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.

Perioperative Evaluation of Arterial and Venous Whole Blood in the Lamb (Ovis aries) Fontan Model.

Whole blood analysis can evaluate numerous parameters, including pH, pCO2, pO2, HCO3 - , base excess, glucose, electrolytes, lactate, blood urea nitrogen, creatinine, bilirubin, and hemoglobin. This valuable tool enables clinicians to make more informed decisions about patient care. However, the current body of literature describing perioperative whole blood analysis in Dorset sheep (Ovis aries) is small, so clinicians lack adequate information to guide their decision-making when evaluating test results. We evaluated arterial and venous whole blood pH, bicarbonate, pCO2, lactate, creatinine, and blood urea nitrogen before and for the first 24 hours after surgery in 2 cohorts of male and female Ovis arie s undergoing one of 2 major cardiovascular procedures, a Single-Stage Fontan or an inferior vena cava to pulmonary artery extracardiac conduit implantation (IP-ECC). The cohort undergoing a Single-Stage Fontan, which is the more complex procedure, exhibited greater deviation from baseline measurements than did the cohort undergoing the IP-ECC for lactate, bicarbonate, and creatinine. The cohort undergoing the IP-ECC showed no significant deviation from baseline for any parameters, potentially indicating a better safety margin than expected when compared with the Single-Stage Fontan. Together, these results indicate the clinical value of arterial and venous whole blood measurements in perioperative management of sheep and can provide a reference for clinicians managing sheep after significant cardiovascular procedures.

Response of plantain (Plantago lanceolata L.) supplementation on nutritional, endo-parasitic, and endocrine status in lambs.

The aim of the present study was to assess the effects of plantain herb (Plantago lanceolata L.) supplementation on growth, plasma metabolites, liver enzymatic activity, hormonal status, gastrointestinal parasites, and carcass characteristics of lambs. A total of 24 lambs, aged 6 months weighing 8.0 ± 0.5 kg were randomly allocated to one of two dietary treatments: (1) CL diet-roadside grass and concentrate mixture; (2) PL diet-CL diet + 5% fresh plantain supplementation on a DM basis. The PL diet group exhibited 23% higher (P = 0.01) average daily gain and 15% improved (P = 0.03) feed conversion efficiency. Circulating cholesterol concentrations were suppressed by 9% (P = 0.03), and liver enzyme activity was improved by 5-25% (P < 0.05) in the lamb fed PL diet, compared with CL diet only. The inclusion of plantain in the diet was highly effective at suppressing the parasites, Paramphistomum spp. (P = 0.003) and coccidial parasites (P = 0.04), but not stomach worms. Moreover, plantain supplementation increased growth hormone and insulin concentrations in plasma level, whereas decreased carcass fat by 32.7%. Therefore, supplementation of the lambs' diet with plantain showed some beneficial effects on productivity and parasitic infection, while it led to a leaner carcass.

Two co-inherited novel SNPs in the MC4R gene related to live body weight and hormonal assays in Awassi and Arabi sheep breeds of Iraq.

Melanocortin-4 receptor (MC4R) gene plays a key role in the regulation of body weight and energy homeostasis. This study aims to evaluate the association of single nucleotide polymorphisms (SNPs) of the MC4R gene with live body weight and hormonal assays in two breeds of sheep that differ in productive performance, Awassi and Arabi. All known coding sequences of the MC4R gene were covered in this study. DNA samples from 150 animals (Awassi and Arabi breed) were genotyped by PCR-single-strand conformation polymorphism (PCR-SSCP) to assess their pattern of genetic variation. Concerning exon 1, clear heterogeneity was detected with three different SSCP-banding patterns. The sequencing reactions confirmed these variations by detecting the presence of the two novel SNPs, 107G/C and 138A/C, and three genotypes, GC, AC and AA. The 107G/C SNP was detected in GC genotype, while the 138A/C was detected on both GC and AC genotypes. The other SSCP-banding pattern (AA genotype) did not show any detectable unique variation. Both SNPs were closely and strongly linked in both breeds (D' and r2 values were 1.00), which signifies that both loci were co-inherited as one unit. Association analysis indicated that both breeds with GC/AC haplotype showed higher live body weight (37.250 ± 0.790) relative to the GG/AA (30.244 ± 0.968) and CC/CC (47.231 ± 1.230) haplotypes (p < .05). Concerning the genotyping of exon 2, only 362 bp showed heterogeneity with a missense mutation, with no significant association (p > .05) with the measured traits. In conclusion, the two novel SNPs (107G/C and 138 A/C) were highly associated with live body weight in both breeds. Haplotype analysis confirmed that these two novel SNPs were in strong linkage disequilibrium (LD) and could be used as genetic markers for sheep phenotypic trait improvement.

