The apparent metabolisable energy and ileal amino digestibility of black soldier fly (Hermetia illucens) larvae meal for broiler chickens.

1. Two experiments were conducted to determine the apparent metabolisable energy (AME) and standardised amino acid digestibility coefficients (SIDC) of black soldier fly larvae (BSFL) for broiler chickens.2. The BSFL contained, on a g/kg dry matter basis: crude protein, 486; crude fat, 320; ash, 58.5; neutral detergent fibre, 181; calcium, 6.8 and phosphorus, 9.1.3. In Experiment 1, an AME assay was performed wherein broilers were fed two experimental diets (a maize-soy basal diet and a test diet containing 250 g/kg BSFL) for 4 d from d 18 posthatch. The AME of BSFL was calculated based on the difference between the AME values of basal and test diets. The AME and nitrogen-corrected AME were determined to be 19.1and 18.0 MJ/kg of dry matter, respectively.4. In Experiment 2, the ileal amino acid (AA) digestibility of BSFL was determined using 22-d-old broilers by the direct method and the digesta was collected on d 25. The ratios between the AA and titanium in the diet and digesta were used to calculate the apparent digestibility and then standardised using previously published endogenous losses to estimate the SIDC of AA. The SIDC of Lys, Met, Thr, Val and average SIDC of AA in our BSFL sample were 0.85, 0.90, 0.91, 0.87 and 0.84, respectively.5. The findings showed that the BSFL meal is a good source of available energy and digestible AA, and could be a potential substitute for soybean meal in broiler diets.

Measurement of true ileal calcium digestibility in meat and bone meal for broiler chickens using the direct method.

The objective of the study that is presented herein was to determine the true ileal calcium (Ca) digestibility in meat and bone meal (MBM) for broiler chickens using the direct method. Four MBM samples (coded as MBM-1, MBM-2, MBM-3 and MBM-4) were obtained and analyzed for nutrient composition, particle size distribution and bone to soft tissue ratio. The Ca concentrations of MBM-1, MBM-2, MBM-3 and MBM-4 were determined to be 71, 118, 114 and 81 g/kg, respectively. The corresponding geometric mean particle diameters and bone to soft tissue ratios were 0.866, 0.622, 0.875 and 0.781 mm, and 1:1.49, 1:0.98, 1:0.92 and 1:1.35, respectively. Five experimental diets, including four diets with similar Ca concentration (8.3 g/kg) from each MBM and a Ca and phosphorus-free diet, were developed. Meat and bone meal served as the sole source of Ca in the MBM diets. Titanium dioxide (3 g/kg) was incorporated in all diets as an indigestible marker. Each experimental diet was randomly allotted to six replicate cages (eight birds per cage) and offered from d 28 to 31 post-hatch. Apparent ileal Ca digestibility was calculated by the indicator method and corrected for ileal endogenous Ca losses to determine the true ileal Ca digestibility. Ileal endogenous Ca losses were determined to be 88 mg/kg dry matter intake. True ileal Ca digestibility coefficients of MBM-1, MBM-2, MBM-3 and MBM-4 were determined to be 0.560, 0.446, 0.517 and 0.413, respectively. True Ca digestibility of MBM-1 was higher (P < 0.05) than MBM-2 and MBM-4 but similar (P > 0.05) to that of MBM-3. True Ca digestibility of MBM-2 was similar (P > 0.05) to MBM-3 and MBM-4, while that of MBM-3 was higher (P < 0.05) than MBM-4. These results demonstrated that the direct method can be used for the determination of true Ca digestibility in feed ingredients and that Ca in MBM is not highly available as often assumed. The variability in true Ca digestibility of MBM samples could not be attributed to Ca content, percentage bones or particle size.

Effect of limestone particle size and calcium to non-phytate phosphorus ratio on true ileal calcium digestibility of limestone for broiler chickens.

