Mineral and potentially toxic element profiles in the soil-feed-animal continuum: Implications for public, environmental, and livestock health in three pasture-based sheep farming systems.

Grazing livestock derive most of their mineral requirements from foraging. The presence of toxic elements in soils has become a significant concern for food safety and ecosystem services. Understanding the mineral content profiles in soil and forage is crucial for assessing animal health, predicting potential transfers of minerals or heavy metals into the food-chain, and assessing threats to the environment and human health. In this study, Na, Mg, P, K, Ca, Mn, Fe, Co, Cu, Zn, Se, As, Cd, Hg, and Pb were measured to determine the mineral status of three different pasture-based farming systems (with grazing sheep livestock) in a Spanish region of significant economic importance. A risk assessment evaluation of animal, environmental, and human health was performed on soil, forage, feed, serum, milk, and wool. Notably, traces of Pb, and As were identified in pastures in all farms. Our calculation of pollution indices revealed moderate levels of contamination by various elements, including Co, Cu, Zn, Se, As, Cd, Hg, and Pb. The two farms with more intense agrosystem practices showed a significant potential ecological risk, characterized by high soil levels of Hg and Cd. Animals from these farms also had high concentrations of these metals in wool. Although the target Hazard Quotient derived from milk consumption suggests that dairy products from this area are safe for consumption for adults, only milk from a dehesa farm (mix of woodland and pastureland) was free of potential health concerns related to Pb exposure. Our assessment of mineral profiles reveals a cohesive relationship between soil quality and derived animal products, particularly of the Merino sheep breeding and farming system. The results reveal the importance of adopting and reinforcing strategies to preserve dehesas as a sustainable and environmentally friendly agrosystem in the western Mediterranean region.

Integrated Multi-Tissue Transcriptome Profiling Characterizes the Genetic Basis and Biomarkers Affecting Reproduction in Sheep (Ovis aries).

The heritability of litter size in sheep is low and controlled by multiple genes, but the research on its related genes is not sufficient. Here, to explore the expression pattern of multi-tissue genes in Chinese native sheep, we selected 10 tissues of the three adult ewes with the highest estimated breeding value in the early study of the prolific Xinggao sheep population. The global gene expression analysis showed that the ovary, uterus, and hypothalamus expressed the most genes. Using the Uniform Manifold Approximation and Projection (UMAP) cluster analysis, these samples were clustered into eight clusters. The functional enrichment analysis showed that the genes expressed in the spleen, uterus, and ovary were significantly enriched in the Ataxia Telangiectasia Mutated Protein (ATM) signaling pathway, and most genes in the liver, spleen, and ovary were enriched in the immune response pathway. Moreover, we focus on the expression genes of the hypothalamic-pituitary-ovarian axis (HPO) and found that 11,016 genes were co-expressed in the three tissues, and different tissues have different functions, but the oxytocin signaling pathway was widely enriched. To further explore the differences in the expression genes (DEGs) of HPO in different sheep breeds, we downloaded the transcriptome data in the public data, and the analysis of DEGs (Xinggao sheep vs. Sunite sheep in Hypothalamus, Xinggao sheep vs. Sunite sheep in Pituitary, and Xinggao sheep vs. Suffolk sheep in Ovary) revealed the neuroactive ligand-receptor interactions. In addition, the gene subsets of the transcription factors (TFs) of DEGs were identified. The results suggest that 51 TF genes and the homeobox TF may play an important role in transcriptional variation across the HPO. Altogether, our study provided the first fundamental resource to investigate the physiological functions and regulation mechanisms in sheep. This important data contributes to improving our understanding of the reproductive biology of sheep and isolating effecting molecular markers that can be used for genetic selection in sheep.

The identification of a novel SNP in the resistin (RETN) gene associated with growth traits in Karakul and Awassi sheep.