Relationships among body condition score, FAMACHA© score and haematological parameters in Pelibuey ewes.

The objective of the present study was to determine the associations between the FAMACHA© score, body condition score (BCS) and several haematological parameters of Pelibuey ewes. In total, 52 clinically healthy Pelibuey ewes were evaluated in this study. A blood sample was collected from each animal to determine haematological variables. The BCS was evaluated on a scale of 1 to 5 and subsequently grouped into four categories: (1) < 1.5, (2) 2.0-2.5, (3) 3.0-3.5 and (4) > 4.0. The coloration of conjunctival mucosa was evaluated using the FAMACHA© system. The analysed haematological parameters were red blood cell (RBC) count, haemoglobin (HGB), haematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), red blood cell distribution width standard deviation (RDW-SD) and red blood cell distribution width coefficient of variation (RDW-CV). A descriptive statistical analysis was performed, and the Pearson correlation coefficients between variables were estimated. Haematological parameters were analysed with one-way analyses of variance, and the Tukey test was applied when significant differences were detected. The FAMACHA© score was only associated with MCHC (r = - 0.30, P < 0.05). The haematological parameters of RBC count, HCT, RDW-SD and RDW-CV statistically differed among BCS groups. The BCS was associated with RBC count, HCT, RDW-SD and RDW-CV, with r values ranging from 0.35 to 0.48. The haematological values were similar to those reported in ewes from Iran and Iraq. Hence, the optimization of the BCS calculation of Pelibuey ewes can generate association tables with haematological parameters to aid in the sanitary and feeding management of sheep.

In vitro propagation and genome sequencing of three 'atypical' Ehrlichia ruminantium isolates.

Three isolates of Ehrlichia ruminantium (Kümm 2, Omatjenne and Riverside), the causative agent of heartwater in domestic ruminants, were isolated in Ixodes scapularis (IDE8) tick cell cultures using the leukocyte fraction of infected sheep blood. All stocks were successfully propagated in IDE8 cells, whereas initiation attempts using endothelial cell cultures were unsuccessful. Therefore, the new technique should be included in any attempt to isolate field strains of E. ruminantium to enhance the probability of getting E. ruminantium isolates which might not be initiated in endothelial cells. Draft genome sequences of all three isolates were generated and compared with published genomes. The data confirmed previous phylogenetic studies that these three isolates are genetically very close to each other, but distinct from previously characterised E. ruminantium isolates. Genome comparisons indicated that the gene content and genomic synteny were highly conserved, with the exception of the membrane protein families. These findings expand our understanding of the genetic diversity of E. ruminantium and confirm the distinct phenotypic and genetic characteristics shared by these three isolates.

Acute-phase proteins, cortisol and haematological parameters in ewes during the periparturient period.

Numerous subclinical diseases in sheep occur in the periparturient period and involve inflammatory processes; therefore, determining markers, such as acute-phase proteins (APPs), can allow an early diagnosis. Therefore, the objective of the present study was to assess changes in the plasma concentration of APPs and cortisol in clinically healthy ewes in the periparturient period for use in future studies. At the same time, haematological parameters were monitored. We showed that plasma APPs and cortisol concentrations were significantly higher in pregnant ewes than before insemination. A gradual increase in the SAA concentration was observed from the 14th day before to the day of parturition, while Hp was reduced from 2 weeks before up to 2 weeks after delivery. A significant increase in the Fb concentration was detected from the 14th day before to the 1st week after delivery. The cortisol concentration did not undergo significant changes in the periparturient period. We found an increase in the SAA and Fb concentrations and decrease in Hp in the periparturient period. The direction of the change in APPs of healthy ewes in the current study may be related to their distinct regulatory mechanisms during pregnancy. The APPs are usually altered during infection, inflammation, neoplasia, stress and trauma; therefore, knowing their reference values could help lead to an early diagnosis of subclinical forms of some diseases and pregnancy complications in ewes. The haematological analysis showed that ewes in late pregnancy and postpartum compared to dry period were under metabolic stress related to pregnancy and lactation.

