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NEWBORN CALVES' FEATURES IN RELATION TO THE TYPE OF DELIVERY
Full text linkDuring recent years, an increase in perinatal mortality has been reported in dairy calves, quite typically not associated with an increase in the rate of dystocia. These perinatal losses not only represent a tremendous economic loss but also mirror an important welfare problem in cattle farms.
In order to reduce the losses occurring during the perinatal and neonatal period, management of the parturient cow and newborn calf have to be addressed critically. As for all newborns, also calf’s survival and subsequent health conditions require a perfect transition from fetal to extra uterine life. Critical observation and/or investigation of the calf during and immediately after calving is important, considering that several problems encountered during the first days after delivery can originate from the calving period itself.
In a crude analysis for fetal and neonatal outcomes related to the type of delivery in the human specie, the highest rates of neonatal morbidity and mortality were seen in the elective caesarean group. Elective caesarean delivery could increase neonatal morbidity and mortality because lack of labour affects the physiological process for initiation of respiration. Caesarean delivery is known to be associated with respiratory distress syndrome and transient tachypnoea possibly mediated by the lower release of catecholamine and prostaglandins, as well as the lack of the mechanical compression of the lungs during labour needed to facilitate postnatal lung adaptation.
Moreover, several studies on babies demonstrated that the type of delivery can deeply influence the adaptational process in the newborn, modifying the immune response, the oxygenation status and the developing endocrine axis; the influence of delivery is not only immediate but extended in time, possibly affecting also the future health status of the subject.
The main focus of this experimental thesis was on the effects of two different types of delivery on the conditions of the calf at birth and during the neonatal period; differences in clinical features and biochemical, metabolic, hormonal, hematological and inflammatory profiles, have been described and discussed in details.
In the first study (chapter 7-8-9), clinical data and biochemical, metabolic and hormonal profiles from newborn calves born by spontaneous parturition or by caesarean section were compared. For each newborn many clinical data (Apgar score, rectal temperature, extimated weight) were collected within 5 minutes from birth. Time for sternal recumbency and time to stand up were registered as soon as evident. Biochemical and metabolic profiles during the first 2 days of life (birth, 24 h, 48 h) were determined. Plasma concentrations of IGF-I, cortisol and thyroid hormones were investigated for the first 14 days of life.
No significant differences between calves from spontaneous parturition and from caesarean section were found concerning clinical features at birth and during neonatal period (chapter 7). Many differences between the two groups were found regarding some biochemical, metabolic and hormonal parameters. These fast changes in biochemical and metabolic parameters in the newborn calf are probably due to the maturational processes of liver, kidney and metabolism for adaptation to the extra uterine life; basing on our data, the caesarean section seems to entail a lower physical effort for calves during birth, and a slower or delayed adaptational process.
In the second study (chapter 10) the plasmatic profile of prostaglandin F2α was determined in 10 newborn calves from spontaneous parturition, and compared with those from neonates of other animal species. Plasmatic levels of prostaglandin metabolite in calves remained high for the first 3 hours of life, unlike newborn horse and donkey foals, in which the metabolite already decreased at 30 minutes after birth.
Differences in placentation type or in gestation length could be the reason for the difference between these species.
In the third study (chapter 11) the hematological profile of the newborn calves during the first 14 days of life was investigated in relation to the type of delivery. Data from 16 Holstein Friesian calves from spontaneous parturition and from 25 Belgian White and Blue calves from caesarean section were compared. Differences were found regarding many parameters; red blood cells count was always higher in the CS group, as hemoglobin concentrations and hematocrit levels. White blood cells count was higher in the CS group at birth and at 14 days after birth, and it was due to an higher neutrophil count.
Different type of delivery can lead to different degree of stress and oxygenation in the newborn, which can represent the reason for variation in hematological pattern; difference in breed could anyway also play a role in this.
In the fourth study (chapter 12) a new acute phase protein (PON1) was investigated in newborn calves from spontaneous parturition, and in calves up to 120 days old. Samples from some calves with inflammation were examined and compared with those of age-matched controls. The profile of PON1 activity in the newborn calves was characterized by a gradual increase starting from day 3 of life, probably due to maturation of hepatic system; this result evidences the importance to establish age-related reference intervals. In sick calves, PON1 was significantly lower than in age-matched controls, confirming the role of PON1 as a negative acute phase protein also in calves.
