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.

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.

ASReml-based estimation of early genetic parameters in hybrid mutton sheep populations.

The aim of this study was to analyze the effects of non-genetic factors on the estimation of genetic parameters of early growth traits in hybrid mutton sheep using ASReml software, in order to provide theoretical basis for screening the optimal hybriding combinations and accelerating the breeding process of new breeds of specialized housed-feeding mutton sheep. We selected the wellgrown hybrid Southhu (Southdown × Hu sheep) and Dorhu (Dorset × Hu sheep) sheep as the research objects, constructed weight correction formulae for SH and DH sheep at 60 and 180 days; and used ASReml software to investigate the effects of non-genetic factors on the estimation of genetic parameters of early growth traits in hybrid sheep. The results showed that the birth month and birth type were found significant for all traits (p < 0.001); the heritability of maternal effects ranged from 0.0709 to 0.1859. It was found that both SH and DH sheep emerged the potential for rapid early growth and development, early growth traits are significantly affected by maternal genetic effects, thereby the maternal effect should be taken into consideration for the purpose of improving accuracy in parameter estimations and therefore increasing the success of breeding programs.

Economic and financial viability of the production of Brazilian somalis sheep fed with different nutritional plans.

The objective of this study was to evaluate the economic and financial viability of finishing of two sexes of Brazilian Somalis sheep in feedlot receiving diets with 0 and 15% reduction in the total digestible nutrients and crude protein contents. A completely randomized design was adopted, in a 2 × 2 factorial arrangement, with treatments consisting of two sexes (non-castrated males (21.13 ± 5.00 kg) and females (17.99 ± 3.79 kg) and two diets (0 and 15% reduction in the levels of total digestible nutrients and crude protein). Four simulations of productive scenarios were carried out: non-castrated males receiving the diet with 0% reduction; non-castrated males receiving the diet with 15% reduction; females receiving the diet with 0% reduction and females receiving the diet with 0% reduction, for a period of 70 days in feedlot. The highest costs of the system were with feeding and other costs, mainly the acquisition of animals. For both sexes, the 0% reduction diet showed the highest total cost, total revenue, break-even point. Non-castrated males fed a non-reduced diet and females fed a 15% reduction diet had higher net income, rate of return, total productivity, net present value, internal rate of return, profitability index and profitability rate. Less favorable situations were not profitable for any scenario. However, the increase in sales price favorability makes the activity viable. The reduction of total digestible nutrients and crude protein affects the economic and financial viability of Brazilian Somalis sheep. For non-castrated males it is recommended the diet without reduction and for females the diet with 15% reduction of nutrients.

Effect of thymol on the efficiency of feed utilization and compensatory growth in severe feed-restricted lambs.

The present study aimed to evaluate the effect of thymol on growth performance and apparent total tract digestibility of nutrients in severely feed-restricted lambs. Twenty-one male Baluchi lambs were randomly blocked by live weight into three groups: control without feed restriction (CON), feed restricted (FR), and feed restricted plus thymol (FR + T). The lambs underwent a four-week feed restriction period followed by four weeks of realimentation. Thymol was administered daily to the FR + T group during the feed restriction period. Average daily gain (ADG), average daily feed intake, feed efficiency (FE), partial efficiency of maintenance (PEM), and residual feed intake (RFI) were measured as growth performance parameters. Results showed that the severe feed restriction had adverse effects on ADG and FE, but improved PEM (P < 0.05). The effects of thymol administration on ADG, FE, PEM, and apparent total tract digestibility were not significant (P > 0.05). However, the lambs that received thymol during the feed restriction period showed a negative RFI during realimentation (P < 0.05). Overall, these findings suggest that feed restriction as well as thymol may have the potential to improve efficiency of feed utilization in growing lambs. However, this positive effect is independent of the improvement in nutrient digestibility.

The comparisons of non-linear models to describe the growth performance of Lori-Bakhtiari sheep.