Resistin is one of the most important adipocytokines in mammalian cells due to its involvement in insulin resistance, obesity, and autoimmune diseases. Resistin is encoded by RETN gene that is primarily expressed in adipose tissues. Mutations in this gene have been associated with several productive traits in animals. This study was conducted to assess the possible biomarker capacity of RETN by evaluating its association with growth traits in two economically important sheep in the Middle East. Genotyping was conducted using PCR-single strand conformation polymorphism (SSCP), and the polymorphism of RETN was associated with several growth traits for three months intervals starting from birth until one year of age. In a total of 190 Karakul sheep and 245 Awassi sheep, only one SNP (233A > C) was detected in the RETN gene. The identified novel SNP showed significant associations with all growth traits at the ages of six, nine, and twelve months. At the age of six months onward, lambs with AC and CC genotypes showed respectively lower body weight and length, chest and abdominal circumferences, and wither and rump heights than those with AA genotype. Due to the remarkable association between RETN;233A > C and lower growth traits, this genotype is suggested as a promising marker to assess growth traits in Karakul and Awassi sheep. This is the first study that demonstrated the importance of RETN as a possible tool for evaluating growth traits in two breeds of sheep with a possibility to be applied to other breeds via large-scale association analysis.

Including genotypic information in genetic evaluations increases the accuracy of sheep breeding values.

The impact of inclusion of genome-wide genotypes into breeding value predictions for UK Texel sheep is addressed in this article. The main aim was to investigate the level of change in the accuracy values for EBVs when information from animal genotypes is incorporated into the genetic evaluations. New genetic parameters for a range of lamb growth, carcass composition and health traits are described and applied in the estimation of conventional breeding values (EBVs) for almost 822,000 animals as well as genomic breeding values (gEBVs) after adding 10,143 genotypes. Principal component analyses showed that there are no major distinct groups; hence, the population is mainly homogenous and genetically well-linked. Results suggested that the highest change in accuracy was observed for the animals that are not phenotyped but have good links to the reference population. This was seen especially for the lowly heritable health traits thereby proving that the use of genotypes in breeding values estimation may accelerate the genetic gain by producing more accurate values especially for young, un-phenotyped animals.

Design and characterization of a high-resolution multiple-SNP capture array by target sequencing for sheep.

The efficiency of molecular breeding largely depends on inexpensive genotyping arrays. In this study, we aimed to develop an ovine high-resolution multiple-single-nucleotide polymorphism (SNP) capture array, based on genotyping by target sequencing (GBTS) system with capture-in-solution (liquid chip) technology. All the markers were from 40K captured regions, including genes located within selective sweep regions, breed-specific regions, quantitative trait loci (QTL), and the potential functional SNPs on the sheep genome. The results showed that a total of 210K high-quality SNPs were identified in the 40K regions, indicating a high average capture ratio (99.7%) for the target genomic regions. Using genotyped data (n = 317) from liquid chip technology, we further performed genome-wide association studies (GWAS) to detect the genetic loci affecting sheep hair types and teat number. A single significant association signal for hair types was identified on 6.7-7.1 Mb of chromosome 25. The IRF2BP2 gene (chr25: 7,067,974-7,071,785), which is located within this genomic region, has been previously known to be involved in hair/wool traits in sheep. The results further showed a new candidate region around 26.4 Mb of chromosome 13, between the ARHGAP21 and KIAA1217 genes, that was significantly related to teat number in sheep. The haplotype patterns of this region also showed differences in animals with 2, 3, or 4 teats. Advances in using the high-accuracy and low-cost liquid chip are expected to accelerate sheep genomic and breeding studies in the coming years.

Large-scale genotyping platforms are valuable tools for animal selection and breeding programs. The bead chip has been widely used in both research and commercial applications for a long time. A highly efficient and economical genotyping platform has been developed recently. In the present study, by combining the advantages of resequencing and bead chips, we developed a high-resolution capture array based on target sequencing with capture-in-solution technology (liquid chip), including updated functional probes according to the latest research. We further evaluated this approach by using 317 individuals and found that 210K single-nucleotide polymorphisms can be accurately genotyped, confirming the ratio of the captured regions compared with the designed rations is around 99.7%. Genome-wide association studies conducted using this chip suggested IRF2BP2 gene may be involved in hair types and ARHGAP21-KIAA1217 locus may be related to teats number. The liquid chip with high accuracy and low cost can be widely used in genome-wide association studies and genome selection, supporting efforts in molecular breeding and genetic improvement of sheep.

Sheep in the Vineyard: Suitability of Different Breeds and Potential Breeding Objectives.

