). The dataset of 100 sheep, consisting of 44 males and 56 females, was randomly divided into training and test sets with a ratio of 80% and 20%, respectively. 10-fold cross-validation method was implemented using the training set to obtain optimum regression models and avoid overfitting. A test set was used to compare the prediction performance of regression methods based on various comparison criteria. Results revealed that LW was significantly correlated with all morphological traits and BW with coefficients ranging from 0.216 to 0.757. RF outperformed the other regression models with a coefficient of determination value (R2) of 0.865, followed by Ridge (R2 = 0.761), LASSO (R2 = 0.755), Elastic Net (R2 = 0.750), and CART (R2 = 0.654). The results indicated that WH and CD contributed the most, while sex and BW contributed the least in constructing the optimum RF model. In conclusion, the use of RF is recommended for predicting the LW of Akkaraman sheep. These results can provide a data-driven approach to improve decision-making in animal breeding.

Detection of putative loci affecting milk yield in Turkish Awassi sheep using microsatellite markers.

On the basis of comparisons between bovine and ovine genome mapping information, the aim of the study was to analyze the genetic diversity of selected DNA microsatellites from the bovine genome and to investigate their correlation with the average daily milk yield in Awassi sheep. 18 informative microsatellite markers were selected from the significant QTL regions affecting milk yield identified in the bovine genome in previous studies. The selected microsatellite markers were then amplified by PCR as reciprocal amplifications on the genomic DNA of Awassi sheep, with standard daily milk yield records. Thus, in this study, 18 microsatellite markers associated with milk yield in the bovine genome were examined for both determination of genetic polymorphism within the flock and the effects of marker loci on average daily milk yield in Awassi sheep. Allele frequencies of markers were determined based on the results of fragment analysis. The analysis of variance showed that the 123 bp allele at the marker locus BMS1341 on BTA2 significantly influenced the average daily milk yield of Ivesi sheep (P < 0.01). On the other hand, the BMS381 locus with a 115 bp allele on BTA2, the MCM140 locus with a 185 bp allele on BTA6, the BMS2721 locus with a 155 bp allele, the BM1237 locus with 174 and 180 bp alleles on BTA7, and finally, the BMS1967 locus with a 117 bp allele, the BM4208 locus with 176 and 182 bp alleles, and the INRA locus with a185 bp allele on BTA8 showed moderately significant effects on the average daily milk yield of Ivesi ewes (P < 0.05).

Media viscosity affects post-thaw ram sperm rheotactic behaviour.

The aim of this experiment was to assess the effect of media viscosity on ram sperm motility, kinematics and rheotaxis in vitro by using methylcellulose as a media thickener. Frozen-thawed semen of three rams was thawed and diluted in Tyrode's albumin lactate pyruvate (TALP) media supplemented with 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6% and 0.7% w/v of methylcellulose. Sperm motility and kinematic characteristics were analysed using computer-assisted sperm analysis (CASA). The rheotactic behaviour was assessed in a microfluidic channel, and the number of spermatozoa that passed the 10 mm point of a microfluidic channel over a 2min period against a flow rate of 30 µm/sec was assessed. The use of media with higher viscosity (higher levels of methylcellulose) resulted in significantly lower (p < .05) sperm motility and kinematic parameters. Moreover, higher levels of methylcellulose reduced (p < .05) the number of spermatozoa that exhibited positive rheotaxis. In conclusion, viscosity affected the kinematic properties and rheotactic behaviour of ram sperm.

Optimizing sheep growth curves using a meta-heuristic algorithm.

