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There are contradicting data in the literature regarding condensed tannins content in carobs. In this study, urea (0.5 g/ml) under reflux conditions increased dramatically the yield of condensed tannins to 17% of dry matter, as compared to 3.5% in acidic methanol extraction. This shows that carob pods are rich source of nonextractable condensed tannins. The effect of PEG in diet rich in carob pods on voluntary feed intake, digestibility and growth in weaning kids was studied during 15 days of balance trials in 24 kids distributed into three dietary treatments. The corn grain and wheat bran components in the control diet (diet 1) were replaced by carob in treatments 2 and 3; treatment 3 was supplemented by 3.3% of PEG of molecular weight-4000. Food intake, diet utilization and growth rate of weaning kids fed a diet containing 52% carob pods were decreased considerably in comparison to kids fed the control commercial diet. Supplementing the kids fed the carob-based diet with PEG increased feed intake, crude protein digestibility and growth to the rate obtained with the control diet. The nutritional experiment highlights the following aspects relevant to all mammals consuming carob pods rich diets: (i) tannins increased the variability in feed intake between days, (ii) hypocholesterolemic effect of carob pods is related to lipid binding capacity of nonextractable condensed tannins in the digestive tract, (iii) supplementing high level of carob pods to animals with normal blood cholesterol level may induce hypocholesterolemia. D 2005 Elsevier B.V. All rights reserved.

Ingestion of condensed tannins decreases feed intake in ruminants. Polyethylene glycol (PEG) forms high-affinity complexes with tannins. In two experiments carried out on Holstein heifers, quebracho (Q) from the Aspidosperma quebracho served as source of condensed tannins. The aims of the study were (i) to quantify the effect of Q on feed intake and eating behaviour in cattle fed complete mixed diets (CMDs); (ii) to clarify if changes induced in ingestive behaviour and feed intake by Q in cattle can be reversed by feeding PEG; and (iii) to clarify if the decrease in feed intake is associated with short-term (astringency, post-ingestive malaise) or longer-term effects. In experiment 1, 500 g/day of Q was found to be the minimal dose that decreased feed intake in heifers. A ratio of PEG:Q equal to 1:12.5 did not fully restore feed intake. In experiment 2, four heifers received a random sequence of four rations in a Latin-square design with feeding cycles of ca. 7 days: CMD containing no supplements (C), or supplemented with 625 g/day of Q without PEG (Q), with 625 g/day of Q and 250 g/day of PEG (Q-PEG), or with 250 g/day of PEG without Q (PEG). Individual rations were continuously weighed in the trough and the behaviour of heifers was observed for 180 min after distribution of CMD. Overall, feeding Q was associated with lowered feed intake and shorter duration of eating bouts, mainly of the first eating bout, immediately after distribution of the diet. A larger portion of the diet was consumed subsequent to 180 min after distribution in Q-fed heifers. Eating rate and the water to food ratio were not affected by Q. The effects of Q on feed intake were attenuated by feeding PEG. Heifers adapted effectively to condensed tannins by increasing the number of eating bouts and the portion of diet consumed subsequent to 180 min after distribution, so that no differences in feed intake were noted on the last day of each feeding cycle. Data are interpreted to show that: (i) negative effects of Q on feed intake derive from astringency of CT and short-term post-ingestive malaise; (ii) the increased number of eating bouts and their wider partition throughout the day are means to preserve the ruminal environment in Q-fed heifers; (iii) PEG has the potential to neutralize negative effects of condensed tannins in cattle.

Glucose metabolism was studied in 31 pregnant ewes fed mixtures (50:50) of chopped alfalfa hay and corn grain given in whole (HWC) or extruded form (HEC). Number of fetuses was 1 (n = 10), 2 (n = 11) or 3 (n = 10). Diets were supplied at three dietary levels: maintenance (1.0 M), 1.25 x maintenance (1.25 M) or twice maintenance (2.0 M). Glucose metabolism was estimated by a double isotope dilution procedure at days 97-121 of pregnancy. Glucose entry rate (GER) was higher (P < 0.04), and glucose irreversible loss rate (GILR) tended to be higher (P < 0.07) in ewes given HEC than HWC. Dietary level (P < 0.001) and the number of fetuses (P < 0.005) affected GER and GILR positively. These results provide a probable explanation for higher birth weights previously found in lambs born to HEC-, compared with HWC-fed dams.

