Search Results (48)

This study evaluated the effects of dietary magnesium sulfate (MgSO₄) addition in twin-bearing ewes during late gestation on the duration of lambing, neonatal behavior, and blood biochemical variables. Fifty-one hogget and 54 adult Finnish × Polwarth ewes were allocated to four groups based on age category (hogget or adult) and dietary addition (MgSO₄ addition or control). Ewes in dietary MgSO₄ treatments received 7 g of MgSO₄/ewe/day. Duration of the expulsion phase (DII), interval between lamb births (IL), and total lambing time (TL) were recorded. Meconium score (0–3), birth weight, time to stand (TS), time to first successful suck (SS), and rectal temperature at birth (T0) and at 3 h of life (T3) were measured. Blood samples were collected from lambs and analyzed for blood biochemical and acid–base variables. MgSO₄ addition did not affect individual or litter birth weight (p > 0.05), but the DII was lower in the lambs from MgSO₄ ewes (p < 0.05). A greater proportion of lambs born to dietary MgSO₄ ewes had higher meconium scores. The treatment did not affect the acid–base variables (p > 0.05); however, the age category had an effect on BEecf, HCO₃⁻, tCO₂, lactate and glucose, and behavior variables (p < 0.05). Acidosis (pH < 7.20) occurred in lambs from control ewes. No differences were observed in T0, but lambs from control hoggets had lower T3 values (p < 0.05). In conclusion, in our conditions, dietary MgSO₄ addition in twin-bearing ewes during late gestation reduced the duration of the expulsion phase without affecting neonatal behavior or the main indicators of neonatal acid–base status. Further studies are needed to elucidate the mechanisms by which MgSO₄ influences the lambing process. Full article

Evaluating the in vivo systemic tolerance of phytogenic feed additives is a crucial prerequisite before their widespread application in vulnerable newborn ruminants. This study aimed to investigate the systemic effects of orally administered cold-pressed Nigella sativa oil on the hematological and biochemical profiles of neonatal lambs (0–45 days of age) fed exclusively on colostrum and maternal milk. The pre-specified primary endpoint was the absence of clinically meaningful change in hepatorenal markers and complete blood count between groups over 45 days. Thirty-two single-born Merino lambs were divided into a treatment group that received 1.5 mL/day of the oil for the first 15 days of life and an untreated control group. Blood samples were collected on days 0, 7, 21, and 45 to evaluate both immediate and carry-over physiological effects. Using a covariate-adjusted linear mixed-effects model to account for baseline variances, the results demonstrated that the oil was physiologically well-tolerated. The supplementation exerted no significant adverse effects (p > 0.05) on hepatorenal markers or the measured acute-phase protein. The supplementation maintained neonatal energy metabolism stability without inducing artificial lipid suppression in serum triglycerides or total cholesterol levels. Furthermore, the oil preserved hematological homeostasis without negatively impacting red blood cell indices and modulated platelet distribution width indices without causing pathological thrombocytosis. In conclusion, the early direct oral administration of N. sativa oil is a physiologically well-tolerated supplement that supports basal metabolic and hematological stability in pre-ruminant lambs without inducing systemic disruptions within the parameters measured. Full article

