Plant Selection and Performance of Two Cattle Types and Camels on Semiarid Rangelands in Kenya

Plant selection pattern and performance of lactating cattle and camels were compared on semiarid savanna rangelands in Kenya in the rainy season (RS) and a transition period (TP) between the RS and the main dry season. It was further evaluated whether supplementation with rumen-degradable protein (RDP) had an effect on these parameters. In both seasons, two cattle types (local ‘Pokot’ cattle and Guernsey × Boran crossbreds) and camels were used, with six females per treatment group (supplemented and nonsupplemented) each (n = 72 animals in total). The experimental periods consisted of 8–10 d of adaptation and 36–40 d of data and sample collection. The diet selected by the cattle types was similar and consisted almost exclusively of grasses. The camel diet consisted mainly of herbs and shrubs with higher contributions of woody plants in the TP than in the RS. Forage from woody plants overall made up a higher proportion of the diet, which was also reflected by a longer browsing time (overall and in the TP) of the supplemented camels compared with the nonsupplemented camels. This result indicates that supplementation of browsers like camels with RDP can be used to increase the intake of forage from woody plants rich in plant secondary compounds, which could be an effective measure for managing rangeland to limit bush encroachment. Overall, no seasonal differences in milk yield were found for the camels and Pokot cattle, but crossbreds had a lower yield in the TP compared with the RS. Overall, the cattle had higher milk fat content than the camels while the camels had slightly higher protein content. Supplementation had no effect on milk yield and composition. The results of diet selection and performance (milk yield) reflect the advantage of camels in arid rangelands.     

Genetic characterization of maedi-visna virus (MVV) detected in Finland

The aim of the study was to characterize the small-ruminant lentiviruses (SRLVs) detected in Finland by defining their phylogenetic relationships and by studying the evolution of the virus based on a well-known epidemiology. The study material comprised lung tissue samples of 20 sheep from 5 different farms, a cell-cultured virus from one of the original sheep lung samples, and a blood sample of a goat. The sheep were identified as positive during seroepidemiologic screenings in 1994-1996 and the goat in 2001. Initial classification of a 251 nucleotide sequence within gag gene amplified from the uncultured samples as well as from the cell-cultured virus showed that the SRLVs were genetically close and that they were more closely related to the prototype ovine maedi-visna viruses (MVVs) than to the caprine arthritis-encephalitis virus (CAEV). The lentivirus detected from the goat aligned within the cluster of the Finnish ovine viruses, demonstrating a natural sheep-to-goat transmission. Further phylogenetic analysis of the proviral gag, pol and env sequences confirmed the initial classification and showed that they constituted a new subtype within the diverse MVV group. The sequence analyses also showed that the virus had remained genetically relatively stable, in spite of the time given for virus evolution, an estimated 20 years, and in spite of the virus crossing the host species barrier.     

Endogenous Action of Cysteine Endopeptidase and Three Carboxypeptidases on Triticale Prolamins

Quantitative and qualitative changes occurring in the prolamin fraction in the starchy endosperm of triticale grains were analyzed by SDS‐PAGE on consecutive days of germination. The most intensive hydrolysis of prolamins was observed after the second day of the process. The high molecular weight fractions of prolamins were degraded with the highest rate. Endopeptidase EP8 was capable of hydrolyzing all fractions of prolamins isolated from dry triticale grains, but the high molecular weight fractions were the most rapidly degraded by the enzyme. Carboxypeptidases I, II, and III isolated from triticale grains hydrolyzed prolamins proteolytically modified by endopeptidase EP8, whereas intact prolamins were degraded slightly. Differences in the activity of the studied carboxypeptidases against crude prolamins indicate that carboxypeptidase II may be involved in the initiation of the hydrolysis process and, together with carboxypeptidases I and III, participates in the later stages of degradation of prolamins to amino acids. Experiments with exogenous GA₃ demonstrated that the synthesis of EP8 is induced by this hormone and takes place in the aleurone layer. Mass spectrometry analysis showed the enzyme to be a homologue of barley endopeptidase EP‐A. Both enzymes belong to the cysteine class endopeptidases.     

Sulfur and nitrogen supply influence growth,product appearance,and glucosinolate concentration of broccoli

The effects of insufficient and optimal sulfur (S) and nitrogen (N) supply on plant growth and glucosinolate formation were studied under controlled experimental conditions in broccoli “Monaco”. Here, we report on the interaction between S and N supply, plant growth, and quality parameters and discuss the relevance of this interaction in relation to crop‐management strategies. Broccoli plants supplied with insufficient amounts of S or N showed typical deficiency symptoms and yield decreases. In contrast, total glucosinolate concentrations were high at insufficient N supply, independent of the S level, and low at insufficient S supply in combination with an optimal N supply. This was mainly due to the presence of the alkyl glucosinolates glucoraphanin and glucoiberin. Furthermore, with S concentrations above 6 g (kg DM)^–1 and an N : S ratio lower than 10:1, the glucosinolate concentrations were on average around 0.33 g (kg fresh matter)^–1 and differed significantly from those plants characterized by an S concentration below 6 g (kg DM)^–1 and an N : S ratio above 10:1. In addition, N : S ratios between 7:1 and 10:1 promoted plant yield and enhanced overall appearance. Therefore, to produce broccoli (and potentially other Brassicaceae) with higher crop yields and enhanced product quality in the field, it is vital to establish the optimal S and N nutritional status of the plant and to integrate this information into crop‐management strategy programs.     

