The reproductive performance of beef cows is highly contingent on the calcium (Ca), phosphorus (P) and copper (Cu). The aim of this study was to evaluate the availability of Ca, P and Cu in peat soil, forage, blood serum and their impact on reproductive performance of beef cows. This study was carried out at peatlands of Pulang Pisau district, Central Kalimantan Province through observation method supported by laboratory analysis. Reproductive performance data were obtained through direct interviews and recording cards. Soil and forage samples were taken from the main forage source locations. A total of 138 blood samples were taken through the jugular vein from Bali cows and their crossbred cows with different physiological status. Soil and blood serum samples were analyzed in laboratory using Atomic Absorption Spectrophotometry (AAS) method, while forage samples were analyzed according to the Association of Official Analytical Chemists (AOAC) method. The results showed that the availability of Ca and Cu both in peat soil and forage was very low, while that of P was quite high. The crossbred cows showed significantly higher concentration of Ca, P and Cu in blood serum if compared to Bali cows. However, the blood serum analysis of minerals suggested that there were Ca and Cu deficiency the beef cows raised in peatlands. In general, Ca and Cu deficiency in breeding cows raised in peatlands of Central Kalimatan Province had negative impact on reproductive performances including delayed age at puberty and first calving, delayed postpartum estrus and longer calving interval.

ABSTRACT. Penelitian ini bertujuan untuk mengevaluasi pengaruh substitusi hijauan dengan silase daun ubi kayu (SDUK) dan konsentrat dengan hay ubi kayu difermentasi ragi (Habira) terhadap produksi susu, kualitas susu, dan efisiensi ekonomi sapi perah. Materi yang digunakan adalah lima (5) ekor sapi Friesian Holstein (FH) periode laktasi kedua (66±11 hari) dengan bobot badan 387,6±6,8 kg diberi perlakuan pakan dalam Rancangan Bujur Sangkar Latin 5 x 5. Perlakuannya adalah T0 (hijauan 60% + 20% konsentrat + 20% ampas tahu), T1 (hijauan 40% + 20% SDUK + 20% konsentrat + 20% ampas tahu), T2 (hijauan 40% + 20% SDUK + 15%. konsentrat + 20% ampas tahu + 5% Habira), T3 (40% hijauan + 20% SDUK + 15% konsentrat + 20% ampas tahu + 10% Habira) dan T4 (60% hijauan + 10% konsentrat + 20% limbah tahu + 10% Habira). Variabel yang diukur adalah indeks suhu kelembapan (THI), konsumsi pakan, produksi susu, kualitas susu, hubungan konsumsi protein dan total nutrien tercerna/total digestible nutrient (TDN) dengan produksi susu serta efisiensi pakan dan ekonomi. Hasil penelitian menunjukkan bahwa nilai THI yang diperoleh mengindikasikan sapi perah mengalami cekaman panas. Perlakuan T1, T2, T3 dan T4 berbeda nyata (P0,05) dengan T0 dalam konsumsi nutrisi dan produksi susu, sedangkan komposisi susu tidak berbeda nyata antar perlakuan. Konsumsi protein dan TDN pakan memiliki hubungan linier dengan produksi susu (P0,05). Tidak ada perbedaan signifikan (P0,05) dalam efisiensi pakan dan ekonomis. Dapat disimpulkan SDUK dan Habira merupakan pengganti hijauan dan konsentrat yang baik untuk sapi perah laktasi.  (Effect of forage and concentrate substitution with cassava leaves silage and cassava hay on milk production and milk composition of Friesian Holstein dairy cows) ABSTRAK. This study aimed to evaluate the effect of forage replacement by cassava leaves silage (CLS) and commercial concentrate by yeast fermented cassava hay (Yefecah) on the production and quality of milk and economic evaluation. Five, early on the second lactation cycle (66±11 day in milk) Holstein Friesian cows were randomly assigned to a 5 (treatments) x 5 (replications). Treatments were T0 (60% forage + 20% concentrate + 20% tofu waste), T1 (40% forage + 20% CLS + 20 % concentrate + 20% tofu waste), T2 (40% forage + 20 % CLS + 15% concentrate + 20% tofu waste + 5% Yefecah), T3 (40% forage + 20 % CLS + 15% concentrate + 20% tofu waste + 10% Yefecah) and T4 (60% forage + 10% concentrate + 20% tofu waste + 10% Yefecah). Variables measured were temperature-humidity index (THI), feed intake, milk production, milk composition, interrelationship crude protein (CP) and total digestible nutrient (TDN) supply to milk production, and economic factors. The Result shows that T1, T2, T3, and T4 were significantly (P0.05) from T0 on nutrients intake and milk production. Whilst, the treatments were not significant (P0.05) affect to 4% fat corrected milk (FCM) and milk quality with T2 and T3 obtained the best value. The variables of CP and TDN intake have a positive relationship to milk production (P0.05). There were no significant differences in (P0.05) in feed and economical efficiency. It could be concluded that cassava foliage silage and yefecah were the good replacement of forage and concentrate for dairy cows.

This study aimed to evaluate the physiological response of female beef cattle to peatland microclimate stress in Central Kalimantan. This study used direct observation on small holder beef cattle farm.  Microclimate data on 41 units cattle barns and physiological parameters of female cattle were collected in the morning, at noon and in the afternoon.  The physiological parameter measurements involved 215 female beef cattle, consisting of 119 Bali and 96 crossbred cattle with different physiological stages including pregnant cows, lactating cows, dry cows, heifers and calves. The microclimate condition within cattle barns on peatland of Central Kalimantan is not the comfort zone for beef cattle.  It is characterized by high air temperature and relative humidity, and low wind speed, which result in high temperature humidity index (THI).  The barn with gable roof type and asbestos materials gave the lowest THI.   This Microclimate caused heat stress to beef cattle reared on the peatlands, indicated by the high rectal temperature, heart rate, respiratory rate, and heat tolerance coefficient, although it was still categorized as mild to moderate stress. Bali cattle showed better physiological responses to microclimate stress than crossbred cattle.  Pregnant crossbred cows were the most susceptible to peatland microclimate stress.