Neonatal Lambs Research Articles

241 Increased Inflammatory Tone and Impaired Skeletal Muscle Growth in Intrauterine Growth-Restricted Neonatal Lambs Is Improved By Daily Supplementation of ω-3 Polyunsaturated Fatty Acid Ca2+ Salts

Abstract Low birthweight due to fetal intrauterine growth restriction (IUGR) often results from maternofetal heat stress. IUGR fetuses exhibit enhanced inflammatory tone, which persists after birth and impacts body composition, skeletal muscle growth, and metabolic function. Therefore, our objective was to determine whether daily oral supplementation of Ca2+ salts of ω-3 polyunsaturated fatty acids (ω-3 PUFA) to IUGR-born neonatal lambs improved inflammatory tone, body composition, and growth metrics. Pregnant ewes were exposed to heat stress (40°C, 35% humidity, THI = 85) from d 40 to 95 of gestation to induce IUGR. Lambs were weaned at birth and hand-reared on milk replacer. Daily oral boluses of 0.5 mL molasses containing 0 or 0.42 g/kg bodyweight of ω-3 PUFA (Virtus Nutrition) were administered. Femoral catheters were placed at d 24 and lambs were necropsied at d 30. At birth, IUGR lambs (n = 8; 3.12 ± 0.34 kg) and IUGR+ω-3 lambs (n = 7; 3.67 ± 0.32 kg) were lighter (P < 0.05) than controls (n = 12; 4.28 ± 0.15 kg). Plasma TNFα concentrations were greater (P < 0.05) at birth for IUGR (557 ± 121 pg/mL) and IUGR+ω-3 lambs (437 ± 82 pg/mL) than for controls (213 ± 78 pg/mL). Plasma TNFα concentrations remained increased (P < 0.05) for IUGR lambs but not for IUGR+ω-3 compared with controls at 2, 3, and 4 wk of age. Adjusted 30-d bodyweights were lighter (P < 0.05) for IUGR lambs (9.83 ± 0.6 kg) but not for IUGR+ω-3 lambs (11.59 ± 0.4 kg) than for controls (12.35 ± 0.2 kg). Heart and brain weights were 17% and 6% lighter (P < 0.05), respectively, for IUGR lambs than for controls. Brain weight deficits were resolved in IUGR+ω3 lambs, but heart weights did not differ between IUGR and IUGR+ω-3 IUGR lambs. Crown circumference/ bodyweight, abdominal circumference/ bodyweight, and cannon bone length/ bodyweight (indicators of asymmetric body composition) were 11% to 15% greater (P < 0.05) for IUGR lambs than for IUGR+ω-3 lambs or controls. At necropsy, IUGR lambs had lighter (P < 0.05) whole hindlimbs (29%) and flexor digitorum superficialis (24%), soleus (36%), biceps femoris (25%), semitendinosus (24%), gastrocnemius (29%), and longissimus dorsi (26%) muscles compared with controls. Weight deficits were partially or fully resolved in IUGR+ω-3 lambs for whole hindlimbs and for all muscles but the soleus, which did not differ from IUGR lambs. These findings demonstrate that daily oral supplementation of Ca2+ salts of ω-3 PUFA reduced the enhanced inflammatory tone observed in IUGR-born offspring, which coincided with improved skeletal muscle growth and indicators of symmetrical body composition.

PSI-19 Neonatal Lamb Growth and Thermoregulation After Nutrient Specific Restriction in Gestation