The purpose of this study was to determine the effect of limestone particle size and calcium (Ca) to non-phytate phosphorus (P) ratio on the true ileal Ca digestibility of limestone for broiler chickens. A limestone sample was passed through a set of sieves and separated into fine (<0.5 mm) and coarse (1-2 mm) particles. The analysed Ca concentration of both particle sizes was similar (420 g/kg). Six experimental diets were developed using each particle size with Ca:non-phytate P ratios of 1.5:1, 2.0:1 and 2.5:1, with ratios being adjusted by manipulating the dietary Ca concentrations. A Ca-free diet was also developed to determine the basal ileal endogenous Ca losses. Titanium dioxide (3 g/kg) was incorporated in all diets as an indigestible marker. Each experimental diet was randomly allotted to 6 replicate cages (8 birds per cage) and fed from d 21 to 24 post hatch. Apparent ileal digestibility of Ca was calculated using the indicator method and corrected for basal endogenous losses to determine the true Ca digestibility. The basal ileal endogenous Ca losses were determined to be 127 mg/kg of dry matter intake. Increasing Ca:non-phytate P ratios reduced the true Ca digestibility of limestone. The true Ca digestibility coefficients of limestone with Ca:non-phytate P ratios of 1.5, 2.0 and 2.5 were 0.65, 0.57 and 0.49, respectively. Particle size of limestone had a marked effect on the Ca digestibility, with the digestibility being higher in coarse particles (0.71 vs. 0.43).

Fatty acid profile differs between organic and conventionally produced cow milk independent of season or milking time.

Differing amounts of fresh forage and concentrates fed, and level of input contributes to the differences reported in fatty acid (FA) composition of organic and conventionally produced cow milk. In many previous studies designed to investigate this phenomenon, comparisons were made between grazed organic cows and housed conventional cows. In the present study, we have investigated differences between organic and conventional milk produced using year-round pasture grazing, as practiced in New Zealand. The FA composition was determined in milk sampled at morning and evening milking in both spring and autumn. Samples were taken from 45 cows from the Massey University organic herd and compared with 50 cows from the corresponding conventional herd grazed and managed similarly at the same location. Forty-three out of 51 analyzed FA were influenced by season, whereas 28 were different between production systems. In addition, one-half were also different due to time of milking. Levels of linoleic acid and α-linolenic acid were higher in organic milk, whereas conjugated linoleic acid (CLA) and vaccenic acid were higher in conventional milk. The first 3 FA (linoleic acid, α-linolenic acid, and CLA) were more abundant in milk harvested during autumn, and the CLA concentration was also significantly influenced by time of milking. Our results confirm reports that the FA profile is affected by season and time of milking, and we also showed an effect due to the production system, when both sets of cows were kept continuously on pasture, even after taking milking time and seasonal effect into account.

Invited review: organic and conventionally produced milk-an evaluation of factors influencing milk composition.

Consumer perception of organic cow milk is associated with the assumption that organic milk differs from conventionally produced milk. The value associated with this difference justifies the premium retail price for organic milk. It includes the perceptions that organic dairy farming is kinder to the environment, animals, and people; that organic milk products are produced without the use of antibiotics, added hormones, synthetic chemicals, and genetic modification; and that they may have potential benefits for human health. Controlled studies investigating whether differences exist between organic and conventionally produced milk have so far been largely equivocal due principally to the complexity of the research question and the number of factors that can influence milk composition. A main complication is that farming practices and their effects differ depending on country, region, year, and season between and within organic and conventional systems. Factors influencing milk composition (e.g., diet, breed, and stage of lactation) have been studied individually, whereas interactions between multiple factors have been largely ignored. Studies that fail to consider that factors other than the farming system (organic vs. conventional) could have caused or contributed to the reported differences in milk composition make it impossible to determine whether a system-related difference exists between organic and conventional milk. Milk fatty acid composition has been a central research area when comparing organic and conventional milk largely because the milk fatty acid profile responds rapidly and is very sensitive to changes in diet. Consequently, the effect of farming practices (high input vs. low input) rather than farming system (organic vs. conventional) determines milk fatty acid profile, and similar results are seen between low-input organic and low-input conventional milks. This confounds our ability to develop an analytical method to distinguish organic from conventionally produced milk and provide product verification. Lack of research on interactions between several influential factors and differences in trial complexity and consistency between studies (e.g., sampling period, sample size, reporting of experimental conditions) complicate data interpretation and prevent us from making unequivocal conclusions. The first part of this review provides a detailed summary of individual factors known to influence milk composition. The second part presents an overview of studies that have compared organic and conventional milk and discusses their findings within the framework of the various factors presented in part one.

