Biomedical subjects

Y Noy

Publications and source records attributed to Y Noy.

At least 19 recordsLinked to original sources

PubMed2005

Direct determination of optimal amino acid intake for maintenance and growth in broilers.

This study has used a direct approach to calculate the optimal dietary supply of amino acids for maintenance and growth in broiler chicks. Amino acid intake and accretion in the carcass in Ross 308 chicks was measured following the feeding of different experimental diets with controlled feed intake from hatching through 42 d. Increasing crude protein levels at constant amino acid:protein ratio improved growth and reducing the crude protein levels at constant amino acid:protein ratios depressed performance. Altering the protein at constant essential amino acid concentrations had little affect on growth. Plotting the amino acid intake per metabolic BW against amino acid accretion per unit of metabolic BW yielded a straight line whose slope represents the efficiency of utilization of the amino acid for growth; the intercept represents maintenance. These values were then used to calculate the amino acid intakes required for any BW and growth rate. For comparison, inputs were calculated for the growth targets recommended in the Ross manual and compared with the dietary recommendations. The measured results were similar to the overall empirical recommendations although values differed slightly, with threonine required at higher levels then recommended. Using the growth rates obtained in this trial, optimal amino acid supply was compared with the NRC (1994) recommendations. This indicated that optimal amino acid supply was higher then NRC (1994) recommendations for most amino acids. The calculation of optimal amino acid supply as a function of BW and growth will allow effective formulation of diets for maximal efficiency.

Amino Acids↗

PubMed2004

Catabolism and deposition of amino acids in growing chicks: effect of dietary supply.

Amino acid (AA) deposition and catabolism were examined in broilers by determining intake and carcass deposition of AA, while defining catabolism as the difference between intake and deposition. The first trial examined the effects of increasing concentrations of a single limiting AA, lysine, on carcass deposition and catabolism. Carcass deposition of all AA increased to a plateau. Catabolism of lysine increased linearly, whereas other AA showed decreased catabolism as dietary lysine increased before reaching a plateau. Carcass AA composition was not influenced by the diet. In the second trial, different dietary ratios of AA were examined and these resulted in increased carcass deposition of lysine, threonine, and arginine before reaching a plateau, whereas other AA showed constant deposition. Catabolism of all AA tended to increase with dietary concentration. Efficiency of AA deposition decreased with age and catabolism comprised a smaller proportion of intake in the first week posthatch. A third trial examined changing AA ratios and composition. No correlation was observed between dietary AA concentrations and carcass deposition, whereas catabolism was linearly correlated with dietary composition. Multiple regression analysis indicated that the catabolic pathways of some AA are interrelated. These data are consistent with a model where carcass accretion is determined by the limiting AA until some maximal rate is achieved, whereby another AA may become limiting. Excess supply of any AA is catabolized and these catabolic processes interact with an accompanying energy cost.

Amino Acids↗

PubMed2003

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.

Amino Acids, Essential↗

PubMed2003

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.

Aging↗

PubMed2002

Nutrient use in chicks during the first week posthatch.

We examined effects of feeding chicks differing levels of macronutrients on performance during the first 7 d posthatch in this study. Four experiments were conducted using male Ross x Ross broiler chicks. The first experiment examined, in a 3 x 3 factorial design, the effect of feeding fat at 3, 7, and 11% and protein at 18, 23, and 28%. With increasing protein and fat levels feed intake and BW decreased. The second experiment examined, in a 3 x 2 factorial design, the effect of fat at 3, 7, and 10% and cellulose at 3 and 13%. Increasing fat in the diet decreased feed intake at both cellulose levels with little effect on BW. High cellulose decreased feed intake and BW. Experiment 3 examined, in a 3 x 2 factorial design, the effect of protein at 19, 23, and 27% and cellulose at 3 and 13%. Increasing protein levels decreased feed intake with little effect on BW. Cellulose decreased feed intake as levels increased. The fourth experiment examined, in a 4 x 2 factorial, the effect of feeding protein at 19, 21, 23, and 25% and fat at 4.5 and 9%, for 1 wk followed by standard diets through marketing. Significant differences in feed intake, BW and feed efficiency were observed at 7 d, but by 18 d differences were not significant and by 31 and 41 d no treatment effects were observed. Fat and protein percentage in the carcass in all experiments were not altered by dietary treatments and thus the efficiency of protein and fat retention decreased with increasing dietary intake. This study indicates that feeding diets with varying macronutrient levels to chicks during the first week post-hatch has distinct effects as compared to older broilers. It appears that once limiting amino acids and energy are provided the influence of dietary composition on immediate posthatch growth is limited.