Abstract Depending on seasonal availability and quality of range forage, extensively managed ewes can experience nutrient restriction during any point of gestation. Neonatal lamb performance after severe experimental nutrient restriction during gestation has been well studied; however, there is a gap in understanding of how practical nutrient restriction experienced over the course of a production cycle impacts lamb success. Therefore, the objective of this study was to investigate the first week fetal growth and development, and thermoregulation biomarkers in neonatal lambs from ewes fed a diet that simulates winter forage. Time-mated and confirmed pregnant Rambouillet x Merino ewes were blocked by body weight and allocated to one of two dietary treatments. Treatments consisted of 1) Control diet (CONT) formulated to meet or exceed the National Research Council (NRC) nutrient requirements for gestating ewes fed throughout gestation; 2) Nutrient restricted diet (NR) formulated to meet 70% of total digestible nutrient (TDN) and 50% of protein requirements from 30 to 125 d of gestation (dGA) and then re-alimented with the CONT diet for the remainder of gestation. Ewes were individually fed from 25 dGA to 137 dGA, then group fed through lambing. From 30 dGA to lambing, weekly body weights, bimonthly body condition scores (BCS), and monthly blood glucose concentrations were recorded for all ewes. A treatment by time interaction was observed where NR ewes weighed less (P < 0.05) starting at week 8 of the treatment period through lambing. There were effects of treatment and time on BCS, as ewes receiving the NR diet had lesser (P < 0.05) BCS compared with CONT ewes regardless of time in gestation. There were no observed differences in blood glucose concentrations between groups. At lambing, rectal temperature, birth weight and morphometrics (crown-rump length, abdominal circumference, head circumference, and cannon bone length) were collected on all lambs. Collection of rectal temperature and bodyweight continued daily for the first week of life. There were no differences in birthweight or birth morphometrics; however, growth by body weight in the first week of life was greater (P < 0.05) in NR (n = 10) compared with CONT lambs (n = 12), with an effect of progeny number. Additionally, treatment by day interactions were observed with NR lambs having lower (P < 0.05) body temperatures on days one, four, and five compared with CONT lambs. These data suggest that sustained nutrient challenge during gestation, even when re-alimented in late gestation, may produce lambs that are at increased risk of hypothermia. While maternal nutrient supplementation in late gestation is a common practice, it is crucial for producers to consider nutritional supplementation strategies throughout gestation to limit the number of lambs that require increased intervention after birth.

Immunity and Behaviour of Lambs Born from Ewes Fed a Flushing Diet Containing EPA and DHA

Nutrition can influence lamb survival and the immune status during the neonatal phase until weaning.  This study aimed to investigate the effect of flushing of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from Lemuru fish oil in the Ewe's diet on lamb immunity and survival. Twenty-eight neonatal lambs were divided into four treatments according to Ewe's diet. Four treatments: control concentrate (P1), flushing concentrate with 6% palm oil (P2), flushing concentrate with 3% lemuru oil and 3% palm oil (P3), and flushing concentrate with 6% lemuru oil (P4). The Ewe were fed Napier grass and concentrated in a 30:70% ratio based on dry matter. Ewe and their lambs remained together until weaning at about two months of age. The parameter observed in ewes was colostrum Immunoglobulin G (IgG).  The parameters in the Lamb are blood Ig G, neonatal behavior of the Lamb, physiological response, and hematology of the Lamb at birth and weaning. The results showed that feeding P4, P3, and P2 to the Ewe resulted in a shorter latency to stand-in lamb (P0.05). P1 has higher leukocytes (P0.05) during weaning than P2 and P3. P1 has the same leukocyte as P4. Treatment has a non-significant effect (P0.05) on Ig G and physiological response. In conclusion, administering 6% Lemuru oil containing EPA and DHA twice can shorten the latency to stand in newborn lambs.

Clostridial enterotoxaemias responsible for deaths of neonatal lambs.

Clostridial enterotoxaemias responsible for deaths of neonatal lambs.

