Massimo Morgante

Behavioural lateralization in sheep (Ovis aries).

This study investigates behavioural lateralization in sheep and lambs of different ages. A flock was tested in a task in which the animals were facing an obstacle and should avoid it on either the right or left side to rejoin flock-mates (adult sheep) or their mothers (lambs). A bias for avoiding the obstacle on the right side was observed, with lambs apparently being more lateralized than sheep. This right bias was tentatively associated with the left-hemifield laterality in familiar faces recognition which has been documented in this species. Differences between adult sheep and lambs were likely to be due to differences in social reinstatement motivation elicited by different stimuli (flock-mates or mothers) at different ages. Preferential use of the forelegs to step on a wood-board and direction of jaw movement during rumination was also tested in adult animals. No population bias nor individual-level lateralization was observed for use of the forelegs. At the same time, however, there was a large number of animals showing individual-level lateralization for the direction of jaw movement during rumination even though there was no population bias. These findings highlight that within the same species individual- and population-level lateralization can be observed in different tasks. Moreover, the results fit the general hypothesis that population-level asymmetries are more likely to occur in tasks that require social coordination among behaviourally asymmetric individuals.

Subacute ruminal acidosis and evaluation of blood gas analysis in dairy cow.

Subacute Ruminal Acidosis (SARA) corresponds to an imbalance between lactate-producing bacteria and lactate-using bacteria, which results in a change in ruminal pH associated with a prevalent consumption of rapidly fermentable carbohydrates. In our study, 216 primiparus and multiparus dairy cows were selected from 20 Italian intensive dairy herds and were divided into three groups based on the risk of SARA. All the dairy cows had high average milk production. After blood sampling, a complete blood gas analysis was performed. One-way ANOVA was performed to compare the three groups. O(2) Cont, PCO(2), blood pH, O(2)Hb, urinary pH, and rumen pH were significantly lower in cows with rumen pH < 5.5. These results indicate that blood gas analysis is a valuable tool to diagnose acidosis in dairy cows because it provides good assessment of acidosis while being less invasive than rumen pH analysis.

Assessment of oxidative stress in dry and lactating cows

The increasing production level requested of livestock, with particular relevance to milk producers, requires scientific studies in order to address management towards breeding that supports, in a qualitative-quantitative manner, production performance and animal welfare. Modern breeding is a rationalized management essentially based on genetic selection, type of breeding, feeding and health of the animals. The high productivity of lactating cows and the physiological phenomenon that characterizes the lactation phase determine endocrine and metabolic modifications, with enhancement of anabolic and catabolic processes. Oxidation leads to an increase of electron flow in the respiratory chain that involves the formation of ‘refuse products’ defined as free radicals. A free radical is defined as any species capable of independent existence that contains one or more unpaired electrons (Auroma, 1994). It should be noted that the terms reactive oxygen species (ROS) and free radicals are often used interchangeably in the literature. ROS are capable of attacking all of the major classes of biomolecules, although lipids are particularly susceptible (McBride & Kraemer, 1999). Oxidative stress, a particular kind of chemical stress, is caused by an imbalance between the production of free radicals and the capability of an organism to absorb their excess. Oxidative stress is extremely dangerous because it does not exhibit any symptoms and is recognizable with great difficulty by means of common methods of analysis. Physiologically, free radicals supply the immune system in defence against bacteria; in case of excess in production that cannot be counteracted by cytoprotective mechanisms, there is an ‘oxidative stress’ that promotes the insurgence of serious pathologies as a result of the degenerative damage of cellular structures (Freidovich, 1999; Matsuo & Kaneko, 2000; McCord, 2000). It seems obvious that free radicals constitute an important factor of risk for health and it is therefore imperative to maintain their levels at basal values. Measure of oxidative stress allows estimation of the real ‘status’ of physiological defence and prevention of the appearance of correlated pathologies. Recently, some preliminary investigations have addressed oxidative status in dairy cows during the ovarian cycle (Trout et al., 1998) and in the periparturition period (Kimura et al., 1999; Stefanon et al., 2005). Given the remarkable zooeconomic impact of metabolic stress, it is interesting to establish in an objective manner the effects of the different lactating phases on the efficiency of the antioxidant mechanisms. The aim of our study was to bring new knowledge to the physiology of lactation, in order to optimize productive performance with respect to animal welfare; it is thus important to consider oxidative stress as a potential index of animal welfare to be able to detect, preventively, excessive animal exploitation, thus protecting health status.

