Liveweight Of Sheep Research Articles

Effects of grazing and climate change on aboveground standing biomass and sheep live weight changes in the desert steppe in Inner Mongolia, China

CONTEXTThe Stipa breviflora desert steppe ecosystem is fragile and sensitive to climate change and grazing disturbance. Previous studies have reported the effects of climate change and grazing on aboveground standing biomass of the plant community and sheep live weight, however, the interaction between climate change and grazing remains unclear. Process models have become ideal tools for the evaluation of the effects of grazing management practices under climate change. OBJECTIVEWe used the Soil-Plant-Atmosphere Continuum System (SPACSYS) model to investigate aboveground standing biomass and the live weight of sheep in the desert steppe of Inner Mongolia under future climate change scenarios and different grazing management. The results will be used to inform adaptive management strategies. METHODSThe grazing experiment consisted of four treatments: no grazing (0 sheep ha−1 half year−1), light stocking rate (0.91 sheep ha−1 half year−1), moderate stocking rate (1.82 sheep ha−1 half year−1), and high stocking rate (2.71 sheep ha−1 half year−1). We used observed data on soil temperature, soil volumetric water content, changes to sheep live weight, and aboveground standing biomass of plant community to provide parameterization and validation for the SPACSYS model. We then predicted aboveground standing biomass of the plant community and sheep live weight changes for different grazing management under three representative concentration pathways (RCP) scenarios (RCP 2.6, RCP 4.5, and RCP 8.5) from 2021 to 2100. RESULTS AND CONCLUSIONSModerate and high stocking rates decreased aboveground standing biomass and sheep live weight changes more than the light stocking rate. A light stocking rate can maintain higher aboveground standing biomass and sheep live weight as well as meet production requirements. Therefore, a light stocking rate is a potentially effective management approach to improve food production security and combat global climate change in the desert steppe. SIGNIFICANCEThe model can inform management strategies for grazing in the desert steppe under climate change, supporting efforts to maintain the stability of the steppe ecosystem and increase economic benefits, while also providing a theoretical basis for adaptive management in the desert steppe.

The greenhouse gas emissions from meat sheep production contribute double of household consumption in a Eurasian meadow steppe

With the rapid development of the economy, household activities have emerged as an important source of greenhouse gas (GHG) emissions, making them a crucial focal point for research in the pursuit of sustainable development and carbon emission reduction. Hulunber, as a typical steppe region in eastern Eurasia, is representative of studying the GHG emissions from household ranches, which are the basic production units in this region. In this paper, based on survey data of 2018 and 2019, we quantified and assessed GHG emissions from household ranches by combining life cycle assessment (LCA) and structural equation modeling (SEM) approaches, with LCA to define household ranches system boundary and SEM to determine the key driving factors of emissions. The results showed that GHG emissions of meat sheep live weight was 23.54 kg CO2-eq/kg. The major contributor to household GHG emissions was enteric methane (55.23 %), followed by coal use (20.80 %) and manure management systems (9.16 %), and other contributing factors (14.81 %). The SEM results indicated that the GHG emissions from household ranches were derived primarily by economic level, while the economic level was significantly affected by income. This study also found a significant positive and linear correlation between household GHG emissions and the number of meat sheep (R2 = 0.89, P < 0.001). The GHG emissions from meat sheep production (67.52 %) were double times greater than household livelihood consumption (32.48 %). These findings emphasized the importance of reducing emissions from meat sheep production and adjusting the energy mix of household livelihood, contributing to the establishment of a low-carbon household livelihood operation.

Correlative variation of economically valuable traits in South Kazakh Merino.