(1) Background: Sunflower hulls (SFHs) are an abundant agro-industrial by-product that may serve as an alternative fiber source in sheep diets, particularly in arid production systems. This study evaluated the effects of graded levels of dietary SFH during late gestation and lactation on colostrum and milk composition, lamb growth performance, neonatal survival, and serum biochemical parameters in Naemi sheep. (2) Methods: Seventy-two primiparous Naemi ewes (initial body weight = 55.0 ± 3.8 kg) were randomly allocated to four dietary treatments containing 0, 12, 20, or 28% SFH (n = 18 ewes per treatment) from late gestation until lamb weaning at 90 days postpartum. Data were analyzed using mixed-model procedures, and treatment effects were considered significant at p ≤ 0.05. (3) Results: Dietary SFH supplementation did not affect lamb birth weight or overall survival rate (p > 0.05). However, weaning weight declined from 28.03 kg in the control group to 25.11 kg in the 20% SFH group, showing a significant linear decrease with increasing SFH inclusion (p = 0.044). Likewise, average daily gain decreased linearly by 10.4% (p = 0.044). Colostrum composition was partially affected by dietary treatment, with fat and protein concentrations at 48 h postpartum increasing quadratically by 46.6% and 33.50%, respectively, in ewes fed 20% SFH compared with the control group (p < 0.05). In contrast, milk fat and total solids contents decreased quadratically by 30.7% and 13.4%, respectively, in ewes receiving 12% SFH (p = 0.01). Most serum metabolite variables were unaffected by dietary treatment and remained within normal physiological reference ranges. However, overall serum triglyceride concentration decreased linearly with increasing SFH inclusion (p = 0.023). (4) In conclusion, SFH can be incorporated into the diets of Naemi ewes during late gestation and lactation as an alternative fiber source without adversely affecting lamb birth weight, survival, or overall metabolic health. However, increasing dietary SFH inclusion reduced pre-weaning lamb growth despite improvements in selected colostrum quality traits. Based on the productive and physiological responses observed, 12% dietary SFH appears to be the optimal inclusion level, providing the best balance between animal performance and sustainable feed utilization. Full article

The present study describes a rare and extreme case of prolonged survival in domestic sheep (Ovis aries) under severe natural conditions, designated as the “Monyak” case (March 2026, Eastern Rhodope Mountains, Bulgaria). A 90-day period of complete isolation involving two adult ewes and a subsequently born lamb on an inaccessible rocky ledge, with very limited access to sources of food or water, was documented. Clinical assessment performed immediately following rescue revealed profound dehydration and cachexia accompanied by multisystemic abnormalities suggestive of a prolonged catabolic state. Biochemical analysis demonstrated marked azotemia, characterized by elevated serum urea and creatinine concentrations, which may indicate reduced renal perfusion and intensified protein catabolism. Electrolyte disturbances, including hypernatremia and hyperchloremia, were compatible with severe dehydration and substantial disruption of water−electrolyte homeostasis. Furthermore, increased total serum protein concentration and hematocrit values were observed, consistent with pronounced hemoconcentration. The metabolic profile demonstrated alterations in glucose homeostasis together with enhanced ketogenesis, findings compatible with an adaptive metabolic response to sustained energy deprivation. Elevated serum activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), accompanied by increased cortisol concentrations, may reflect hepatocellular stress and activation of the hypothalamic–pituitary–adrenal (HPA) axis associated with chronic physiological stress. Hematological evaluation revealed neutrophilia and lymphopenia, constituting a leukocyte pattern compatible with a stress leukogram and suggestive of endogenous glucocorticoid stimulation. Morphological examination of peripheral blood smears demonstrated pronounced echinocytosis and increased relative cellular density secondary to plasma volume depletion associated with dehydration. Additionally, neutrophilic hypersegmentation was observed, consistent with chronic physiological stress and cellular exhaustion. Ethological assessment suggests that maternal behavior and instinctive maternal care played a pivotal role in ensuring neonatal survival under conditions of extreme resource scarcity and sustained environmental stress. In conclusion, the “Monyak” case provides a unique natural model for investigating the physiological, metabolic, and behavioral adaptive mechanisms of ruminants subjected to prolonged starvation, dehydration, and chronic stress. The findings contribute valuable insights to veterinary physiology, clinical pathophysiology, and ethology, with potential implications for understanding the limits of adaptive capacity and survival under extreme environmental conditions. Full article