Voluntary exercise in pregnant rats improves post-lactation maternal bone parameters but does not affect offspring outcomes in early life.

OBJECTIVES: The objectives of this study were to examine the effects of voluntary exercise during pregnancy on maternal post-lactation bone parameters and offspring growth. METHODS: Pregnant Wistar rats were housed in conventional cages (control), or were housed in raised cages requiring them to rise to an erect, bipedal stance to obtain food/water, throughout pregnancy. Dual energy X-ray absorptiometry and peripheral quantitative computed tomography scans were performed pre-mating and post-weaning. Maternal stress was assessed by fecal corticosterone measurement. Offspring weights were assessed at postnatal days 1 and 25 (weaning). RESULTS: Changes in bone mineral over the pregnancy/lactation period were site-specific. Exercise did not affect loss of bone mineral from the lumbar spine, but did attenuate the loss of trabecular bone mineral from the tibial metaphysis and enhance the strength strain index and cross-sectional moment of inertia at the tibial diaphysis (P≤0.05) in dams in the exercised group. Fecal corticosterone did not differ between dam groups. There were no significant differences in offspring weight between the exercised and control group at either time point. CONCLUSIONS: Voluntary exercise in the pregnant rat can improve some post-lactation bone parameters and does not adversely affect early postnatal outcomes of the offspring.

Chemical composition characteristics of the longissimus and semimembranosus muscles for pigs from New Zealand and Singapore.

A range of composition characteristics of the longissimus (LL) and semimembranosus (SM) muscles were compared between pigs raised in intensive and extensive production systems in New Zealand (NZ), and pigs raised in an intensive system in Indonesia for supply to the Singapore market (n=8/group). Ultimate pH was slightly higher for the Singaporean LL muscles (P<0.05), while LL muscle of the NZ extensive group was redder (higher a(∗) values) and contained more fat (P<0.05). Muscle iron levels were highest for the NZ extensive group and lowest for a lighter group within the Singapore pigs (P<0.05). Differences in fatty acid concentrations, which were also measured in a sample of the belly cut, could largely be attributed to the effects of diet, with higher levels of alpha linolenic acid for the NZ extensive group (P<0.05) due to linseed in the diet, and much higher levels of linoleic acid and the P:S ratio for the Singapore group (P<0.05). Some statistically significant differences in amino acid concentrations were shown between muscles and groups, but they were not large. With respect to compounds with potential bioactive properties, coenzyme Q10, and taurine levels were higher in pork from NZ pigs, and carnosine levels were highest for the NZ intensive group (P<0.05). The LL muscle contained more coenzyme Q10 and taurine, but less carnosine than the SM muscle (P<0.001). It is concluded that some of these composition differences in the pork from the muscles and groups compared may be of commercial importance, but several are likely to have been due to dietary or weight differences.

Induced seasonal reproductive performance in two breeds of sheep.

