Indonesian Journal of Tropical Agriculture (IJTA)

POPULATION OF SECRETORY CELLS AND SYNTHETIC ACTIVITIES IN MAMMARY GLAND F LACTATING SHEEP AFTER CONSUMING Sauropus androgynus (L.) Merr. LEAVES

A. Suprayogi — 2020-02-28

Thirty-five lactating ewes were divided into four groups and given Sauropus androgynus (SA) leaf extract solution at 1.89 g/day orally twke a day (Sax-group), SA leaf powder solution at 7.44 g/day (SAp-group), distilled water (control-group), and untreated group. Milk yield was measured. After 14 and 35 days, half of the udders were excised and the DNA and RNA determined. SAp administration increased total milk yield for 35 days administration (P>0.05), compared to the control values. The population of secretory cells (total DNA) and synthetic activites (total RNA) were also increased significantly (P<0.05) by SA leaves administration for 14 days.

THE PROFILES OF WEEKLY PROGESTERONE AND STRADIOL CONCENTRATIONS DURING PREGNANCY IN EWES : 2. THEIR CORRELATIONS WITH MAMMARY GROWTH INDICES AT PARTURITION

M.Y. Sumaryadi — 2020-02-28

Fifteen pregnant (9 and 6 carrying a single and multiple fetuses, respectively) and 5 nonpregnant ewes, as a control, were used to study the correlations of weekly maternal serum progesterone and estradiol concentrations during pregnancy with mammary growh indices at parturition. Blood samples were drawn weekly (weeks 0 to 20) during gestation period for determination of progesterone and estradiol concentrations. The experimental ewes were sacrificed at parturition to determine mammary growth indices (mammary dry fat-free tissue [DFFT], DNA, RNA, and collagen). Concentrations of progesterone at week 1 and weeks 3 to 19 of pregnancy positively correlated with mammary DFFT, DNA, and RNA at parturition. Maternal serum progesterone concentration at weeks 1, 3 and weeks 6 to 20 of pregnancy positively correlated with mammary collagen at parturition. Concentration of estradiol at weeks 5, 7, 9, and 11 to 20 positively correlated with the mammary DFFT, DNA, RNA, and collagen at parturition. The higher the maternal serum progesterone and estradiol concentration during pregnancy the greater the mammary growth and development at parturition.

THE EFFECT OF LIGNIN COMPOSITION ON DELIGNIFICANTION RATE OF SOME TROPICAL HARDWOODS

W. Syafii — 2020-02-28

The effect of lignin composition on delignification rate and pulp properties of albizin (Paraseriantes falcataria L. Nielsen). Gmelina (Gmelina arborea Linn), yellow meranti (Shorea acuminatissima Sym), and kapur (Dryobalanaps aromatica Gaertn.) woods was determined. The lignin characterization showed that the syringl-guaiacyl rattio of albizia, gmelina, kapur, and yellow meranti woods are 2.03, 2.02, 1.87, and 1.30, respectively. It means that the lignin structure of the above mentioned woods are predominated by syringyl units. To asseas the influence of lignin structure on delignification rate and pulp properties, these wood samples were then subjected to the kraft pulping process under the following conditions: wood-to-liquor ration = 1:4, cooking temperature = 170°C, time to cooking temperature = 90 minutes, cooking time = 90 minutes, total active alkali =16%, sulfidity = 22.5%. From the present investigation it can be explained that the delignification rate of hardwood containing syringyl-rich lignin was higher than that of hardwood containing syringyl-poor lignin. The physical properties of pulp from hardwood containing syringyl-rich lignin are also higher than that of hardwood containing syringyl-poor lignin.

WOOD HARVESTING DAMAGES, REGENERATION AND GROWTH IN THE RESIDUAL STAND OF DIPTEROCARP FORESTS (A Case Study in the Forest Concession Area of PT. Narkata Rimba, East Kalimantan, Indonesia)

. Elias — 2020-02-28

The research was conducted in the concession area of PT. Narkata Rimba (NR), Muara Wahau, Kabupaten Kutai, Kalimantan Timur, Indonesia. The result obtained indicated that the levels of residual stand damages positively correlated to the wood harvesting intensity, the incident of damages on small trees was greater and most of the damaged trees were heavily injured. The tree’s mortality occurred during the wood harvesting year was 6.0-26.6% and one year after wood harvesting was 2.0-13.6%. After than the tree’a mortality was 0.5-3.6%, meanwhile the mortality of tree’s in a virgin forest was 0.9-3.4% per year. It seems that higher damage occurred in residual stands causes the higher tree mortality. The seedling density of commercial dipterocarp species, in both the logged-over forests and a virgin forest were more then the recommended minimum amount (1.000 sedlings per ha) as stated in the regulation of the Indonesian Selective Cutting and Planting (Tebang Pilih Tanam Indonesia/TPII) System. The average growth of diameter and volume of 25 nucleus tree hectare per year during the fist five years after wood harvesting was 0.70 cm/years and 1.4235m³/ha/year, respectivety, to anticipate the second cutting cycle, it is recommended to control the residual stand damages with an optimal wood harvesting intensity and to improve the technique of silviculture of dipterocarp forest with the purpose to increase the diameter growth of nucleus tree.