BACKGROUND: The study of growth traits is of interest to many animal scientists, regardless of specialization, due to the economic importance of growth rate, mature weight and other related traits. OBJECTIVE: This study aimed to compare six non-linear models for describing the growth of Lori-Bakhtiari sheep. METHODS: In order to collect weight data, 85 lambs (41 males and 44 females) were reared from birth to 140 days of age, and their growth patterns were recorded by measuring their body weight at 10-day intervals. Various mathematical functions, including the negative exponential, Brody, Gompertz, Logistic, Morgan-Mercer-Flodin (MMF) and Weibull, were used to model the relationship between body weight records and age. RESULTS: The results showed that the MMF and Gompertz models provided the best fit to the body weight data, whereas the negative exponential model exhibited the worst fit. In all models, the asymptotic weight of male lambs was higher than females. The research also revealed differences in growth patterns between male and female lambs. Overall, females had a lower absolute growth rate than males, but they reached their peak growth at an earlier period, and their growth rate declined faster. CONCLUSIONS: The differences in growth patterns between males and females indicate the importance of analysing male and female data separately when describing growth. As a result, Gompertz model can be recommended to Lori-Bakhtiari female and male lamb breeders to determine more accurate growth traits. In addition, it should be considered that feeding male and female lambs separately according to absolute growth rate values may increase growth performance.

Comparative assessment of growth curves in Brazilian white Morada Nova hair sheep breed.

The Morada Nova sheep breed is essential for the economy of the semi-arid region of Northeast Brazil, standing out for its adaptability, resistance to parasites and reproductive ability. However, the white variant is endangered, highlighting the importance of studies on its productivity to support conservation efforts. This study focuses on the growth curve of the Morada Nova sheep breed, using nonlinear models and analyzing flock profiles. Total of 764 observations of 165 animals from four farms in Ceará and Rio Grande do Norte, Brazil, were analyzed. Canonical discriminant analysis (CDA) was used for the exploratory analysis and four nonlinear models were used to study the growth curve. Weight from birth to 270 days of age, absolute growth rate (AGR), and the impact of sex on growth curves were assessed. Sex and farm are significant discriminating variables (P < 0.05) for the studied effects (weight and age). Weight was the primary phenotypic biomarker that discriminated between the two indicators, while age was a discriminating indicator only for the core effect. The Gompertz model was the most efficient, presenting the lowest residuals and greatest convergence. The study reveals new information about the growth of Morada Nova sheep, the white variety, including weight differences between the sexes at all analyzed ages and an inflection point before 90 days of age. These discoveries contribute to the understanding of the breed's growth and help in the formulation of conservation strategies.

The role of olive leaves and saccharomyces cerevisiae supplementation in enhancing the performance and economic feasibility of fattening lambs.

Objectives were to assess the use of olive leaves (OL) to replace wheat straw, the forage source, and the supplementation of Saccharomyces cerevisiae (SC) on nutritional intake, growth performance, blood parameters, and carcass quality in lambs. A total of twenty-one newly weaned Awassi lambs, weighing an average of 19 ± 0.6 kg, were randomly distributed to three groups. These three diets were: CON: 0% OL control diet; OL diet of 25%; and OL plus 0.4 g SC/head/d (OLSC) diet of 25% of dietary dry matter (DM). The first seven days were devoted to adaptation and the next sixty days were devoted to gathering data. Daily records of nutrient intake were made. On the 49th day of data collection, four animals were randomly selected from each group and kept in individual metabolism cages (1.0 × 0.8 m) with slatted mash for eight days (four days for data collection and four days for cage adaptation) to evaluate N balance and nutrient digestibility. All lambs were slaughtered after the study to assess the quality of the meat and the carcass features. No difference in DM consumption (P > 0.05) between the treatment groups. When OL-containing diets were compared to the CON diet, the consumption of acid detergent fiber and neutral detergent fiber (NDF) was lower (P ≤ 0.0002), whereas metabolizable energy and ether extract were higher (P < 0.0001). While the OL diet was intermediate, the final BW, total gain, and average daily gain for the OLSC diet tended to be higher (P < 0.087) than the CON diet. Lambs fed the OL-containing diets had a lower (P = 0.0020) cost of growth ($US/kg) than lambs in the CON group. All other nutrient digestibilities were comparable between the treatment diets, except NDF digestibility, which was greater (P = 0.045) in the OLSC group than in the CON group. The N balance variables showed a similarity between the various diets (P > 0.05). Lambs fed the OLSC diet tended to have higher weights (P ≤ 0.098) for fasting live weight, hot carcass weight, carcass cuts weights, and cold carcass weight than lambs on the CON diet. The OLSC diet resulted in higher (P < 0.025) loin weight and intermuscular fat in comparison to the CON and OL diets. No difference (P ≥ 0.05) in the dissected tissues between diets. The longissimus dorsi muscle's dimensions and physicochemical characteristics did not alter (P > 0.05) across the treatment diets. In comparison to the CON and OL diets, the OLSC diet resulted in higher serum glucose levels (P = 0.044). Nonetheless, there were similarities (P ≥ 0.05) in various serum blood parameters between the treatment diets. In conclusion, using OL or/and supplemented SC is positively associated with nutrient intake, growth performance, some carcass parameters, and loin cut tissue, and the most effective aspect is decreasing production cost ($US/kg gain), which makes it a good solution to pass inflation feedstuff prices and cover animal needs.