Ewe udder and teat traits as potential selection criteria for improvement of Merino lamb survival and growth

Neonatal lamb mortality is a major economic and welfare issue for Australian sheep producers. The contribution of udder and teat traits of the dam to the survival and subsequent growth of the lamb is relatively unknown. This study aimed to estimate phenotypic and genetic parameters associated with objectively measured and visually scored udder and teat traits in Australian Merino sheep, and to evaluate the impacts of udder and teat traits of the dam on survival and growth of their lambs to weaning. Ewes from the New England Merino Lifetime Productivity flock (n = 1341 ewes) were assessed for udder and teat traits, and phenotypic and genetic parameters for individual traits and relationships among them were estimated using linear mixed models. Odds ratios were calculated to investigate the influence of udder soundness on lamb mortality. Further, the influence of udder traits on variation in lamb weaning weight was explored. Measured udder and teat size traits were estimated to have moderate to high heritabilities (0.32 (0.09) to 0.56 (0.10)), while the heritabilities of visually scored traits were lower (0.09 (0.05) to 0.17 (0.07)). Measured traits were highly correlated genetically with their equivalent visually scored traits. The odds ratio of mortality for lambs born to ewes with unsound versus sound udders was 1.54 (95 %CI 1.1–2.2, P < 0.05). The odds ratio of lamb mortality from starvation compared to all other causes of death for lambs born to ewes with unsound versus sound udders was 4.62 (95 %CI 2.4–8.9, P < 0.001). Dam udder and teat traits collectively contributed 8 % of the variation in lamb weaning weight observed. Results suggest that targeting optimal ewe udder and teat characteristics in sheep breeding programs has the potential to significantly improve lamb survival and growth in extensive production systems.

Neonatal mortality of lambs in production systems in a semi-arid environment: main risk factors

AbstractThe sheep farming has economic and sociocultural importance in semi-arid regions worldwide. Of the total of 1.2 billion sheep in the world, 0.4 are found in semi-arid regions. In this review, we have discussed the main risk factors for neonatal lamb mortality and its association with the prevailing environmental conditions of tropical semi-arid regions. Over the last decades, the average mortality rate of newborn lambs remained relatively constant (~15%) around the world. This rate is reported to be higher (Up to 30%) in small-scale sheep farming systems from developing countries. Overall, the main risk factors of neonatal mortality include low birth weight, dystocia, adverse weather conditions, inadequate milk, or colostrum supply, competition between siblings in multiple births, and poor expression of maternal behaviour. In tropical semi-arid regions, recent findings revealed that newborn lambs from hair coat sheep breeds are less vigorous to perform the first suckling when even exposed to moderate cold conditions (18–20°C). On the other hand, the high radiant heat load in these areas can also challenge the thermoregulation of ewes and newborn lambs, especially if they are kept in areas without protection against direct short-wave solar radiation. Under such circumstances, newborn lambs were reported to be hyperthermic. The heat stress as risk factor for neonatal lamb mortality is a topic that deserves more investigation, particularly in tropical semi-arid areas, where is expected to be drier and hotter as consequence of rapid advances in climate change.

Osteogenesis imperfecta confirmed in neonatal Valais blacknose lambs

Veterinary RecordVolume 192, Issue 10 p. 402-404 Surveillance Osteogenesis imperfecta confirmed in neonatal Valais blacknose lambs First published: 19 May 2023 https://doi.org/10.1002/vetr.3077Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume192, Issue1020/27 May 2023Pages 402-404 RelatedInformation

Developmental exposure to a real-life environmental chemical mixture alters testicular transcription factor expression in neonatal and pre-pubertal rams, with morphological changes persisting into adulthood

Environmental chemical (EC) exposure may be impacting male reproductive health. The translationally relevant biosolids treated pasture (BTP) sheep model was used to investigate gestational low-level EC mixture exposure on the testes of F1 male offspring. Adult rams from ewes exposed to BTP 1 month before and throughout pregnancy had more seminiferous tubules with degeneration and depletion of elongating spermatids, indicating possible “recovery” from previously reported testicular dysgenesis syndrome-like phenotype in neonatal and pre-pubertal BTP lambs. Expression of transcription factors CREB1 (neonatal) and BCL11A and FOXP2 (pre-pubertal) were significantly higher in the BTP exposed testes, with no changes seen in adults. Increased CREB1, which is crucial for testes development and regulation of steroidogenic enzymes, could be an adaptive response to gestational EC exposure to facilitate the phenotypic recovery. Overall, this demonstrates that testicular effects from gestational exposure to low-level mixtures of ECs can last into adulthood, potentially impacting fertility and fecundity.

