[Relationship between body condition (back fat thickness and body condition scoring) and fertility in dairy cows (German Black Pied/HF)].
It was the aim of this study to compare body condition scoring with ultrasonographic back fat thickness. Additionally, the relationship between back fat thickness and fertility, milk yield, number of parity and stage of lactation in dairy cows was examined. Body condition of 211 cows (German Black Pied/HF) was determined by means of ultrasonographic back fat thickness (BFT) and body condition scoring (BCS). The BFT and the BCS were measured at four different stages during the course of lactation (Time point 1 (T1) = 1.-3. d postpartum (pp); T2 = 40.-42. d pp; T3 = 90.-92. d pp and T4 = 130.-150. d pp). Number of parity, 100-day-milk-yield, incidence of ovarian cysts, incidence of acyclicity and fertility measures were recorded. There was a significant correlation between body condition scoring and ultrasonographic measurement of back fat thickness at the four time points (r = 0.68 to 0.74). Therefore, both methods were suitable to evaluate body condition. The number of lactations had an influence on body condition. At T1, the BFT in older cows was significantly higher than in younger cows (P < 0.05). At T3, the BFT in younger cows was higher than in older cows (P < 0.05). With regards to the stage of lactation, there was a significant decrease in body condition from T1 to T2 and T3. At T4, body condition increased, but did not reach the level of the postcalving values. In addition, cows with a high BFT at the beginning of lactation had a higher milk yield and a higher loss of body fat than cows with lower milk yield. Heifers compensated this loss of body fat significantly faster than older cows. Particularly at T3, body condition had an impact on fertility. Cows with a high loss of body condition between T1 and T3 developed significantly more often ovarian cysts than cows with low loss of back fat thickness. Cows with the lowest BFT at T3 had the longest calving to first service intervall and the highest 200-day-non-pregnancy index. In conclusion, our results suggest that there might be a certain relationship between body condition and fertility (delayed first service, ovarian disorders, reduced pregnancy results).
Gossen
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Arbeitsbereich Bestandstiermedizin der Klinik für Rinder der Stiftung Tierärztliche Hochschule Hannover. natascha.gossen@tiho-hannover.de
Fietze
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S
Mösenfechtel
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S
Hoedemaker
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M
D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000502:physiology; D000818:Animals; D001823:Body Composition / Q000502:physiology*; D002417:Cattle / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000502:physiology*; D007774:Lactation / Q000502:physiology*; D008892:Milk; D010048:Ovarian Cysts / Q000662:veterinary; D010298:Parity / Q000502:physiology; D049590:Postpartum Period / Q000502:physiology; D011247:Pregnancy; D012044:Regression Analysis; D013997:Time Factors; D014463:Ultrasonography