Plasma anti-Müllerian hormone concentration as a predictive endocrine marker for selection of donor lambs to improve success in juvenile in vitro embryo transfer programs.

The use of juvenile invitro embryo transfer (JIVET) is limited by variation between prepubertal lambs in ovarian response to exogenous gonadotrophins. In cattle, anti-Müllerian hormone (AMH) is a predictive endocrine marker of antral follicle count. In this study we measured plasma AMH concentrations in lambs at 3 and 5 weeks of age and determined associations between AMH concentrations and ovarian response to gonadotrophins and invitro blastocyst production at 6-8 weeks of age in a JIVET program. At 5 weeks, AMH (n=38) was positively correlated with surface antral follicle count (r=0.87, P<0.001), blastocysts produced (r=0.92, P<0.001) and blastocysts produced as a proportion of oocytes collected (r=0.44, P<0.01) or cleaved (r=0.43, P<0.01). Similar associations were observed between AMH at 3 weeks (n=30) and follicle number (r=0.70, P<0.05) and blastocysts produced (r=0.87, P<0.05). Lambs with high (>2.2ngmL-1) compared with medium (0.4-2.2ngmL-1) and low (<0.4ngmL-1) AMH at 5 weeks had more antral follicles (mean (±s.e.m.) 118.7±13.9 vs 68.2±8.1 and 30.4±12.3 respectively; P<0.05) and more blastocysts produced (mean (±s.e.m.) 54.9±6.9 vs 18.9±4.0 and 7.5±6.1 respectively; P<0.05). These results suggest that AMH concentration at 5 weeks of age can be used to select donor lambs which enhance the success of JIVET programs.

Comparative metabolome analysis of serum changes in sheep under overgrazing or light grazing conditions.

BACKGROUND: Overgrazing is a primary contributor to severe reduction in forage quality and production in Inner Mongolia, leading to extensive ecosystem degradation, sheep health impairment and growth performance reduction. Further studies to identify serum biomarkers that reflect changes in sheep health and nutritional status following overgrazing would be beneficial. We hereby hypothesize that reduced sheep growth performance under overgrazing conditions would be associated with metabolic and immune response alterations. This study used an untargeted metabolomics analysis by conducting ultra-high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) of sheep serum under overgrazing and light grazing conditions to identify metabolic disruptions in response to overgrazing. RESULTS: The sheep body weight gains as well as serum biochemical variables associated with immune responses and nutritional metabolism (immunoglobulin G, albumin, glucose, and nonesterified fatty acids) were significantly decreased with overgrazing compared with light grazing condition. In contrast, other serum parameters such as alanine and aspartate aminotransferase, alkaline phosphatase, total bilirubin, blood urea nitrogen, and interleukin-8 were markedly higher in the overgrazing group. Principal component analysis discriminated the metabolomes of the light grazing from the overgrazing group. Multivariate and univariate analyses revealed changes in the serum concentrations of 15 metabolites (9 metabolites exhibited a marked increase, whereas 6 metabolites showed a significant decrease) in the overgrazing group. Major changes of fatty acid oxidation, bile acid biosynthesis, and purine and protein metabolism were observed. CONCLUSIONS: These findings offer metabolic evidence for putative biomarkers for overgrazing-induced changes in serum metabolism. Target-identification of these particular metabolites may potentially increase our knowledge of the molecular mechanisms of altered immune responses, nutritional metabolism, and reduced sheep growth performance under overgrazing conditions.

Effects of ammoniated pearl millet silage on intake, feeding behavior, and blood metabolites in feedlot lambs.

The aim of this study was to evaluate the effects of urea as an additive in the ensiling of pearl millet on the intake, feeding behavior, and metabolic parameters of feedlot-finished lambs. Thirty-two uncastrated, mixed-breed male lambs were used in the experiment. Diets were composed of pearl millet silage enriched with 0, 2, 4, or 6% urea plus a concentrate containing ground corn, soybean meal, and a mineral mixture. The treatments did not affect feed intake (P > 0.05) but influenced (P < 0.05) eating time (in min/day, in min/kg of dry matter (DM), and in min/kg of neutral detergent fiber (NDF)) and chewing time in min/kg of DM. Eating efficiency (in g DM/h and in g NDFap/h) responded linearly (P < 0.05) to the increasing urea levels in the silages. By contrast, there was no effect (P > 0.05) of diets on the blood protein profile (total proteins and albumin), although the serum urea levels responded quadratically (P < 0.05). Increasing urea levels in the silage did not change the blood energy profile (cholesterol and triglycerides) or blood enzyme activity (alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT); P > 0.05). In conclusion, the treatment of pearl millet silage with urea does not influence the DM intake or metabolic parameters of lambs, but leads to increased eating time and decreased eating efficiency.