The role of the Cryptosporidium parvum in diarrhea in calves and lambs

Cryptosporidiosis is an important parasitic disease that leads to morbidity and mortality among young ruminants. In our study, 200 neonatal calves and lambs were examined for Cryptosporidium parvum (C. parvum). The prevalence of infection in cattle calves, buffalo calves and lambs was 38.7%, 22% and 40%, respectively, by microscope and was 82.7%, 84% and 62.7%, respectively using Enzyme-linked immunosorbent assays (ELISA) in Assiut Governorate. The total prevalence in young ruminants was 75.5%. According to the sex, the prevalence in cattle calves, buffalo calves and lambs was 82.1% and 90.5% and 54.2%, respectively in males and was 83.3% and 79.3% and 77.8%, respectively in females. Concerning the age, it was 90.6% and 96.2% and 96% in cattle calves, buffalo calves and lambs, respectively, with age less than 1 month and was 96.6% and 63.6% and 26.9%, respectively, with age 1-2 months. While, it was 35.7% and 76.9% and 66.7% in cattle calves, buffalo calves and lambs, respectively, in age more than 2 to 3 months. The prevalence of cattle calves, buffalo calves and lambs was 97.1%, 90% and 100% of farm rearing, respectively, and was 70%, 75% and 37.8% of household rearing, respectively. The prevalence according to the feces consistency of cattle calves, buffalo calves and lambs was 77.3%, 78.9% and 49% of normal feces, respectively, and was 90.3%, 87.1% and 91.7% of diarrheic feces, respectively. This finding showed a high infection rate with C. parvum in calves and lambs.

ABORTION AND NEONATAL MORTALITY DUE TO TOXOPLASMA GONDII IN BIGHORN SHEEP (OVIS CANADENSIS).

Low lamb recruitment can be an obstacle to bighorn sheep (Ovis canadensis) conservation and restoration. Causes of abortion and neonate loss in bighorn sheep, which may affect recruitment, are poorly understood. Toxoplasma gondii is a major cause of abortion and stillbirth in domestic small ruminants worldwide, but no reports exist documenting abortion or neonatal death in bighorn sheep attributable to toxoplasmosis. Between March 2019 and May 2021, eight fetal and neonatal bighorn lamb cadavers from four western US states (Idaho, Montana, Nebraska, and Washington) were submitted to the Washington Animal Disease Diagnostic Laboratory for postmortem examination, histologic examination, and ancillary testing to determine the cause of abortion or neonatal death. Necrotizing encephalitis characteristic of toxoplasmosis was identified histologically in six of eight cases, and T. gondii infection was confirmed by PCR in five cases with characteristic lesions. Other lesions attributable to toxoplasmosis were pneumonia (3/5 cases) and myocarditis (2/5 cases). Protozoal cysts were identified histologically within brain, lung, heart, skeletal muscle, adipose tissue, or a combination of samples in all five sheep with PCR-confirmed T. gondii infections. Seroprevalence of T. gondii ranged from 40-81% of adult females sampled in the Washington population in October and November 2018-2021, confirming high rates of exposure before detection of Toxoplasma abortions in this study. Of 1,149 bighorn sheep postmortem samples submitted to Washington Animal Disease Diagnostic Laboratory between January 2000 and May 2021, 21 of which were from fetuses or neonates, a single case of chronic toxoplasmosis was diagnosed in one adult ewe. Recent identification of Toxoplasma abortions in bighorn sheep suggests that toxoplasmosis is an underappreciated cause of reproductive loss. Abortions and neonatal mortalities should be investigated through postmortem and histologic examination, particularly in herds that are chronically small, demographically stagnant, or exhibit reproductive rates lower than expected.

