Biochemical reference ranges for groups of ewes of different ages

Local and systemic inflammation after implantation of a novel iron based porous degradable bone replacement material in sheep model

Despite the high potential of healthy bone to regenerate, the reconstruction of large bone defects remains a challenge. Due to the lack of mechanical stability of existing bone substitutes, recently developed degradable metallic alloys are an interesting alternative providing higher load-bearing capabilities. Degradable iron-based alloys therefore might be an attractive innovation. To test the suitability of a newly-designed iron-based alloy for such applications, an animal experiment was performed. Porous iron-based degradable implants with two different densities and a control group were tested. The implants were positioned in the proximal tibia of Merino sheep. Over a period of 6 and 12 months, blood and histological parameters were monitored for signs of inflammation and degradation. In the histological evaluation of the implants` environment we found degraded alloy particles, but no inflammatory reaction. Iron particles were also found within the popliteal lymph nodes on both sides. The serum blood levels of phosphorus, iron and ferritin in the long term groups were elevated. Other parameters did not show any changes. Iron-based degradable porous bone replacement implants showed a good biocompatibility in this experiment. For a clinical application, however, the rate of degradation would have to be significantly increased. Biocompatibility would then have to be re-evaluated.

Effects of the fat-tailed ewes' body condition scores at lambing on their metabolic profile and offspring growth

This experiment aimed to evaluate the effect of body condition score (BCS) of fat-tailed Barbarine ewes at lambing on their metabolic profile around parturition and lamb's growth. The experiment was carried out on 69 Barbarine ewes, divided into three groups according to BCS, which were inferior to 2, between 2 and 2.5 and superior to 2.5 for the thin, middle and fat group, respectively. Along the trial, all groups received the same dietary treatment based on hay, pasture and concentrate. Birth weight (Bi-W), weights at 30 and 70 d (W30 and W70) and average daily gains (ADGs) of lambs were recorded. Metabolites were determined at late pregnancy and at the beginning of lactation. Ewes' BCS at lambing had no effect on lambs' Bi-W ( P > 0.05 ), which was 3.8, 3.8 and 3.9 kg, respectively, for thin, middle and fat groups. However, W30, W70 and ADG increased with a mother's BCS. A positive correlation between lamb growth parameters and ewe body weight and BCS at weaning was recorded. Energetic metabolites (glucose and triglycerides) and proteic metabolites (creatinine, total protein and urea) were similar among groups according to BCS but significantly different between pregnancy and lactation stages except triglycerides and urea. In conclusion, BCS may be used as dietary management tool during ewe lactation. With the transition from pregnancy to lactation, the content of some metabolites has changed irrespective of BCS; this aspect needs more investigations.

Haemato-biochemical profile and acid-base status of Croatian spotted goats of different ages

The aim of the present research was to determine the haemato-biochemical profile and blood acid–base status of Croatian spotted goats in a traditional Mediterranean production system. The 60 non-gravid female Croatian spotted goats of different ages were included in the research. They were divided into four groups of 15 goats according to age: group I – ≤1 year old; group II – 2–3 years; group III – 3–6 years; and group IV – 7–10 years. Haematological parameters were determined in whole blood, biochemical parameters in serum and acid–base status in plasma by automatic analyser. Total leukocyte number (WBC), haemoglobin (HGB) and mean corpuscular volume (MCV) in the blood were the highest, while mean haemoglobin concentration in erythrocytes (MCHCs) was the lowest in yearlings compared to other groups. Concentrations of urea, Mg, Cl, non-esterified fatty acids (NEFAs) and lactate were the highest in yearlings. Concentrations of Ca, Na, total cholesterol, high-density lipoprotein (HDL), very low-density lipoprotein (VLDL) and beta hydroxybutyrate (BHB) as well as the activity of alanine aminotransferase (ALT) were higher in older goats compared to yearlings, while the opposite was determined for the activities of creatine kinase (CK) and alkaline phosphatase (ALP). Values of pH, the strong ion difference (SID), anion gap (AG) and z values as well as the content of HCO3 and total pressure of carbon dioxide (ctCO2) were higher in older goats compared to yearlings. The results obtained may help in monitoring the health and nutritional status and improve the management of Croatian spotted goats. Based on the results of the present study, the effect of age needs to be included in the model when preparing the reference values for the haemato-biochemical profile and acid–base status of goats.