Fine-fleeced sheep are distinguished by numerous economically valuable traits that constitute the foundation for productive distinctions among breeds, populations, lines, and individuals. Many of these traits have already been mentioned or thoroughly examined during studies on the correlative variability of productivity indicators, blood parameters, characteristics of pulmonary gas exchange, histological structures of the skin, and features of the experimental sheep's coat. The objective of our research was to investigate the correlative variability of key economically valuable traits that characterize the overall functional state of sheep organisms under varying environmental conditions. The study was conducted at the "Sharbulak" breeding farms and the "Samat" peasant farms in the Kazygurt district of the Turkestan region. Our findings reveal that one-year-old rams surpass ewes in terms of live weight by 32-37% and in terms of unwashed wool shearing by 21-23%. Two-year-old rams outperform ewes in live weight by 2.15-2.17 times and in unwashed wool shearing by 2.38-2.44 times. The highest phenotypic variability in relative terms (as indicated by the coefficient of variation) is observed in the shearing of pure wool, with an average coefficient of variation of 18.1% across all sex and age groups of sheep. This is followed by the wool coefficient (17.4%) and the yield of pure fiber (12.5%). For each group of animals, the most substantial phenotypic correlation coefficients were observed between the live weight of sheep and the shearing of unwashed wool. On average, across all groups of sheep at the "Sharbulak" breeding farm, this phenotypic correlation reaches +0.411 ± 0.077. Correspondingly, for the sheep herd at the "Samat" peasant farm, it is +0.326 ± 0.075. The second-highest phenotypic correlation pertains to the cut of unwashed wool and the length of wool (with correlation coefficients of +0.156 ± 0.058 and +0.145 ± 0.057, respectively, for the herds). The third-highest correlation involves live weight and wool length (+0.131 ± 0.085 and +0.105 ± 0.078, respectively). No statistically significant differences were identified in the average correlation coefficients between the live weight of sheep, the shearing of unwashed wool, and the length of the staple among the flocks of sheep at the "Sharbulak" breeding farm and the "Samat" peasant farm.

Оценка биологического действия комбинированного облучения овец для определения «безопасных» уровней радиационного воздействия

After a ground-based nuclear explosion, a large amount of fused melted radioactive particles (MRP) is formed. Entering the body of pasture animals with food, they accumulate in the proventriculus and abomasum, irradiating them against the background of total radiation exposure in sublethal doses. Research on combined irradiation of sheep (MRP+1.6 Gy) was carried out under the guidance of Professor B.N. Annenkov in 1978 on 48 sheep irradiated at a dose of 1.6 Gy in combination with feeding sheep with ORF activity from 9.99 to 51.80 MBq/kg of live weight. One group of animals served as non-irradiated controls. In addition, the work used experimental data obtained on 10 sheep irradiated at a dose of 2 Gy. Experimental data were analyzed using mathematical statistics methods. Combined irradiation is accompanied by moderate leukopenia, increased blood viscosity and damage to the gastrointestinal tract. Changes in the gastrointestinal tract are characterized by atony of the proventriculus, pain in the area of the xiphoid cartilage (mesh) and abomasum, hemorrhages and ulcers on the mucous membranes, as well as a decrease in the consumption of feed and water, which led to loss of live weight and death of animals. A study of the dynamics of death of irradiated sheep (probit analysis) showed that the minimum values of death (1 and 5%) can be caused by the consumption of MRP + 1.6 Gy with activity from 4.07 to 6.57 MBq/kg of live weight. Similar data were obtained when analyzing the values of ruminal motility (rumination) in irradiated sheep (3.6 and 5.4 MBq/kg live weight). Therefore, the “safe” level of ORS activity can reach 6.6 MBq/kg live weight of sheep +1.6 Gy of total irradiation.

Search for Candidate Genes for Live Weight in Sheep of the Southern Meat Breed

Search for Candidate Genes for Live Weight in Sheep of the Southern Meat Breed

Search for candidate genes associated with live weight in north Caucasian meat and wool sheep

Genome-wide association study is currently one of the most effective methods for identifying polymorphisms and loci associated with economically significant traits of productive animals. The article presents data obtained during a genome-wide association study for the “live weight” indicator in the Severocavcazskaya sheep breed. Animal genotyping was carried out using Ovine Infinium HD BeadChip 600K DNA biochips. Genotyping quality control, as well as genome-wide association analysis, was performed using PLINK V.1.07 software. Visualization and plotting were carried out using the QQman package in the R programming language. As a result of the work done, six single nucleotide polymorphisms were identified that overcame the significance threshold – log10(p) = 5. The rs419523766, rs418460707, rs420899508, rs425865365, and rs422334764 polymorphisms are located in the intergenic regions, and rs398681425, in the downstream part of the protein-coding gene. Based on the studies carried out, we can propose four new candidate genes associated with sheep live weight: C1H1orf94, KCNA4, S100-A7 and ZNF706. The function of the C1H1orf94 gene has yet to be clarified, while the rest of the genes perform essential functions, including in the regulation of metabolic processes. Further studies should be aimed at confirming the influence of the proposed candidate genes on the phenotype of animals and at proving th\e relationship of the detected polymorphisms with confirmation indicators of sheep.