Survival and morphologic changes of entodiniomorphid ciliate Troglodytella abrassarti in chimpanzee feces

Entodiniomorphid ciliates occur in the hindgut of both captive and wild African great apes. These ciliates do not form cysts, and therefore they are more susceptible for degradation. This present study focused on the survival, quantification, and decomposition processes of Troglodytella abrassarti trophozoites in the feces of captive chimpanzees. Fecal samples were examined using wet mounts and the merthiolate-iodine-formaldehyde concentration method, and the number of ciliates was expressed as ciliates per gram, which did not differ when examined from three different samples of the same feces. Trophozoites of T. abrassarti survived 5-15 hr after defecation at 25 degrees C under aerobic conditions. Decomposition of trophozoites began immediately after defecation; however, most of the trophozoites had a compact shape and visible cilia. Trophozoites, although without cilia, can be detected in the feces 55-65 hr after defecation, although most of the trophozoites were fragmented. The total number of ciliates in the sample started to decrease 35-55 hr after defecation. The absence of entodiniomorphid ciliates in fecal samples could not be caused by delayed feces fixation; instead, the absence was due to low sensitivity of coproscopic techniques. However, because of quick morphologic changes of trophozoites, accurate identification of ciliates in older samples may be difficult or even impossible.     

Use of transmittance near-infrared spectroscopy to predict the mechanical properties of 1- and 2-year-old transgenic aspen

The investigation of genetically modified trees requires rapid and reliable techniques to measure the mechanical properties at an early age in order to give timely feedback to forest geneticists. In this study, transmittance near-infrared (NIR) spectroscopy was used to predict the green mechanical properties of 1- and 2-year-old transgenic and wild-type aspen. Green modulus of elasticity (MOE) in three-point bending and green ultimate compression strength (UCS) parallel to the grain were predicted from the NIR spectra of dry wood meal pellets. Green UCS had strong correlation (R ² = 0.91) and green MOE had good correlation (R ² = 0.78) with the spectra. The latter could be explained by the moderate correlation of MOE with the lignin content of the transgenic samples, suggesting that besides chemical composition MOE also depends on anatomical properties. The ratio of performance to deviation value suggested that the calibration model of both UCS (2.94) and MOE (1.91) could be used for screening.     

Variation of seed mass and its effects on germination in <Emphasis Type="Italic">Polylepis australis</Emphasis>: implications for seed collection

South American Polylepis mountain forests are recognised as being one of the most endangered forest ecosystems in the world. Reforestation measures have been strongly recommended but may be hampered due to the very low seed germination reported for several Polylepis species. In order to facilitate reforestation we analysed the influence of seed mass on germination probability for Polylepis australis seeds in the Córdoba mountains (central Argentina). We collected seeds from 43 trees distributed throughout five woodland fragments located within two regions differing in size, topographical position, and altitude (1,900 m a.s.l. and 2,200 m a.s.l.). Seeds of Polylepis australis exhibited a great variation in terms of mass and percent seed germination among individual trees and among geographical regions. The results of logistic regression showed that germination probability was highly correlated with seed mass. However, the explained deviance significantly increased by including the region, the woodland fragment and especially the individual tree in addition to seed mass in the regression models. We conclude that selecting seeds on the basis of mass is an appropriate way to enhance germination prospects for reforestation projects. However, no absolute mass values are applicable in this context as the highest germination probabilities were reached at varying seed mass values depending on geographical region, woodland fragment or individual tree. We suggest collecting the relatively heaviest available seeds, even though the absolute seed mass may be low.     

Reproductive dynamics and nursery habitat preferences of two commercially important Indo-Pacific red snappers <Emphasis Type="Italic">Lutjanus erythropterus</Emphasis> and <Emphasis Type="Italic">L. malabaricus</Emphasis>

Red snappers were examined for reproductive biology and age-0 habitat preferences. Spawning in red snappers occurred throughout the year in northern Australia and eastern Indonesia; at least 10–30% of females and 40–80% of males were in ripe or spawning condition in most months. Northern Australian populations showed a spawning peak from July to December (L. erythropterus) and September to March (L. malabaricus). Eastern Indonesian L. malabaricus had a less defined pattern with two peaks: January–March and October. Size at first maturity was 240 mm for males and 250–300 mm for females. L ₅₀ estimates were similar between species in northern Australia: 270–280 mm (males) and 350–370 mm (females). Maximum batch fecundity was 676,100 oocytes for L. erythropterus and 997,000 oocytes for L. malabaricus. Higher mean abundances of age-0 L. erythropterus were found in silty and coarse sand/rubble estuarine habitats of northern Australia (456 ± 119 fish/km²) compared with sandy coastal habitats (5 ± 3 fish/km²). Most age-0 snapper caught at Sape (eastern Indonesia) were L. malabaricus (91%) with mean abundances of 312 ± 14 fish/km². The similarities in the reproductive characteristics of red snappers suggest that successful management approaches adopted in northern Australia should be considered in eastern Indonesia.     

In-vitro study on the effect of pesticides on neuronal activity

Experiments have been conducted to examine the effect of chronic administration of bromoxynil, fluroxipir and bensultap on the in-vitro seizure susceptibility (induced by 4-aminopyridine) and excitability of neocortical slices of rat brain. The treatment regimes were (A) administration of spray solution in place of drinking water for seven days, and (B) feeding wheat which had been sprayed at growth stage Feekes 9–10 and consumed four to six weeks after spraying. The latency of appearance of the first seizure was significantly increased by fluroxipir (B) bensultap (B) and bromoxynil (A&B). Fluroxipir (A&B) decreased the frequency of seizure, and fluroxipir (A) and bensultap (B) doubled the duration of seizures. Excitability following electrical stimulation of the corpus callosum was not significantly changed by any treatments. The changes in brain activity were not related to the residue levels of the pesticides in the rat brains. Our results suggest that these chemicals may alter the functional properties of neuronal network activity and neurotransmission in rat neocortex after environmental exposure.