The effect of ruminally degradable starch on the reproductive performance of sheep was studied in 50 Booroola x Assaf crossbred ewes, of which 32 were carriers of the FeCB (Booroola) allele and 18 were not carriers. The sheep were group-fed, according to body weight (BW), diets composed of pea straw, soybean concentrate and corn grain offered in two meals per day. Dietary differences in ruminally undegradable starch (RUS) were obtained during the 29 day treatment period by feeding grain as whole corn (WC, 1.4 g RUS day−1 kg−1 BW) or extruded (EC, 0.4 g RUS day−1 kg−1 BW ). Oestrus was synchronized by inserting progestagen pessaries at Day 8, and withdrawing pessaries and injecting 400 IU of pregnant mare serum gondaotrophin at Day 20 after initiation of dietary treatments (Day 0). Ovulation rate (OR) was estimated by laparoscopy. The FecB allele was associated with a significant increase in OR (2.88 vs. 1.40, P⪕ 0.0001) and prolificacy (1.85 vs. 1.32 lamb born per ewe lambing, P⪕0.09). Within FecB allele carriers, all WC-fed ewes had multiple ovulations, compared with 61% of EC-fed ewes (P⪕0.005). OR values were 3.29±0.27 and 2.46±0.31 corpora lutea (CL) per ewe ovulating and prolificacy was 2.13±0.22 and 1.57±0.23 lamb per ewe lambing in WC- and EC-fed ewes, respectively (P⪕ 0.09). In non-carrier ewes, dietary treatments did not affect OR (1.44 and 1.36 CL per ewe ovulating in WC- and EC-fed ewes) or prolificacy (1.20 and 1.44 lamb per ewe lambing, in the same order). In a second experiment, aimed to assess the effect of dietary RUS on circulating insulin levels, blood was sampled before and at hourly intervals for 10 h after a meal from ten ewes fed rations with WC or EC. Insulin levels were higher in EC than in WC-fed ewes before and 3 h after a meal (P⪕ 0.05). EC feeding may be associated with higher peripheral insulin concentration but does not enhance OR. Data are used to show that: (1) provision of about 100 g RUS day−1 exerts a positive effect on the OR and prolificacy of FecB carriers; (2) dietary treatments may affect OR in sheep of different ovulation potential differently; (3) no positive relationship was found between circulating plasma insulin concentration and OR.

Day-old male meat-type chicks were fed a commercial starter diet supplemented with 2 levels of enzyme preparations containing amylase and proteases up to 14 d of age. Enzyme supplementation had no significant effect on feed intake or growth rate, and was accompanied by a significant decrease in gizzard content and small intestine weight. The intestine contents increased and this increase was accompanied by a significant decrease in its pH. Enzyme supplementation depressed the activity of chymotrypsin in the pancreas and the activity of amylase, trypsin and chymotrypsin in the intestinal contents. Some carry-over effects were observed on d 42, 4 weeks after the cessation of the enzyme supplements. These were mainly a significant depression in the activity of trypsin in the intestinal contents. In a balance study, diets supplemented with 0,250 and 1,000 micrograms/kg enzyme preparations were supplied. Exogenous enzyme supplements had no significant effect on the digestibility of all the nutrients studied except for the highest level of enzyme supplementation, which improved slightly but consistently the digestibility of amino acids. Some age effects were observed, mainly a decrease in the digestibility of fat and starch, and in the ME of the diet from weeks 1 to 2 followed by an increase during week 3. Protein digestibility and retention of nitrogen decreased with age.