Sheep were among the first animals domesticated by humans, and to this day, small ruminants are primarily raised for their meat, milk, and wool. This study evaluated the goodness of fit for growth curve models using observed age and weight data from crossbred lambs of various breeds based on the mean values between paired breeds. We employed a hybrid metaheuristic algorithm, combining a simulated annealing (SA) algorithm and a genetic algorithm (GA) called SAGAC, to determine the optimal parameter values for growth models, ensuring the best alignment between simulated and observed curves. The goodness of fit and model accuracy was assessed using the coefficient of determination (R2), Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Mean Absolute Percentage Error (MAPE). Errors were measured by comparing the criteria differences between simulated and observed data. Thirty crossbreed combinations were simulated, considering the average weight. Analysis of the observed and simulated growth curves indicated that specific crossbreeding scenarios produced promising results. This simulation approach is believed to assist geneticists in predicting potential crossbreeding outcomes, thereby saving time and financial resources in field research.

The Effects of Concentrate Supplement Levels on Feed Utilization and Red Meat Production of Blackhead Somali Sheep Fed Natural Pasture Grass Hay as a Basal Diet.

BACKGROUND: In recent years, consumers have become aware of their health, and their preference has been rapidly changing to consume less fatty meat. Therefore, devising a strategy to produce lean meat is a concern in this study. One of the strategies, among others, for lean meat production is controlling the amount of supplements given to sheep. Hence, muscle (lean) and adipose tissue (fat) require different amounts of energy to lie down. OBJECTIVES: This study was conducted to evaluate the effects of concentrate supplementation levels on feed utilization and red meat production in Blackhead Somali sheep (BHS) fed natural pasture grass hay as a basal diet. MATERIALS AND METHODS: A total of 16 BHS sheep weighing 19.5 ± 0.2 kg (mean ± SE) at the beginning of the experiment were kept for 90 days by feeding two levels (1% [T1] and 1.75% [T2] body weight [BW] of sheep) of supplement. The sheep were blocked according to their initial BW (IBW), and the supplements were randomly assigned within a block. At the end of the feeding period, all sheep were slaughtered, and carcass and non-carcass data were recorded. Data were analysed using the SAS software version 9.1 of PROC GLM programme. RESULTS: Sheep fed T1 and T2 consumed 6.1 and 8.2 MJ/day metabolizable energy (ME), respectively, and 73.1 and 93.6 g/day crude protein (CP), in that order. Consequently, sheep fed T2 produced 1.37 kg extra BW by growing an average rate of 15 g/day greater (p < 0.0001) over their counterpart fed T1. They also produced 0.9 kg, 0.8 cm2 and 2.64% heavier carcasses, a wider rib eye area and a higher intramuscular fat content (p < 0.0001), respectively, over the sheep fed T1. On the other hand, the lean-to-fat ratio was significantly lower in sheep fed T2 than T1. In most parameters considered in this study, sheep fed T2 (1.75% BW) were superior, but its intramuscular fat (IMF) content was much higher than the limit that the consumers needed. CONCLUSION: Therefore, it can be concluded that 1% BW supplementation is enough for BHS to produce lean meat containing the optimal fat content in stall feeding condition.

Genetic evaluation of early reproductive traits of Harnali sheep.

The aim of this study is to examine early reproductive traits and assess genetic parameters associated with them in Harnali crossbred ewes through Bayesian inference. The dataset encompasses 555 reproduction records spanning 24 years from 1998 to 2021. The traits under investigation include age at first lambing (AFL), weight at first lambing (WFL), and first lambing interval (FLI). First, least-squares modeling was conducted, incorporating fixed effects such as the period of birth and the dam's weight at lambing for the targeted traits. Subsequently, Bayesian estimation involved a series of animal models that accounted for direct additive effects, with or without maternal effects, along with significant fixed effects. The overall least-squares mean for AFL, WFL and FLI was observed as 851.49 ± 12.20 days, 27.5 ± 0.16 kg, 455.04 ± 10.66 days, respectively. The period of birth significantly influenced AFL and WFL, while the dam's weight at lambing showed a significant association with WFL only. Bayesian estimates revealed low direct heritability for AFL, WFL, and FLI, ranging from 0.12, 0.16 and 0.04, suggesting limited potential for improvement through selection. However, maternal effects accounted for a proportion of phenotypic variance ranging from 0.04 to 0.14 across these traits. It was concluded that enhancing reproductive efficiency in Harnali ewes would require a greater focus on management aspects, particularly feeding and breeding practices, while also considering maternal influences within the existing breeding plan.