Protecting a breed of sheep is simple when there is demand for its breed traits, but new market options are often hard to find. In general, grazing sheep are able to take over some viticultural work. Here, we address a new and promising integrated crop-livestock system that involves the integration of sheep in the vineyard during the growing season. Using sheep in a vineyard entails opportunities but also risks, such as the current lack of information, specifically in relation to breed traits. In our survey, we evaluated 26 breeds for their suitability for grazing as long as possible in Central European vineyards during the growing season. First, the breed traits required were identified. Then, 94 flock book breeders were interviewed about specific breed traits. The height of a sheep's muzzle is particularly important for assessing the suitability of a breed, as it defines the potential impact on the foliage area during the growing season. To determine the height of the muzzle, 179 flock book animals were measured. We found that the most important breeding objective for a new breed of sheep is the inability to stand on two legs. Adult animals of the breed Shropshire, and among these especially the shorter-legged Danish type, and Southdown, show a widespread inability to stand on two legs. Ouessant sheep are able to do so, yet are suitable with some limitations. Due to their extraordinarily small size, their reach is limited, as is their grazing performance. Thus, three of the 26 breeds studied here seem suitable for use in the most widespread vine training systems of Central Europe during the growing season. Targeted breeding could further improve the suitability of sheep for viticulture. Our findings could help to protect breeds and breed traits.

Whole Genome Sequencing Analysis to Identify Candidate Genes Associated With the rib eye Muscle Area in Hu Sheep.

In sheep meat production, the rib eye area is an important index to evaluate carcass traits. However, conventional breeding programs have led to slow genetic progression in rib eye muscle area. Operationalizing molecular marker assisted breeding is an optimized breeding method that might improve this situation. Therefore, the present study used whole genome sequencing data to excavate candidate genes associated with the rib eye muscle. Male Hu lambs (n = 776) with pedigrees and 274 lambs with no pedigree were included. The genetic parameters of the rib eye area were estimated using a mixed linear mixed model. The rib eye area showed medium heritability (0.32 ± 0.13). Whole-genome sequencing of 40 large rib eye sheep [17.97 ± 1.14, (cm2)] and 40 small rib eye sheep [7.89 ± 0.79, (cm2)] was performed. Case-control genome-wide association studies and the fixation index identified candidate rib eye-associated genes. Seven single nucleotide polymorphisms (SNPs) in six genes (ALS2, ST6GAL2, LOC105611989, PLXNA4, DPP6, and COL12A1) were identified as candidates. The study population was expanded to 1050 lambs to perform KASPar genotyping on five SNPs, which demonstrated that SNPs in LOC105611989, DPP6, and COL12A1 correlated significantly with the rib eye area, which could be used as genetic markers for molecular breeding of the rib eye area. The results provided genetic parameters estimated on the rib eye area and information for breeding based on carcass traits in Hu sheep.

A desired gains approach for the prediction of genetic gain in resistance to gastrointestinal nematodes in a multi-trait breeding objective in Uruguayan Merino sheep.

Gastrointestinal nematodes (GIN) constitute a problem in many sheep production systems, including those in Uruguay, causing reduced productivity and increased expenses. The main strategy to control GIN has consisted of the use of anthelmintics. However, GINs have developed resistance to anthelmintics, reducing their effectiveness. Genetic resistance to GINs has been found in flocks of different breeds. To date, there have been no reports about GINs breaking down genetic resistance in sheep. Heritability estimates of resistance to GIN within breeds are generally moderate, so that achieving genetic gain within a flock is possible. In this study, we predicted genetic gain in worm egg count (WEC), an indirect (and generally preferred) criterion of resistance to GIN, following different strategies. A multi-trait breeding objective including wool and meat traits was assumed and genetic gain over 10 years of selection in a Merino flock was estimated. We used a desired gains approach, examining situations in which the economic contribution of genetic gain in resistance to GIN in percentage terms was 0, 25, 50, 75 or 100. Except when the level of infestation with GIN was low, a considerable amount of emphasis had to be placed on selection for low WEC in order to reach the threshold below which the administration of anthelmintics is not required. High emphasis on reducing WEC lead to a reduction in genetic gain in wool and meat traits, or to their deterioration in the extreme case of 100 per cent emphasis on WEC. Given this finding, coupled with the difficulties encountered in accurately recording and selecting for WEC, we concluded that in addition to embarking upon a programme of within flock selection, sheep breeders interested in improving genetic resistance to GIN should also consider using breeding stock identified as superior for both resistance and production traits in across flock genetic evaluations.

