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Frequency of Oestrus Signs and Pregnancy Rates in Oestrus Synchronised Kedah-Kelantan Crossbred Cows Offered Two Metabolizable Energy Levels

Azizah¹*, A., Ahmad², J., Ahmad Nazri³, A.R., Saadiah¹, J. and Yaakub⁴, H.

¹ Strategic Livestock Research Centre, MARDI Serdang, Selangor,
² Strategic Livestock Research Centre, MARDI Kluang Station, Johor,
³ Ruminant Section, Livestock Commodity Development Division, Department of Veterinary Services, Putrajaya,
⁴ Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, Serdang, Selangor

Malaysian J. Anim. Sci. 2014 17(2): 1-9

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Synchronisation of oestrus in cattle can facilitate the use of artificial insemination by reducing the time needed for detection of oestrus compared to cows entering oestrus spontaneously. The purpose of the study was to determine the oestrous signs characteristics and pregnancy rates in Kedah-Kelantan crossbred cows offered two levels of metabolizable energy. The study was conducted on 30 Kedah-Kelantan crossbred cows (of mean age: 3-5 y, average body weight: 300 kg, parity: first to third). Cows were allocated into two diet groups based on maintenance energy (ME): single (1ME) and double (2ME) dietary energy requirement (0.02 Mcal /kg body weight) with crude protein level of 15% based on ARC (1980) recommendation. The results showed that the proportion of cows expressing standing oestrus in first and second oestrous cycles were 73.3 and 66.7% (p>0.05), and 80 and 53.3% (p>0.05) in 1ME and 2ME diet groups, respectively. The percentage of cows expressing oestrus was not significantly different between the first and second cycles of oestrus. There was a decrease in the percentage of cows pregnant for 1ME diagnosed at day 30 (78.6%) and day 90 (57.1%) post AI whereas cows on 2ME showed no significant difference (p>0.05) in percentage of pregnancy at day 30 (66.7%) and day 90 post AI (53.3%). However, the percentage of cows pregnant in the 1ME group was not significantly different compared with 2ME group (p>0.05). In conclusion, the diet formulated to provide twice the metabolizable energy requirement for maintenance was not able to accelerate the frequency of cows showing oestrous signs and pregnancy rate of Kedah-Kelantan crossbred cows.