Aging↗

PubMed2001

Yolk and exogenous feed utilization in the posthatch chick.

This study examined in posthatch chicks the partition of yolk utilization between transport to the circulation and secretion to the intestine and determined absorption and plasma concentrations of some metabolites. The presence of feed in the gastrointestinal tract enhanced yolk secretion to the small intestines. Absorption of glucose, methionine, and oleic acid was determined in vivo close to hatch using 141Ce as a nonabsorbed reference substance. Glucose and methionine uptake was low posthatch and increased with age and feed intake. Oleic acid uptake was high at hatch and changed little with age. Increased intake of lipids depressed the percentage oleic acid absorption. Plasma concentrations of glucose, Na, phospholipids, and nonesterified fatty acids did not change with age. Triiodothyronine and triglyceride concentrations increased with age in the plasma of fed chicks but decreased during feed deprivation. Feed intake stimulated posthatch secretion of yolk to the small intestines and triggered uptake mechanisms for hydrophilic compounds.

Aging↗

PubMed2001

The effect of early feeding on growth and small intestinal development in the posthatch poult.

Poults with early access to feed in the hatchery or turkey house grew more than those reared under standard commercial practice. During 48 h posthatch, fed poults utilized yolk and exogenous feed to increase BW by 11 g. The small intestine increased from 3.8% of BW at hatch to 8.9% after 48 h. In contrast, BW in feed-deprived poults decreased by 10 g, whereas the small intestine increased slightly in weight and composed 4.5% of BW after 48 h. The number of cells per villus and the villus surface area increased dramatically posthatch in the duodenum but more slowly in the jejunum and ileum. Enterocyte width changed little, but length increased more than twofold in the duodenum and by approximately 50% in the jejunum and ileum by 6 d posthatch. Lack of access to feed depressed the rate of growth of villi and enterocyte length in all intestinal segments until 6 d posthatch. All intestinal epithelial cells were proliferating at hatch, which changed rapidly within 48 h posthatch, with proliferating cells becoming located mainly in the intestinal crypts where about half of the cells were proliferating. In feed-deprived poults, the decrease in the proportion of proliferating cells in the crypt was greater than that of fed poults; after refeeding, an increase in the rate of proliferation was observed in feed-deprived poults. Plasma concentrations of Na, glucose, triglycerides, and phospholipids were not affected by feed deprivation; however, nonesterified fatty acid concentrations were enhanced in feed-deprived poults, indicating a greater use of fatty acids for energy. Plasma triiodothyronine (T3) concentrations, which may mediate some of the intestinal effects of feed deprivation, were depressed in poults without access to feed.

Aging↗

PubMed2000

Hydrolysis and absorption in the small intestines of posthatch chicks.

In the immediate posthatch period, chicks must transfer from metabolic dependence on yolk to utilization of exogenous feed. This study describes changes in intestinal luminal pancreatic enzyme activity and mucosal uptake posthatch as influenced by feed and Na intake. Chicks with access to feed increased in BW and small intestinal weight in the 48-h posthatch, whereas chicks without access to feed decreased in BW; however, small intestinal weight increased during this period. Chicks ingesting feed showed increases in total intestinal trypsin, amylase and lipase activities that were correlated with intestinal weights and BW. Chicks without access to feed showed little change in trypsin and amylase activities, and these increased only after feed consumption. Feeding a low-Na diet did not significantly change the regression coefficient between pancreatic enzyme activity and BW. Mucosal uptake was estimated by measuring Na+,K+-adenosine triphosphatase (ATPase) activity in small intestinal segments. In fed birds this activity increased in relationship to growth, whereas in nonfed birds uptake increased only after access to feed. Low-Na diets allowed only minimal mucosal uptake in all intestinal segments. This study indicates that secretion of trypsin and amylase into the intestine was triggered by feed intake. In addition, Na plays a critical role in intestinal uptake in the immediate posthatch period.

Amylases↗

PubMed1999

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.

Animals↗

PubMed1999

Energy utilization in newly hatched chicks.