Supplementation of lamb ewes with different protein sources in deferred marandu palisadegrass (Brachiaria brizantha cv. marandu) pasture / [Suplementação de matrizes ovinas com diferentes fontes de proteína em pasto diferido de capim-marandu (Brachiaria brizantha cv. Marandu)]

The objective of this study was to evaluate the effect of different protein sources on the performance of lamb ewes and their offspring supplemented in deferred pasture. The treatments were the different protein sources: soybean meal, cotton cake, babassu cake and coconut cake. The ewes were weighed and evaluated for their body condition score during the gestation, parturition and weaning phases. The lambs were weighed at birth and at weaning. The structural variables and chemical composition of the pasture were evaluated during the usage period. Grass height and forage mass were higher when the ewes were in the gestation and weaning stages. The leaf mass was not altered during the pasture usage with a mean value of 566.1kg ha-1 DM. The highest levels of crude protein in the leaf blade were observed during the parturition and weaning phases. The body weight of the ewes did not differ between the sources with averages 45.0, 39.9 and 36.6kg for the gestation, parturition and weaning phases, respectively. Weights at birth and at weaning had an effect from protein sources, with the highest values observed in the lambs of ewes who received soybean meal and babassu cake supplementation. The lambs of ewes supplemented with soybean had higher average daily gain and total gain. Babassu, coconut and cotton cakes can replace soybean meal in supplementation of ewes in deferred pasture.(AU)

O objetivo deste estudo foi avaliar o efeito de diferentes fontes de proteína no desempenho de ovelhas e suas crias suplementadas em pastagem diferida. Os tratamentos foram as diferentes fontes proteicas: farelo de soja, tortas de algodão, babaçu e coco. As ovelhas foram pesadas e avaliadas quanto ao escore de condição corporal durante as fases de gestação, parição e desmame. Os cordeiros foram pesados no nascimento e no desmame. As variáveis estruturais e a composição química do pasto foram avaliadas durante o período de uso. A altura do dossel e a massa de forragem foram maiores quando as ovelhas estavam nas fases de gestação e desmame. A massa foliar não foi alterada durante o uso do pasto, com um valor médio de 566,1kg ha-1 MS. Os maiores teores de proteína bruta na lâmina foliar foram observados durante as fases de parto e desmame. O peso corporal das ovelhas não diferiu entre as fontes proteicas, com médias de 45,0, 39,9 e 36,6kg para as fases de gestação, parto e desmame, respectivamente. Os pesos ao nascimento e ao desmame tiveram efeito das fontes proteicas, com os maiores valores observados nos cordeiros de ovelhas que receberam suplementação com farelo de soja e torta de babaçu. Os cordeiros suplementados com soja apresentaram maior ganho médio diário e ganho total. As tortas de babaçu, coco e algodão podem substituir o farelo de soja na suplementação de ovelhas em pastagem diferida.(AU)

Polymorphism of CLPG gene in three sheep breeds grown in the steppe zone of the Russian Federation.

OBJECTIVE: This study aims to investigate the callipyge gene (CLPG) polymorphism in sheep of Edilbay, Volgograd, and Kalmyk breeds. MATERIALS AND METHODS: The analysis was performed by the polymerase chain reaction-restriction fragment length polymorphisms method. The objects of the study were Edilbay fat-tailed sheep (n = 500) at the breeding plant Volgograd-Edilbay (Volgograd region), Volgograd fine-wool sheep (n = 500) at the breeding plant Romashkovskiy (Volgograd region), and Kalmyk fat-tailed sheep (n = 500) at the breeding plant Kirovsky (the Republic of Kalmykia, Yashkul rayon). To conduct the research, tissue samples of 1 cm² from sheep of Kalmyk and Edilbay breeds were taken from the auricle. RESULTS: The allelic CLPG gene variants have been determined and genotypes of representative sampling of the three breeds of livestock grown in the steppe zone of Russia. The presented results of the CLPG gene polymorphism in these sheep breeds grown in Russia were obtained for the first time. The research study has revealed that in terms of the CLPG gene, the Edilbay, Volgograd, and Kalmyk sheep breeds have only a homozygous form. CONCLUSION: The results obtained expand the current understanding of the molecular markers that characterize the meat qualities of sheep.

Pre-pubertal growth, muscle and fat accumulation in male and female sheep-Relationships with metabolic hormone concentrations, timing of puberty and reproductive outcomes.