From this thesis, the following general conclusion can be drawn:
- during the first minutes, hours and days after delivery, a wide number of physiological changes take place in the newborn calf;
- circulating levels of many hormones, which are responsible for maturation and adaptation of the neonate, rapidly change with age; most of these hormones reach stable values after the first 24 hours of life, so that the first day after birth has a key role in the adaptational process of the newborn to the extra uterine life;
- prostaglandins F2α metabolite plasma concentrations in the newborn calf remain high for the first 3 hours of life, unlike newborn horse and donkey foals, in which the metabolite already decreased at 30 minutes after birth. Differences in placentation type or in gestation length could be the reason for the difference between these species;
- PON1 activity in the newborn calves is characterized by a gradual increase starting from day 3 of life, probably due to maturation of hepatic system; this result evidences the importance to establish age-related reference intervals;
- in sick calves, PON1 is significantly lower than in age-matched controls, confirming the role of PON1 as a negative acute phase protein also in calves;
- the type of delivery does not seem to influence the immediate clinical conditions of the newborn calf, above all in terms of viability;
- the type of delivery seems to influence the biochemical, metabolic, haematological and hormonal profiles of the newborn calf: these differences are probably due to a different stress stimulation, which is normally lower during elective caesarean section
Clinical Scoring Systems in the Newborn Calf: An Overview
Full text linkA scoring system is an instrument that enables the scorers, including farmers, technicians, and veterinarians, to adopt a systematic approach for diagnosis or monitoring, as it decreases bias and confounding and increases objectivity. Practically, it is a number assigned to a patient that correlates with a probability that a diagnosis can be confirmed or that a specific outcome will follow. This article examines the clinical scores designed or adapted to bovine medicine that aim to assess newborn calf viability and to diagnose and monitor neonatal calf diarrhea and respiratory diseases, helping the clinician promptly recognize calves needing medical assistance. Despite the large number of clinical scores described in the literature, these are still barely used in farm animal practice; possibly, the complexity of the scores and missing recommendations for intervention are reasons for their lack of popularity as well as the crosswise lack of consistency among scores designed for the same purpose. Further research is needed in this regard to increase scores validation and encourage their application in bovine calf neonatology
Fluctuation of neutrophil counts around parturition in Holstein dairy cows with and without retained placenta
Full text linkRetained placenta (RP) is often diagnosed in high-yielding dairy cows and can negatively affect reproductive performances. The objective of the present study was to investigate the hematological and biochemical profile of cows with RP before and immediately after parturition, with particular emphasis on neutrophil counts, since a previous study demonstrated the presence of peripheral neutropenia in dairy cows with RP sampled a few days after parturition. Results from 12 Holstein cows affected by RP and from 17 clinically healthy controls sampled one week pre-partum, within 12 h after calving and between 48 and 72 h after parturition were compared between groups and over time. Compared with controls, cows with RP had lower lymphocyte counts before parturition, lower leukocyte and neutrophil counts at parturition, lower monocyte counts at all times, and higher β-hydroxybutyrate before and after parturition. Erythroid and biochemical parameters were similar over time in both groups, whereas RP cows did not show the increase of neutrophil counts that occurs in controls at parturition. Hence, the finding of a lower neutrophil count in a routinely hemogram performed at parturition could be used as an alarm signal suggesting to monitor the affected animals. Moreover, although the underlying pathogenetic mechanism should be better investigated, the present study describes for the first time the association between altered blood leukocyte concentrations at parturition in RP compared to control cows
Hematological changes around parturition in dairy cows with and without retained placenta
No full textLaboratory reference intervals of Holstein lactating cows at 3 and 30 days post-partum
Full text linkThe establishment of specific reference intervals (RIs) is advisable when different metabolic status in the patient population are present, or when existing RIs are not suitable for the laboratory's patient population. Healthy Holstein dairy cows, at the start of lactation, experience a state of negative energy balance and altered immune system function that can lead to different laboratory results compared with cows at peak lactation, when a more balanced metabolic state is present. RIs created taking into account these differences have not been published to date.
The aim of this study was the a posteriori determination of RIs of Holstein cows at 3 ± 1 and 30 ± 3 days in milk (DIM). To this aim, data from 145 cows, from 4 herds, were selected from our database. Serum biochemistry and protein electrophoresis were performed with automated instruments (ILAB 300 plus, International Laboratory, Italy and Hydrasis, Sebia, Italy, respectively). Hematology was performed on an ADVIA 120 analyzer (Siemens, Italy). RIs were generated and the effects (regression analysis, p < 0.05) of stage of lactation, herd and day of sampling were
analyzed with Reference Value Advisor and Analyse-it. Data from 32/39 analytes (RBC, Hb, Ht, MCV, MCHC, PLT, neutrophil, lymphocytes, monocytes, total globulin, α1-globulin, α2-globulin, β2-globulin, γ-globulin, A/G ratio, ALP, AST, creatinine, Cl, K, total bilirubin, NEFA, BOHB, Ca, GGT, Mg, Pi, total protein, urea, glucose, cholesterol and zinc) were significantly different according to lactation stage and specific RIs were adopted. On the contrary, 7/39 analytes (WBC, MCH, RDW, eosinophils, potassium, albumin, β1-glubulin) were not significantly different between the two groups, thus common RIs were adopted for these parameters. Creatinine at 3 ± 1 DIM was significantly different in the different sampling days. Statistical analysis revealed some herd-specific differences at 3 ± 1 DIM (MCHC, RDW, β1-globulin, AST, total protein, glucose, and NEFA) or at day 30 ± 3 (MCHC, eosinophils, albumin, β1-, β2- and γ-globulin, ALP, Mg, total protein, glucose, zinc, NEFA, and
BOHB). The adoption of day-specific or herd-specific RIs, however, has practical limitations and in routine practice it may be advisable to take into account the possible herd-specific peculiarities when results are close to the lactation-specific RI rather than generating additional RIs. In conclusion, the use of RIs specific for the lactation stage is highly justified from both a statistical and a biological point of view. Preanalytical factors associated with day of sampling or management need to be considered in the evaluation of results from some analytes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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