Impact of the ovarian cycle and pregnancy on plasma chemistry values in ewes

Normative data for plasma chemistry values in pregnant and non-pregnant reproductive age ewes are scant. Availability of data would aid monitoring of ewe health for both research and veterinary medicine. We determined specific plasma chemistry 95% confidence reference intervals (RIs) in non-pregnant and pregnant ewes. Mixed Western-breed ewes were grouped based on phase of ovarian cycle: luteal ( n = 15), follicular ( n = 17), or late-gestation pregnant ( n = 102). Plasma samples were collected for analysis on a commercial biochemical analyzer. For RIs, chemistry panels for the 3 groups of ewes included nutrients and metabolites (glucose, triglycerides, cholesterol, urea, creatinine, total protein, albumin, and bilirubin), enzymes (lactate dehydrogenase, aspartate transaminase, gamma-glutamyl transferase, alanine aminotransferase, and alkaline phosphatase [ALP]), and micronutrients (calcium, phosphorus, iron, sodium, potassium, and chloride). Sample chemistry values for glucose and total protein in pregnant ewes were lower than in follicular ewes; cholesterol was lower in pregnant and luteal ewes than in follicular ewes. In addition, total bilirubin in pregnant ewes differed from that in luteal ewes, and that in follicular ewes also differed from luteal ewes. ALP in pregnant ewes was higher than other groups; phosphorus in pregnant ewes was lower than in luteal ewes. Iron was higher in pregnant ewes than in luteal ewes, with iron in luteal ewes lower than in follicular ewes. These data provide clinical RIs comparing pregnant and non-pregnant ewes for use in monitoring ewe health in both human research and veterinary medicine.

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

During pregnancy and lactation, female physiology adapts to meet the added nutritional demands of fetuses and neonates. An average full-term fetus contains ∼30 g calcium, 20 g phosphorus, and 0.8 g magnesium. About 80% of mineral is accreted during the third trimester; calcium transfers at 300-350 mg/day during the final 6 wk. The neonate requires 200 mg calcium daily from milk during the first 6 mo, and 120 mg calcium from milk during the second 6 mo (additional calcium comes from solid foods). Calcium transfers can be more than double and triple these values, respectively, in women who nurse twins and triplets. About 25% of dietary calcium is normally absorbed in healthy adults. Average maternal calcium intakes in American and Canadian women are insufficient to meet the fetal and neonatal calcium requirements if normal efficiency of intestinal calcium absorption is relied upon. However, several adaptations are invoked to meet the fetal and neonatal demands for mineral without requiring increased intakes by the mother. During pregnancy the efficiency of intestinal calcium absorption doubles, whereas during lactation the maternal skeleton is resorbed to provide calcium for milk. This review addresses our current knowledge regarding maternal adaptations in mineral and skeletal homeostasis that occur during pregnancy, lactation, and post-weaning recovery. Also considered are the impacts that these adaptations have on biochemical and hormonal parameters of mineral homeostasis, the consequences for long-term skeletal health, and the presentation and management of disorders of mineral and bone metabolism.

Effect of postweaning handling strategies on welfare and productive traits in lambs

Postweaning management strategies that include an element of social enrichment may reduce weaning stress and improve welfare and productive performance. We analyzed the effect of postweaning handling strategies on welfare and production traits in lambs. After weaning, 36 lambs were assigned to 3 experimental groups with 12 lambs each (control [C], fattening with gentle human female contact [H], and fattening with 2 adult ewes [E]). The average daily gain (ADG) was estimated. Blood samples were taken, and infrared thermography was used to estimate stress variables. There were significant differences among treatments (in favor of alternative strategies) regarding production and stress variables (cortisol, glucose, and creatine kinase). The results suggest that the lambs handled gently during the fattening were less reactive and better able to modulate their physiological stress. The E group adapted better to acute stress than the C group but was less efficient in modulating chronic stress. Both treatments showed higher slaughter live weights and better ADGs compared with the control. The use of social enrichment at weaning, especially to establish a positive human-nonhuman animal bond, alleviates lamb weaning stress and improves welfare and performance.

Maternal protein-energy malnutrition during early pregnancy in sheep impacts the fetal ornithine cycle to reduce fetal kidney microvascular development

This paper identifies a common nutritional pathway relating maternal through to fetal protein-energy malnutrition (PEM) and compromised fetal kidney development. Thirty-one twin-bearing sheep were fed either a control (n=15) or low-protein diet (n=16, 17 vs. 8.7 g crude protein/MJ metabolizable energy) from d 0 to 65 gestation (term, ∼145 d). Effects on the maternal and fetal nutritional environment were characterized by sampling blood and amniotic fluid. Kidney development was characterized by histology, immunohistochemistry, vascular corrosion casts, and molecular biology. PEM had little measureable effect on maternal and fetal macronutrient balance (glucose, total protein, total amino acids, and lactate were unaffected) or on fetal growth. PEM decreased maternal and fetal urea concentration, which blunted fetal ornithine availability and affected fetal hepatic polyamine production. For the first time in a large animal model, we associated these nutritional effects with reduced micro- but not macrovascular development in the fetal kidney. Maternal PEM specifically impacts the fetal ornithine cycle, affecting cellular polyamine metabolism and microvascular development of the fetal kidney, effects that likely underpin programming of kidney development and function by a maternal low protein diet.—Dunford, L. J., Sinclair, K. D., Kwong, W. Y., Sturrock, C., Clifford, B. L., Giles, T. C., Gardner, D. S.. Maternal protein-energy malnutrition during early pregnancy in sheep impacts the fetal ornithine cycle to reduce fetal kidney microvascular development.