Metabolic homeostasis is aligned with changes in growth and body composition, through processes mediated by circulating metabolites and metabolic hormones, and is eventually linked to reproductive success. In the present study with sheep, we determined the relationships among phenotypic and genotypic rates of growth, muscle and fat accumulation, and the circulating concentrations of metabolic and tested for relationships with the timing of puberty and subsequent reproductive outcomes. We used 64 females and 62 males with known phenotypic values for depth of eye muscle (EMD) and fat (FAT) and known Australian Sheep Breeding Values at post-weaning age for live weight (PWT), depth of eye muscle (PEMD) and depth of fat (PFAT). Blood plasma sampled every 20 min for 8 hr via was assayed for growth hormone (GH), insulin-like growth factor I (IGF-I), insulin, leptin, ghrelin, follistatin, glucose and non-esterified fatty acids (NEFA). In males, PWT was positively related to the concentrations of GH, follistatin and glucose, whereas FAT and PFAT were positively related to IGF-I concentrations (p < .01). Testosterone concentration was negatively related to muscle variables (p < .001) and to PFAT (p < .05). In females, the only significant relationship detected was the positive link between EMD and insulin concentrations (p < .05). Reproductive variables were only measured in females. Live weight at first oestrus was related positively to insulin concentration and negatively to GH concentration (p < .05). No other relationships with reproductive variables were significant. The relationships that were detected suggest subtle differences between the sexes in the way their metabolic homeostasis responds to changes in the rates of growth, and muscle and fat accumulation, perhaps due to interference by testosterone in the males.

Multiple anthelmintic resistance in Southern Brazil sheep flocks / Múltipla resistência anti-helmíntica em rebanhos ovinos no sul do Brasil

Abstract Gastrointestinal parasites represent an important cause of reduced productivity of sheep worldwide. As anthelmintic are still the main control tool for these parasites, this work evaluated the efficacy of commercially available active principles in 22 sheep flocks in the southern region of Rio Grande do Sul, Brazil. In each farm 10 sheep were randomly distributed in seven groups with the following treatments: abamectin; albendazole; closantel; levamisole; monepantel; trichlorphon and no anthelmintic (control). All flocks showed resistance to at least three anthelmintics and in 20 farms only two products demonstrated efficacy for parasitic control. In two farms, there was no susceptibility to the six active principles tested. The results of this study provide evidence that the common commercially available anthelmintic are not assuring effective chemical control of gastrointestinal parasitic infections in ovine flocks in the southern region of Rio Grande do Sul. Monepantel, the newest introduced drug in the Brazilian market was not effective in 18% of the flocks tested, confirming that the parasitic resistance can be established quickly after the introduction of new molecules mainly when alternative program of parasite control is not performed.

Resumo As parasitoses gastrintestinais representam importante causa de queda na produtividade na ovinocultura mundial. Como a utilização de anti-helmínticos é, ainda, a principal forma de controle parasitário, o presente estudo avaliou a eficácia de princípios ativos comercialmente disponíveis, em 22 rebanhos ovinos da região Sul do Rio Grande do Sul, Brasil. Em cada propriedade foram utilizados 10 ovinos divididos em sete grupos que receberam os seguintes tratamentos: abamectina; albendazole; closantel; levamisole; monepantel; e triclorfon. Um grupo permaneceu como controle, sem tratamento anti-helmíntico. Nas 22 propriedades do estudo houve resistência, no mínimo, a três anti-helmínticos. Em 20 propriedades apenas dois produtos demonstraram eficácia para o controle parasitário. Em duas propriedades não houve sensibilidade aos seis princípios ativos testados. Os resultados do presente estudo demonstraram que os anti-helmínticos disponíveis no marcado Brasileiro não asseguram um controle parasitário efetivo nos rebanhos ovinos da região Sul do Rio Grande do Sul, incluindo o monepantel que foi ineficaz em 18% dos rebanhos testados, confirmando que a resistência dos parasitos aos princípios ativos pode se estabelecer rapidamente após a introdução de novas moléculas, principalmente quando programas alternativos de controle não são realizados.