Birth weight is a key early-life trait in sheep that influences neonatal survival and subsequent growth, but its genetic basis remains incompletely understood. Here, we used low-coverage whole-genome sequencing (lcWGS)-based genotyping and genome-wide association analysis (GWAS) to investigate birth weight in 671 East Friesian × Hu crossbred lambs, achieving high imputation accuracy (98.5% allelic concordance). A total of 148 SNPs reached the suggestive significance threshold, of which 20 reached genome-wide significance. Among these signals, the chromosome 7 locus contained 69 suggestive variants spanning an approximately 6 kb interval within the SPATA7 region, including 14 genome-wide significant SNPs. Notably, 13 of these suggestive variants overlapped annotated enhancer intervals, of which 3 reached genome-wide significance. Portions of the associated interval also coincided with pituitary ATAC-seq and liver H3K4me1 ChIP-seq signals. Chr7:98,178,889 A > G, the most strongly associated SNP in this region, showed birth-weight differences among genotypes. Lambs carrying the AG genotype had significantly higher adjusted least-squares mean birth weight than AA lambs (3.81 vs. 3.56 kg; Δ = 0.25 kg, +7.0%). These findings prioritize the SPATA7 region as a candidate regulatory locus for birth-weight variation and provide a basis for future fine-mapping and functional validation. Full article

Early-life microbial community assembly is important for gastrointestinal development, immune maturation, and feed utilization in young ruminants, but the maternal reservoirs associated with neonatal lamb gut microbial profiles remain insufficiently defined. This exploratory study characterized bacterial and archaeal communities in maternal vaginal secretions, amniotic fluid, and colostrum, together with rectal feces from Hu lambs at birth and at 5 days of age, using 16S rRNA gene amplicon sequencing in six matched ewe–lamb pairs. Alpha-diversity differences were evaluated using the Kruskal–Wallis test followed by pairwise Wilcoxon rank-sum tests where appropriate, beta-diversity was assessed by principal coordinate analysis based on Bray–Curtis distance, and discriminatory taxa were identified using LEfSe; statistical significance was defined as p < 0.05. Microbial community structure differed among sample types. Feces collected at birth showed low bacterial richness and a distinct community profile, whereas feces from 5-day-old lambs displayed higher bacterial richness and a more complex taxonomic composition. Shared-ASV and LEfSe analyses suggested that vaginal-associated taxa were more closely associated with the initial fecal microbiota at birth, while colostrum-associated taxa were more evident in day-5 feces. Archaeal communities showed weaker separation than bacterial communities, but methanogenic lineages became more distinguishable by day 5. These findings suggest that early gut microbial assembly in Hu lambs is associated with multiple maternal reservoirs and rapid postnatal ecological selection. However, due to the limited sample size, short observation period, lack of formal source-tracking analysis, and absence of low-biomass negative controls, the results should be interpreted cautiously as preliminary associations rather than definitive evidence of vertical transmission. Full article

Newborn sheep rely on passive transfer of immunity via colostrum as well as innate immunity for survival and adaptation to the extrauterine environment. This study examined associations between immunomodulatory constituents of colostrum, namely, immunoglobulin G (IgG), acute-phase proteins (APPs; serum amyloid A (SAA), and haptoglobin) and interleukin-6 (IL-6), and their corresponding concentrations in serum of 2–3-day-old offspring in a cohort of 296 Dorper lambs across three consecutive years. It also assessed the effects of these immunological markers on average daily weight gain (ADWG) during the first four months of life. IgG, APP, and IL-6 concentrations were measured, and mixed linear regression models were used for all analyses. Colostrum and serum concentrations of IgG and IL-6 were positively associated, whereas SAA levels in colostrum were negatively associated with IgG concentrations in serum. Serum IL-6 concentration was negatively associated with colostrum concentrations of IgG and SAA. Serum IgG concentration was positively associated with ADWG, while SAA and IL-6 concentrations were negatively associated with ADWG. These results show the importance of immunomodulating factors in colostrum other than IgG and emphasize the long-term effect of the serum concentrations of these factors on growth performance. Full article