Enhanced LiteHRNet based sheep weight estimation using RGB-D images

Sheep farming is a strategic sector of livestock husbandry, and its production has large market demand in many countries. The live weight of sheep provides important information about the health state and the time point for marketing. Manual weighing sheep is time-consuming for farmers even with the help of a ground scale. With the development of Artificial Intelligence (AI) and smart sensors, non-contact sheep weighing methods have gradually been used to estimate weight. However, the performance of prior studies tends to degenerate with varying postures and light conditions in practical natural environments. In this study, we propose a sheep live weight estimation approach based on LiteHRNet (a Lightweight High-Resolution Network) using RGB-D images. Class Activation Mapping (CAM) guided the design of efficient network heads embracing visual explanation and applicability in practical natural environments. Experiments are conducted on our challenging dataset (of 726 sheep RGB-D images, weight range between 19.5 to 94 kg). Comparative experiment results reveal that the lightweight Convolutional Neural Network (CNN) model trained on RGB-D images can reach an acceptable weight estimation result, Mean Average Percentage Error (MAPE) is 14.605% (95% confidence interval: [13.821%, 15.390%], t test) with only 1.06M parameters. Our works can be viewed as preliminary work that confirms the ability to use lightweight CNNs for sheep weight estimation on RGB-D data. The results of this study are potential to develop an embedded device to automatically estimate sheep live weight and would contribute to the development of precision livestock farming.

Automatic multi-weigh-station for assessing sheep liveweight in small flocks

Sheep liveweight is a vital physiological parameter to monitor as it is directly correlated with the animals internal energy balance. Increases in liveweight in mature sheep coincide with an increase in fat and protein tissue while weight loss denotes an inverse relationship. This relationship underscores appropriate pasture stocking rates, production outputs, the correct dosing of medicinal treatments for maintaining a healthy flock and finding target markets. The sheep production industry is yearning for an accurate platform to provide real-time and accurate liveweight measurements without extensive labour. The two main methods for measuring sheep liveweight include; static yard weighting, which while accurate is labour intensive, and walk-over-weighing — which has the advantage of autonomy but lacks accuracy and requires the flock to be trained. In this work we describe a custom platform that accurately measures the liveweight of up-to three sheep simultaneously while they drink or eat from a field trough. A plywood frame consisting of three separated static weigh platforms — each with two commercially available weigh bars — was constructed to fit along side a conventional 3 metre trough. These strain gauges plug directly into a custom circuit board with a Teensy 3.6 microcontroller connected to several Analog-to-Digital converters, SDI-12, I2C and OneWire interfaces for additional environmental/agricultural sensors — all powered by a commonly available 12 V lead–acid battery and commercial solar charger. The device can communicate over LoRaWAN — a long range, low-power wireless communication architecture — making it suitable for remote deployment on large farms where traditional 3/4G telecommunications are unavailable. Firmware on the device sends device status updates every 15 min and calculates/transmits liveweight parameters in real-time — as animals use the trough. Five untrained mature wethers were given access to the device over a period of 57 days. A total of 1149 weights were captured, of that 853 were automatically flagged as reliable using algorithms provided in this work — equating to ∼74% of the original dataset. This work aims to enable producers to a quantify the physiological state of their flock without extensive labour, acting to increase their available decision making information in regards to flock productivity, stocking rates and animal welfare.

Studying the relationship between a number of carcass traits and their regression on live weight in sheep

This study was conducted in Suq Al-Shuyoukh district, south of Thi Qar province, for the period from 5/11/2021 to 8/5/2022 on a sheep sample consisting of 49 local Iraqi sheep (Arabi ) from one of the private sector herds.The study included slaughtering sheep in a butcher's shop, recording the traits of the carcass and the weight of the thigh inside the shop, and then taking a sample of the thigh meat to study some of its chemical traits .Chemical tests were conducted on the meat sample in the laboratories of the Faculty of Agriculture and the Marshes of the University of Thi Qar, and the genetic material was extracted and genetic analysis was done in the laboratory of the Marsh Research Center at the University of Thi Qar. We reached the following results: The traits of hot carcass weight, carcass length, carcass diameter, and thigh weight showed a highly significant and positive correlation among them, while the rest of the traits differed in their correlations in terms of morality or in terms of being negative or positive. Through the results of the statistical analysis, it was found that the value of the regression coefficient for the characteristics of hot carcass weight, carcass length, thigh weight, dressing percentage, pH of meat, and muscle fiber diameter on the live weight of the animal was positive (except for the dressing percentage) and highly significant (P≤0.01).

