Ultrasonic evaluation of uterine involution in Bulgarian Murrah buffalo after administration of oxytocin
Introduction
The prolonged interval between two consecutive parturitions is the cause for the poor reproductive efficiency and economic losses of buffalo husbandry (El-Wishy, 2007b, Perera, 2011). The attainment of the optimal intercalving interval of 13–14 months supposes a rapid uterine involution, obvious estrous expression and fertilization within 80–115 days after the last parturition (Pires et al., 2002, Ramoun et аl., 2006, El-Wishy, 2007a).
The postpartum period is essential for the shortening of the intercalving interval (Palta and Madan, 1995, Shah et al., 2002, Snel-Oliveira et al., 2010) due to the fact that the duration of pregnancy is relatively constant and species-determined (Usmani et al., 1985, Ryan et al., 2007).
Most researches related to uterine involution in buffaloes are based on results from either rectal palpation or uterine parameters determination in slaughterhouse material (Chauhan et al., 1977, Agrawal et al., 1978, Jainudeen et al., 1983, Usmani et al., 1985, Chaudhry et al., 1990). The rectal examination is however related to a certain subjectivity arising from examiner's experience, which is sometimes responsible for the low accuracy in determining the uterine and ovarian status in the early post parturient period (El-Wishy and Ghoneim, 1995, Honparkhe et al., 2004).
The detection of changes in the genital organs in slaughterhouse material, apart raising some ethical concerns, does not permit the monitoring of occurring events with time (Hauser and Bostedt, 2002). Ultrasonography is an alternative method for detection of dynamic changes in the reproductive tract after the parturition, which allows more accurate, quick and safe examination of the reproductive system (Okano and Tomizuka, 1987, Terzano, 2005, Yindee et al., 2007). The method is widely used for control of uterine involution and ovarian function during the postpartum period in cattle (Saito et al., 2001, Dimitrov et al., 2002, Kask et al., 2003, Melendez et al., 2004, Kocamuftuoglu and Vural, 2008). In buffalo, early ultrasonographic data related to uterine parameters are still controversial (Lohan et al., 2004, Presicce et al., 2005, Yindee et al., 2007), as cited reports did not specify whether the milking management included treatment of animals with oxytocin.
Varma and Sastry (1994) outlined that the difficulties for milking buffalo were overcome by administration of oxytocin in 13% of buffalo farms in India. Similar data could be found in the investigation of Saltalamacchia et al. (2005), who reported oxytocin therapy in 24% of primiparous buffaloes in Italy. Borghese et al. (2007) established that at least 15–20% of buffalo in each farm received an oxytocin injection to stimulate milking. The application of oxytocin in the postpartum period did not improve production and reproduction traits in buffalo and cows (Mustafa et al., 2008), whereas according to Qureshi and Ahmad (2008) the uterine involution was complete after an appropriate period of time after oxytocin treatment. Detailed ultrasonography data on postpartum uterine involution in Bulgarian Murrah buffalo with oxytocin-stimulated milking are not available.
The aim of the present study was to determine the ultrasonographic parameters of uterine horns, the cervix and caruncles in buffalo after normal parturition and oxytocin-stimulated milking and to establish the time to complete uterine involution.
Section snippets
Мaterials and methods
The study was conducted with 17 Bulgarian Murrah buffalo cows, weighing 480–550 kg, at the age of 3–6 years, average parity 2.17 ± 0.18 and body condition scores 3.5–4 by the scoring system of Edmonson et al. (1989). The average daily milk yield was 5.9 ± 0.6 l with milking twice daily – morning and evening. Fifteen minutes before each milking, buffaloes were treated i.m. with 20 UI oxytocin (Oxytocin®, Biovet Peshtera, Bulgaria).
All animals were reared and fed uniformly as each buffalo was fed a
Results
On Day 1 postpartum, cross-sectional ultrasonic image of the cervix, the cervical canal appeared as a rounded structure with echogenic walls, filled with hypoechogenic cervical mucous, and the lumen was seen as a ring-shaped anechogenic area (Fig. 1A). The ultrasonography of the cervix showed that the respective mean diameters (8.2 ± 1.0 cm and 4.7 ± 0.6 cm) decreased with more than 45% (P < 0.01) between Days 1 and 7 postpartum. Within Days 7–10 and 13–16, the reduction and related differences in size
Discussion
The events related to uterine involution in buffalo are still provoking the interest of researchers during the last years (Ramoun et аl., 2006, Qureshi and Ahmad, 2008, Snel-Oliveira et al., 2010, Amer et al., 2010). The average reported time intervals for complete involution of the uterus are 25.6 ± 1.0 days (Usmani and Lewis, 1984) and 28.37 ± 1.36 days (Chaudhry et al., 1990) in the Nili-Ravi breed, 40.3 ± 1.2 days (Aboul-Ela et al., 1988) and 36.20 ± 1.65 days (Ramoun et аl., 2006) in Egyptian buffalo,
Conclusions
The combination of rectal palpation and transrectal ultrasonography provided a reliable method of evaluating changes in the uterus over time and determining the time of uterine involution. The present study showed that complete uterine involution, with the uterus located in the pelvic cavity, was achieved by day 34 after parturition in all 17 Bulgarian Murrah buffalo treated with oxytocin before milking. Future investigations of ovarian activity together with the aforementioned criteria for
References (43)
- et al.
A body condition scoring chart for Holstein dairy cows
J. Dairy Sci.
(1989) The postpartum buffalo. I. Endocrinological changes and uterine involution
Anim. Reprod. Sci.
(2007)The postpartum buffalo. II. Acyclicity and anestrus
Anim. Reprod. Sci.
(2007)- et al.
Increased myometrial responsiveness to oxytocin during term and preterm labor
Am. J. Obstet. Gynecol.
(1989) - et al.
Postpartum ovarian activity and uterine involution in the suckled swamp buffalo (Bubalus bubalis)
Theriogenology
(1983) - et al.
Uterine involution and fertility of holstein cows subsequent to early postpartum PgF2α treatment for acute puerperal metritis
J. Dairy Sci.
(2004) - et al.
Ultrasonic observation of postpartum uterine involution in the cow
Theriogenology
(1987) - et al.
Alterations in hypophysical responsiveness to synthetic GnRH at different postpartum intervals in Murrah buffalo (Bubalis bubalis)
Theriogenology
(1995) Reproductive cycles of buffalo
Anim. Reprod. Sci.
(2011)- et al.
Postpartum ovarian follicular dynamics in primiparous and pluriparous Mediterranean Italian buffaloes (Bubalus bubalis)
Theriogenology
(2005)