Ovine KRT81 Variants and Their Influence on Selected Wool Traits of Commercial Value.

Keratins are the main structural protein components of wool fibres, and variation in them and their genes (KRTs) is thought to influence wool structure and characteristics. The PCR-single strand conformation polymorphism technique has been used previously to investigate genetic variation in selected coding and intron regions of the type II sheep keratin gene KRT81, but no variation was identified. In this study, we used the same technique to explore the 5' untranslated region of KRT81 and detected three sequence variants (A, B and C) that contain four single nucleotide polymorphisms. Among the 389 Merino × Southdown cross sheep investigated, variant B was linked to a reduction in clean fleece weight, while C was associated with an increase in both greasy fleece weight and clean fleece weight. No discernible effects on staple length or mean-fibre-diameter-related traits were observed. These findings suggest that variation in ovine KRT81 might influence wool growth by changing the density of wool follicles in the skin, the density of individual fibres, or the area of the skin producing fibre, as opposed to changing the rate of extrusion of fibres or their diameter.

Effect of quantitative feed restriction and sex class on sheep skin quality.

The aim was to evaluate the quality of the sheep skin of different sex classes submitted to different levels of feed restriction. Sheep without defined racial pattern of different sex classes (15 non-castrated males, 15 castrated males and 15 females), with initial body weight of 18.1 ± 0.4 kg and mean age of 90 days were distributed in a factorial 3 × 3, with three sex classes and 3 levels of feed restriction (ad libitum intake and restricted intake at 70 and 80%), with 5 repetitions. After slaughter, the skins were collected for physical-mechanical tests. The effect of the sex classes x levels of dietary restriction interaction was observed for transverse thickness and longitudinal rupture elongation (p < 0.05). Animals fed ad libitum had greater longitudinal transverse thickness (p < 0.05). Animals fed ad libitum and 70% feed restriction showed greater transverse elongation at break (p < 0.05). As for the difference between sex classes in the transverse thickness variable for tearing strength, the interaction sex classes x levels of feed restriction for transverse thickness, longitudinal thickness, transverse tearing strength and longitudinal tearing strength occurred (p < 0.05). Feed restriction reduces the physical quality of the skin of sheep of different sex classes, and the use of castrated male sheep in positive energy balance is recommended to obtain leather with greater thickness, longitudinal rupture elongation and transverse tear strength.

Estimation of the genetic parameters of sheep growth traits based on machine vision acquisition.

