Crude protein and essential amino acid requirements in chicks during the first week posthatch

1. This study examined optimal lysine and sulphur amino acid supply in the first week posthatch in broilers and the relationship between essential amino acids and dietary crude protein during the first week posthatch on performance at 7 d and through marketing. 2. The optimal supply during the 7 d posthatch using a 230 g/kg crude protein diet for sulphur amino acids was 9.1 and for lysine was 10.3-10.8 g/kg with maximal body weight (BW) or feed efficiency as the criteria. 3. Feeding diets with crude protein content ranging from 200 to 260 g/kg with either constant amounts of essential amino acids at different crude protein levels or constant ratios of essential amino acids to crude protein resulted in enhanced performance at 7 but not at 4 d with high protein intake and proportionally increased essential amino acids. 4. Performance on diets with crude protein ranging from 160 to 280 g/kg, with constant ratios of essential amino acid to crude protein, was much enhanced with the high crude protein diets at 7 d. All chicks were transferred to standard diets after 7 d and the BW advantage due to the balanced amino acid-high crude protein diet remained through marketing. 5. Thus increasing essential amino acids in a constant ratio to crude protein enhanced performance during the 7 d posthatch.     

Functional development and intestinal absorption in the young poult

1. Absorption, secretion of digestive enzymes and intestinal morphology were determined in poults from hatching to 19 d. 2. Oleic acid was approximately 80% absorbed at hatch and this changed little with age and was not influenced by fasting. In contrast, glucose and methionine were 48 to 56% absorbed at hatch and this increased to 75 to 80% at 4 d; however, this increase in absorption was inhibited by fasting. Percentage absorption of protein did not change between 5 and 19 d, whereas absolute uptake of fat and protein and net secretion of digestive enzymes and fatty acids and N to the duodenum increased with age and body weight (BW). 3. The length and diameter and villus size in the small intestines increased rapidly after hatch whereas the number of villi per cross section did not change with age. Duodenum and ileum surface area reached a plateau after 11 d whereas jejunal surface area continued to increase until 19 d. Duodenal and ileal surface area were not related to BW, but jejunal surface area was significantly correlated. 4. While the major part of the absorption occurred in the duodenum and upper jejunum, uptake of both protein and fat increased in the distal segments of the small intestine with age. Overall absorption of both fat and protein was correlated with BW. 5. It appears that in the posthatch poult intestinal surface area is not a limiting factor in growth, which was correlated with digestive secretions, fat and protein uptake.     

Fast mass transport through sub-2-nanometer carbon nanotubes

We report gas and water flow measurements through microfabricated membranes in which aligned carbon nanotubes with diameters of less than 2 nanometers serve as pores. The measured gas flow exceeds predictions of the Knudsen diffusion model by more than an order of magnitude. The measured water flow exceeds values calculated from continuum hydrodynamics models by more than three orders of magnitude and is comparable to flow rates extrapolated from molecular dynamics simulations. The gas and water permeabilities of these nanotube-based membranes are several orders of magnitude higher than those of commercial polycarbonate membranes, despite having pore sizes an order of magnitude smaller. These membranes enable fundamental studies of mass transport in confined environments, as well as more energy-efficient nanoscale filtration.     

Breeding for boron tolerance in lentil (Lens culinaris Medik.) using a high‐throughput phenotypic assay and molecular markers

This study describes the identification of a quantitative trait locus (QTL) in the recombinant inbred line population of ILL2024 × ILL6788 and subsequent validation of associated molecular markers. A high‐quality genetic linkage map was constructed with 758 markers that cover 1,057 cM, with an average intermarker distance of 2 cM. QTL analysis revealed a single genomic region on Lc2 to be associated with B tolerance and accounted for up to 76% of phenotypic variation (Vp). The best markers for B tolerance were assessed for their utility in routine breeding applications using validation panels of diverse lentil germplasm and breeding material derived from ILL2024. A marker generated from the dense genetic map of this study was found to be the most accurate of all markers available for B tolerance in lentil, with a success rate of 93% within a large breeding pool derived from ILL2024. However, given the number of the unrelated lines for which the marker–trait association was not conserved, B tolerance screening is still required at later stages to confirm predicted phenotypes.     

Evaluation of juvenile silver perch Bidyanus bidyanus (Mitchell) nutritional needs using high- and low-protein diets at two feeding levels

Juvenile silver perch Bidyanus bidyanus (Mitchell) of 3.2 g average weight were reared under controlled conditions on diets containing 23.4% and 40.6% protein. Diets were administered at 3% or 6% of the fish biomass per day. Both the protein concentrations and the feeding level of the diet influenced growth and proximate composition of the fish at the end of the 100-day growth trial. The energy requirement for these fish for maintenance was found to be 81.9 kcal × BW^–0.8 and, for each unit of energy retained per metabolic body weight, 7.05 needed to be supplied, whereas for each gram of protein retained per metabolic body weight, 5.79 g were required. The results indicate that it is possible to obtain the same weight increment when feeding a 23.4% protein diet at a level of 6% body mass day^–1 compared with only 3% body mass day^–1 of a 40.6% protein diet. This study provides the first estimation of nutrient requirements for juvenile silver perch, and these estimations require further refinement.     