Randomized Trial of 21% versus 100% Oxygen during Chest Compressions Followed by Gradual versus Abrupt Oxygen Titration after Return of Spontaneous Circulation in Neonatal Lambs

The combination of perinatal acidemia with postnatal hyperoxia is associated with a higher incidence of hypoxic-ischemic encephalopathy (HIE) in newborn infants. In neonatal cardiac arrest, current International Liaison Committee on Resuscitation (ILCOR) and Neonatal Resuscitation Program (NRP) guidelines recommend increasing inspired O2 to 100% during chest compressions (CC). Following the return of spontaneous circulation (ROSC), gradual weaning from 100% O2 based on pulse oximetry (SpO2) can be associated with hyperoxia and risk for cerebral tissue injury owing to oxidative stress. We hypothesize that compared to gradual weaning from 100% O2 with titration based on preductal SpO2, abrupt or rapid weaning of inspired O2 to 21% after ROSC or use of 21% O2 during CC followed by upward titration of inspired O2 to achieve target SpO2 after ROSC will limit hyperoxia after ROSC. Nineteen lambs were randomized before delivery and asphyxial arrest was induced by umbilical cord occlusion. There was no difference in oxygenation during chest compressions between the three groups. Gradual weaning of inspired O2 from 100% O2 after ROSC resulted in supraphysiological PaO2 and higher cerebral oxygen delivery compared to 21% O2 during CC or 100% O2 during CC followed by abrupt weaning to 21% O2 after ROSC. The use of 21% O2 during CC was associated with very low PaO2 after ROSC and higher brain tissue lactic acid compared to other groups. Our findings support the current recommendations to use 100% O2 during CC and additionally suggest the benefit of abrupt decrease in inspired oxygen to 21% O2 after ROSC. Clinical studies are warranted to investigate optimal oxygen titration after chest compressions and ROSC during neonatal resuscitation.

P-028 Challenges encountered in the evaluation of non-antibiotic treatments for housed neonatal lambs

P-028 Challenges encountered in the evaluation of non-antibiotic treatments for housed neonatal lambs

Rumen microbiota-host transcriptome interaction mediates the protective effects of trans-10, cis-12 CLA on facilitating weaning transition of lambs.

Developing alternatives to antibiotics for prevention of gastrointestinal dysbiosis in early-weaning farmed animals is urgently needed. This study was to explore the potential effects of trans-10, cis-12 conjugated linoleic acid (CLA) on maintaining ruminal homeostasis of young ruminants during the weaning transition period. Thirty neonatal lambs were selected (6 lambs per group) and euthanized for rumen microbial and epithelial analysis. The lambs were weaned at 28d and experienced the following 5 treatments: euthanized on d 28 as the pre-weaning control (CON0), fed starter feed for 5 (CON5) or 21 (CON21) d, fed starter feed with 1% of CLA supplemented for 5 (CLA5) or 21 (CLA21) d. Results showed that the average daily weight gain and dry matter intake were significantly higher in CLA5 than CON5 group. As compared with the CON5 and CON21 group, the relative abundances of volatile fatty acid (VFA) producing bacteria including Bacteroides, Treponema, Parabacteroides and Anaerovibrio, as well as the concentrations of acetate, butyrate and total VFA were significantly increased in CLA5 and CLA21 group, respectively. Integrating microbial profiling and epithelial transcriptome results showed that 7 downregulated inflammatory signaling-related host genes IL2RA, CXCL9, CD4, CCR4, LTB, SPP1, and BCL2A1 with CLA supplementation were significantly negatively correlated with both VFA concentration and VFA producing bacteria, while 3 (GPX2, SLC27A2 and ALDH3A1) and 2 (GSTM3 and GSTA1) upregulated metabolism-related genes, significantly positively correlated with either VFA concentration or VFA producing bacteria, respectively. To confirm the effects of CLA on epithelial signal transduction, invitro experiment was further conducted by treating rumen epithelial cells without or with IL-17A+TNF-α for 12h after pretreatment of 100μM CLA or not (6 replicates per treatment). The results demonstrated the anti-inflammatory effect of CLA via suppressing the protein expression of NF-кB p-p65/p65 with the activation of peroxisome proliferator-activated receptor gamma (PPARγ). In conclusion, CLA supplementation enhanced the ruminal microbiota-driven transcriptional regulation in healthy rumen epithelial development via rumen VFA production, and CLA may therefore serve as an alternative way to alleviate early-weaning stress and improve physiological and metabolic conditions of young ruminants.