Dietary supplementation of 11 different plant extracts on the antioxidant capacity of blood and selected tissues in lightweight lambs.

BACKGROUND: Due to the growing public concern regarding the addition of chemical antioxidants to foods, focus has shifted towards natural alternatives. Because of their antioxidant potential, culinary herbs and spices have long been used to extend the shelf-life of foods. However, a better understanding of the fate of these products following intake is required to assess their use in lamb diets. RESULTS: Two hundred and eighty-eight Rasa Aragonesa male lambs (70 days old) were supplemented (5.0 g kg-1 compound feed) with bay, marjoram, oregano, rosemary, thyme, turmeric, cumin, caraway, dill, cinnamon and nutmeg extracts for 14 days before slaughter. Dietary supplementation with plant extracts had no effect on intake, growth performance or antioxidant activity in blood (TEAC values). In muscle, nutmeg supplementation increased (P < 0.05) the radical-scavenging capacity (TEAC), whereas a decrease in the radical-scavenging capacity was found for lambs supplemented with oregano, dill, cinnamon and nutmeg (ORAC values). In liver, nutmeg supplementation increased (P < 0.05) the antioxidant capacity (TEAC), whereas bay (ORAC), turmeric, cinnamon and nutmeg (DPPH• values) decreased (P < 0.05) the radical-scavenging capacity of the tissue. In kidney, a lower (P < 0.05) radical-scavenging capacity (TEAC values) was found in lambs supplemented with oregano, cumin and caraway, whereas, turmeric, cumin, caraway, cinnamon and nutmeg increased (P < 0.05) the antioxidant capacity (ORAC values) in kidney. CONCLUSION: Supplementation of lamb diets with plant extracts affected radical-scavenging activity in muscle, liver and kidney. However, due to the divergent results of the different assays for the same tissue, it is not advisable to discriminate plant extracts using this approach. © 2019 Society of Chemical Industry.

Amino acids profile within peripheral blood and follicular fluid based on high-performance liquid chromatography methods may explain differences in folliculogenesis between short-term under/over-fed treatments during luteal phase of Hu sheep.

The nutritional alteration of amino acids (AAs) profile in physiological fluid was poorly characterized in livestock. After oestrus synchronization, 24 ewes were randomly assigned to two groups based on the nutrient requirement recommended for maintenance (M): the feed-supplemented group (S, 1.5 × M, N = 12) and feed-restricted group (R, 0.5 × M, N = 12) on days 6-12 of their oestrous cycle, which occurred shortly before ovulation. The concentration of 30 AAs in peripheral blood (PB) and follicular fluid (FF) was quantified to calculate the PB-to-FF concentration gap for each AA and determine its correlation with metabolites and hormones in PB and FF. Results showed that the feed restriction enlarged the oestrous cycle length, decreased the number of follicles 2.5-3.5 mm, increased the number of follicles >3.5 mm and augmented the volume of follicles >2.5 mm. Nineteen AAs from PB were significantly different between the groups. The phosphoethanolamine (PEtN) and ration of essential AAs to nonessential AAs (EAA/NEAA) in FF significantly (p < 0.05) increased and decreased in the R group, respectively. Most AAs, except aspartate (Asp) and carnosine (Car) in the R group and alanine (aAla) in both groups, were significantly lower within FF than those within PB. The correlation of AAs with FSH and progesterone (P4 ) was more significant than that of AAs with other endocrine milieu characteristics. In conclusion, our results revealed that the influence of short-term nutritional manipulation during luteal phase on folliculogenesis might not be due to the variation of intrafollicular AAs profile but rather attribute to the peripheral blood AAs profile alteration.

Effects of late gestation shearing on BW, feed intake and plasma metabolite concentrations in Rambouillet ewes managed outdoors during winter.