Effect of Grape Marc Added Diet on Live Weight Gain, Blood Parameters, Nitrogen Excretion, and Behaviour of Sheep.

Simple SummaryThis experiment explored how feeding grape wine production waste product grape marc impacts on sheep production. Forty merino sheep were divided into two groups; one group received a sheep industry standard diet (control), and one group received a treatment diet which had 20% of the control diet replaced by grape marc. The results showed that the grape marc diet led to a higher intake and faecal nitrogen/urinary nitrogen ratio, but no difference in sheep live weight gain, behaviour, and parasitic egg count compared with control diet-fed sheep. Overall, the results showed that feeding grape wine production waste product grape marc as a cheap feed, to replace 20% of the control ration, can maintain sheep productivity, health, and environmental sustainability.A 39-day field experiment was conducted to assess the effect of grape marc (GM) feeding on sheep productivity, health, and environmental sustainability. Forty merino sheep were divided into two dietary groups, each having five replications (n = 4 sheep/replication). Experimental diet consisted of: (i) control: 55% lucerne hay + 40% wheat grain + 5% faba bean; (ii) GM treatment: control diet with 20% replaced by GM on a dry matter (DM) basis. The GM treatment contained 2–10% higher phytochemical contents than the control. The DMI from the GM treatment was 15% higher than the control (p < 0.001). No difference was found in sheep live weight gain, behaviour, and quality between groups (p > 0.05). No difference was found in total faecal production, faecal organic matter, and nitrogen contents (p > 0.05) and parasitic egg count. The GM treatment led to higher nitrogen intake (23.1 vs. 27.2 g/d) and faecal nitrogen excretion (6.3 vs. 8.7 g/d) compared to the control. Urinary creatinine, allantoin, and purine derivatives were lower in the GM treatment than control (p < 0.05). However, both groups had similar purine derivatives/DMI (i.e., indicator of rumen microbial protein synthesis efficiency; p > 0.05). Overall, the results showed that GM can replace 20% of the control ration to maintain sheep productivity, health, and environmental sustainability.

In Vitro Effect of Aqueous Extract of Fresh Cassava Leaves (Manihot Esculenta, Crantz) on The Larvae of Haemonchus Contortus as an Intestinal Parasite of Sheep

Cassava is frequently fed to animals. In the case of sheep, the producer relates consumption to a reduction in the parasite load. The literature has proven the effect of phenolic compounds as an anthelmintic in vivo, but no evidence for cyanogenic compounds, also present in all parts of the cassava plant, was found. A controlled in vitro bioassay was used to evaluate the aqueous extract of fresh cassava leaves. The efficiency parameter was the immobility of Haemonchus contortus larvae at the L3 stage, also used to evaluate commercial anthelmintics. Cell culture plates with 100 active L3-stage larvae per well were used, being each replicate constituted by three wells. Aqueous extract of fresh cassava leaves (FCL), Ivomec® 0.01% (PCI) as the positive control, and distilled water as negative control (NCW), were placed in the culture plate wells. Considering the immobility of the larvae as a positive anthelmintic effect, the results showed that in NCW treatments all larvae were mobile, while in PCI all 300 larvae were immobile. FCL produced a gradient of larval inactivation correlation (R2 0.996). The best-fit equation was y = -33.39ln(x) + 40.517, a logarithmic equation, which allowed the calculation of the Lethal Concentration (CL) of 3.44 µg CN- ml, or 80.0 mg of fresh cassava leaves per milliliter of water, with a performance equivalent to ivermectin. This concentration of free cyanide is compatible with the safe consumption of fresh leaves by live weight of sheep. The exact amount of cassava roots, leaves, or shoots, consumed to provide an effective dose for controlling H. contort should be established in vivo. Although phenolic compounds must also be present in the extract, the immobility was attributed to cyanogenic compounds since the correlation was proportional to the increase in the cyanide concentration. It can be concluded that the consumption of fresh cassava leaves has the potential as an anthelmintic agent to be evaluated in vivo by feeding sheep and goats. Local use could also add value to the production of fresh cassava leaves, with an average potential production of 2.5 tonnes ha-1, available throughout the year, with greater production at the beginning of cultivation and in the summer months. These leaves could be used after the roots harvesting or even after pruning for this purpose. Currently, this amount of good quality protein material remains without use in the field.