Effects of chickpea grain feeding on the growth and carcass features of growing lambs.

An investigation was conducted to find out how diet formulation of chickpea grains (CHPE) rather than soybean meal and barely grain affected the performance, blood metabolites, carcass, and meat quality features of Awassi lambs. Thirty lambs, with an average age of 73 ± 0.85 days and an initial body weight of 21.0 ± 1.29 kg, were randomly assigned into one of three diets, with 10 lambs per treatment diet. The diets were designed to replace a portion of the barley grain and soybean meal and included no CHPE (CON), 7.5% CHPE (CHPE7.5), and 15% CHPE (CHPE15). Lambs were individually housed, fed every day, and weighed every two weeks to measure performance characteristics over the 60-day study period. Four lambs per treatment were chosen at random on day 42 to participate in an N balance study and assess diet digestibility. All lambs were slaughtered at the termination of the trial period to measure the features of the carcass characteristics and meat quality. As the amount of CHPE included in the diets increased, the cost of diets reduced. As the amount of CHPE in the diets increased, so did the intake of ether extract (EE). The CON group's cost per kilogram of increase was higher (P = 0.017) than that of the CHPE7.5 and CHEP15 groups. The digestibility of EE was higher (P = 0.024) in the CHPE15 diet as opposed to the CHPE7.5 and CON diets. The various treatments did not impact blood metabolites, carcass features, or meat quality. Therefore, the present study suggested that chickpeas might be added to the diets of finishing lambs up to 15% of dry matter.

Optimising Laparoscopic Artificial Insemination in Lohi Sheep: Effects of Timing, Sperm Concentration and Body Condition on Fertility Outcome in Subtropical Climates.

The objective of this study was to determine the optimal timing, sperm concentration, and body condition score (BCS) for laparoscopic artificial insemination (LAI) in the subtropical Lohi sheep breed. In Experiment 1, Lohi ewes (n = 80) were synchronised through progestin-sponges (day 0-day 11), administering PGF2α (d-cloprostenol 75 µg/mL; i.m. @ 75 µg /ewe) on day 09 and eCG (i.m. @ 300 IU/ewe) on day 11. Ewes were divided equally into four groups (n = 20 each) and then LAI was performed at 48 (T48), 60 (T60), 72 (T72) and 96 (T96) hours post-sponge removal using 200 million sperm/insemination. In Experiment 2, ewes (n = 81) were synchronised as in Experiment I. Following synchronisation ewes were divided into four groups, each subjected to LAI employing varying sperm concentrations: 10 (S10; n = 21), 20 (S20; n = 20), 50 (S50; n = 20), or 100 (S100; n = 20) million per insemination. Inseminations were performed within a time window of 48-60 h post-sponge removal, based on the findings from Experiment 1. In both experiments ewes were categorised according to BCS, that is, medium 3 and high > 3. Results of Experiment 1 revealed a quadratic response that ewes inseminated at 60-h post-sponge removal exhibited significantly higher pregnancy and twinning rates (p = 0.02). The results of Experiment 2 revealed that sperm concentration had a quadratic effect, 50 million sperm per insemination resulted in maximal pregnancy rates (p = 0.01). Additionally, ewes with medium BCS (≤ 3) had higher pregnancy rates than high BCS (> 3) ewes. In conclusion, ewes with medium BCS (≤ 3) are ideal candidate for LAI and can be inseminated at 60 h with minimal sperm 50 × 106/dose post-sponge removal to achieve a maximum pregnancy rate.

Evaluation of performance and estimation of genetic parameters for milk yield and reproductive traits in Awassi and Asaf sheep breeds and crosses in the Palestinian territory.