Clinical, microbiological and histological findings in lambs affected by 'salivary abomasum disease'

'Salivary abomasum disease' is a common syndrome in Greece affecting lambs and kids from three to 17 days of age. In this case series, we present clinical and laboratory findings from 37 affected lambs presented alive and subsequently euthanased for welfare reasons and necropsied, and also from 24 other lambs submitted dead that were also necropsied. The clinical signs in the 37 lambs presented alive included lethargy (100 per cent), absence of sucking (83.8 per cent), weakness (37.8 per cent), abdominal distension (40.5 per cent) and increased frequency of urination (24.3 per cent). Diarrhoea was not observed in any affected lambs. At necropsy of these 37 lambs, the abomasum was distended with gas (70.3 per cent), saliva (43.2 per cent) along with mixed milk clots and gastric secretions; while multiple small mucosal and serosal haemorrhages with blood clots ('coffee grains') were recorded (91.9 per cent). Eight of 37 lambs that were examined alive, had elevated blood urea nitrogen concentrations (21.6 per cent). The pH of the abomasal contents ranged from 1.0 to 2.8; Escherichia coli was cultured from six of 37 (16.2 per cent) abomasal fluid samples. A mild to moderate inflammatory cell infiltrate was present in the mucosal lamina propria of 13 of 15 abomasal samples (86.6 per cent). Kidneys were paler than normal in 13 of the total 61 lambs necropsied (21.3 per cent); while acute tubular necrosis was evident on histopathological examination of 11 of 12 examined pale kidneys (91.6 per cent). The low abomasal pH and reported successful treatment with oral sodium bicarbonate suggest that metabolic acidosis may develop during the disease; however, further studies, including blood gas analysis, and determination of D- and L-lactic acid concentrations, are necessary to confirm this hypothesis.

Presence of an acute phase response in sheep with clinical classical scrapie

Background

Work with experimental scrapie in sheep has been performed on-site for many years including studies on PrP^Sc dissemination and histopathology of organs and tissues both at preclinical and clinical stages. In this work serum was sampled at regular intervals from lambs which were infected immediately after birth and from parallel healthy controls, and examined for acute phase proteins. In contrast to earlier experiments, which extensively studied PrP^Sc dissemination and histopathology in peripheral tissues and brain, this experiment is focusing on examination of serum for non-PrP^Sc markers that discriminates the two groups, and give insight into other on-going processes detectable in serum samples.

Results

There was clear evidence of an acute phase response in sheep with clinical scrapie, both experimental and natural. All the three proteins, ceruloplasmin, haptoglobin and serum amyloid A, were increased at the clinical stage of scrapie.

Conclusion

There was evidence of a systemic measurable acute phase response at the clinical terminal end-stage of classical scrapie.

Effect of lairage on lamb welfare and meat quality

The study analysed the effect of lairage on some indicators of welfare and meat quality in lambs. Forty-eight lambs were divided into two treatments: T1 without lairage and T2 with 12 h of lairage. Blood samples were collected at slaughter to analyse cortisol, lactate, glucose, creatinine kinase, non-esterified fatty acid, white blood cells, red blood cells, haematocrit and ratio of neutrophil : lymphocytes. Meat from the M. longissimus was analysed in terms of pH 24 h post-mortem, water-holding capacity, texture and colour. Sensory analyses were performed by a trained panel. Lairage had a significant effect on stress response, but had no effect on haematological variables. The lambs with a lairage period before slaughter (T2) had significantly (P ≤ 0.001) lower values of cortisol at the time of slaughter. A similar result was observed for lactate and glucose, with T1 lambs showing significantly (P ≤ 0.05) higher values than T2 lambs. The creatinine kinase activity and non-esterified fatty acid concentrations were highest in T2 lambs (P ≤ 0.05). Instrumental and sensory meat quality were not affected, with the exception of water-holding capacity and some meat colour indicators. The water-holding capacity was significantly higher for T2 (P ≤ 0.05), while T1 lambs had a higher yellow index (P ≤ 0.05) and hue (P ≤ 0.05). The results obtained in this study suggest that animals will be less stressed at the time of slaughter with an overnight lairage compared with slaughter on arrival at the abattoir. While stress at the time of slaughter can influence meat quality, these changes were small and always within the normal commercial range.