The objective of the present experiment was to determine whether failure to become pregnant through out-of-season reproductive management regimes is attributable to a failure to stimulate normal corpora lutea (CL) production. Romney ewes and East Friesian Composite (EF) ewes were mated in summer, autumn, winter, and early and late spring after administration of intravaginal progesterone inserts (plus eCG in spring and summer) in a factorial (two breedsxfive mating periods) experimental design. Oestrus rate was determined from mating data, and the numbers of CL were determined by laparoscopy 9 days after ram introduction. Conception rate, pregnancy rate and litter size were determined by transabdominal ultrasonography 62 days after ram introduction. Proportions of ewes displaying oestrus did not differ significantly (75-100%) between seasons or breeds, except for the Romney ewes in summer (67%; P<0.05). Numbers of CL on Day 9 for EF ewes was lowest in autumn (1.5) and winter (1.5), and highest in late spring (2.1; P<0.05). In contrast, Romney ewes had the lowest CL count in summer (1.3), and the highest in autumn (1.8) and winter (1.6; P<0.05). Only in summer was there a difference between breeds (EF 1.8; Romney 1.3; P<0.01). The proportion of ewes that failed to conceive despite having one or more CL present was highest in late spring (EF 41%, Romney 43%), and lowest in autumn (EF 9%, Romney 4%) and winter (EF 14%, Romney 4%; P<0.05). Conception and pregnancy rates followed similar patterns with values for autumn (EF 91%, 91%; Romney 96%, 96%) and June (EF 86%, 82%; Romney 91%, 83%) being significantly (P<0.05) higher than in early (EF 50%, 40%; Romney 54%, 50%) and late spring (EF 44%, 36%; Romney 42%, 36%). Pregnancy rate in summer was higher for EF ewes (60%) than for Romney ewes (39%) but conception rates were not statistically different (EF 68%; Romney 60%). Numbers of foetuses identified at scanning was highest in autumn (1.5) and lowest in late spring (0.5 P<0.001): Litter size in pregnant EF ewes was highest in early spring and lowest in winter (1.8 versus 1.2; P<0.01), but for pregnant Romney ewes was highest in winter and lowest in early spring (1.9 versus 1.3; P<0.001). It was concluded that seasonal differences in the ability of ewes to conceive are not the consequence of failure to display oestrus or to ovulate, but probably are a result of failure of fertilisation or the establishment of pregnancy.

Preliminary investigation of the effects of low-level dietary inclusion of fragrant essential oils and oleoresins on pig performance and pork quality.

Since the tissue characteristics of monogastric species are readily influenced by the composition of the feeds they consume, the objectives of this preliminary study were to assess the performance of finisher pigs on diets containing 0.05% of essential oils or oleoresins of rosemary, garlic, oregano, or ginger, and to determine the effect of these diets on pork quality. The pigs preferred the garlic-treated diet, and feed intake and average daily gain were significantly increased although no difference in feed efficiency was observed. Carcass and meat quality attributes were unchanged by dietary treatment, although a tendency towards reduction of lipid oxidation was noted in oregano-fed pork. Sensory panelists were unable to detect a flavour/aroma difference between treated and control pork. These results indicate that a higher level of dietary supplementation may be required in order to effect observable differences in pork characteristics.

Stress, Emotions, and Motivational States Among Traditional Dancers in New Zealand and Japan.

This study used a reversal theory framework to examine motivational dominance and changes in motivational state, arousal, stress, and emotions among members of traditional Japanese (Nihon Odori Sports Science (NOSS)) and New Zealand (Kapa Haka) dance groups. Eighty-four participants (50 in Japan and 34 in New Zealand) completed questionnaires on each variable before and after a dance class. The findings indicated that the Kapa Haka dancers were significantly more playful and arousal-seeking than the NOSS dancers. They also reported higher overall arousal, preferred arousal, and effort during performance while the NOSS dancers became more serious afterward. Data on emotions matched those of arousal in that the Kapa Haka dancers felt significantly more excited and provocative after the session. The NOSS dancers were more relaxed and placid, both overall and after dancing. These patterns were consistent with the dancers' respective motivational states and motivational dominance, and suggest that both dances can be effective in reducing negative affect. They also suggest that psychological effects are dependent upon performers' personal and cultural affiliation with the two dance forms.

The effect of modified atmosphere packaging with carbon monoxide on the storage quality of master-packaged fresh pork.