Daily Rhythmicity of Core and Surface Temperatures of Sheep Kept Under Thermoneutrality or in the Cold

We compared the daily rhythms of body core temperature and surface temperature in 10 Comisana ewes housed at thermoneutrality (25°C) and in the cold (9°C). Core temperature was measured with a rectal probe, whereas surface temperature (in the eye, forehead, and foot) was measured by infrared thermography, at 3h intervals for 27 consecutive hours under each condition. We found a robust rhythm of core temperature, whose amplitude doubled from 0.2°C at thermoneutrality to 0.4°C in the cold. The surface temperatures were all lower than core temperature and exhibited weaker but significant daily rhythmicity. At thermoneutrality, foot temperature (an indicator of vasodilation in the service of heat loss) peaked 3h before rectal temperature. Studies on other species are needed to clarify whether the latency between the peaks of the oscillations in foot and core temperature vary in a species-specific manner and are responsible for the generation of the core temperature rhythm.

Blood gas analyses, ruminal and blood pH, urine and faecal pH in dairy cows during subacute ruminal acidosis

The aim of this study was to investigate the variations of some physiological parameters in dairy cows during subacute ruminal acidosis (SARA), a common important disorder of dairy cows that occurs in early lactation. pH changes in ruminal fluid collected by rumenocentesis were measured at ten farms stationed in different zones in the north of Italy. Additionally, the following parameters were measured: blood pH, faecal pH, urine pH, partial pressure of carbon dioxide oxygen, partial pressure of oxygen, bicarbonate level, base excess of extracellular fluid and oxygen content. Herds were divided into two groups according to their average ruminal pH: group A included farms with average ruminal pH > 5.8 (normal) and group B farms with average ruminal pH < 5.8 (acidosis). Unpaired Student’s t test was used to reveal statistical significances between the two groups. Ruminal pH changes due to pathogenesis can be diagnostic for SARA.

Effect of induced ruminal acidosis on blood variables in heifers

BackgroundRuminal acidosis is responsible for the onset of different pathologies in dairy and feedlot cattle, but there are major difficulties in the diagnosis. This study modelled the data obtained from various blood variables to identify those that could indicate the severity of ruminal acidosis. Six heifers were fed three experimental rations throughout three periods. The diets were characterised by different starch levels: high starch (HS), medium starch (MS) and low starch, as the control diet (CT). Ruminal pH values were continuously measured using wireless sensors and compared with pH measurements obtained by rumenocentesis. Blood samples were analysed for complete blood count, biochemical profile, venous blood gas, blood lipopolysaccharide (LPS) and LPS-binding proteins (LBP).ResultsThe regression coefficient comparing the ruminal pH values, obtained using the two methods, was 0.56 (P = 0.040). Feeding the CT, MS and HS led to differences in the time spent below the 5.8, 5.5 and 5.0 pH thresholds and in several variables, including dry matter intake (7.7 vs. 6.9 vs. 5.1 kg/d; P = 0.002), ruminal nadir pH (5.69 vs. 5.47 vs. 5.44; P = 0.042), mean ruminal pH (6.50 vs. 6.34 vs. 6.31; P = 0.012), haemoglobin level (11.1 vs. 10.9 vs. 11.4 g/dL; P = 0.010), platelet count (506 vs. 481 vs. 601; P = 0.008), HCO3- (31.8 vs. 31.3 vs. 30.6 mmol/L; P = 0.071) and LBP (5.9 vs. 9.5 vs. 10.5 μg/mL; P < 0.001). A canonical discriminant analysis (CDA) was used to classify the animals into four ruminal pH classes (normal, risk of acidosis, subacute ruminal acidosis and acute ruminal acidosis) using haemoglobin, mean platelet volume, β-hydroxybutyrate, glucose and reduced haemoglobin.ConclusionsAlthough additional studies are necessary to confirm the reliability of these discriminant functions, the use of plasma variables in a multifactorial model appeared to be useful for the evaluation of ruminal acidosis severity.