In the realm of animal phenotyping, manual measurements are frequently utilised. While machine-generated data show potential for enhancing high-throughput breeding, additional research and validation are imperative before incorporating them into genetic evaluation processes. This research presents a method for managing meat sheep and collecting data, utilising the Sheep Data Recorder system for data input and the Sheep Body Size Collector system for image capture. The study aimed to investigate the genetic parameter changes of growth traits in Ujumqin sheep by comparing machine-generated measurements with manual measurements. The dataset consisted of 552 data points from the offspring of 75 breeding rams and 399 breeding ewes. Six distinct random regression models were assessed to pinpoint the most suitable model for estimating genetic parameters linked to growth traits. These models were distinguished based on the inclusion or exclusion of maternal genetic effects, maternal permanent environmental effects, and covariance between maternal and direct genetic effects. Fixed factors such as individual age, individual sex, and ewe age were taken into account in the analysis. The genetic parameters for the yearling growth traits of Ujumqin sheep were calculated using ASReml software. The Akaike information criterion, the Bayesian information criterion, and fivefold cross-validation were employed to identify the optimal model. Research findings indicate that the most accurate models for manually measured data revealed heritability estimates of 0.12 ± 0.15 for BW, 0.05 ± 0.07 for body slanting length, 0.03 ± 0.07 for withers height, 0.15 ± 0.12 for hip height, 0.11 ± 0.11 for chest depth, 0.13 ± 0.13 for shoulder width, and 0.53 ± 0.15 for chest circumference. The optimal models for machine-predicted data showed heritability estimates of 0.1 ± 0.09 for body slanting length, 0.14 ± 0.12 for withers height, 0.55 ± 0.15 for hip height, 0.34 ± 0.15 for chest depth, 0.26 ± 0.15 for shoulder width, and 0.47 ± 0.16 for chest circumference. In manually measured data, genetic correlations ranged from 0.35 to 0.99, while phenotypic correlations ranged from 0.07 to 0.90. In machine data, genetic correlations ranged from -0.05 to 0.99, while phenotypic correlations ranged from 0.03 to 0.84. The results suggest that machine-based estimations may lead to an overestimation of heritability, but this discrepancy does not impact the selection of breeding models.

Compilations and updates on residual feed intake in sheep.

The increasing global demand for food and the strong effect of climate change have forced animal science to advance regarding new methods of selection in search of more efficient animals in production systems. Feed consumption represents more than 70% of the costs of sheep farms, and more efficient animals can increase the farmers' profitability. One of the main measures of feed efficiency is estimated residual feed intake (RFI), created in 1963 by Robert Koch for estimation in cattle and later adapted for sheep. Animals with negative RFI values (RFI-) are more efficient than animals with positive values (RFI+), with influence on the variables of performance, carcass quality and production of enteric gases. The RFI is the most common and accepted metric of the feed efficiency trait for genetic selection, since it is independent of growth traits, unlike the feed conversion ratio. The purpose of this review article was to present updated literature information on the relationship of RFI estimates with performance measures, molecular markers, greenhouse gas production and feed efficiency, the technical aspects and physiological basis of metabolic in sheep.

Effect of nonstructural carbohydrates on production performance, rumen metabolism and rumen health in lambs fed with isocaloric and isonitrogenous complete diets.

Nonstructural carbohydrates (NSC) are readily fermentable in the rumen and, are a critical factor while preparing protracted feed for higher animal performance. Four isocaloric and isonitrogenous complete feeds were prepared for this investigation to contain varying levels of nonstructural carbohydrates viz., 40.13 (NSC1), 45.21 (NSC2), 50.00 (NSC3) and 55.85 (NSC4) per cent, respectively. The four isocaloric and isonitrogenous complete feeds were tested in 32 Mecheri ram lambs (around three months of age) in a completely randomised block design (n = 8), and the lambs were fed their respective feed for six months. The study revealed that the increased NSC level in the complete diet increased the body weight and weight gain linearly (P < 0.05). The dietary NSC level affected the dry matter consumption in a quadratic manner (P < 0.05) and the lambs of the NSC4 group consumed significantly (P < 0.05) less DM compared to other dietary groups. The overall average feed conversion efficiency differed significantly (P < 0.05) among dietary groups. The correlation between dietary NSC level and faecal score was quadratic (r2 = 62.7, P < 0.05). The rumen pH, total nitrogen and NH3-N concentration were linearly decreased (P < 0.05) and the molar proportion of total short-chain fatty acids and propionic acid were increased (P < 0.05). The energy loss expressed as methane production was significantly (P < 0.01) lower for the high NSC diet-fed lambs. The lambs fed on a low NSC diet had significantly (P < 0.05) lower carcass weights, dressing percentage and loin eye area. The per cent share of rumen weight in the total fore stomach and the rumen papillae measurements length, width and surface area were significantly (P < 0.05) higher in high NSC diet-fed lambs. Increased levels of NSC in the diet increased (P < 0.05) fat deposition in the internal organs. The saturated fatty acids content in the meat was significantly (P < 0.05) lowered, whereas, the oleic acid and linoleic acid were increased (P < 0.05) as the NSC level increased in the diet. The study revealed that as the level of NSC increased in the complete diet there was a concomitant improvement in the final body weight, ADG and feed efficiency of post-weaned Mecheri lambs. It can therefore be recommended that the complete feed with 50 per cent NSC levels would be optimum to reap maximum returns from fattening Mecheri lambs.