The effect of 3-day-old ‘guides’ of broiler or White Leghorn type chickens on posthatch behaviour (eating, drinking, standing and sitting), growth rate and livability was measured in broiler and Leghorn type chickens. Four trials were conducted. One trial was in cages and three were on a litter floor. Although the guides did not influence the behaviour of either breed in cages, growth of the broilers, but not of Leghorns, was depressed by the presence of broiler guides. In floor experiments, the presence of guides of both breeds increased ingestive behaviour (eating and drinking), with reduced growth of broilers reared with broiler guides, consistent with that observed in cages. Whereas in unstressed chickens vitality was not affected by the guides, cold stressing of Leghorn chickens in the hatcher most markedly increased the positive effect of the guides on ingestive behaviour, vitality and growth rate. Responses of the posthatched chickens to 3-day-old guides were dependent on housing, management, genetic breed and stressful settings.

1. Male broilers selected for high (HF) or low (LF) abdominal fat were fed from 8 to 53 d of age on diets containing different concentrations of protein: according to N.R.C. (1984) recommendations (IP), 14% lower (LP) or 14% higher (HP). 2. The growth of LF birds fed on the LP diet was depressed until 35 d of age, but did not differ from the other groups later on. 3. The HF birds had heavier adipose tissues (AT) (g/kg body weight) than the LF birds. Significant line by diet interactions indicated a difference in magnitude of the response of the lines to dietary protein content. 4. Fat concentration of the AT and skin was higher, and in the tibia lower in the HF than in the LF birds. The fat concentration in liver and in breast muscle was not affected by line or by diet. 5. The ratio of saturated plus monoenoic fatty acids to polyenoic fatty acids, considered as an index of fat synthesis, was higher in the abdominal adipose tissue (AAT) of HF compared with LF birds. In AAT, liver and in breast muscle, this ratio was inversely related to dietary protein content.

1. Two-week-old male chicks of a light-bodied strain were fed one (1M) or two (2M) 2-h meals per day. An additional group was pair-fed (P1M) the amount consumed by the 1M group on the previous day. 2. After 21 days, final body weight of the 1M and 2M chicks attained 65% and 80%, respectively, of that of the control group fed ad libitum. The weight gain of the P1M chicks was equal to that of the 1M chicks. 3. Food consumption of chicks adapted to meals was not even throughout the feeding period. On day 16 of the experiment, the 1M birds consumed 65% of the meal during the first 30 min. P1M chicks behaved similarly to the 1M ones. The intake of the 2M chicks during each meal was exactly half of their daily consumption, despite the uneven time period between meals. 4. The time during which food remained in the gastrointestinal tract (GIT) was longer under the meal feeding regimes than in the ad libitum-fed groups. 5. Although neither body composition nor metabolisable energy was affected by meal regime, food utilisation was poorer in the 1M and P1M than in the ad libitum and 2M-fed chicks.

Weights of internal organs and levels of digestive enzymes were obtained through the first 15 days posthatch for cockerels from three lines of chickens known to differ greatly in body weight. On Day 15 body weights from the fastest growing line were eight times greater than those from the slowest growing line. Differences among lines were found for weights at hatching and for growth patterns (both absolute and relative to body weight) of the vitellinee residue, heart, lungs, liver, pancreas, crop, proventriculus, gizzard, and segments of the small intestine. Line differences were also evident for levels of trypsin, chymotrypsin, and amylase in the pancreas and contents of the small intestine. Ranking of lines for these traits varied with age. In all lines weights of the small intestine, liver, and pancreas increased relatively more than did total body weight during the 1st wk posthatch, after which the relationship reversed.

1. Body weight and the weight of the digestive organs and activities of some digestive enzymes were determined from hatching to 23 d of age. 2. Relative daily growth rate peaked at 11 d of age (22% gain/d) and then decreased gradually. 3. The vitelline residue was decreased rapidly from 4.6 g at hatching to negligible values from 4 d of age. 4. Maximal allometric growth of the pancreas and small intestine was 4-fold and that of liver 2-fold greater than that of the body. 5. Activities (units/kg body weight) of the digestive enzymes measured in the pancreas and intestinal contents increased with age. In the pancreas maximal values were attained on day 8 for amylase and lipase and 11 for trypsin and chymotrypsin. In the small intestine maxima were attained on day 4 for lipase, 11 for trypsin and chymotrypsin and 17 for amylase. 6. The development of secretion of digestive enzymes in the post-hatched chick could be a limiting factor in digestion and subsequently in food intake and growth.