Studying the relationship between a number of carcass traits and their regression on live weight in sheep

Studying the relationship between a number of carcass traits and their regression on live weight in sheep

The conservation method effects of the Barley-Vetch mixture planted together on theperformance of pregnant ewes

The aim of this study was to examine the effects of barley-vetch hay and barley-vetch silage on liveweight change in pregnant sheep and birthweight in lambs and to determine the optimal form of barley-vetch roughage usage in sheep feeding. Forty-eight (Kıvırcık x Akkaraman (G1) sheep were blocked according to age and randomly distributed to three groups: barley-vetch hay (H, n = 16), barleyvetch silage (S, n = 16), and the control group (C, n = 16). The H group was fed barley-vetch hay ad libitum and limited concentrate, the S group was fed barley-vetch silage ad libitum and limited concentrate, and the C group was fed barleygrass straw + alfalfa hay (50/50%) and limited concentrate feed. The trial was started in the final trimester period of the pregnancy and lasted 90 days. Liveweight and feed intake of the pregnant sheep were recorded in the last period of pregnancy. The liveweight of the lambs were measured at lambing and then on d 15 and 30. There is no diet effect on liveweights measure 1 and 2 months after lambing (p > 0.05). The liveweight value of sheep at lambing was 67.01 ± 1.32, 64.07 ± 1.54, and 64.89 ± 1.48 kg for the groups H, S, and C, respectively. The birth type was significant on birth weight (p < 0.05). Lamb liveweights on d 15 and 30 for the group H was greater than those for the group S (p < 0.05). Lambs' birth weight and weights on d 15 and 30 were 4.94 ± 0.13, 4.44 ± 0.15, and 4.77 ± 0.17 kg; 9.30 ± 030, 8.03 ± 0.30, and 8.94 ± 0.34, 13.36 ± 0.43, 10.85 ± 0.56, and 12.37 ± 041 for groups respectively. In conclusion, barley-vetch mixture can be used as hay and silage in pregnant sheep feeding, being hay superior to silage.

Enhancement of the Reliability of Animal Genotyping Regarding the Betterment of Wool Productivity in South-Kazakh Merino Sheep in Kazakhstan.

Enhancement of the production and productivity in animals is possible by improving the environment and changing the genetic structure of the herd which is done through selection. The present study aimed to investigate the efficiency of using genetic resources in the population of South-Kazakh merino sheep breed to improve and enhance the quality of wool productivity by determining a combination of phenotypic traits, morphobic and chemical parameters, as well as immunogenetic factors. Wool productivity was studied and accounted for by cutting each animal's wool during the period of shearing with an accuracy of 0.1 kg. At the age of 14 months, samples of wool were taken from 10 ewes of each group to study the yield of pure wool using physical and technological indicators. The value of reproducibility coefficients was determined by conducting correlation analysis. The value was estimated from 0.439 to 0.871 and 0.331 to 0.776 for the live weight and wool cutting, respectively. The number of woolens per 1 mm2 of skin positively correlated with pure wool cutting (0.276±0.135) and woolliness factor (0.293±0.134), while it negatively correlated with the live weight of sheep (-0.055±0.140), staple length (-0.146±0.139), and toner wool (-0.180±0.138). This negative correlation implies that the most densely woolly sheep will not necessarily have a breeding advantage for the herd improvement on a combination of signs. However, the outstanding wool density as a separate indicator of sheep woolen productivity has a great breeding advantage; therefore, in the merino population, it is necessary to create a small factory line of sheep with a very large wool density. A variety of sheep productivity indices in each age had a high correlation with a variety of maximum productivity levels of animals bred in the conditions of "Batay-Shu" LLP.