Effect of seasonal variations on electrophoretic pattern of serum proteins and some biochemical indices in Ossimi ewes and their neonatal lambs

This study aimed to observe the impact of seasonal variations on the behaviour of serum proteins electrophoretic patterns by the Hellabio Agarose Gels and the changes of some metabolic indices in Ossimi ewes and their lambs (15-30 days postpartum). Serum samples from 20 ewes and their lambs during each season (summer and winter) were used in this study. Temperature-humidity index (THI) in winter was 72 (comfort), but a severe stress was shown in July, when the THI exceeded 90. Blood albumin decreased by 7.31% and 9.92% in summer, but the contrary was shown for α-globulins in ewes and lambs:α1-globulins increased by 52.94 % and 22.22 %, α2-globulins by 27.85 % and 93.02 % and albumin/globulin (A/G) ratio by 13.11% and 20% in summer, compared with winter. The values of β-globulins and γ-globulins did not differ between seasons. Ewes had higher values for protein fractions than lambs, but the reverse was true for A/G ratio. Summer serum glucose increased by 16.16% and 13.42%, urea by 16.16% and 25.78% and creatinine by 21.49% and 26.63%, whereas summer calcium (Ca) decreased by 6.81% and 5.18% and inorganic phosphorus (P) by 12.68% and 13.89% in ewes and their lambs respectively compared with winter. Lambs had higher values of serum glucose, Ca and P than their mothers, however the opposite was true for urea and creatinine. The presented results indicate that hot environment in summer season causes changes in serum protein electrophoretic patterns and metabolic indices in Ossimi ewes and their newborn lambs, which indicates an adaptive performance of these animals to seasonal variations and heat stress.

Reaction-norm analysis of neonatal lamb mortality suggests heritability varies with cold-stress: an example in the Elsenburg Merino selection lines

Context Coping with high levels of cold stress should be beneficial to survival of lambs, given the high mortality rate associated with severe winter storms. The Elsenburg Merino selection experiment involved divergent selection for reproduction. Phenotypic results comparing the positively selected H-Lines and negatively selected L-Lines suggested that cold-stress adaption could have contributed to the favourable genetic trends for survival of H-Line lambs. However, observing the genetic merit of better adapted animals depends on the presence of cold stress at the time of recording. A genotype by environment component (G × E) could, thus, be important when assessing survival/mortality phenotypes. Aim This study proposed the genetic analysis of this possible G × E component and compared the H- and L-Lines in this regard. Methods The sire model allowed the use of progeny phenotypes for neonatal mortality recorded during different levels of cold stress, and the possible G × E could be investigated through the reaction-norm approach. Genetic parameters were evaluated as random regression components by implementing a Gibbs sampling approach. A data set of 5723 individual lamb records was analysed as the progeny of 213 sires. Results A modelled G × E component played an important role in mortality outcomes, with the mean estimate (and 95% confidence interval) for the slope ( σ s b 2 = 0.113 [ 0.0019 – 0.28 ] AN22464_IE1.gif) only marginally smaller than the corresponding estimate for the intercept ( σ s a 2 = 0.124 [ 0.003 – 0.26 ] AN22464_IE2.gif). The reaction-norm model showed a higher heritability (h2 ± posterior standard deviation) for mortality at 3 days of age during high cold-stress (0.22 ± 0.16 at ~1100 KJm−2h−1) than during mild (0.13 ± 0.10 at ~960 KJm−2h−1) conditions, suggesting a greater ability to discriminate between sires at increasing stress levels. Conclusions Failure to account for this G × E component putatively contributes to the low h2 commonly reported for survival traits. The higher h2 at increased levels of cold stress could have played an important part in the higher survival of the H-Line progeny, who were better at coping with cold, wet and windy conditions. Implications Larger studies representing a wider environmental trajectory are recommended. This should be very feasible since cold stress can be derived from commonly available weather-station data.

