Evaluation of the metabolomic profile through 1H-NMR spectroscopy in ewes affected by postpartum hyperketonemia.

Ketosis is one of the most important health problems in dairy sheep. The aim of this study was to evaluate the metabolic alterations in hyperketonemic (HYK) ewes. Forty-six adult Sardinian ewes were enrolled between 7 ± 3 days post-partum. Blood samples were collected from the jugular vein using Venosafe tubes containing clot activator from jugular vein after clinical examination. The concentration of ß-hydroxybutyrate (BHB) was determined in serum and used to divide ewes into assign ewes into: Non-HYK (serum BHB < 0.80 mmol/L) and HYK (serum BHB ≥ 0.80 mmol/L) groups. Animal data and biochemical parameters of groups were examined with one-way ANOVA, and metabolite differences were tested using a t-test. A robust principal component analysis model and a heatmap were used to highlight common trends among metabolites. Over-representation analysis was performed to investigate metabolic pathways potentially altered in connection with BHB alterations. The metabolomic analysis identified 54 metabolites with 14 different between groups. These metabolites indicate altered ruminal microbial populations and fermentations; an interruption of the tricarboxylic acid cycle; initial lack of glucogenic substrates; mobilization of body reserves; the potential alteration of electron transport chain; influence on urea synthesis; alteration of nervous system, inflammatory response, and immune cell function.

Changes in plasma fatty acids profile in hyperketonemic ewes during early lactation: a preliminary study.

The transition from late pregnancy to early lactation is characterized by marked changes in energy balance of dairy ruminants. The mobilization of adipose tissue led to an increase in plasma non-esterified fatty acids (NEFA) and ß-hydroxybutyrate (BHB). The aim of this study was to analyze the total plasma fatty acids of healthy and hyperketonemic dairy ewes in early lactation through gas chromatography (GC) to evaluate metabolic alterations. An observational study was used with a cross-sectional experimental design. Forty-six Sarda dairy ewes were enrolled in the immediate post-partum (7 ± 3 days in milk) and divided into two groups according to serum BHB concentration: non-hyperketonemic group (n = 28; BHB < 0.86 mmol/L) and hyperketonemic group (n = 18; BHB ≥ 0.86 mmol/L). A two-way ANOVA included the effect of group and parity was used to evaluate differences in fatty acids (FA) concentrations. A total of 34 plasma FA was assessed using GC. 12 out of 34 FA showed a significant different between groups and 3 out of 34 were tended to significance. Only NEFA concentration and stearic acid were influenced by parity. The results may suggest possible links with lipid metabolism, inflammatory and immune responses in hyperketonemic group. In conclusion, GC represents a useful tool in the study of hyperketonemia and primiparous dairy ewes might show a greater risk to develop this condition.

Milk Fatty Acids Composition Changes According to ß-Hydroxybutyrate Concentrations in Ewes during Early Lactation.

Ketosis is a metabolic disease of pregnant and lactating ewes linked to a negative energy balance which can cause different economic losses. The aims of this study were to understand the metabolic status of the early-lactating ewes and to identify biomarkers for early diagnosis of subclinical ketosis. Forty-six Sarda ewes were selected in the immediate post-partum for the collection of the biological samples. A blood sample from the jugular vein was used to determine ß-Hydroxybutyrate (BHB) concentrations. Animals were divided into two groups: BHB 0 or healthy group (n = 28) with BHB concentration < 0.86 mmol/L; and BHB 1 or subclinical ketosis (n = 18) with a BHB concentration ≥ 0.86 mmol/L. Ten mL of pool milk were collected at the morning milking for the analyses. The concentration of 34 milk fatty acids was evaluated using gas chromatography. Two biochemical parameters and 11 milk fatty acids of the total lipid fraction presented a p-value ≤ 0.05. The study revealed different relationships with tricarboxylic acid cycle, blood flows, immune and nervous systems, cell functions, inflammatory response, and oxidative stress status. Eight parameters were significant for the receiver operating characteristic (ROC) analysis with an area under the curve greater than 0.70.

On-farm use of a water hardness test kit to assess total blood calcium level in dairy cattle.

In this Research Communication we report the measurement of total blood calcium concentration with a water hardness test kit (WHTK) in dairy cattle and compare the results to a reference method. The study was carried out on 107 Holstein Friesian cows from three commercial dairy farms in Sardinia (Italy). Blood samples were collected ≤7 d from calving and total serum calcium concentration was determined using a biochemical analyzer and a WHTK. The relationship between the laboratory results and the WHTK results was investigated using Spearman's rank correlation test and simple linear regression was determined. Sensitivity, specificity, negative and positive predictive values, intra and inter-assay coefficient of variation were also calculated. The test values were highly correlated with the laboratory values (R2 = 0.72, P < 0.001). Sensitivity and specificity were respectively 88 and 83% for the WHTK and intra and inter-assay coefficients of variation were 7.3 and 11.3% respectively. The WHTK was identified as a potential on-farm tool for monitoring early postpartum Ca concentrations at herd level.

Evaluation of Oxidative Stress in Dairy Cows with Left Displacement of Abomasum.