Parameters of breeding traits of sheep of the new breed Artlukhsky merino

The planned breed for breeding in the Republic of Dagestan is Dagestan mountain breed. However, from sheep of this breed fine merino wool is not obtained, and the breeding of special merino breed for mountain and transhumant breeding system is an urgent problem. The purpose of the research was to characterize the main breeding traits in different sex and age groups of sheep of the new breed Artlukhsky merino, such as live weight, wool shearing and its qualitative parameters. Artlukhsky merino breed was bred by using Dagestan mountain breed on the ewes at the beginning stage of the rams of Stavropol breed, and at the final stage – Manych merino breed. The research of the parameters of the breeding traits has been made on elite and class I animals in the breeding farm of the APC “Krasny Oktyabr” in the Kazbekovsky area in the Republic of Dagestan. The live weight of sheep of different sex and age groups of the tested breed was 45–97 kg. The average fineness of wool fibers in adult rams was 23,3 microns (60 quality), in ewes – 22,9 microns (64 quality), in rams aged 12 months – 22,1 microns and young ewes – 20,9 microns (64 quality). The difference in the fineness of the wool on the side and thigh did not exceed one quality. The length of the wool fibers on the side on average in adult rams was at least 9,9 cm, in ewes – 9,4 cm, in young ewes – 10,2 cm and young rams – 10,4 cm. The yield of washed wool in the herd was at the level of 64 %, the fertility of ewes was 125 to 135 %. Thus, the indicators of the main selected traits in sheep of the new breed Artlukhsky merino are at the level of the best domestic breeds, such as Volgograd and Vyatka.

Results of Changes in the Live Weight of Karakul Sheep in the Experiment

In this article, the live weight of sheep is of great economic and biological importance, large karakul sheep are able to accumulate more sensitive substances in their bodies and are usually more viable than others. Sheep with a large body in a breed or flock have been reported to have strong constitution and health.

Integration of a single-step genome-wide association study with a multi-tissue transcriptome analysis provides novel insights into the genetic basis of wool and weight traits in sheep

BackgroundGenetic improvement of wool and growth traits is a major goal in the sheep industry, but their underlying genetic architecture remains elusive. To improve our understanding of these mechanisms, we conducted a weighted single-step genome-wide association study (WssGWAS) and then integrated the results with large-scale transcriptome data for five wool traits and one growth trait in Merino sheep: mean fibre diameter (MFD), coefficient of variation of the fibre diameter (CVFD), crimp number (CN), mean staple length (MSL), greasy fleece weight (GFW), and live weight (LW).ResultsOur dataset comprised 7135 individuals with phenotype data, among which 1217 had high-density (HD) genotype data (n = 372,534). The genotypes of 707 of these animals were imputed from the Illumina Ovine single nucleotide polymorphism (SNP) 54 BeadChip to the HD Array. The heritability of these traits ranged from 0.05 (CVFD) to 0.36 (MFD), and between-trait genetic correlations ranged from − 0.44 (CN vs. LW) to 0.77 (GFW vs. LW). By integrating the GWAS signals with RNA-seq data from 500 samples (representing 87 tissue types from 16 animals), we detected tissues that were relevant to each of the six traits, e.g. liver, muscle and the gastrointestinal (GI) tract were the most relevant tissues for LW, and leukocytes and macrophages were the most relevant cells for CN. For the six traits, 54 quantitative trait loci (QTL) were identified covering 81 candidate genes on 21 ovine autosomes. Multiple candidate genes showed strong tissue-specific expression, e.g. BNC1 (associated with MFD) and CHRNB1 (LW) were specifically expressed in skin and muscle, respectively. By conducting phenome-wide association studies (PheWAS) in humans, we found that orthologues of several of these candidate genes were significantly (FDR < 0.05) associated with similar traits in humans, e.g. BNC1 was significantly associated with MFD in sheep and with hair colour in humans, and CHRNB1 was significantly associated with LW in sheep and with body mass index in humans.ConclusionsOur findings provide novel insights into the biological and genetic mechanisms underlying wool and growth traits, and thus will contribute to the genetic improvement and gene mapping of complex traits in sheep.

The Effect of Herbage Availability, Pregnancy Stage and Rank on the Rate of Liveweight Loss during Fasting in Ewes