Supplementation of Acacia dealbata versus Acacia mearnsii leaf-meal has potential to maintain growth performance of lambs grazing low-quality communal rangelands in South Africa.

Supplementing livestock grazing communal rangelands with leaf-meals from Acacia trees, which are currently considered as problematic invasive alien plants globally, may be a sustainable way of exploiting their desirable nutritional and anthelmintic properties. The current study evaluated worm burdens and growth performance of lambs grazing low-quality communal rangelands supplemented with leaf-meals prepared from the invasive alien plant species; Acacia mearnsii or A. dealbata. Forty, three-month-old ewe lambs weighing an average of 18.9 ± 0.60 kg were randomly allocated to four supplementary diets: (1) rangeland hay only (control), (2) commercial protein supplement plus rangeland hay, (3) A. mearnsii leaf-meal plus rangeland hay and (4) A. dealbata leaf-meal plus rangeland hay. All the supplementary diets were formulated to meet the lambs' minimum maintenance requirements for protein. All the lambs were grazed on communal rangelands daily from 0800 to 1400 after which they were penned to allow them access to their respective supplementary diets until 08:00 the following morning. The respective supplementary diets were offered at the rate of 400 g ewe- 1 day- 1 for 60 days. Lambs fed the commercial protein supplement had the highest dry matter intake followed by those fed the Acacia leaf-meals and the control diet, respectively (P ≤ 0.05). Relative to the other supplementary diets, lambs fed the commercial protein supplement and A. dealbata leaf-meal had higher (P ≤ 0.05) final body weight and average daily gains. Dietary supplementation did not affect lamb faecal worm egg counts over the study period (P > 0.05). There was no association between supplementary diets and lamb FAMACHA© scores (P > 0.05). It was concluded that supplementation of Acacia dealbata versus Acacia mearnsii has the potential to emulate commercial protein in maintaining growth performance of lambs grazing communal rangelands in the dry season.

Effects of refused melon fruit in Canarana grass ensilage on intake, digestibility, serum biochemistry, performance, carcass characteristics and meat attributes of feedlot lambs.

Ensilage of refused fruit with forage is a viable approach to increase resource use in ruminant feed. The objective of this study was to investigate the impact of ensiling refused melon fruit (RMF) with Canarana grass on the intake, apparent digestibility, serum biochemistry, performance, carcass traits, and meat attributes of feedlot lambs. Four distinct silage treatment types were prepared by ensiling RMF at 0 g/kg (control), 70 g/kg, 140 g/kg, and 210 g/kg (as fed) with Canarana grass. Twenty-eight male Santa Inês lambs (7 lambs per treatment), initially weighing 22.3 ± 1.0 kg at 120 days of age, were distributed in a completely randomized design and confined for a total of 96 days, including a 23-day adaptation period and 73 experimental days in a feedlot. The lambs received the treatment-silage in diets as a complete mixture with a roughage: concentrate ratio of 30:70. The inclusion of RMF in Canarana grass ensilage decreased (P < 0.05) the lambs' intake of dry matter, crude protein and metabolisable energy. The inclusion of RMF in ensilage had a quadratic effect (P < 0.05) on the digestibility of non-fibrous carbohydrates. The serum total protein and cholesterol levels decreased (P < 0.05) with the inclusion of RMF in the ensilage, but we observed no effect on the final weight and average daily gain of the lambs. The feed efficiency increased (P < 0.05) by including RMF in the Canarana grass ensilage. The RMF in the ensilage did not influence cold carcass weight and yield. The fat content of the meat decreased (P < 0.05) with the inclusion of RMF in the ensilage. It is recommended the inclusion of up to 210 g/kg of RMF in Canarana grass ensilage to increase feed efficiency and avoid impacts on the performance and carcass attributes of confined lambs.