The changes in body weight and composition were examined in broilers that either had immediate access to feed and water or had not been fed for 48 h posthatch. Chicks without access to feed decreased in BW by 7.8% in the 48 h posthatch, which was equivalent to 5.3 kcal/45 g chick/d. However, during this period the small intestines increased in weight and protein content by 80% or more. The decrease in yolk fat and protein could account for most of the changes in body composition in the feed-deprived chick. In contrast, fed chicks grew by 5 g and used 4.5 kcal/d for maintenance; during this period small intestines increased in weight by 110%. Intestinal absorption of exogenous nutrients was determined from hatch through 4 d posthatch by administration of a bolus of labeled glucose, methionine, or oleic acid, together with a nonabsorbed reference substance. Absorption of fatty acids was more than 80% at hatch and was higher than that of glucose and methionine, which was low especially when the bolus was administered as a solution. Absorption of all components tested increased with age and was more than 80% on Day 4. Duodenal in situ uptake determinations in hatching chicks indicated that uptake of oleic acid was high from yolk and saline solutions compared with glucose and methionine, which exhibited low uptake from yolk but higher uptake from saline solutions. These studies indicate that, although the small intestine has the capacity to absorb carbohydrates and amino acids at hatch, uptake may be dependant on the development of suitable conditions, including sufficient pancreatic and brush border enzymes for digestion and adequate sodium for function of the glucose-sodium cotransporters.

Animal Feed↗

PubMed1999

Posthatch development of small intestinal function in the poult.

The size, morphology, and mucosal enzyme activity of small intestines in poults were determined from hatch to 12 d of age. Mass and length of the small intestines increased at different rates in the duodenum, jejunum, and ileum and mass increased more than length. Intestinal weight increased more rapidly then other body organs, reaching a peak at about Day 6, and then decreased. Examination of the morphology of the small intestine showed that villus height and area increased several fold in the jejunum and duodenum and less in the ileum over the period examined. Enterocyte size increased slightly in the initial posthatch period. Activities of mucosal enzymes also increased at different rates in the different intestinal segments and sucrase, maltase, and gamma-glutamyltransferase activities per gram of intestine peaked at 2 to 5 d posthatch before decreasing. Regional mucosal intestine activities exhibited a steady increase, which was highly correlated with BW and thus mucosal hydrolysis may be a determining step in digestion. Poult villus size and area were smaller and mucosal enzyme activity was lower than that found in broilers and this may explain the initial slower growth rate in poults.

Animals↗

PubMed1998

Yolk utilisation in the newly hatched poult.

1. Routes of yolk utilisation and some aspects of intestinal digestion and absorption were determined in the hatching poult and compared to the chick. 2. Transfer from yolk to blood was observed pre-hatch and up to 72 h post-hatch. From hatch the transport pattern was similar to the chick. 3. Transport from the yolk sac into the intestine via the yolk stalk was observed up to 120 h after hatch. Secretion was initially to the proximal ileum and reflux occurred, transporting contents to the proximal small intestine and gizzard. Antiperistaltic movements increased after hatch and secretion continued for longer post-hatch than in the chick. 4. In situ uptake of glucose per unit of duodenum did not change with age, whereas uptake of methionine and oleic acid decreased with age. In contrast, in the chick glucose and methionine uptake capacity increased slightly between hatch and 7 d. 5. The lipid class distribution of intestinal contents resembled that of yolk close to hatch, however, some lipolysis was observed in the duodenum. With age the proportion of free fatty acids increased rapidly, first in the duodenum then in the ileum and finally in the caecum. Yolk in the distal small intestine close to hatch did not appear to be utilised.

Aging↗

PubMed1996

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.

Aging↗

PubMed1996

Routes of yolk utilisation in the newly-hatched chick.

1. This study was conducted to study the routes by which yolk is utilised in the chick during the initial posthatch phase. 2. Transfer from yolk to blood was examined by injecting, in the form of labelled compounds, oleic acid, triolein, inulin and dextran into the yolk; movement from yolk to blood was observed up to 72 h posthatch. 3. Transport of these molecules from blood to yolk was also observed by injecting them into the circulation and determining label in yolk. The yolk sac membrane was permcable in both directions for all labelled materials tested. 4. In the newly-hatched chick, blue dextran injected into the yolk sac could be seen moving in pulses into the intestine at irregular intervals. Transport of labelled materials from the yolk sac into the intestine was observed up to 72 h after hatching, and marker was found in the proximal small intestine and gizzard. The yolk stalk provided a pathway for transport to the intestine until lymphoid cells began to accumulate, with passage becoming partially occluded at 72 h posthatch. 5. Yolk utilisation was more rapid in fed than in fasted birds suggesting that the transport of yolk through the intestine could be increased by the greater intestinal activity found in fed chicks.

Animals↗

PubMed1996

Uptake capacity in vitro for glucose and methionine and in situ for oleic acid in the proximal small intestine of posthatch chicks.