This study aimed to estimate genetic parameters, including heritability and repeatability, for milk yield and prolificacy in sheep. It included 3682 records from 1837 ewes across various breeds: Awassi, Assaf, and Awassi x Assaf crosses, two Awassi lines: Improved Awassi, AFEC Awassi. The study measured total milk yield (TMY), yield up to 120 days (TMY120), and yield up to 150 days (TMY150), alongside reproductive traits: litter size (LS), number of lambs born alive (NLBA), and lambing interval (LI). The analysis utilized a mixed model and the REML procedure to estimate genetic parameters. Results indicated that litter size (LS) had no significant impact on milk traits, whereas breed, location, ewe parity, and lambing season showed significant effects. Lactation length also significantly influenced TMY. For reproductive traits, treatment was significant for NLBA, with location associated with breed, parity, and season affecting all traits. Heritability estimates for TMY ranged from 0.00 in Awassi x Assaf crosses to 0.11 in Awassi, and for TMY120 and TMY150, from 0.00 in Awassi x Assaf crosses to 0.16 in Awassi. Estimates for LS and NLBA varied similarly. The heritability for LI was 0.03 in Awassi and zero in other breeds and crosses. The findings suggest that in the northern West Bank regions of Nablus and Jenin, Assaf or Awassi x Assaf breeds are preferable. The study underscores the importance of comprehensive performance and pedigree recording for effective sheep farm management.

Effects of drinking saline water on carcass traits and meat quality of growing and mature Blackhead Ogaden sheep and Somali goats.

Water salinity has a significant impact on water quality, posing challenges for livestock production and productivity, particularly in arid regions where climate change affects freshwater availability. This study aimed to determine the effect of drinking saline water on the carcass and meat quality traits of sheep and goats in Ethiopia. A total of 100 males with an average initial body weight of growing (18.17 ± 0.51) and mature (22.22 ± 0.52 kg) Blackhead Ogaden sheep and growing (17.99 ± 0.50) and mature (21.99 ± 0.54) kg) Somali goats were used. The design of the experiment was a three-way factorial RCBD with three-factor combinations (5 treatment levels, 2 species, and 2 age groups).Water treatments were natural water (Lake Basaka water (control), low saline water (L-SW), moderate saline water (M-SW), high saline water (H-SW), and very high saline water (VH-SW); that is, NaCl was added to natural water at concentrations of 7.95, 11.93, 15.90, and 19.88 g TDS/L, respectively. The finding showed that increasing salinity levels in drinking water reduced slaughter body weight (SBW), carcass weight (CW), dressing percentage (DP), rib eye area (RAE), total edible components (TEC), and increased total non-edible components (TNEC) (P < 0.05). Similarly, sheep and mature animals had higher (P < 0.001) SBW, CW, DP, RAE, and TEC than goats and growing animals. Sensory evaluation, shear force, and proximate analysis were affected by water salinity, species, and age groups (P < 0.05). Overall, the study revealed that consuming saline water above 11 g TDS/L affected carcass traits and meat quality in Somali goats and Blackhead Ogaden sheep.

Comparison of machine learning algorithms and multiple linear regression for live weight estimation of Akkaraman lambs.

This study was designed to predict the post-weaning weights of Akkaraman lambs reared on different farms using multiple linear regression and machine learning algorithms. The effect of factors the age of the dam, gender, type of lambing, enterprise, type of flock, birth weight, and weaning weight was analyzed. The data was collected from a total of 25,316 Akkaraman lambs raised at multiple farms in the Çiftlik District of Nigde province. Comparative analysis was conducted by using multiple linear regression, Random Forest, Support Vector Machines (and Support Vector Regression), Extreme Gradient Boosting (XGBoost) (and Gradient Boosting), Bayesian Regularized Neural Network, Radial Basis Function Neural Network, Classification and Regression Trees, Exhaustive Chi-squared Automatic Interaction Detection (and Chi-squared Automatic Interaction Detection), and Multivariate Adaptive Regression Splines algorithms. In this study, the test dataset was divided into five layers using the K-fold cross-validation method. The performance of models was compared using performance criteria such as Adjusted R-squared (Adj-[Formula: see text]), Root Mean Square Error (RMSE), Mean Absolute Deviation (MAD), and Mean Absolute Percentage Error (MAPE) by utilizing test populations in the predicted models. Additionally, the presence of low standard deviations for these criteria indicates the absence of an overfitting problem. [Formula: see text]The comparison results showed the Random Forest algorithm had the best predictive performance compared to other algorithms with Adj-[Formula: see text], RMSE, MAD, and MAPE values of 0.75, 3.683, 2.876, and 10.112, respectively. In conclusion, the results obtained through Multiple Linear Regression for the live weights of Akkaraman lambs were less accurate than the results obtained through artificial neural network analysis.