Modified atmosphere packaging with carbon dioxide is effective for prolonging shelf-life of fresh meat. Addition of carbon monoxide to the system provides the advantage of enhancing meat colour. The study objective was to determine the effect of CO(2)-MAP+0.4% CO, vs. 100% CO(2)-MAP, on the bacteriology and colour of retail-ready fresh pork stored for 8 weeks in a master-package system. Total plate counts were not affected and listeria was present on meat from both treatments. Colour was enhanced with the inclusion of CO, while no effect on lipid oxidation was observed. Use of CO in MAP provides sufficient storage life and product colour quality to permit shipment of fresh pork to distant markets. However, given the stable fresh colour of CO-treated meat and the lack of inhibition of pathogen growth by CO, there is concern that CO-MAP under certain conditions may pose a food safety risk.

Influence of an Escherichia coli-derived phytase on nutrient utilization in broiler starters fed diets containing varying concentrations of phytic acid.

The influence of an Escherichia coli-derived phytase, on nutrient utilization was investigated in broilers fed starter diets containing different concentrations of phytate. The study was conducted as a 3 x 4 factorial arrangement of treatments with 3 concentrations of phytic acid (10.4, 11.8, and 13.6 g/kg; equivalent to 2.8, 3.3, and 3.8 g of phytate P/kg) and phytase (0, 500, 750, and 1,000 FTU/kg). One unit of phytase (FTU) is defined as the quantity of enzyme that releases 1 micromol of inorganic phosphorus/min from 0.00015 mol/L of sodium phytate at pH 5.5 at 37 degrees C. The dietary phytic acid concentrations were manipulated by the inclusion of rice bran. Increasing dietary concentrations of phytic acid resulted in reductions (P < 0.01) in AME. Phytase additions tended to increase AME (P = 0.07), regardless of dietary phytate concentrations. Apparent ileal digestibility coefficients of protein and most amino acids were influenced by phytate (P < 0.05 to 0.001) and phytase (P < 0.001). Phytase improved ileal protein and amino acid digestibility at all phytate concentrations, but the trend in responses to increasing phytase additions was different at different phytate concentrations as shown by significant phytate x phytase interactions (P < 0.01 to 0.001). At the lowest phytate concentration, the ileal digestibility coefficients increased with increasing phytase supplementation. At the medium and high phytate concentrations, the greatest responses were observed at 500 FTU/kg of phytase, with little improvement attributable to further additions. Ileal digestibility of P was lowered (P < 0.01) by increasing phytate concentrations and increased (P < 0.001) with increasing additions of phytase. A significant phytate x phytase interaction (P < 0.05) was also observed, where the improvements in P absorption with added phytase were found to be greater at high phytate concentrations. These data demonstrate the anti-nutritive effects of phytic acid and the potential of microbial phytase to improve energy utilization and the availability of P and amino acids in broilers fed starter diets.

Effect of different feeding regimens on energy and protein utilization and partitioning for maintenance and growth in pre-weaned lambs reared artificially.