Good quality sheep embryos produced by superovulation treatment without the use of progesterone devices

Multiple ovulation and embryo transfer (MOET) is a very important tool for the genetic improvement and preservation of endangered livestock. However, the success of a MOET programme highly depends on the number of transferable embryos in response to a superovulation treatment. Thus, the aim of this study was to compare the number and quality of embryos produced during natural oestrus under porcine FSH treatment without the use of progesterone devices to more traditional protocols. Forty Sarda sheep were divided into 2 groups: without sponges (WS) (n = 20) and with sponges (S) containing 40mg FGA for 12 d (n = 20) (control group); 350 I.U. of porcine FSH per sheep was administered in eight decreasing doses twice daily starting four days after estrus was detected (Day 0) in group WS and 48 h before sponge removal in group S. A single i.m. dose of 125 μg of cloprostenol was administered on Day 6 after estrus in group WS to induce luteolysis. Sheep were naturally mated 24 h after cloprostenol injection or sponge removal. Seven days after mating, an inguinal laparotomy was performed and the number of corpora lutea (CL) recorded. Embryos were recovered surgically by flushing each uterine horn. A total of 38 fresh and 22 vitrified embryos were transferred in pairs into 3 groups of recipients seven days after estrus detection: fresh embryos from group S (S-F) (n = 9), fresh embryos from group WS (WS-F) (n = 10) and vitrified embryos from group WS (WS-V) (n = 11). Data on the number of corpora lutea (CL), recovered ova and embryos (OER), and quality 1-2 and 3 embryos (EQ(1-2), EQ(3)) per ewe were analyzed by ANOVA. Recovery (RR), fertility (FR) and quality 1-2 embryo (Q(1-2)R) rates per treatment were analyzed by a Chi Square analysis. A Chi Square analysis was also applied to pregnancy rate (PR), lambing rate (LR) and twinning rate (TR) of fresh and vitrified embryos in order to analyze embryo transfer results. Among all superovulation variables analysed, results show statistically significant differences in mean number of CL/ ewe (9.3 ± 3.9 vs 7 ± 3.2), RR (67% vs 80 %) and FR (100% vs 80%) (P < 0.05) between WS and S groups respectively. There were no significant differences in PR (78%, 70% and 82%), LR (67%, 60% and 59%) and TR (71%, 71% and 44.4%) among S-F, WS-F and WS-V groups respectively. In conclusion, it is possible to produce a good number of transferable embryos during natural oestrus avoiding the use of sponges.

Thermographic Applications in Veterinary Medicine

Veterinary infrared thermography is a term indicating in vivo digitally imaging an animal with an infrared camera using computer interpretation of thermal maps. Various trials were performed with different species (horse, pig and cows)1,2,3,4,5 to assess the validity of thermographic instrument. Infrared thermographic systems are capable of seeing energy emitted by most objects at a temperature above -35°C. Therefore colour or visible light does not interfere with the possible images seen by thermographic system. The maximum heat emitter is considered a black body which have an emissivity of 1 because it adsorbs all radiated heat. The emission factor of skin is approximately 0.93-0.98 depending on coat quantity and length. Heat is the primary sign of inflammation process and different disease processes affect the microcirculation of the skin. Therefore variations of the skin temperature become interesting indicator of such conditions that can range from specific vascular alterations to referred conditions also physiologically. Since skin temperature may be used in order to estimate tissue integrity because it reflects the underlying circulation and tissue metabolism.

Short-term adaptive response in strongly versus weakly lateralized dairy ewes

Abstract The effects of lambs separation and manual milking, which are stressors usually associated with the productive cycle of dairy sheep farm, were investigated by comparing short-term (24 h) adaptive responses in strongly versus weakly lateralized dairy ewes. Functional lateralization was scored with a series of behavioural tests (direction of free turning, direction of obstacle turning, preferential leg use in front of an obstacle) followed by a daily period of hormonal, biochemical and clinical parameters assayed on two groups of 6 strongly (SLS) and two groups of 6 weakly (WLS) lateralized ewes divided for lamb presence or separation. Differences were observed for several parameters as a function of the degree of lateralization score and stressors application. The results suggest that behavioural lateralization parameters should be taken into consideration as a crucial variable to understand stress responses and their modulation in relation to animal welfare.

Serum acute phase proteins in cows with SARA (Subacute Ruminal Acidosis) suspect

The aim of this study was to evaluate the variations of Acute Phase Proteins (APPs) and other blood constituents during the onset of the sub-acute ruminal acidosis (SARA) pathological status. A total of 108 cows from 12 dairy herds were randomly selected and divided into three Groups of 36 animals each. All animals were subjected to a rumenocentesis. Group A was composed by subjects with a rumen pH>5.8, Group B was composed by subjects with a rumen pH ≤5.5≤5.8 and Group C was composed by subjects with a rumen pH<5.5. Blood samples were collected by jugular venipuncture and Haptoglobin (Hp), Serum Amyloid A (SAA), Total Proteins, Albumin and White Blood Cells (WBC) were determined. Oneway ANOVA showed a statistical significance on Rumen pH, Hp, SAA. SARA seems not stimulate the APPs production from liver.