Sheep liveweight and liveweight change are vital tools both for commercial and research farm management. However, they can be unreliable when collection procedures are not standardized or when there are varying time delays between sheep removal from grazing and weighing. This study had two stages with different objectives: (1) A liveweight loss study to determine the effect of herbage availability (Low and High) on the rate of liveweight loss of ewes at different pregnancy stages (approximately 100 days of pregnancy: P100 and 130 days: P130) and ranks (single and twin); (2) A follow-up liveweight loss study to develop and validate correction equations for delayed liveweights by applying them to data sets collected under commercial conditions. Results from each stage showed that the rate of liveweight loss varied by herbage availability and stage of pregnancy (p &lt; 0.05) but not pregnancy-rank (p &gt; 0.05). Further, the rate of liveweight loss differed by farm (p &lt; 0.05). Applying liveweight correction equations increased the accuracy of without delay liveweight estimates in P100 ewes by 56% and 45% for single-bearing and twin-bearing ewes, respectively, when offered the Low-level diet. In ewes offered the High-level diet, accuracies of without delay liveweight estimates were increased by 53% and 67% for single-bearing and twin-bearing ewes, respectively. Among P130 ewes, accuracy was increased by 43% and 37% for single-bearing and twin-bearing ewes, respectively, when offered the Low herbage level and by 60% and 50% for single-bearing and twin-bearing ewes, respectively, when offered the High herbage level. In conclusion, a short-term delay of up to 8 hours prior to weighing, which is commonly associated with practical handling operations, significantly reduced the liveweight recorded for individual sheep. Using delayed liveweights on commercial farms and in research can have consequences for management practices and research results; thus, liveweight data should be collected without delay. However, when this is not feasible, delayed ewe liveweights should be corrected and, in the absence of locally devised correction equations, the ones generated in the current study could be applied on farms with similar management conditions and herbage type.

Determination of CAST gene polymorphism in sheep of the Volgograd breed

The scientific publication presents the results of studies of CAST polymorphism in sheep of the Volgograd breed. Against the background of the limited application of the results of genetic studies when working with the Volgograd breed, the search for polymorphic variants of the calpastatin gene, which is a potential marker of meat quality during maturation after slaughter, and also, according to some data, the live weight of sheep, is an urgent task. Calpastatin is an enzyme belonging to the calpain family of enzymes. CAST gene polymorphism was determined by PCR-RFLP analysis. To carry out molecular genetic studies in sheep of the Volgograd breed (n = 131), tissue samples were taken from the auricle with an area of 1 cm2 (ear pinches). In sheep of the Volgograd breed, the presence of two genotypes MM, MN was established with a frequency of 88 and 12%, respectively. The M allele and the homozygous MM genotype had the highest frequency. The analysis of the materials obtained as a result of the control slaughter shows that the Volgograd sheep of the MN/CAST genotype exceeded their peers with the MM/CAST genotypes by 3.7 kg in pre-slaughter weight. The presence of variability at these loci provides a basis for controlling meat productivity in sheep of the Volgograd sheep population, therefore, in breeding farms, monitoring of polymorphism and selection for the calpastatin gene should be carried out.

Productivity and nutritional value of 20 species of perennial legumes in a low‐rainfall Mediterranean‐type environment in southern Australia

AbstractIn the rain‐fed mixed‐farming systems of southern Australia, the consistent supply of high‐value forage is limited by a range of climatic, edaphic and systems constraints. Over 2 years, we compared biomass production and nutritional value of 30 accessions of perennial legumes, and predicted intake, grazing days and growth of ewes and lambs. There was significant variation in nutritional value and biomass production between and within species. Lucerne (Medicago sativa) and sulla (Hedysarum coronarium) produced the greatest amount of biomass and energy. There was variability among accessions in digestibility (DMD), acid detergent fibre (ADF) and crude protein, and the rate of change in these traits as plants matured. Trifolium species had the highest DMD across all growth stages. Hairy canary clover (Dorycnium hirsutum), erect canary clover (Dorycnium rectum), greater birdsfoot trefoil (Lotus uliginosus), Australian trefoil (Lotus australis) and running postman (Kennedia prostrata) had energy levels that would not maintain liveweight of mature sheep. In the second year, species differed in response to harvesting treatments. Lucerne and sainfoin (Onobrychis viciifolia) were more productive under a frequent cutting regime. Accessions of white clover (Trifolium repens), red clover (Trifolium pratense), alsike clover (Trifolium hybridum), cullen (Cullen australasicum), strawberry clover (Trifolium fragiferum), sainfoin and birdsfoot trefoil (Lotus corniculatus) showed some promise, while Tedera (Bituminaria bituminosa) and milkvetch (Astragalus cicer) performed poorly under the experimental conditions. We conclude by discussing additional agronomic and nutritional factors that need consideration when developing novel perennial legumes for mixed‐farming systems in the context of a changing climate.