Left Displacement of the Abomasum (LDA) is a condition that occurs in high-producing postpartum dairy cows and it causes economic losses. Studies performed in the last decade indicate that adult dairy cows experience oxidative stress. Increasing interest in the role of oxidative status in ruminant medicine has emphasized the need to develop reliable methods to assess it. A few studies have evaluated the relationship between LDA and oxidative status, mostly through the determination of single parameters of oxidation and the determination of antioxidant status separately, with contrasting results. The aim of this study was to assess the oxidative status by the measurement of Reactive Oxygen Metabolites with d-ROMs and Biological Antioxidant Potential BAP and the calculation of the Oxidative Status index in 74 multiparous dairy cows with LDA. Each case was matched with a control herdmate. The amount of free oxygen radicals in plasma samples was determined using the d-ROMs test, the concentration of antioxidants was measured using the BAP test and the Oxidative Status index was also calculated. The concentration of d-ROMs was significantly higher in the study group compared to the control group (179 ± 37.7 U CARR and 158 ± 23.0 U CARR, respectively), while the concentration of BAP was significantly lower in the study group than in the control group (2156 ± 98.1 µmol/L vs. 2558 ± 108.5 µmol/L). The Oxidative Status index value was significantly higher in cows with LDA than in healthy cows (8.3 ± 1.51 vs. 6.2 ± 0.76). The results of this study indicated that an inbalance between oxidants and antioxidants occurred in cattle with LDA.

Association between left-displaced abomasum corrected with 2-step laparoscopic abomasopexy and milk production in a commercial dairy farm in Italy.

BACKGROUND: Left displacement of the abomasum (LDA) is a condition of dairy cows that causes huge economic losses. The aim of the study was to evaluate the effect of LDA after on-farm correction by the 2-step laparoscopic abomasopexy on milk production based on 305-d milk yield on a commercial dairy farm in Italy.The study was performed between January 2011 and January 2014 on 58 Holstein Friesian cattle with left displacement of the abomasum in a commercial dairy farm in the farmland of Ozieri, Sardinia (Italy). Each cow underwent a 2-step laparoscopic abomasopexy performed by the same veterinarian. Each case was matched with a control herdmate by age, parity and calving date. Cows with LDA and healthy control cows also had a similar 305-d milk yield in the previous lactation. Data on milk production were collected using a dairy herd management software programme (Afimilk®, Afimilk Ltd., Israel). The 305-d lactation yield was obtained from the sum of daily milk yields for each cow. An unpaired Student's t-test was used to compare changes in milk production, mean fat and protein percentage of cases and controls before and after surgical procedure. RESULTS: Data from 4 cows were excluded from the analysis due to post-surgical complications. 54 cases and 54 control cows participated in the study. We found that milk production significantly decreased from a baseline of 12,295 ± 1690 kg to 11,165 ± 1989 kg in the affected lactation. Conversely, a significant increase was observed for mean fat and protein percentage during lactation in case cows. CONCLUSIONS: In the present study cows with left displacement of the abomasum corrected with 2-step laparoscopic abomasopexy produced less milk than their control herdmates. Each case and control pair in the present study came from the same farm in order to eliminate farm to farm differences in management, housing, season, etc. However, this limits the validity of our data to the specific situation described here.

An Antioxidant Dietary Supplement Improves Brain-Derived Neurotrophic Factor Levels in Serum of Aged Dogs: Preliminary Results.

Biological aging is characterized by a progressive accumulation of oxidative damage and decreased endogenous antioxidant defense mechanisms. The production of oxidants by normal metabolism damages proteins, lipids, and nucleotides, which may contribute to cognitive impairment. In this study 36 dogs were randomly divided into four groups and fed croquettes of different compositions for 6 months. We monitored derivatives of reactive oxygen metabolites (dROMs) and biological antioxidant potential (BAP) levels in dogs' plasma samples as well as brain-derived neurotrophic factor (BDNF) serum levels at the beginning and at the end of the dietary regime. Our results showed that a dietary regime, enriched with antioxidants, induced a significant decrease of plasma levels of dROMs (p < 0.005) and a significant increase in BDNF serum levels (p < 0.005) after six months. Thus, we hypothesized a possible role of the diet in modulating pro- and antioxidant species as well as BDNF levels in plasma and serum, respectively. In conclusion the proposed diet enriched with antioxidants might be considered a valid alternative and a valuable strategy to counteract aging-related cognitive decline in elderly dogs.

West Nile Virus outbreak in Sardinia, Italy, in 2011.

West Nile Virus (WNV) is an enveloped, positive-sense RNA virus belonging to the genus Flavivirus, antigenically related to the Japanese encephalitis complex in the family Flaviviridae. The principal vectors are mosquitoes, in particular Culex spp, and virus amplification seems to occur in susceptible birds that are the principal vertebrate reservoir hosts, whereas humans, horses and other vertebrates are considered incidental or dead-end hosts. The first Italian equine outbreak was reported in late summer of 1998 in Tuscany, in the area surrounding the Fucecchio marshes, where 14 clinical cases of WND in housed equines were recorded. In 2011 WNV appeared for the first time in Sardinia, representing the first clinical cases in equines in Italy in 2011. The outbreak occurred both in humans and in equines. The serological survey performed on 253 equines living in the province of Oristano detected a total of 87 IgG-positive subjects. Among them, 46 horses showed neurological signs such as ataxia, paresis, paralysis, hyperesthesia, muscle fasciculations, seizures, or fever. Nine of them died or were euthanized. In forthcoming years, surveillance of wild birds and insects will be used to forecast the extension and spread of WNV. The information gathered will be used to direct or optimise strategies intended to prevent virus transmission.