Estimation of metabolizable energy (ME) requirement for maintenance (ME) and growth (ME) in pre-weaned lambs have been limited to milk-only fed lambs. This study aimed to determine energy and nitrogen metabolisability of milk and pellets when fed together, compare the growth and chemical body composition of lambs fed varying levels of pellets in addition to milk, and to estimate ME, ME, and the CP:ME ratio requirements for growth. The study included 32 twin-born Romney-cross ram lambs. Four lambs were slaughtered at 24 h post-partum to estimate initial body composition and the remaining 28 were assigned to 1 of 4 treatment groups of 7. Group 1 was fed milk replacer (MR) only; group 2 was fed MR and allowed ad libitum access to pellets; groups 3 and 4 were offered 30% and 60%, respectively of the average pellet intake of the ad libitum group the previous day while being fed MR. Milk replacer was fed as a proportion of the lamb's live weight (LW). Lambs from each treatment were placed in metabolic cages at 17 kg LW for 4 d to allow for total fecal and urine collection. All lambs were slaughtered at 18 kg LW. The ADG, ADG:ME ratio, stomach and liver weight, and rumen papillae lengths increased ( < 0.05) with increasing pellet intake. Increasing daily ME intake increased ( < 0.05) both daily energy and protein deposition but had no effect ( > 0.05) on fat deposition. However, the total chemical body composition was unaffected ( > 0.05) by dietary treatment. Digestibility of energy and N decreased ( < 0.05) with increasing ME intake. Percent energy and N retained for growth were 96% vs. 71% and 72% vs. 30% for milk and pellets, respectively. The ME and ME values obtained were 0.40 MJ ME/kg LW·d and 13.8 MJ ME/kg ADG, respectively. The CP:ME ratio of MR and pellet was 11.1 and 15.7, respectively. However, a simulation model suggested that lambs require a CP:ME ratio of 13.1 at 5 kg and 10.9 at 18 kg LW, indicating that protein intake may be limiting to lamb growth in early life and in excess by 18 kg LW. In conclusion, increasing pellet intake was associated with decreased N retention. The inclusion of pellets, however, improved the efficiency of ME utilization for growth in pre-weaned lambs and was beneficial for rumen development. The ME was higher than previously recommended values and the CP:ME intake of lambs does not match their requirements which may warrant further studies.

Relationships between prenatal ewe traits, milk production, and preweaning performance of twin lambs.

There is limited information on factors affecting twin lamb growth before weaning, which limits the options available to farmers to actively manage lamb growth. Data from 2 multiyear experiments involving 402 twin-bearing Romney ewes were used to evaluate the effects of prenatal ewe traits (live weight at mating and set stocking and BCS at mating and set stocking) and combined twin lamb birth weight on ewe milk production and lamb growth from birth to weaning as well as the proportion of variation in twin lamb growth that could be explained by these variables. Additionally, the effect of accumulated ewe milk yield over a 42-d period (MY; Days 0 to 42) and accumulated milk components (protein, fat, and lactose) on twin lamb growth were investigated. The effects of prenatal variables on MY, birth weight, and combined twin lamb live weight gain from Day 0 to 42 (LWG) were inconsistent across the 2 experiments. In addition, prenatal ewe traits ( < 0.05) explained less than 30% of the variation in MY and lamb growth from birth to weaning in both experiments. Combined twin lamb birth weight was positively ( < 0.001) correlated with MY ( = 0.34 and = 0.43 in Exp. 1 and 2, respectively). Combined twin lamb LWG was dependent on ewe MY ( = 0.43 for Exp. 1 and = 0.30 for Exp. 2). Lactose, fat, and milk CP yields explained 47 and 42% of the variation in lamb LWG in Exp. 1 and 2, respectively. Lactose and milk CP yield positively affected ( < 0.05) LWG in Exp. 1 and 2, respectively. Fat yield had a positive relationship with LWG in Exp. 1 and a negative relationship with LWG in Exp. 2. In conclusion, the measured prenatal ewe traits had a minimal effect on milk yield and twin lamb growth to weaning. Milk yield and composition explained the greatest proportion of variation in LWG. This suggests that farmers should select ewes with higher milk yields to maximize twin lamb growth to weaning. However, less than 50% of the variation in LWG and weaning live weight was explained by the measured ewe and lamb parameters. Therefore, further studies are required to determine additional ewe or lamb variables that control variation in twin lamb growth.

Elevating maternal insulin-like growth factor-I in mice and rats alters the pattern of fetal growth by removing maternal constraint.