Characterization of the sheep industry in the medium northern region of Mato Grosso, Brazil

Nas últimas décadas o mercado brasileiro de carne ovina aumentou substancialmente, e o estado de Mato Grosso apresentou a maior taxa de crescimento do Brasil, apesar da falta de informações sobre os sistemas de produção nesta região. Este estudo teve como objetivo caracterizar os sistemas de produção de ovinos da região meio-norte do Mato Grosso, utilizando um questionário com perguntas qualitativas e quantitativas. Dentre as 40 propriedades avaliadas foram predominantes (82,5%; 33/40) rebanhos com menos de 100 animais, com exploração semi-intensiva, voltada para a produção de carne. A ovinocultura foi citada como atividade econômica secundária em 92,5% (37/40) dos rebanhos e, em 60,0% (24/40) das propriedades, os animais eram mantidos apenas para consumo familiar. O manejo sanitário deficiente resultou na ocorrência de diversas doenças, sendo os casos de miíases os mais citados (65,0%; 26/40). A ovinocultura possui grande potencial para o desenvolvimento em Mato Grosso. No entanto, a atividade ainda é negligenciada em muitos aspectos, incluindo a saúde animal.

In recent decades, the Brazilian market for sheep meat has increased substantially, and the State of Mato Grosso had the highest growth rate in Brazil. However, information about ovine production systems in this region is lacking. This study aimed to characterize productive systems of sheep in the medium northern region of Mato Grosso, by application of qualitative and quantitative questionnaires. Among 40 properties evaluated, herds there were predominately with fewer than 100 animals (82.5%, 33/40), with semi-intensive exploration focused on meat production. Livestock sheep was a secondary economic activity in 92.5% (37/40) of farms, and sheep were kept only for family consumption in 60.0% (24/40). Poor health management resulted in the occurrence of various diseases, and myiasis was the most frequently cited disease (65.0%, 26/40). Sheep farming has a great potential for development in Mato Grosso. However, the activity is neglected in many ways, including animal health.

Sheep fed with banana leaf hay reduce ruminal protozoa population.

A ciliate protozoa suppression can reduce methane production increasing the energy efficiency utilization by ruminants. The physicochemical characteristics of rumen fluid and the profile of the rumen protozoa populations were evaluated for sheep fed banana leaf hay in replacement of the Cynodon dactylon cv. vaqueiro hay. A total of 30 male sheep were raised in intensive system during 15 days of adaptation and 63 days of experimental period. The animals were distributed in a completely randomized design that included six replicates of five treatments with replacement levels (0, 25, 50, 75, and 100%) of the grass vaquero for the banana leaf hay. Samples of fluid were collected directly from the rumen with sterile catheters. Color, odor, viscosity, and the methylene blue reduction potential (MBRP) were evaluated and pH estimated using a digital potentiometer. After decimal dilutions, counts of genus protozoa were performed in Sedgewick Rafter chambers. The averages of pH, MBRP, color, odor, and viscosity were not influenced by the inclusion of the banana leaf hay. However, the total number of protozoa and Entodinium spp. population significantly decreased at 75 and 100% inclusions of banana leaf hay as roughage.

Spineless cactus as a replacement for sugarcane in the diets of finishing lambs.

The effects of replacement of sugarcane by spineless cactus (0, 33, 66, and 100 % on dry matter (DM) basis) were evaluated on intake, digestibility of nutrients, ingestive behavior, and performance of finishing lambs. Thirty-six non-castrated Santa Ines lambs at 4 months of age and an initial body weight of 22 ± 2.3 kg were assigned in a randomized block design. A quadratic effect was found for intake of DM, organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and digestible organic matter (DOM), with maximum values of 1.31, 1.19, 0.219, 0.358, and 0.845 g/day estimated with 42.5, 38.5, 38.8, 21.3, and 44.9 % replacement level, respectively. The digestibility of DM, OM, CP, and EE increased linearly; however, there was a quadratic effect on NDF digestibility with maximum value estimated of 500 g/kg with 64.2 % replacement level. Rumination time, total chewing, and rumination efficiency decreased linearly with the replacement levels; however, idle time increased linearly. A quadratic effect was found for final weight, body weight gain, and total weight gain with maximum values estimated of 38.6 kg, 0.232 kg/day, and 16.2 kg with 39.1, 38.2, and 40.4 % replacing levels. The replacement of 49.5 % sugarcane by spineless cactus can be recommended as optimal level, and problems related to intake, digestibility, and performance are concentrated outside that level.