Background/Objectives: Circulating inflammatory cytokines and tissue sensitivity are both elevated following heat stress-induced intrauterine growth restriction (IUGR). Cytokines disrupt myoblast function and muscle growth, and thus we hypothesized that suppressing inflammatory tone in IUGR-born lambs by supplementing anti-inflammatory nutraceuticals would improve early postnatal growth. Methods: IUGR lambs produced by maternal heat stress were supplemented daily with 42 mg/kg oral omega-3 polyunsaturated fatty acid (ω-3 PUFA) Ca²⁺ salts or placebo from birth to 28 days of age. Results: By day 28, the 21% lighter bodyweights for IUGR lambs were fully resolved by ω-3 PUFA due to the complete recovery of average daily gain. Subcutaneous fat deposition and visceral organ growth were modestly diminished in IUGR-born lambs, but skeletal muscle mass was more markedly restricted. This coincided with 63% less muscle AdipoR2 but 27% greater circulating adiponectin. ω-3 PUFA reduced or eliminated deficits in subcutaneous fat, visceral organs, and five of the six individual muscles assessed, which corresponded with rescue of myoblast populations and AdipoR2 content. In turn, asymmetric growth restriction was resolved at one month of age. Conclusions: These findings show that targeting heightened inflammatory tone during the neonatal period in IUGR-born offspring can recover early growth in skeletal muscle and other soft tissues. Full article

Background: Neonatal myocytes rely predominantly on glycolytic metabolism for survival during hypoxic conditions. During asphyxia, metabolic pathway dysregulation impairs cardiac myocyte contractility. Co-administration of dextrose and insulin may help restore metabolic homeostasis and improve cardiac function. Methods: Following blinded randomization and instrumentation, near-term lambs (138–140 days gestational age) were asphyxiated by umbilical cord occlusion until complete cardiac arrest, followed by 7 min of continued arrest to model severe asphyxia. Return of spontaneous circulation (ROSC) was defined as heart rate ≥ 100 beats per minute (bpm) and diastolic blood pressure ≥ 20 mmHg. Results: The incidence of ROSC was 3/6 in the control group compared to 5/5 in the experimental group receiving dextrose–insulin therapy, although this difference did not reach statistical significance. Conclusions: In this proof-of-concept study using a near-term ovine model of prolonged asphyxial cardiac arrest, dextrose and insulin co-administered with epinephrine were associated with improved ROSC rates although could be an association. Larger studies are needed to confirm these findings and evaluate clinical translation Full article

The gestational period is a critical developmental window where maternal nutrition programs offspring growth and long-term health. This study evaluated dietary rumen-protected glutamine (RP-Gln) supplementation during late gestation on lamb growth performance, and its regulatory effects on metabolic, immune, and microbial parameters in ewes and offspring. Compared with controls, moderate RP-Gln significantly improved lamb growth, increasing birth weight, 15-day body weight, and average daily gain (p < 0.01). In ewes, RP-Gln elevated serum GGT activity (p < 0.05), improved lipid metabolism, and reduced offspring muscular stress. Antioxidant capacity was enhanced in both ewes and lambs, with higher antioxidant enzyme activities and lower MDA levels (p < 0.05). RP-Gln also remodeled gut microbiota by promoting beneficial genera like Lactobacillus and Faecalibacterium, and reinforcing dam–offspring microbial transmission. Metabolomics revealed elevated polyunsaturated fatty acids, vitamin C, and tyrosine derivatives in ewes, and enhanced aromatic amino acid biosynthesis in lambs. In summary, glutamine supplementation in late-gestation ewes enhances maternal antioxidant and anti-inflammatory capacity, optimizes gut microbiota, and stimulates n-3 PUFA synthesis. These benefits are transmitted to the fetus, improving offspring antioxidant function, immune regulation, and intestinal health. Glutamine also promotes aromatic amino acid synthesis while inhibiting the tryptophan–kynurenine pathway, collectively supporting lamb growth and health. Full article