Ege bölgesi neonatal kuzu ölümlerinde Escherichia coli septisemisinin ve antibiyotik duyarlılığının araştırılması

In this study, Escherichia coli (E. coli) septicemia was investigated in neonatal (0-28 days) lamb deaths in 7 provinces of the Aegean region (Aydın, Denizli, İzmir, Kütahya, Manisa, Muğla, Uşak) between 2019-2021, and antimicrobial susceptibility was determined. The material of the study consisted of 150 lamb visceral organs and tissues (lung, liver, spleen, lymph, bone marrow and intestine). The samples were incubated in nutrient broth under aerobic conditions and then inoculated on 7% blood agar and Macconkey agar, and incubated at 37°C for 24-48 hours. Gram-negative bacilli that form grayish S-type on blood agar and pink, non-mucoid colony on Macconkey agar were evaluated as E. coli and were also confirmed by the Vitek 2 system. E. coli agent was detected in 88.66% (133/150) of the samples. Agent isolation was most common in İzmir (31/133; 23.30%) and Aydın (25/133; 18.80%). Findings in other provinces showed a similar trend. In antibiotic susceptibility test, amoxicillin-clavulanic acid, cefoperazone, erythromycin, penicillin G, gentamicin, tetracycline, trimethoprim-sulfomethoxazole and enrofloxacin commercial discs were used. Of the isolates, 110 (73.33%) were sensitive to gentamicin, 80 (53.33%) to cefoperazone, and 70 (46.66%) to amoxicillin-clavulanic acid. In addition, all of the isolates were resistant to penicillin G (100%), erythromycin (97.33%), tetracycline (81.33%), and sulfamethoxazole-trimethoprim (79.33%). As a result, E. coli septicemia characterized by visceral involvement is seen in the Aegean region. It is thought that mortality will decrease with the right treatment approaches and rational antibiotic use and will contribute positively to the economy.

Overnutrition of Ewe in Late Gestation and the Impact on Placental Efficiency and Lamb's Performance.

The objective of the study was to evaluate energy or energy/protein supplementation in the ewe diet, in the last third of gestation, on maternal placental and endocrine characteristics, as well as its effects on the behavior of neonatal lambs and productive performance until weaning. A total of 128 ewes were used, and the experimental diet was fed from 100 days gestation until lambing, with the birth of 172 lambs. The ewes were distributed into three treatments: CTL (control, n = 43) with metabolizable energy (ME) and crude protein (CP) intake according to NRC (1985); ME (energy supplementation, n = 44) plus 21% ME; and MECP (energy/protein supplementation, n = 41) plus 26% ME and CP. Body weight, body condition score, serum hormone concentrations, placental characteristics, lamb performance and behavior, and production efficiency of the ewe from lambing to weaning were measured. ME and MECP ewes were heavier before (p = 0.006) and just after lambing (p = 0.002) and had higher serum triiodothyronine (p = 0.001) and cortisol (p = 0.004) concentrations on the day of lambing. ME ewes had higher placental efficiency (p = 0.036) and lower total cotyledon weight (p = 0.011). ME and MECP diets increased both lamb birth weight (p = 0.015) and weaning weight (p = 0.009). Production efficiency at birth and at weaning was not influenced (p > 0.05) by treatments. Lamb behavior was influenced by the ME and MECP diets, reducing the time to kneel (p ≤ 0.05), to try to stand (p ≤ 0.05), and the latency to stand (p ≤ 0.005). It is concluded that overnutrition in the last third of gestation was positive for the ovine production system, with improved production rates, hormonal profile, placental characteristics, and neonatal behavior.