Fetal growth is normally constrained by maternal factors. This constraint is demonstrated by the usual inverse linear relationship between litter size and mean fetal weight. Cross-breeding experiments between mice of lines selected for high or low plasma insulin-like growth factor (IGF-I) levels suggested that elevations in maternal IGF-I abolish (P less than 0.01) this constraining effect and reverse the usual positive relationship between fetal and placental size in late gestation. This was confirmed by treating mice and rats throughout pregnancy with IGF-I. In normal mice and in low IGF-I line mice treatment with IGF-I (10 micrograms 8-hourly s.c. from day 1 to 19 of pregnancy) abolished maternal constraint whereas 0.9% (w/v) NaCl treatment did not. In Wistar rats osmotic pumps were implanted to deliver IGF-I (1 microgram/g body weight per day), bovine GH (bGH; 0.6 microgram/g body weight per day) or saline from day 1 to 19 of pregnancy. IGF-I therapy but not bGH or saline abolished (P less than 0.01) maternal constraint and altered (P less than 0.01) the relationship between placental and fetal weight. When high or low IGF-I line mice embroys were transplanted into a normal line of mice, the expected negative relationship (P less than 0.05) between mean fetal weight and litter size was maintained. However, the embryos of the high line were heavier (P less than 0.05) than those from the low line irrespective of fetal number, suggesting a direct role for IGF-I in the regulation of fetal growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Cuticular hydrocarbon composition, phenotypic variability, and geographic relationships in allopatric populations of Amblyomma variegatum (Acari: Ixodidae) from Africa and the Caribbean.

Gas chromatography of cuticular hydrocarbons is used to determine the degree of genetic similarity and heterozygosity among 20 populations of Amblyomma variegatum (F.) collected from Africa and the Caribbean. Twenty-one compounds were detected in at least 90% of the specimens studied; another 57 hydrocarbons were detected in a variable number of specimens, ranging from 50 to 90% of all ticks extracted. Visual inspection of chromatograms revealed prominent differences in the relative abundance of hydrocarbons among the populations. Average heterozygosity was unexpectedly high (41.61%), whereas the average genetic identity among all populations was 0.8397. Principal components analysis for the relative amounts of several compounds did not provide adequate separation of populations according to geographical origin. Our data suggested that A. variegatum ticks are rapidly evolving and, while using several separate pathways, are sharing an undifferentiated genetic pool and retaining features that are typical for each population cluster.

Ticks of domestic animals in the Macedonia region of Greece.

A study was carried out on ticks of domestic animals in the Macedonia region of Greece. During 1983-1986, 11,620 tick specimens, belonging to 18 species and subspecies, were collected from cattle, sheep, goats and dogs, in 64 localities throughout Macedonia. Rhipicephalus bursa, the most common tick, and Hyalomma marginatum marginatum occurred in all bioclimatic zones, as well as the two one-host ticks, Boophilus annulatus and H. detritum scupense, which were present in fewer localities. R. turanicus, R. sanguineus, Ixodes gibbosus and H. anatolicum excavatum occurred essentially in the mesomediterranean bioclimatic zone. I. ricinus, Dermacentor marginatus and Haemaphysalis ticks (Hm. inermis, Hm. punctata, Hm. sulcata, Hm. parva) were found frequently in the biotopes of the attenuated mesomediterranean and submediterranean bioclimates. Rhipicephalus adults and the two-host Hyalomma ticks were active in the spring-summer period. Ixodes spp., Haemaphysalis spp., D. marginatus, as well as H. detritum scupense and the immature stages of R. bursa appeared during autumn and winter. Hyalomma and Boophilus ticks fed mainly on cattle. R. sanguineus almost exclusively parasitized dogs, which were also the only hosts from which I. hexagonus has been collected. The infestations were generally weak or moderate. Few heavy infestations were observed on cattle, especially in autumn. Most of the tick species showed a strong preference for some particular sites on the vertebrate body. This predilection could vary according to the host species.

Relationships between species of the Rhipicephalus sanguineus group: a molecular approach.

The biosystematic status of species belonging to the Rhipicephalus sanguineus group is difficult to determine by phenotypic methods and has been subject to frequent revisions and ongoing debate. Yet, the differentiation of species within this complex is of clinical importance especially in veterinary medicine due to different host specificities of the transmitted pathogens. In order to generate quantifiable and comparable data independent of environmental influences, a section of the second internal transcribed spacer (ITS2) of the rRNA gene was sequenced for 6 species belonging to the Rhipicephalus sanguineus complex: Rhipicephalus sanguineus sensu stricto, R. turanicus, R. rossicus, R. pumilio, R. pusillus, and R. camicasi. Rhipicephalus sanguineus s. str. and R. turanicus as well as R. pumilio and R. rossicus were found to have a close genetic relationship compatible with possible conspecificities. Conversely, R. pusillus was found to have the most distant relationship to the other species.