Carcass traits and morphometry, typification of the Longissimus dorsi muscle and non-carcass components of hair lambs: can biscuit bran completely replace corn? A machine learning approach.

Biscuit bran (BB) is a co-product with worldwide distribution, with Brazil as the second largest cookie producer in the world with 1,157,051 tons. We evaluate the impact of completely replacing corn with BB on the characteristics and morphometry of carcass of purebred and crossbred Morada Nova lambs using machine learning techniques as an auxiliary method. Twenty male lambs from two genetic groups (GG) were used: purebred red-coated Morada Nova (MNR) and crossbred MNR × white-coated Morada Nova (MNF1). Supervised and unsupervised machine learning techniques were used. No interaction (P > 0.05) was observed between diets (D) and genetic groups (GG) and no simple isolated effect was observed for carcass characteristics, qualitative-quantitative typification of the Longissimus dorsi muscle, weight of non-carcass components, weight and yield of commercial cuts and carcass morphometric measurements. The formation of two horizontal clusters was verified: (i) crossed lambs with corn and BB and (ii) purebred lambs fed corn and BB. Vertically, three clusters were formed based on carcass and meat characteristics of native lambs: (i) thermal insulation, body capacity, true yield, and commercial cuts; (ii) choice, performance, physical carcass traits, and palatability; and (iii) yield cuts and non-carcass components. The heatmap also allowed us to observe that pure MN lambs had a greater body capacity when fed BB, while those fed corn showed superiority in commercial cuts, true yields, and non-carcass components. Crossbred lambs, regardless of diet, showed a greater association of physical characteristics of the carcass, performance, palatability, and less noble cuts. Crossbred lambs, regardless of diet, showed a greater association of physical characteristics of the carcass, performance, palatability, and less noble cuts. BB can be considered an alternative energy source in total replacement of corn. Integrating of machine learning techniques is a useful statistical tool for studies with large numbers of variables, especially when it comes to analyzing complex data with multiple effects in the search for data patterns and insights in decision-making on the farm.

Nutrient utilization, growth performance, and antioxidative status of Barki lambs fed diets supplemented with black (Nigella sativa) and rocket (Eruca sativa) seeds.

The current study aimed to determine the polyphenol compounds in Nigella sativa (NS) and Eruca sativa (ES) seeds, and evaluate the impact of their addition either as a sole additive or in combination on the growth performance, digestibility, some rumen and blood parameters and antioxidative status of Barki lambs. Forty-eight male lambs (27.18 ± 0.22 kg, 5-6 months), were divided into 4 balanced groups. The experimental diets were randomly distributed to the control group (CON); fed alfalfa hay plus concentrate feed mixture at a ratio of 30:70% without additives, while, NSD, ESD, and NESD groups: fed CON diet plus 2% NS, 2% ES or 1% NS + 1% ES, respectively as a ratio from total mixed ration (TMR). Results indicated that rutin and catechin were the most phenolic compounds observed either in NS or ES seeds. The NS and ES-supplemented groups recorded the highest (P < 0.05) values for dry matter digestibility, nutritive values, average daily gain, and the best feed conversion ratio. However, growth performance, nutritive value, and all nutrient digestibility except for dry matter were not significantly altered with the NESD group. Concentrations of ruminal NH3-N and TVFA were significantly (P < 0.05) reduced with the NESD group, with no significant differences in pH values among different groups. Values of blood parameters showed significant increases in WBCs, PCV, and T-AOC, and decreases in cholesterol, triglycerides, and MDA with the addition of NS and ES seeds or both. Therefore, the addition of NS and ES seeds is recommended to improve lambs' health and antioxidant status.