Mother’s scent for motherless neonates: Responses of artificially reared lambs to ewe’s inguinal wax odor

Mammalian newborns depend on their mother’s milk to satisfy their initial needs of protection and nutrition. They reach the source of milk in following visual, tactile and olfactory cues. In particular, parturient ewes produce an odorous wax in the inguinal glands close to the teats. When presented separately to newly born lambs, this inguinal wax (IW) elicits arousal, head orientation, licking and increased respiratory rate indicative of their avidity for it. The present study assessed whether transferring IW into the environment of artificially fed lambs would improve their responses to the novelty of the situation. We first assessed whether suckled lambs preferred an IW-scented teat to a scentless control teat. Then, we assessed whether a teat odorized with IW was more easily learned as suckable relative to a control teat. Finally, the lambs’ growth performance from postnatal days (PND) 0 and 20 was compared in groups reared with or without IW spread on the milk-feeder in their home pen. The behavioral assays did not evidence any significant effect of IW odor on previously suckled lambs’ attraction and appetence responses. However, relative to the scentless control condition, being exposed to an IW-smeared milk-feeder led to a higher body weight at 20 days after birth. In the conditions of the present study, namely after suckling initiation, IW odor appeared not to be a strong determinant of short-term attraction or appetitive behavior in neonate lambs. The continued presence of IW, a familiar odor, in the artificial suckling context may improve artificially-reared lambs’ emotional state that may affect their weight gain.

Coronary conductance in the normal development of sheep during the perinatal period.

Birth is associated with substantial shifts in cardiovascular physiology. Little is known about coronary vascular adaptations during this period. We used fetal and neonatal lambs to measure coronary function at late gestation (92% of term) and shortly after birth (5-6 days postnatal age). In each animal we measured unanesthetized myocardial perfusion and oxygen delivery using a circumflex artery flow probe. We used inflatable occluders and adenosine to determine coronary conductance and flow reserve. In a subset of animals, we used myocardial contrast echocardiography (MCE, anesthetized) to assess its utility as a tool for studying changes in regional myocardial perfusion in normal development. Separate age-matched animals were instrumented with aortic and coronary sinus sampling catheters to determine myocardial oxygen extraction (unanesthetized). With an average of 17 days of developmental time separating our neonatal and fetal cohorts we found that heart-to-body weight ratio was significantly greater in neonates than fetuses. In resting animals, we found significant decreases in weight-normalized perfusion of, and oxygen delivery to, neonatal relative to fetal myocardium. Similar results were seen when measuring baseline MCE-derived perfusion. Pressure-flow relationship studies revealed lower baseline and maximal coronary conductance in neonates than fetuses, with similar coronary flow reserve between groups. There was greater oxygen extraction in neonates than fetuses. Combined analysis of oxygen extraction with coronary flow suggested greater oxygen consumption by the fetal than neonatal myocardium. We conclude that, during the immediate perinatal period, cardiac growth outpaces coronary microvascular growth resulting in lower capacity for microvascular perfusion in the early neonate.

The use and impact of auditory stimulation in animals

Music can cause pleasant sensations in humans whereas some noises can cause discomfort. The effects of music and noise have also been somewhat studied in animals, showing different impacts. In this review we aim to illustrate the differences and similarities between animals, in terms of their sensitivity to auditory stimuli (noise or music), by first recalling some generalities about the physical characteristics of sound and the biological bases of hearing. Second, based on the studies reported in this review, we conclude that ambient noise is harmful and/or stressful, and that musical sounds can take many forms with a large range of impacts in animals. Finally, we present two practical examples of the use of music with animals (one in the context of a zoo and the other in cattle breeding) and an example of an experiment designed to understand the impact of music on neonate lambs. These three examples highlight how music can help to improve animal welfare.