1. Activities of digestive enzymes in meat-type chickens under ad libitum or alternate-day feeding were determined from 14 to 83 d of age. 2. Final body weight of intermittently fed birds attained 75% of that of the ad libitum-fed controls. 3. When compared with the ad libitum-fed counterparts, a marked increase in the relative weight of the pancreas and intestinal contents were found on repletion days. On depletion days the relative weights of the pancreas and of the intestinal contents were about half those found in ad libitum-fed birds. 4. The activity of the digestive enzymes in the pancreas, expressed as U/g pancreas or U/kg body weight, was not affected consistently by the feeding regime. In the small intestine a marked increase in relative activity (U/kg body weight) was observed on repletion days and a marked decrease on depletion days as compared with ad libitum-fed controls. The activities per g intestinal contents following food restoration did not differ significantly from those of ad libitum-fed controls except for trypsin, which was higher in the former. On depletion days the activities per g intestinal contents were lowest, lipase excepted.

Twenty Saanen kids at average age of 7±1.5 days were fed 19 days a commercial milk replacer (MR) or a milk replacer in which 20% or 40% was substituted by heat-treated, expanded starch-soy mixture (20ES, 40ES), or 40% untreated starch-soy mixture (40US). Soy concentrate contained 65% protein and was toasted to inactivate trypsin and chymotrypsin inhibitors. Weight gain and food utilization of kids fed 20ES diet were the highest but did not differ significantly from kids fed MR. Substituting 40% of the milk replacer by expanded or untreated starch-soy mixtures reduced food consumption, body weight gain and food utilization 40%–50%. During weaning period, differences in body weight gain between the groups were smaller and non-significant, but performance of the 20ES group was still the best in comparison with the other groups. Apparent digestibility of dry matter, ash and protein was higher in the MR group than in the other groups. Heat treatment did not affect apparent digestibility of starch. Blood glucose levels were higher before and after feeding in the MR and 20ES groups than in the 40ES and 40US. Peaks of blood glucose were lower and delayed in groups fed starch compared with the MR group. The pH of rumen liquor dropped after meals more in the 40US and 40ES than in the MR and 20ES kids. The drop was accompanied by concurrent increase in concentration of total volatile fatty acids. During the suckling period, kids fed MR, 20ES and 40US were more active before than after meals. They stood more, none of them was sleeping, and only a few were sitting before meals. These differences were minor in the 40ES group. Differences in behaviour before and after meals were much smaller in all groups during the weaning period; 40ES and 40US groups spent more time in eating concentrate before and after the liquid meal than MR and 20ES kids.

Five 7-day-old Frisian bull calves, raised in Israel received twice a day a mixture of 40 g of soybean concentrate (65% protein) and 80 g of one of the following carbohydrates: glucose (G), expanded (heat-treated) (ES) or untreated (US) corn starch. In the afternoon the calves received in addition 400 g of milk replacer. Until weaning at experimental day 25, ES calves showed better growth and food utilization than their counterparts. Daily weight gain for the entire growing period up to slaughter was higher for the starch than for the glucose-fed group (P less than 0.05 for ES vs G). Heat treatment of starch increased its in vitro availability to amylase and its in vivo digestibility. Bypass of the rumen was complete in all G calves. In the ES and US groups, partial diversion of the liquid feed into the rumen was evident. The G group showed hyperglycemia after meals, while almost no increase in blood glucose level was observed after soy-starch meals (either US or ES).