Whole-genome resequencing of Hu sheep identifies candidate genes associated with agronomic traits.

The phenotypic diversity resulting from artificial or natural selection of sheep has made a significant contribution to human civilization. Hu sheep are a local sheep breed unique to China with high reproductive rates and rapid growth. Genomic selection signatures have been widely used to investigate the genetic mechanisms underlying phenotypic variation in livestock. Here, we conduct whole-genome sequencing of 207 Hu sheep and compare them with the wild ancestors of domestic sheep (Asiatic mouflon) to investigate the genetic characteristics and selection signatures of Hu sheep. Based on six signatures of selection approaches, we detect genomic regions containing genes related to reproduction (BMPR1B, BMP2, PGFS, CYP19, CAMK4, GGT5, and GNAQ), vision (ALDH1A2, SAG, and PDE6B), nervous system (NAV1), and immune response (GPR35, SH2B2, PIK3R3, and HRAS). Association analysis with a population of 1299 Hu sheep reveals that those missense mutations in the GPR35 (GPR35 g.952651 A>G; GPR35 g.952496 C>T) and NAV1 (NAV1 g.84216190 C>T; NAV1 g.84227412 G>A) genes are significantly associated (P < 0.05) with immune and growth traits in Hu sheep, respectively. This research offers unique insights into the selection characteristics of Hu sheep and facilitates further genetic improvement and molecular investigations.

Human social enrichment is linked with reduced mortality in artificially reared ewe lambs.

Growth of lambs in an artificial rearing system is key to the economic success of sheep-milking farms. Social enrichment in the form of quiet human contact has been shown to increase growth rates of lambs after weaning, perhaps by reducing stress and enhancing immune function. One hundred fourteen artificially reared dairy ewe lambs were assigned either to a Social condition receiving quiet human company in three 20-min segments per day, or a Control condition without quiet human contact. Feeding and housing conditions were otherwise identical. Starting weights for the Social (M = 6.29 kg; SD = 1.19 kg) and Control (M = 6.38 kg; SD = 0.93 kg) lambs were the same, as were their weights after 3 weeks (Mcontrol = 8.89 kg, SD = 2.55 kg, Msocial = 8.63 kg, SD = 2.16 kg). Mortality rates were significantly lower (p = 0.041) in the Social condition (0%) than Control (8%). Thus, social enrichment may be important for the wellbeing of lambs and for economic viability in lamb-rearing.

Economic values of reproductive and growth traits in Chinese Yiling sheep.

This study aimed to calculate the economic value (EV) of reproductive and growth traits for Yiling sheep. A bio-economic model was developed to assess the economic value of litter size (LS), litter size at weaning (LSW), age at first lambing (AFL), lambing interval (LI), birth weight (BW), weaning weight (WW), and 6-month body weight (6MW). The sensitivity of the economic value of traits to changes in market prices was also analyzed. In this study, the trait with the highest EV was LSW (427.97 ¥), followed by LS (419.96 ¥), BW (52.13 ¥), 6MW (14.46 ¥), WW (11.03 ¥), AFL (-0.51 ¥), and LI (-9.09 ¥). LS was the most important trait in the production system with a relative economic weight of 22.81%, followed by 6MW and LSW with relative economic weights of 18.98% and 19.01%, respectively. All traits assessed, except AFL and LI, had positive economic values, indicating that genetic improvement of these traits would have a positive impact on profitability. The results of the sensitivity analysis showed that the economic value of AFL was not sensitive to price changes. All growth traits were unaffected by price changes in labor and medical costs. In addition, the LS, LSW, LI, WW, and 6MW were sensitive to changes in liveweight and feed prices. Generally, as feed prices increased, the economic value of all traits except LI and BW decreased. Except for LI and BW, the economic value of all traits increased due to the rise in liveweight prices. This suggested that liveweight and feed prices significantly affect the profitability of the production system.