The uptake capacity of the duodenum and jejunum was determined in vitro for glucose and methionine using 14C-inulin as an unabsorbed reference substance in posthatch chicks. Fatty acid uptake in situ was also determined in the duodenum. Methionine uptake capacity increased in both duodenum and jejunum between hatch and 7 d and was constant between 7 and 14 d. Calculation of apparent Michaelis constant (Kt) for both substrates indicated little change with age and thus the amount of carrier in the intestine may be increasing. Uptake capacity of the duodenum for glucose increased between hatch and 7 d of age but no changes were found between 7 and 14 d. In the jejunum, uptake capacity was constant from hatch to 14 d of age. In situ uptake of oleic acid in the duodenum did not change between hatch and 14 d of age. These results suggest that intestinal uptake capacity changes little after 7 d of age, and thus feed intake may be the major factor controlling nutrient uptake in chicks.

Aging↗

PubMed1995

Digestion and absorption in the young chick.

Digestion, enzyme secretion and intestinal rate of passage were determined in broiler chicks from hatch until 21 d using 141Ce as a nonabsorbed reference substance. Body weight and feed intake increased more rapidly after 10 d posthatch, and, in parallel, time of passage of feed through the intestines decreased by approximately 33%. Net duodenal secretion of amylase, trypsin, and lipase was low at 4 d and increased 100-, 50-, and 20-fold, respectively, by 21 d. Enzyme activity decreased distally in the small intestine. This change was greater with age. The contribution of the ileum to fatty acid absorption decreased after 7 d. Small intestine digestion of nitrogen increased from 78% at 4 d to 92% at 21 d, whereas fatty acid and starch digestion ranged from 82 to 89% in this period. It appears that digestibilities of starch and lipids are not limiting factors in the growth of young chicks.

Age Factors↗

PubMed1995

Posthatch changes in morphology and function of the small intestines in heavy- and light-strain chicks.

The morphology of the small intestines of heavy (Arbor Acres) and light (Lohman) chicks was determined posthatch in parallel with digestion, enzyme secretion, and passage time. Villus height and volume increased from 4 to 10 d, particularly in the jejunum and ileum. The number of enterocytes per villus increased with age, but enterocyte density was greater in jejunum than ileum. Villus volume and enterocyte density was greater in Arbor Acres than Lohman chicks from hatching and the rate of change with age was similar in both strains. Enzyme secretion to the duodenum was higher per gram of feed intake in heavy-strain birds on Day 4 after hatching but thereafter no differences were apparent. Passage time was 50% shorter in light-strain chicks on Day 4 but the difference between the strains was not significant from Day 10. No differences in fatty acid digestion were observed with age or between strains. Nitrogen digestion increased in both strains from approximately 70% on Day 4 to close to 90% on Day 14. Starch digestion was 90 to 95% from 4 to 14 d in Arbor Acres birds, but increased from approximately 80% on Day 4 in Lohman chicks to 93% on Day 14. Feed intake may determine the amount of uptake in posthatch chicks.

Animals↗

PubMed1994

Comparative study of extra-amniotic prostaglandin F2 alpha infusion and increasing intravenous oxytocin for termination of second trimester missed abortion.

Extra-amniotic infusion of prostaglandin F2 alpha (PGF2 alpha) and intravenous (IV) oxytocin in increasing doses were compared in a retrospective study to establish the efficacy of the two methods for termination of pregnancies with second trimester missed abortion. Sixty women with this complication underwent pregnancy termination, 28 by extra-amniotic infusion of PGF2 alpha and oxytocin augmentation, if necessary, and 32 by IV oxytocin in increasing doses. All patients in the PGF2 alpha group aborted within 24 hours from onset of infusion and seven of them needed oxytocin augmentation. There were nine failures in the oxytocin group and the other 23 aborted within 17 hours. The mean (plus or minus standard error of the mean) induction-abortion interval was significantly less in the oxytocin group (6.9 +/- 3.4 hours) than in the PGF2 alpha group (12.6 +/- 5.7 hours) p < 0.001. Eight patients in the group had mild side effects, such as nausea, flushes or transient hypotension. Uterine hypertonus was observed in two women receiving PGF2 alpha and treated by temporary interruption of the infusion. In the oxytocin group, one patient had coagulation disturbances and one, hemorrhage. We conclude that extra-amniotic PGF2 alpha infusion is more effective than IV oxytocin in increasing doses, for termination of second trimester missed abortion, but takes effect more slowly. We can assume that further use of IV oxytocin immediately after termination of the PGF2 alpha administration can shorten the induction-abortion interval.

Abortion, Missed↗