1. The 'extra caloric' effect of added soyabean oil, as reflected in improved body weight gain, food utilisation, metabolisable energy or net energy deposition in the body was determined. 2. Two diets were formulated to contain 12.1 MJ/kg, one with no added fat and the second with 30 g/kg soyabean oil. Addition of oil improved body weight gain by 6.9% (P0.05). Two other diets were formulated to contain 13.0 MJ/kg, one with 30 and one with 60 g/kg added soyabean oil bringing the total fat in the high energy, high fat diet to 84 g/kg. Addition of oil in this case improved weight gain by only 3.4% (ns). Addition of soyabean oil increased the apparent digestibility of total dietary fat and reduced that of starch. 3. The effect of soyabean oil supplementation on mash diets at both energy concentrations or to the pelleted diet (formulated to contain 12.1 MJ) on AMEn was consistently positive although not significant. Addition of soyabean oil improved net energy deposition in the body by 17% within the 12.1 MJ/kg diets, (30 g/kg soyabean oil addition) (P0.05), but was reduced by 2% (ns) within the 13.0 MJ/kg diets (60 g/kg soyabean oil addition). 4. Supplementing a pelleted diet formulated to contain 12.1 MJ/kg, with 30 g/kg soyabean oil, improved food utilisation (P0.05). The 'extra caloric' effect of added soyabean oil, defined as the beneficial effect of the oil above that predicted from its energy value, varied according to the parameter chosen to express this effect and was influenced by the concentration of added soyabean oil and the dietary energy.

The effect of residual yolk removal at hatch on growth and feeding behavior was assessed in lines of chickens divergently selected for low (LW) or high (HW) 56-day body weight. At hatch chicks were assigned to 1 treatment: removal of the residual yolk (R) or no surgery (I). Twenty-four chicks per line (12 I and 12 R) were assigned to an all-mash regimen (M) and 48 per line (24 I and 24 R) to a choice (C) between mash and dietary residual yolk. HW were heavier than LW chicks regardless of treatment. On day 5 and thereafter, chicks given a choice were heavier than those eating mash. HW chicks ate more than LW ones. The percentage of yolk eaten increased during the 2-3 d after hatch, remained constant for 2 d, then decreased. Results are discussed in term of yolk need and development of the gastrointestinal tract in the divergent lines.

1. Body weight, the weight of digestive organs and activities of some digestive enzymes were determined from hatching to 14 d of age in meat- and egg-type chickens. 2. Relative daily food intake and growth rate were much higher in meat- than in egg-type chickens. Relative daily food intake peaked at 30% of body weight at 3 d of age in meat-type, and at 20% of body weight at 6 d of age in egg-type chickens and then decreased gradually. The corresponding values for growth rate were 20 and 14%. 3. Allometric growth of the small intestine, intestinal contents and liver was greater in meat-type chickens, but the growth of the pancreas attained a higher value in the egg-type birds. Diminution of the vitelline residue was similar in the two breeds. 4. Pancreatic digestive enzyme activities were similar between stocks, but activities in the small intestinal contents were lower in meat-type chickens. 5. The secretion of digestive enzymes in the newly-hatched meat-type chicken could be a limiting factor in digestion and, consequently, in food intake and growth.

1. Fat deposition in abdominal, mesenterial, sartorial and gizzard adipose tissues (AT), liver, breast muscle, skin and carcase was studied in male broilers, selected for high (HF) and low (LF) abdominal fat and fed on diets differing in energy density and total fat content. 2. There were no significant differences in body weight in the experimental groups. The relative weight (g/kg body weight) of the dissected adipose tissues was higher in HF than in LF birds. Fat concentration in the AT (sartorial excepted), skin and body was higher in the HF compared with the LF birds. The lines did not differ significantly in liver and breast muscle fat content. 3. Abdominal AT was affected by selection or dietary fat more than other AT and total body fat. 4. In the HF birds increasing energy density from 12.3 to 13.4 MJ/kg (dietary fat kept constant: 5.46 g/MJ) significantly increased the weight of the abdominal, mesenterial and sartorial AT. Increasing dietary fat (at both energy densities) decreased the weight of the AT, whereas increasing both energy and fat did not affect it. In the LF birds, similar but milder and insignificant trends were observed. It is suggested that this interaction has biological significance.