Investigating the chemical composition, digestion and fermentation of Alternanthera sessilis red plant and its effect on the performance of fattening lambs.

The present experiment was conducted to evaluate the nutritional value of red Alternanthera sessilis for fattening lambs when they were replaced with alfalfa forage. Forty growing lambs with an average weight of 21.12 kg and an age of 5 months were randomly assigned to four experimental treatments. Growth performance, nutrient digestibility, rumen fermentation parameters, protozoa population, blood parameters, and composition of carcass components were evaluated. The results of this experiment showed that the use of Alternanthera sessilis in the diet significantly reduced feed intake, increased the average daily weight gain, and improved the feed conversion ratio compared to the control treatment (P < 0.05). The digestibility of dry matter and protein was significantly increased (P < 0.05), while the digestibility of neutral detergent fiber, acid detergent fiber, and organic matter showed a numerical increase. Diets containing different levels of the Alternanthera sessilis plant did not affect pH, but the increase in the amount of this plant in the diet led to an increase ammonia nitrogen concentration and rumen protozoa population (P < 0.05). The addition of Alternanthera sessilis to the diet significantly reduced the concentration of blood glucose and cholesterol and increased the concentration of blood urea nitrogen (P < 0.05). Except for the weight of the thigh and neck, the effect of experimental treatments on other carcass components was not significant. Overall, the results of this experiment showed that using the Alternanthera sessilis plant in the rations of fattened lambs as a substitute for alfalfa forage not only had no negative effect on the studied parameters but also improved them in some cases. Therefore, Alternanthera sessilis can be used in rations of fattened lambs as a substitute for part of alfalfa forage.

The use of infrared thermography as an indicator of methane production in hair sheep.

Infrared thermography may be an alternative technology for measuring the amount of CH4 produced and has the advantages of low cost, speed and efficiency in obtaining results. The study's objective was to determine if the infrared thermography is adequate for predicting the emission of CH4 in hair sheep and the best time after feeding to carry out the measurement. Twelve Santa Inês lambs (females, non-pregnant, with twelve months old and mean body weight of 39.3 ± 2.1 kg) remained for two days in respirometric chambers, in a semi-closed system, to determine the CH4 production. The animals were divided into two treatments, according to the diet provided. During this period, seven thermographic photographs were taken, at times - 1 h, -0.5 h, 0 h, 0.5 h, 1 h, 2 h, 3 h, 5 h, and 7 h, according to the feeding time, defined as 0 h. CH4 production was measured over 24 h. Thermographic images measured the maximum, minimum, average and point temperatures at the left and right flanks. The temperature difference between the left and right flanks (left minus right) was calculated each time. Pearson correlation coefficients, multiple regression and principal component analysis were carried out in SAS®. The best prediction of emission intensity of CH4 (kg of CH4 per dry matter intake) was obtained at 3 h after feeding: CH4/DMI = 13.9016-0,38673 * DifP2 + 3.39089 * DifMed2 (R² = 0.48), using the difference between left and right flanks for point and average temperature measures. Therefore, infrared thermography can be used as an indicator of CH4 production in hair sheep three hours after feeding.

Comparative study of the reproductive and growth performance of the Hamra and Rumbi ovine breeds.

