Research Article: Energy balance, leptin, NEFA and IGF-I plasma concentrations and resumption of post partum ovarian activity in swedish red and white breed cows

Date Published: January 9, 2008

Publisher: BioMed Central

Author(s): Kristian Konigsson, Giovanni Savoini, Nadia Govoni, Guido Invernizzi, Alberto Prandi, Hans Kindahl, Maria Cristina Veronesi.

http://doi.org/10.1186/1751-0147-50-3

Abstract

In the purpose to provide further information in respect of the relationship between metabolism and post partum (PP) ovarian activity resumption in dairy cows, the aim of the present study was to characterize the energy balance (EB) and leptin, NEFA and IGF-I plasma levels in Swedish Red and White (SRW) cows with and without ovarian activity re-initiation within 7 weeks PP. The study was conducted on 12 primiparous SRW cows fed the same diet as total mixed ration for ad libitum intake. The EB was calculated weekly from parturition until seven weeks PP. Blood samples were collected weekly from one week before until 7 weeks after calving for leptin, NEFA and IGF-I analysis. For progesterone (P4) analysis, blood samples were collected two times per week from parturition until the end of the study. P4 profile was used in addition to the clinical examination to detect cows with and without ovarian activity resumption. The clinical and ultrasonographic examination, coupled with P4 profile analysis showed the resumption of ovarian activity within 7 weeks after calving in 8 (group A) and no ovarian resumption in 4 cows (group B). No significant differences were detected in the whole period of observation in the amount of milk production between the two groups, while the mean milk protein content was significantly lower in group B at the third week PP. The calculated EB was negative in both groups in the first three weeks after calving, but more marked in group B. NEFA and Leptin plasma levels did not show significant differences between the two groups. In conclusion, the results of the present study showed that, when low milk producing primiparous cows are concerned, no significant differences in BW loss, milk yield, EB and leptin and NEFA plasma levels between the cows with and without resumption of ovarian activity within 7 weeks post partum were seen. However, significantly higher IGF-I levels in the first two weeks after calving were found in cows with post partum ovarian activity resumption, highlighting the important role of IGF-I as sensitive signal between metabolism and reproduction.

Partial Text

After parturition almost every cow experiences a period with high energy requirement related to milk production, frequently associated to an insufficient feed intake. This situation leads to the well known negative energy balance (NEBAL), that seems to be the most important factor affecting the reproductive efficiency after calving. In particular, the resumption of ovarian activity seems to be related to the metabolic status of the cows after calving. However, the interaction between the hypothalamic-pituitary-ovarian axis and the metabolic status of the animal is very complex and not completely explained. Parity has also been considered as an important factor affecting some metabolic, hormonal and reproductive parameters [1,2].

The study was conducted on 12 primiparous SRW cows housed in tie-stall barn. Herd production was about 9000 kg of energy corrected milk/cow/year. All the cows were fed the same diet as total mixed ration for ad libitum intake. Diet composition is reported in Table 1.

The clinical and ultrasonographic examination, coupled with P4 profile analysis showed the resumption of ovarian activity within 7 weeks after calving in 8 out of 12 cows. Therefore the cows were classified as follows:

The present study was aimed to characterize the features of BW loss, milk production, EB and some hormonal profiles in SRW primiparous cows within 7 weeks after calving. Since the effect of negative EB on reproductive performances in high yielding dairy cows is well known [19-23], in the present study the interest was focused on a breed with a typical medium-low milk production, in order to evaluate the extent of the negative EB and the subsequent effects on reproduction. In addition, since a difference in the adaptation to post partum negative EB has been reported [1,2,24] in primiparous compared to multiparous cows, the study was performed on only primiparous cows.

The results of the present study showed that, when low milk producing primiparous cows are concerned, no significant differences in BW loss, milk yield, EB and leptin and NEFA plasma levels between the cows with and without resumption of ovarian activity within 7 weeks post partum were seen. However, higher significant IGF-I levels in the first two weeks after calving were found in cows with post partum ovarian activity resumption, highlighting the important role of IGF-I as sensitive signal between metabolism and reproduction.

KK and MV carried out the clinical trial, GS took care of energy balance evaluation, NG carried out the NEFA and leptin analysis, GI carried out the statistical analysis, AP performed the IGF-I analysis, and HK designed the study and coordinate the work. All the authors contributed to manuscript draft and results discussion.

 

Source:

http://doi.org/10.1186/1751-0147-50-3

 

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