Bayesian inference of genetic parameters for ultrasound scanning traits of Kivircik lambs.

Ultrasound scanning traits have been adapted in selection programs in many countries to improve carcass traits for lean meat production. As the genetic parameters of the traits interested are important for breeding programs, the estimation of these parameters was aimed at the present investigation. The estimated parameters were direct and maternal heritability as well as genetic correlations between the studied traits. The traits were backfat thickness (BFT), skin+backfat thickness (SBFT), eye muscle depth (MD) and live weights at the day of scanning (LW). The breed investigated was Kivircik, which has a high quality of meat. Six different multi-trait animal models were fitted to determine the most suitable model for the data using Bayesian approach. Based on deviance information criterion, a model that includes direct additive genetic effects, maternal additive genetic effects, direct maternal genetic covariance and maternal permanent environmental effects revealed to be the most appropriate for the data, and therefore, inferences were built on the results of that model. The direct heritability estimates for BFT, SBFT, MD and LW were 0.26, 0.26, 0.23 and 0.09, whereas the maternal heritability estimates were 0.27, 0.27, 0.24 and 0.20, respectively. Negative genetic correlations were obtained between direct and maternal effects for BFT, SBFT and MD. Both direct and maternal genetic correlations between traits were favorable, whereas BFT-MD and SBFT-MD had negligible direct genetic correlation. The highest direct and maternal genetic correlations were between BFT and SBFT (0.39) and between MD and LW (0.48), respectively. Our results, in general, indicated that maternal effects should be accounted for in estimation of genetic parameters of ultrasound scanning traits in Kivircik lambs, and SBFT can be used as a selection criterion to improve BFT.

Risk factors for Toxoplasma gondii infection in sheep in the northeastern region of Brazil / Fatores de risco para a infecção de Toxoplasma gondii em ovinos da região nordeste do Brasil

Toxoplasma gondii is an infective parasite that causes reproductive disorders such as abortion, fetal mummification, birth of weak offspring, and stillbirth, thereby causing economic losses to sheep production. The northeastern region of Brazil has approximately 171 million small ruminants, of which 5.4% are sheep. The present study aimed at determining the rate of occurrence of T. gondii in sheep flocks on 60 farms in 19 municipalities in the three mesoregions (eastern, semi-arid, and sertão or backlands) of the state of Sergipe, Brazil, and the risk factors associated with this infection. Serum samples were collected between 2011 and 2012, from 60 farms located in 19 municipalities in the three mesoregions: 680 in the eastern region, 280 in the semi-arid region, and 240 in the backlands, totaling 1,200 samples (990 females and 210 males). Anti-T. gondii antibodies were detected by means of the indirect fluorescence antibody test (IFAT ≥ 64). The highest occurrence was detected in the eastern region (45.3%, p = 0.001). On farms with subsistence production, the risk of having animals infected by T. gondii was approximately twice as high as on breeding/rebreeding/fattening farms (OR: 3.03; CI: 1.97-4.68). There was a significant lack of sanitary care, such as absence of a dunghill (p = 0.000; OR: 1.60; CI: 1.26-2.03), quarantine (p = 0.000; OR: 1.87; CI: 1.45-2.41) and disinfection (p = 0.003; OR: 1.46; CI: 1.13-1.88). Regarding feeding, the risk of infection was 1.74 and 1.37 times higher in places that used a trough and/or that cats could access, respectively. The present study allows the conclusions that T. gondii is found on farms in the three mesoregions of the state of Sergipe and that environmental and management factors have an influence on sheep infection.(AU)