Growth and reproductive performance traits are important economic indicators for analyzing the overall performance of breeding systems. This study aims to evaluate the comparative performance of two Algerian sheep (Rumbi and Hamra) in terms of growth and reproductive performance, and the effect of factors such as breed, season of birth, mode of birth and age of the mother on this performance in a semi-intensive breeding system. The reproductive performance of 577 Rumbi ewes and 1328 Hamra ewes bred at the Tiaret and Saïda experimental stations respectively, was analyzed using performance monitoring data. Fertility rates for the Rumbi and Hamra breeds of 87.14% and 78.8% respectively were practically similar (p > 0,05). Litter size at birth and weaning was significantly higher in the Hamra breed than in the Rumbi breed (p < 0,05). Weaning mortality was significantly higher in the Hamra breed than in the Rumbi breed, with an average of 22.60% versus 14.94% (p < 0,05). The effect of factors showed that there was a highly significant effect of the mother's age and season of birth on the reproductive performance of the Hamra and Rumbi breeds with a p < 0.0001 on fertility, litter size at birth, litter size at weaning and fertility. There was a significant effect of the year factor on reproductive performance with p = 0,013 for the Hamra breed and p = 0,031 for the Rumbi breed. The results of this study showed that Rumbi lambs were heavier at birth than Hamra lambs. The values observed were 4,86 kg versus 3,10 kg for the Hamra breed, with a highly significant difference (p < 0,0001), so that the average daily pre-weaning weight gains of Rumbi lambs were higher than those of Hamra lambs, at 0,195 kg/day versus 0,113 kg/day for Hamra lambs, with a high significance (p < 0,0001). The effect of factors showed that there was a significant effect of the mother's age on the ADGs (0-30), (30-70) and (70-90) of the Hamra and Rumbi breeds with a p = 0,034 and p = 0,02 respectively. There was also a highly significant effect of the birth mode effect on ADGs (0-30), (30-70) and (70-90) only for the Hamra breed with a p = 0,004. The effect of the birth weight on ADGs was not significant for both Hamra and Rumbi breeds with a p > 0,05. According to the findings of this study, the Hamra breed had superior reproductive potential and the Rumbi breed had superior growth. The Hamra breed showed better maternal skills in terms of fertility and prolificacy, while the Rumbi breed showed better lamb growth performance. Consequently, these results could be used for selective sheep breeding, taking into account the random effects of the environment and the potential of each breed.

Soybean oil, linoleic acid source, in lamb diets: carcass traits and meat quality.

We developed a study to determine the ideal level of inclusion of soybean oil (SBOil) in the diet without affecting the quantitative and qualitative parameters of the carcass and meat of lambs in a feedlot system; therefore, determining the ideal level of inclusion. Forty male lambs (Santa Inês breed) were used. The initial body weight and age averaged 34.88 ± 3.19 kg and 5 months, respectively. Experimental units (lambs) were randomly distributed in 5 different diets: inclusion levels of SBOil: 0, 30, 60, 90, and 120 g/kg of dry matter (DM). The SOil inclusion reduced the DM intake (P < 0.001), Total digestible nutrients (P = 0.004), and crude protein (P < 0.001). Total weight gain (P < 0.001) decreased with the SBOil inclusion and subcutaneous fat thickness (P = 0.017) showed the same behaviour. The final body weight decreased by 42.9 g/kgDM until the inclusion level of 30 g/kgDM; from this level it was reduced by 145 g/kgDM. The hot and cold carcass weights (P = 0.013) decreased by 36.6 g/kgDM after including 30 g/kgDM of SBOil. Meat physicochemical composition was not altered (P > 0.05). Lower meat tenderness values ​​were obtained at the levels of 60 and 90 g/kgDM. The inclusion above 30 g/kgDM decreased meat tenderness. It is concluded that soybean oil should be included up to 30 g/kgDM in diets. It is important to note that with diets with 60% concentrate, SBOil levels greater than 30 g/kgDM promote yield losses.