Haematological variations during peripartum period in Magra sheep

Introduction

The value of blood parameters are influenced by several factors such as physiological status, stress, sex, breed, age, diet, handling, climate, and the laboratorial methodology (Kaneko et al., 2008) [1] . According to Rens and Lende (2004) [2] parturition is the most important event of an animal's life. It is a complex process that involves changes at the hormonal, physiological, morphological, and behavioural levels. Metabolism of an animal's is influenced by the physiological states of pregnancy and lactation (Iriadam, 2007) [3] . Blood parameters are used for evaluating the individual's health conditions and monitoring the nutritional and metabolic conditions of the animals. During pregnancy period, increased metabolic activity and negative energy balance might also lead the sheep to a compromised state. During pregnancy there is drastic increase in energetic and oxygen demands to ensure an adequate foetal development and growth. All of the parameters that were analyzed during this research are related to a group whose blood levels can be used as a diagnostic tool to evaluate the cellular function of animal during the stage of pregnancy. The research was carried out to assess the hematological parameters impacted by the peripartum period in Magra Sheep.

Materials and Methods

Experimental Material

To achieve the objectives of the proposed plan, seventy-five apparently healthy Magra sheep above eight months of age belonging to the Livestock Research Station, Kodamdesar, Bikaner were examined. Fifteen non-pregnant sheep served as control and sixty sheep during peripartum were screened to observe the effect. To fulfill the aim of research, blood samples

Experimental Design

The experiment's goal was to determine the haematological indices in the blood samples of Magra Sheep during peripartum. The sampling was done as shown below in Table 1.

Methodologies of analysis used for evaluating the haematological indices 1. Haemoglobin (Hb) 1.1 Method employed: Sahli's hemoglobinometer method, as described by Schalm (1986) [4] .

1.2 Procedure: Haemoglobin was converted to acid haematin by N/10 HCl. The acid separates the globin from the haemoglobin, resulting in the formation of acid haematin, which is a brown-coloured substance. The tube was kept for 10 minutes for formations of acid haematin then distilled water was added slowly until the colour matched the standard yellowish haemoglobinometer brown glass tubes fitted in the haemoglobinometer.

Packed cell volume (PCV)

2.1 Method employed: Standard technique described by Schalm (1986) [4] .

Procedure:

Wintrobe's tube was filled with anticoagulant-mixed blood up to mark 10 and centrifuged for 30 minutes at 3000 rpm. The recording of PCV (packed cell volume) was expressed in percent.

Statistical Analysis

The obtained data were analysed using the statistical package for the social sciences (SPSS, Version 26.0) software, and the comparison of mean values was done using one-way analysis of variance (ANOVA) techniques.

Post Hoc Duncan's new multiple range test (Duncan, 1955) [5] was applied to explain the significance difference between the means of various physiological states. Per cent variations of each physiological state were also calculated with respect to the mean value of the respective nonpregnant animals (control). Pearson's correlation test was used to determine the relationship between the parameters.

Ethical Considerations

Proper care was taken to minimize stress and ensure animal welfare throughout the study. All the sampling were done as per standard protocol and permission from IAEC had been obtained (Approval no. CVAS/IAEC/2023-2024 Dated 19/07/2023).

Results and Discussion

Each parameter was assigned a control value based on fifteen non-pregnant animals. The mean values are obtained from sixty sheep, fifteen each in their mid-pregnancy, latepregnancy, on the day of lambing (within 12 hours of lambing) and one week after lambing for each parameter. Significance has been exhibited in the form of superscripts on the mean values and is well illustrated as footnotes.

The obtained control value of Hb and PCV was to be 11.30 ± 0.36 g/dl and 34.58 ± 0.45% respectively. This value was used to analyze the data collected from 60 Magra sheep during their peripartum period. It was observed during the study that a significant decrease in Hb and PCV mean values from mid-pregnancy to late-pregnancy, while there was start to significant increase in these values from on the day of lambing (within 12 hours of lambing) to one week after lambing. Analysis of variance revealed a highly significant (p ≤ 0.01) effect of pregnancy and lambing on the mean values of haemoglobin and packed cell volume (PCV) during this study period. No significant difference was observed between the mean value of Hb during midpregnancy and late-pregnancy, but in PCV a significant difference was observed. On the day of lambing and one week after lambing, a significant effect was observed between the mean values of haemoglobin but a nonsignificant difference in PCV was observed. Overall the maximum per cent decline in Hb and PCV was observed during on the day of lambing and during late-pregnancy respectively.

The observations of haematological studies are presented according to different peripartum stages of female Magra sheep in Table 2, Analysis of variance of haemoglobin and packed cell volume (PCV) in Table 3 & 4 respectively. The data presented in Table 5 show a strong positive correlation between the Hb and PCV (r = 0.549), which is highly significant (p ≤ 0.01), it indicates that if Hb decreases, then PCV will also decrease that is also investigated by Weatherall and Sherry, 1997 [6] (PCV = Hb x 2.941).

The results are also shown in graphical form for Haemoglobin in Fig. 1 & 2 and for Packed Cell Volume in Fig. 3 &4.

The results of this study show that Hb and PCV sharply decline with the advancement of pregnancy. As pregnancy progresses, physiological adaptation results in "Pregnancy-Associated Physiologic Anemia," which dilutes hemoglobin and red blood cells because plasma volume increases more than red blood cell volume, which paradoxically leads to lower hemoglobin levels to improve nutrient delivery to the growing foetus.

The results of the current study also consistent with the previous researchers, a decrease in mean values of haemoglobin (Hb) and packed cell volume (PCV) with the advancement of pregnancy was also observed by Iriadam (2007) [3] and Abdul-Rahaman et al. (2019) [7] in goats and Simsek et al. (2015) [8] in cats; however, Bamerny et al.

(2022) [9] in goats, EI-Sherif and Assad (2001) [10] observed increase in mean values of haemoglobin with the advancement of pregnancy in Barki ewes. Contrary to present investigation, Azab et al. (1999) [11] observed that the maximum value haemoglobin was on the day of lambing and decreased after lambing in goats but similar effect was also observed by Anosa and Ogbogu (1979) [12] in sheep and Iriadam (2007) [3] in goats. They found PCV was increased on the day of lambing. Hb and PCV were significantly decreased with the advancement of pregnancy. This decrease was in agreement with the results of previous research conducted on sheep and goats (Vihan and Rai, 1987) [13] , and by Ate et al. (2009) [14] in cattle. Abraham et al. (2019) [15] in sheep also observed that the mean value of Hb was lower in pregnant animals than in non-pregnant animals.

Acknowledgement

AcknowledgmentsMy profound appreciation goes out to the Department of Veterinary Physiology at the College of Veterinary and Animal Science in Bikaner, Rajasthan, for their encouragement and support. There is no conflict of interest related to the work.

References

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