The nutritional effects of giving raw (RSF) or heated (HSF) soya-bean flour to young guinea-pigs were investigated in trials 1 and 2, in which the levels of dietary protein were 120 and 190 g/kg diet respectively. The growth rate of animals fed on RSF was lower than that of those fed on HSF. Growth retardation of guinea-pigs fed on RSF was accompanied by a lower apparent digestibility of the protein (0.49–0.53) compared with HSF (0.67–0.76) and lower food conversion efficiency. In RSF-fed animals, increasing dietary protein affected growth and food conversion efficiency negatively. The pancreas of animals fed on RSF and HSF was similar in weight but secreted less trypsin, chymotrypsin and amylase, in RFS-fed animals. It was concluded that the mechanism by which raw soya-bean negatively affects the growth rate of guinea-pigs by reducing the activity of intestinal enzymes, differs from that suggested for rats and chicks, but is similar to that of pigs and calves.

One cycle of divergent sib selection, for or against abdominal fat weight, combined with within-family selection for body weight, was performed in a population of a commercial female grandparent line (White Rock type). Chicks from the first generation (S1 G1) of high-fat (HF) and low-fat (LF) selection lines were raised in three different environmental and climatic conditions. A second generation (S1 G2) of the selection lines was obtained by within-line selection for body weight only. The HF line had about 60% more abdominal fat than the LF line in all three environments. The realized heritability of this trait was calculated to be .73, almost identical to the heritability estimated from the base population. The LF line mean body weight was between 1% and 5% lower than that of the HF line. This difference was not significant and it was almost abolished in S1 G2, after both lines were selected for body weight only. The difference between lines in abdominal fat weight was increased to 80% in S1 G2. It can be concluded that reduction in abdominal fat weight was not associated with a decrease in body weight. Selection for body weight, in a line previously selected against abdominal fat, did not reverse the reduction in fat. The difference between the HF and LF lines had the same magnitude in both sexes and under different environmental conditions that increase or decrease fat deposition.

Chicks of a heavy-bodied strain were deprived of food on alternate days from 14 to 83 days of age. Relative food intake was depressed by intermittent feeding to 25 days of age, after which the deprived chicks resumed the relative intake of the ad libitum-fed controls, i.e., the relative intake on repletion day was twice that of the control chicks. Following an adaptation period of 2 weeks, the relative growth rate of the intermittently fed chicks exceeded that of the control group, the excessive growth being due to an increase on the day of repletion which was more than twice that of the control birds. Body fat concentration was depressed by intermittent feeding throughout the experimental period. Although, in ad libitum-fed chicks, periodical deposition of body protein and fat was parallel throughout the experimental period, in the treated chicks, protein deposition prevailed initially and fat deposition prevailed at the end of the experimental period. Intermittent feeding was accompanied by a consistent increase in the relative weight of the liver, pancreas, and gastrointestinal tract, including the small intestine. The differences in food intake, growth, body composition, and gastro-intestinal tract between heavy- and light-breed chicks exposed to intermittent feeding are discussed.

1. The effects of feeding meals, in amounts equivalent to ad lib. intake or to 75% and 50% restriction by intubation, were studied in chicks.2. Growth estimated by body-weight gain and shank length was improved by tube feeding in the 50%-restricted chicks.3. Tube feeding increased energy retention at all feeding levels and nitrogen retention in the restricted chicks only.4. Body fat was increased in the full-fed chicks by intubation and decreased in the 50%-restricted chicks only.5. Crop and gizzard weights were increased by food restriction and by intubation. Tube-feeding increased the weight of the small intestine at all feeding levels.6. The activities of the digestive enzymes were lower in the pancreas and higher in the small intestine of the tube-fed chicks than in the voluntarily-fed ones at all feeding levels.7. It is suggested that synthesis, secretion and stablity of the different pancreatic enzymes could be affected diversely by feeding regimens.