Effects of energy intake and body weight on physical and chemical body composition in growing entire male pigs.

Two experiments were conducted to determine independent effects of BW and DE intake on body composition and the partitioning of retained body energy between lipid and protein in pigs with high lean tissue growth potentials and when energy intake limited whole-body protein deposition. In a preliminary N-balance experiment involving 20 entire male pigs at either 30 or 100 kg BW, it was established that whole-body protein deposition increased linearly (P < 0.05) with DE intake at both BW. These results indicate that DE intake controlled whole-body protein deposition and that these pigs did not achieve their maximum whole-body protein deposition when fed semi-ad libitum. In the main serial slaughter experiment, 56 pigs, with a BW of 15 kg, were assigned to one of four DE intake schemes and slaughtered at 40, 65, 90, or 115 kg BW. Within DE intake schemes, DE intake was increased linearly (P < 0.05) with BW, allowing for an assessment of effects of DE intake and slaughter BW on chemical and physical body composition (carcass, viscera, blood). Between 15 and 90 kg BW, average DE intake of 16.1, 20.9, 25.2, and 28.8 MJ/d supported average BW gains of 502, 731, 899, and 951 g/d, respectively. The proportion of whole-body protein present in the carcass increased with BW and decreased with DE intake (P < 0.05), whereas the distribution of whole-body lipid between carcass and viscera was not influenced by BW and DE intake. A mathematical relationship was developed to determine the relationship between DE intake at slaughter (MJ/d) and chemical body composition in these pigs: whole-body lipid-to-protein ratio = 1.236 - 0.056 x (DE intake) + 0.0013 x (DE intake)2, r2 = 0.71. The data suggests that absolute DE intake alone was an adequate predictor of chemical body composition in this population of entire male pigs over the BW and DE intake ranges that were evaluated, simplifying the characterization of this aspect of nutrition partitioning for growth in different pig populations.

Effect of microbial phytase on ileal digestibility of phytate phosphorus, total phosphorus, and amino acids in a low-phosphorus diet for broilers.

The study aimed to assess the effect of a commercially available microbial phytase added to a corn-soybean meal diet on phytate P and total P in terminal ileal digesta as well as on true ileal amino acid digestibility. Three low-P diets containing 0, 500, or 750 U/kg of microbial phytase were fed to 21-d-old broiler chickens. Titanium dioxide was used as an indigestible marker. Ileal contents were collected from euthanized birds and analyzed, along with the diets, for total P, phytate P, and amino acids. Endogenous P determined at the terminal ileum was 446 +/- 59 mg/kg food dry matter (mean +/- SE). Endogenous ileal amino acids ranged from 219 +/- 33 mg/kg food dry matter for tryptophan to 1,255 +/- 166 mg/kg food dry matter for glutamic acid. Supplementation with microbial phytase resulted in a significantly (P < or = 0.05) greater phytate P disappearance (11% greater disappearance vs. unsupplemented control) from the terminal ileum. Similarly, true ileal total P digestibility was (P < or = 0.05) higher (10 to 12%) when microbial phytase was added. True ileal amino acid digestibility was significantly (P < or = 0.05) greater in the presence of microbial phytase for all the amino acids examined with the exception of methionine, tyrosine, histidine, and tryptophan. The mean increase in true ileal amino acid digestibility was 3.4%. The effect of phytase on true ileal phytate P, total P, and amino acid digestibility was similar for the 2 phytase inclusion levels tested. Microbial phytase improved phytate P and total P digestibility, as well as true ileal amino acid digestibility, for a corn-soybean diet.