Background: There is inadequate evidence to support recommendations for the delayed clamping of umbilical cords in preterm neonates who are born non-vigorous. Objective: In a preterm bradycardic ovine model, our objective was to compare the effects of early cord clamping with ventilation (ECCV) and various time periods of delayed cord clamping with ventilation (DCCV) at 1 min (DCCV1), 2 min (DCCV2), 3 min (DCCV3), 4 min (DCCV4), and 5 min (DCCV5). The primary composite outcome was (i) incidence of achieving a combined heart rate (HR) ≥ 100 bpm and preductal saturation (SpO₂) ≥80% by 5 min, and (ii) time to attain this outcome. Secondary outcomes were to evaluate gas exchange/hemodynamics. Methods: 32 preterm lambs of 126–128-day gestational age were randomized to one of six groups: ECCV (n = 5), DCCV1 (n = 6), DCCV2 (n = 5), DCCV3 (n = 6), DCCV4 (n = 6), and DCCV5 (n = 4). Asphyxia was induced by umbilical cord occlusion to attain a HR ≤ 90 beats per minute (bpm). Results: All lambs in DCCV5 achieved a primary composite outcome by 5 min. The time taken to achieve the primary composite outcome in DCCV5 was significantly lower (p = 0.02). Partial pressure of arterial carbon dioxide (PaCO₂) was significantly lower (p = 0.0001) in DCCV5. Peak pulmonary blood flow (PBF) was significantly higher (p = 0.0001) in DCCV5 while peak carotid blood flow (CBF) was highest in the ECCV (p < 0.0001) compared to other groups. Conclusions: In a preterm ovine model of asphyxia, resuscitation with an intact umbilical cord for 5 min increased the incidence and reduced the time to achieve the primary composite outcome, while also improving gas exchange by enhancing pulmonary blood flow, compared to shorter durations of DCCV and ECCV. These findings suggest that DCCV for 5 min may offer physiological advantages in the resuscitation of non-vigorous preterm neonates, warranting further investigation in clinical settings. Full article

Background/Objectives: Intrauterine growth restriction (IUGR) is associated with enhanced inflammatory activity, poor skeletal muscle glucose metabolism, and pancreatic β cell dysfunction that persist in offspring. We hypothesized that targeting heightened inflammation in IUGR-born neonatal lambs by supplementing anti-inflammatory ω-3 polyunsaturated fatty acids (ω-3 PUFAs) would improve metabolic outcomes. Methods: Maternal heat stress was used to produce IUGR lambs, which received daily oral boluses of ω-3 PUFA Ca²⁺ salts or placebo for 30 days. Results: Greater circulating TNFα and semitendinosus IL6R in IUGR lambs were fully resolved by ω-3 PUFA, and impaired glucose-stimulated insulin secretion, muscle glucose oxidation, and hypertension were partially rescued. Impaired glucose oxidation by IUGR muscle coincided with a greater glycogen content that was completely reversed by ω-3 PUFA and greater lactate production that was partially reversed. Ex vivo O₂ consumption was increased in IUGR muscle, indicating compensatory lipid oxidation. This too was alleviated by ω-3 PUFA. Conversely, ω-3 PUFA had little effect on IUGR-induced changes in lipid flux and hematology parameters, did not resolve greater muscle TNFR1, and further reduced muscle β2-adrenoceptor content. Conclusions: These findings show that targeting elevated inflammatory activity in IUGR-born lambs in the early neonatal period improved metabolic outcomes, particularly muscle glucose metabolism and β cell function. Full article