Chick small intestine brush border contains lipase and phospholipase activity.

1. Uptake of triglycerides and phosphoglycerides was demonstrated in ligated washed chick intestinal segments in situ. Mucosal uptake was observed both in the jejunum and ileum of chicks and was not accompanied by significant luminal hydrolysis of acylglycerides. 2. Brush border membrane vesicles were prepared and lipase and phospholipase activities were demonstrated. These activities were enriched in parallel to the increase in activity of maltase and gamma-glutamyl transpeptidase in all small intestinal areas. 3. In order to determine if the pancreatic and brush border membrane lipolytic activities were similar different properties of these activities were examined. The relative activities of pancreatic and brush border membranes towards triolein and phosphatidylcholine differed. The pH-triolein activity curve and the use of different additives showed some diverging effects between the activities. These differences were not, however, sufficient to conclude that the brush border activity towards triolein is distinct from that of pancreatic lipase. 4. Lipolytic activity in the brush border may play a role in acylglyceride digestion, uptake and transport in the small intestine of the chick.     

Functional group imaging by chemical force microscopy

Mapping the spatial arrangement of chemical functional groups and their interactions is of significant importance to problems ranging from lubrication and adhesion to recognition in biological systems. A force microscope has been used to measure the adhesive and friction forces between molecularly modified probe tips and organic monolayers terminating in a lithographically defined pattern of distinct functional groups. The adhesive interactions between simple CH(3)/CH(3), CH(3)/COOH, and COOH/COOH functional groups correlate directly with friction images of sample surfaces patterned with these groups. Thus, by monitoring the friction between a specifically functionalized tip and sample, one can produce friction images that display predictable contrast and correspond to the spatial distribution of functional groups on the sample surface. Applications of this chemically sensitive imaging technique are discussed.     

Comparison of post‐hatch holding time and subsequent early performance of broiler chicks and Turkey poults

1. The effect of a holding period, lasting up to 48 h post‐hatch, on early growth and mortality rate was studied in broiler chicks and turkey poults.

2. After 48 h of food and water deprivation, birds of both species lost about a tenth of their initial post‐hatch weight. Weight loss was more marked in poults subjected to heat stress. Thus, duration of the holding period adversely affected early growth.

3. During the 48‐h holding period, the relative weight of residual yolk decreased in both species by approximately half of its weight in the just hatched chicks and poults. Relative yolk size was much higher in poults than in broilers.

4. On day 1 weight loss was attributed to degradation of the yolk sac, whereas on day 2 only about two‐thirds of the loss could be attributed to residual yolk. Body composition of newly‐hatched broiler chicks did not differ from those held for 24 h despite shortages of energy. However, after 48 h body fat content was markedly reduced compared to newly‐hatched or 24‐h‐old birds.

5. Irrespective of access to food, the relative size of the gastrointestinal tract increased with holding time in both species, reflecting its importance.

6. It was concluded that post‐hatch birds deprived of food and water for 48 h face a severe shortage of energy, causing alterations in body composition. This in turn adversely affects early growth and increases mortality rate under heat stress.     

Activated coagulation test in normal and heparinized ponies and horses.

Activated coagulation test (ACT) was performed in 37 adult ponies and 31 adult horses. The mean ACT time of all ponies and horses was 2 minutes 38 seconds, with a standard deviation (SD) of 29 seconds. The ACT was compared with the Lee-White clotting test in heparinized ponies. The correlation of ACT with the Lee-White test was 0.95. Anticoagulation heparinized ponies during prolonged cardiopulmonary bypass was successfully monitored with the ACT. The ACT is simple and reproducible, has a definite end point, and would seem to be an ideal screening test for hemorrhagic diathesis in equine animals.     

Development of the small intestine in heavy and light strain chicks before and after hatching

1. Intestinal development was examined in Arbor Acres and Lohmann chicks from one week before hatching until one week after. Changes in morphology and concentrations of DNA, RNA and protein in the duodenal tissue were determined.

2. Villus height and perimeter increased 9 to 11 fold from day 14 of incubation until 7 d after hatching. Arbor Acres chicks had values which were consistently higher than Lohmann chicks.

3. DNA concentration of duodenal tissue increased with age in parallel to the increase in the number of enterocytes per villus. In the pre‐hatch period tissue activity as indicated by RNA/DNA, and ribosomal capacity as shown by the RNA/protein ratios, were high for both strains; values for Arbor Acres embryos and chicks were greater than for Lohmann.

4. DNA concentrations, RNA/DNA, RNA/protein and protein/DNA ratios correlate with morphological measurements and can be used as additional criteria for evaluating development in chick intestine.

5. In the last week of incubation and immediately after hatching, intestinal growth appears to arise mainly from cellular hyperplasia and not from cellular hypertrophy. Intestinal development patterns were similar for both strains but growth was more rapid in Arbor Acres chicks.