The majority of lambs in the United States are born from late winter to early spring and pregnant ewes are generally sheared in the last third of pregnancy. Although there are benefits to shearing before parturition, shorn animals may be more vulnerable to the cold, highly variable climatic conditions associated with these seasons. The objective of this study was to determine if late gestation shearing induces differences in individual BW, dry matter intake (DMI) and plasma metabolite concentration of finewool ewes managed outdoors during winter. Thirty-six mature, pregnant Rambouillet ewes (3.8±0.45 years; 76.8±11.4 kg) were managed in a drylot with ad libitum access to pelleted alfalfa in bunks capable of measuring individual daily DMI. The treatment group consisted of ewes sheared at ~5 weeks before the estimated parturition date (shorn; n=18). Unshorn ewes (n=18) remained in full fleece throughout the experiment and were shorn on the last day of the experiment ~2 weeks before the estimated parturition date. Blood was collected on days 0 (before shearing shorn group), 7, 14 and 21 (before shearing unshorn group) of the trial, and plasma was isolated and analyzed for non-esterified fatty acid (NEFA), ß-hydroxybutyrate (BHB) and glucose (GLU) concentrations. There was no effect of shearing on ewe DMI or BW during the trial (P⩾0.35). Plasma NEFA and GLU concentrations were similar (P⩾0.36) between shearing groups, though plasma BHB concentration was 103.7 µmol/l greater (24.1%; P<0.01) in unshorn ewes. Lamb BW at birth was not affected (P=0.30) by ewe shearing treatment. Under conditions of this study, no differences in economically important aspects of sheep production were observed between shorn and unshorn pregnant ewes.

Relationships between handling, behaviour and stress in lambs at abattoirs.

There is community concern about the treatment of farm animals post-farm gate, particularly animal transport and slaughter. Relationships between lamb behavioural and physiological variables on farm, stockperson, dog and lamb behavioural variables pre-slaughter and plasma cortisol, glucose and lactate in lambs post-slaughter were studied in 400 lambs. The lambs were observed in three behavioural tests, novel arena, flight distance to a human and temperament tests, before transport for slaughter. Closed-circuit television video footage was used to record stockperson, dog and lamb behaviour immediately before slaughter. Blood samples for cortisol, glucose and lactate analyses were collected on farm following the three behavioural tests and immediately post-slaughter. The regression models that best predicted plasma cortisol, glucose and lactate concentrations post-slaughter included a mixture of stockperson and dog behavioural variables as well as lamb variables both on-farm and pre-slaughter. These regression models accounted for 33%, 34% and 44% of the variance in plasma cortisol, glucose and lactate concentrations post-slaughter, respectively. Some of the stockperson and dog behaviours pre-slaughter that were predictive of the stress and metabolic variables post-slaughter included the duration of negative stockperson behaviours such as fast locomotion and lifting/pulling lambs, and the duration of dog behaviours such as lunging and barking at the lamb, while some of the predictive lamb behaviour variables included the durations of jumping and fleeing. Some of the physiological and behavioural responses to the behavioural tests on farm were also predictive of the stress and metabolic variables post-slaughter. These relationships support the well-demonstrated effect of handling on fear and stress responses in livestock, and although not direct evidence of causal relationships, highlight the potential benefits of training stockpeople to reduce fear and stress in sheep at abattoirs.

Effect of altered ambient temperature through shelter modifications on physiological indicators of Malpura lambs reared in semi-arid region during winter.