Background: Early gut microbiome development is critical for neonatal health, and its dysbiosis may impact long-term animal productivity. This study examined the effects of parenteral Ceftiofur Crystalline Free Acid (CCFA) on the composition and diversity of the neonatal lamb fecal microbiome. The emergence of antimicrobial resistance genes associated with CCFA exposure was also investigated. Results: There were distinct microbial populations in the CCFA-treated lambs compared to the control group at each time point, with a highly significant decrease in alpha and beta diversity. The CCFA treatment showed a reduction in several key microbial taxa during nursing, but these differences were diminished by day 56. Unlike the control group, CCFA-treated lambs had core microbes potentially carrying multiple antibiotic resistance genes, including those for beta-lactam, fosfomycin, methicillin, and multidrug resistance. Methods: Twenty-four healthy neonatal lambs were randomly assigned to CCFA-treated (n = 12) and control (n = 12) groups. Fecal samples were collected on days 0, 7, 14, 28, and 56. Genomic DNA was extracted and sequenced using the Illumina MiSeq platform. Microbial composition was analyzed using the MG-RAST pipeline with the RefSeq database. Conclusions: Despite temporary reductions in critical bacterial populations during nursing, the early sheep fecal microbiome demonstrated resilience by repopulating after CCFA antibiotic disruption. While this highlights microbiota stability after short-course antibiotic exposure, the transient disturbance underscores potential risks to early gut health. Importantly, persistent CCFA resistance poses environmental dissemination risks, emphasizing the need for cautious antibiotic use in livestock to mitigate ecological impacts. Full article

Neonatal hypoxia–ischemia is a major cause of infant death and disability. The only clinically accepted treatment is therapeutic hypothermia; however, cooling is less effective in the most severely encephalopathic infants. Here, we wanted to test the neuroprotective effect of the antioxidant dimethyl fumarate after severe hypoxia–ischemia in neonatal rats. We used a modified Rice–Vannucci model to generate severe hypoxic–ischemic brain damage in day 7 postnatal rats, which were randomized into four experimental groups: Sham, Sham + DMF, non-treated HI, and HI + DMF. We analyzed brain tissue loss, global and regional (cortex and hippocampus) neuropathological scores, white matter injury, and microglial and astroglial reactivity. Compared to non-treated HI animals, HI + DMF pups showed a reduced brain area loss (p = 0.0031), an improved neuropathological score (p = 0.0016), reduced white matter injuries by preserving myelin tracts (p < 0.001), and diminished astroglial (p < 0.001) and microglial (p < 0.01) activation. After severe hypoxia–ischemia in neonatal rats, DMF induced a strong neuroprotective response, reducing cerebral infarction, gray and white matter damage, and astroglial and microglial activation. Although further molecular studies are needed and its translation to human babies would need to evaluate the molecule in piglets or lambs, DMF may be a potential treatment against neonatal encephalopathy. Full article

Twin lamb mortality is a significant economic problem impacting the Australian sheep industry. Maternal betaine supplementation improved lamb vigour and early post-natal survival when ewes and lambs were housed indoors, suggesting that betaine may be beneficial to feed under extensive pasture systems. This study investigated whether maternal betaine supplementation during late gestation would improve Merino twin lamb live weight, thermoregulation, vigour and survival to weaning under field conditions. Ewes received dietary betaine at either 0 g/day (CTL; n = 115) or 4 g/day from day 110 of gestation (dG 110) until ~49 days post-partum (pp) (BET; n = 115). Measures indicative of lamb viability and survival were collected within 4–24 h of birth and at ~49 days pp and ~93 days pp. BET ewes had higher creatine and creatinine concentrations at dG 130 than CTL ewes (p < 0.05). BET lambs had a higher rectal temperature within 4–24 h following birth than CTL lambs (p < 0.05). CTL lambs were heavier at ~49 days pp and grew faster from birth to ~49 days pp than BET lambs (both p < 0.05). The time taken after release from the researcher to first suckling was quicker in the CTL lambs than BET lambs (p < 0.05). This study demonstrated that supplementing betaine increased creatine concentration in twin-bearing ewes and thermoregulatory capacity in neonatal lambs under extensive grazing systems. Full article