Toxoplasma gondii é um parasita cuja infecção leva a desordens reprodutivas como aborto, mumificação fetal, nascimento de cordeiros fracos e natimortos, provocando perdas econômicas na produção ovina. A região nordeste do Brasil possui aproximadamente 171 milhões de pequenos ruminantes, dos quais 5,4% são ovinos. Este estudo tem como objetivo determinar a ocorrência de T. gondii nos rebanhos ovinos de 60 propriedades de 19 municípios de três mesorregiões (leste, semiárido e sertão) do estado de Sergipe, Brasil, e os fatores de risco associados a essa infecção. Amostras de soro foram coletadas entre 2011 e 2012, em 60 propriedades localizadas em 19 municípios das três mesorregiões: 680 na região leste, 280 no semiárido e 240 no sertão, totalizando 1.200 amostras (990 fêmeas e 210 machos). Anticorpos anti-T.gondii foram detectados por reação de imunofluorescência indireta (RIF ≥ 64). A maior ocorrência foi detectada na região leste (45,3%, p = 0.001). Em propriedades com produção de subsistência, o risco de animais infectados por T. gondii é aproximadamente duas vezes maior que nas de cria/recria/engorda (OR = 3.03/ IC: 1.97-4.68). A ausência de cuidados sanitários, como ausência de esterqueira (p = 0.000/ OR: 1.60; CI: 1.26-2.03); quarentena (p = 0.000/ OR: 1.87; CI: 1.45-2.41) e desinfecção (p = 0.003/ OR: 1.46; CI: 1.13-1.88) foram significantes. Em relação à alimentação, o risco de infecção aumenta 1.74 e 1.37 em locais que utilizam cocho ou com presença de gatos, respectivamente. Este estudo permite concluir que o T. gondii é encontrado em propriedades das mesorregiões do estado de Sergipe e fatores ambientais e de manejo estão influenciando nas infecções em ovinos.(AU)

Using the choice experiment method in the design of breeding goals in dairy sheep.

Market failures are the main cause of poor acknowledgement of the true impact of functional sheep traits on the management and economic performance of farms, which results in their omission from the breeding goal or the estimation of non-representative economic weights in the breeding goal. Consequently, stated-preference non-market valuation techniques, which recently emerged to mitigate these problems, are necessary to estimate economic weights for functional traits. The purpose of this paper is to present an example of the use of a choice experiment (CE) in the estimation of economic weights for sheep traits for the design of breeding goals. Through a questionnaire survey the preferences of sheep farmers are recorded and their marginal willingness to pay (MWTP) for 10 production and functional traits is estimated. Data are analysed using random parameter logit models. The results reveal unobserved preference heterogeneity for fertility, adaptability to grazing and resistance to disease, thus highlighting that these traits are appreciated differently by farmers, because their needs are diverse. Positive MWTP is found for Greek breeds, high milk production and lambs with low fat deposition, for which there is high demand in Greek markets. On the other hand, MWTP for the cheese-making ability of milk is negative, stemming from the fact that sheep milk prices in Greece are not formulated according to milk composition. In addition, farmers seem to understand differences between udder shapes and attribute different values to various types. This application of the CE method indicates that communication channels among farmers and breeders should be established in order to enhance market performance and to provide orientation to the design of breeding programmes. Non-market valuation can be used complementarily to market valuation techniques, in order to provide accurate estimates for production and functional traits.

Ewe lambs with higher breeding values for growth achieve higher reproductive performance when mated at age 8 months.

We studied the relationships among growth, body composition and reproductive performance in ewe lambs with known phenotypic values for depth of eye muscle (EMD) and fat (FAT) and Australian Sheep Breeding Values for post-weaning live weight (PWT) and depth of eye muscle (PEMD) and fat (PFAT). To detect estrus, vasectomized rams were placed with 190 Merino ewe lambs when on average they were 157 days old. The vasectomized rams were replaced with entire rams when the ewe lambs were, on average, 226 days old. Lambs were weighed every week and blood was sampled on four occasions for assay of ghrelin, leptin and ß-hydroxybutyrate. Almost 90% of the lambs attained puberty during the experiment, at an average live weight of 41.4 kg and average age of 197 days. Ewe lambs with higher values for EMD (P < 0.001), FAT (P < 0.01), PWT (P < 0.001), PEMD (P < 0.05) and PFAT (P < 0.05) were more likely to achieve puberty by 251 days of age. Thirty-six percent of the lambs conceived and, at the estimated date of conception, the average live weight was 46.9 ± 0.6 kg and average age was 273 days. Fertility, fecundity and reproductive rate were positively related to PWT (P < 0.05) and thus live weight at the start of mating (P < 0.001). Reproductive performance was not correlated with blood concentrations of ghrelin, leptin or ß-hydroxybutyrate. Many ewe lambs attained puberty, as detected by vasectomized rams, but then failed to become pregnant after mating with entire rams. Nevertheless, we can conclude that in ewe lambs mated at 8 months of age, higher breeding values for growth, muscle and fat are positively correlated with reproductive performance, although the effects of breeding values and responses to live weight are highly variable.