Respon termoregulasi dan tingkah laku bernaung sapi perah dara peranakan fries holland pada energi ransum yang berbeda | Termoregulatory response and shade occupation behaviour of dairy heifers PFH offered diet content

Di daearah tropis, daya tahan ternak terhadap panas merupakan salah satu faktor yang sangat penting agar ternak dapat berproduksi optimal sesuai kemampuan genetisnya. Ternak sapi Fries Holland (FH) yang tidak tahan terhadap panas, produktivitasnya akan turun akibat dari menurunnya konsumsi pakan. Sementara itu ternak yang tahan terhadap panas dapat mempertahankan suhu tubuhnya dalam kisaran yang normal tanpa mengalami perubahan status fisiologis dan produktivitas. Penelitian mengenai sifat daya tahan panas telah banyak dilakukan pada ternak berdasarkan pada sumber panas dari luar tubuh, sedangkan sumber panas dari dalam tubuh seperti pakan belum banyak dilakukan. Sejak lama diketahui bahwa pakan yang dikonsumsi berpengaruh meningkatkan laju produksi panas dalam tubuh atau biasa juga disebut efek kalorigenik pakan (EKP).

A research was conducted to study, the effect of energy diets and environmental conditions on termoregulatory and behaviour responses of dairy heifers. A 4 x 4 latin square design was used for data analysis using 4 dairy heifers and 4 treatments of feed energy for 21 days periods. The treatments were A (TDN : 55%), B (TDN : 60%), C (TDN : 65%), and D (TDN : 70%). All diets content 12 – 15 % of CP. Observed variables were environment factors (air temperature, relative humidty, THI, wind speed, and solar radiation) and termoregulatory responses (Tr, mTs, Tb, HR and RR), TDN intake, animal growth and their behaviour especially shade occupation. Data were analized by variance and/or regression analysis followed by the LSD for any significant difference among treatments. The results showed that TDN intake for A, B, C, D were 4.2, 4.3, 4.4 and 4.3 kg/d, respectively. There was no differences in body gain among treatments (P>0.05). The treatments significantly influenced the thermoregulatory responses (P<0.01). The D treatment resulted in more heat stress than that of the other treatments. Shade occupation showed significantly correlated to environtmental factors or TDN intake (P<0.01). It was concluded that the animals under 60-65% of TDN intake showed optimum growth rate without experiencing of severe heat stress; The combination of environmental conditions and higher feed energy intake increased heat load on dairy heifers.