Microclimatic factors are of crucial aspect for the welfare of animals. Therefore, a study was conducted to assess the effect of altered ambient temperature through shelter modifications on physiological indicators of Malpura lambs reared in the semi-arid region during winter. Twenty-one Malpura lambs of 3-5 week age and average body weight 9.97 ±â€¯0.51 kg were used in the present study. The lambs were divided into three groups (eg. G1, G2, and G3) and were kept in the different microenvironment by manipulation of shelter design. The G1 lambs were maintained at lower minimum temperature (8.59 ±â€¯0.71 °C) in asbestos roofed shed, while G2 lambs were maintained at higher minimum temperature (14.59 ±â€¯0.54 °C) in local handmade bamboo dome structure, and G3 lambs were kept at a medium minimum temperature (11.84 ±â€¯0.64 °C) in thermocol insulated roofed shed from evening 18:30 h to morning 07:00 h. The study was carried out for one month between January and February. The parameters studied were physiological response (respiration rate, pulse rate, rectal temperature), skin temperature, blood metabolites and endocrine profile. The data were analyzed by general linear models. Higher average daily weight gain was recorded in the lambs kept in higher minimum temperature groups (20.54% higher in G2 and 24.68% higher in G3) as compared to G1 lambs. Microenvironment manipulation had no significant (P > 0.05) effect on most of the physiological response and skin temperature except morning respiration rate within low-temperature range. The present study reveals that Hb, PCV, T3, and cortisol level were significantly (P < 0.05) influenced by microenvironment manipulation. The results of the study indicated that altered ambient temperature through altered shelter design of housing for raising of lambs in the semi-arid tropical region may support animal welfare during chilling nights of the winter.

Long-distance transport of hair lambs: effect of location in pot-belly trailers on thermo-physiology, welfare and meat quality.

Livestock transport exposes animals to a range of potential stressors that may compromise their welfare and final product quality, and those effects typically increase with the distance travelled. In North America, producers often use pot-belly vehicles for long hauls but little is known about their suitability for transporting lambs. We followed two long-distance trips using pot-belly trailers carrying 500 lambs (each) from Northern to Central Mexico in winter, to measure possible effects on animal welfare and meat quality. Sixty lambs per trip were placed at different locations within the pot-belly trailer. Animals were equipped with iButton Thermochron® temperature devices, which registered body temperature throughout pre- and post-slaughter stages. Despite the rather cool winter conditions, lambs placed in the "belly" and "nose" compartments had higher body temperatures at loading, during transport and lairage and after slaughter (carcass temperature). Those lambs also had higher levels of plasma cortisol, glucose and creatine kinase (CK), and a higher neutrophil/lymphocyte ratio. Regarding meat quality, ultimate pH (24 h) was higher in all locations, especially in LT4 location. Overall, the results suggest a link between thermal stress during transport, elevated physiological indicators of stress and poorer meat quality.

Genetic differentiation and phylogeny of 27 sheep populations based on structural gene loci.

To explore the genetic divergence and phylogeny of Chinese indigenous sheep breeds, in the current study, we analyzed the polymorphisms of 5 structural loci in ten sheep populations, including Sishui Fur, Sunite, Wurank, Bayinbuluke, Altay, Small-Tailed Han, Wadi, Tan, Tong and Hu sheep. The data were then compared with those from an additional 13 Asian and 4 European sheep populations acquired by the same experimental method. Based on the genetic distance and the results of a cluster analysis, we constructed the phylogenetic relationship of 27 populations. The results showed that the sheep populations in this study could be classified into four genetic groups: "Mongolian", "Tibetan", "South-Southeast Asian" and "European" sheep groups. All 10 Chinese sheep breeds belonged to the "Mongolian sheep" lineage; however, Finnish Landrace sheep and Yunnan sheep could not be classified into any of the four groups. These results could provide a good reference for the protection and utilization of primary breed resources in China and phylogenic research on Asian sheep populations.

Assessing the protective effect of bentonite against lead toxicity in growing lambs.

The objective of the present experiment was to investigate the effect of bentonite supplementation in lead (Pb)-exposed lambs on serum Pb, Ca, P, Cu, Zn, and Fe concentrations, blood hematological parameters, and hepatic enzymes. Twenty Zandi male lambs (initial BW, 17.5 ± 1.6 kg) were randomly assigned to one of the four treatments: (1) control (no Pb or bentonite), (2) 15 mg/kg DM Pb as Pb acetate with no bentonite, (3) 15 mg/kg DM Pb as Pb acetate with 1.5% bentonite, and (4) 15 mg/kg DM Pb as Pb acetate with 3% bentonite. The experiment lasted after 90 days. Lead intake resulted in a decrease (P < 0.05) in serum Fe and an increase in serum Pb, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities (P < 0.05). Bentonite supplementation at 1.5 or 3% of DM decreased blood Pb concentration (P < 0.01) in lambs fed diets containing Pb and reduced (P < 0.05) blood concentration of Cu and Zn compared to control group (P < 0.01). However, the hematological parameters were not affected by any of the treatments. Our results showed that the dietary supplementation of bentonite could protect lambs against lead toxicity.