Three hundred chickens from pedigree matings in a commercial female grandparent stock were slaughtered at 7 or 9 weeks of age. Data were obtained for live body weight and various carcass parts. Coefficients of variation of abdominal fat (g and g/100 g body weight) were above 30%. Coefficients of variation of the weights of muscular and skeletal parts were much lower (about 10%) and were further reduced when calculated per 100 g body weight. Heritability of abdominal fat was higher (.82) than that of live body weight (.55) and parts: breast (.55), thighs (.31), and drumsticks (.51). Phenotypic and genetic correlations between each of the heavier parts (breast, thighs, and drumsticks) and body weight were over .8; for smaller parts (legs, wings, etc.) correlations (.49 to .79) were lower. Abdominal fat showed the lowest correlation (.26 to .36) with body weight. The genetic correlations seemed free of the part-whole relationship. Simultaneous selections for live body weight and for breast weight, or against abdominal fat, were simulated using "independent culling levels". The theoretical calculations showed that adding breast weight as a selection criterion had no advantage over selection for body weight alone due to the high genetic correlation between the two traits. However, simultaneous selection for body weight and against abdominal fat, using optimum combination of culling, was economically superior to selection for body weight alone. The advantage of this two-trait selection depends on the correlation between the traits and their relative values.

The effect of intermittent feeding (every 2nd day) on in vitro muscle protein synthesis and degradation was studied in adapted and nonadapted broiler chicks. Protein synthesis, estimated by in vitro incorporation of L-[14C]-tyrosine into muscle protein, was higher in the intermittently fed birds than that in ad libitum fed counterparts or nonadapted birds. In chicks exposed to one 24-hour cycle of food deprivation and restoration, protein synthesis was slightly depressed (nonsignificant). Protein degradation, estimated by free tyrosine released from muscle into the medium, decreased after 24 h of food deprivation and increased after 24 h of food restoration, to the same extent in both adapted and nonadapted birds.

Apparent digestibility and absorption of nitrogen and amino acids from raw and heated soy flour were studied in rats. The apparent digestibility of all the amino acids from raw soybean was lower than from the heated flour. The net absorption was also significantly lower in the group fed raw soy flour for most of the amino acids, with the exception of cystine and methionine. The pattern of the amino acids along the digestive tract showed that while the levels of amino acids from heated soy flour started to decline in the jejunum and continued to decline in the ileum, in the group fed raw soy flour, the decline in levels of the amino acids did not begin until the ileum. The delay in the absorption might affect the overall absorption and utilization of the amino acids, and might explain the lower percentage retention of total nitrogen and amino acids in the carcasses of rats fed raw soy flour as compared with those fed heated soy flour. Possible reasons for the markedly lower cystine retention (relative to other amino acids) in the carcasses of the raw-soybean-fed rats are discussed.

1. The effect of intermittent feeding in chickens of heavy breed (HB; meat type) and light breed (LB; egg type) on skeletal muscle growth and composition was studied in adapted and non-adapted chickens.2. Food intake, relative to body-weight, was similar in both breeds but was higher inad lib.-fed than in intermittently fed birds.3. On repletion days the relative growth rate was similar in both breeds, while on depletion the LB chickens lost more weight than the HB chickens. In both breeds, the relative growth was higher in the intermittently fed birds during days of food restoration than in those fedad lib.4. The relative weight of the breast muscle was higher in HB birds than in LB birds, but deposition rate on the day of food restoration was similar in both breeds. This growth was more pronounced in chickens adapted to alternate feeding than in chickens exposed to this feeding regimen for one cycle.5. Protein concentration in breast muscle was not affected by age and was slightly higher in LB chickens than in HB chickens. Soluble protein was markedly reduced on days of repletion, and more at 46d than at 18d of age.6. The RNA:DNA ratio was higher in HB than in LB chickens, and lower on days of food deprivation than on days of food restoration. After repletion this ratio returned to the level of thead lib.-fed chickens. While in LB chickens cell size (as estimated by DNA concentration) remained constant on repletion and depletion days, in the HB chickens it decreased.7. The rapid growth of breast muscle in HB chickens was attributed to the higher rate of protein synthesis (estimated by RNA:DNA ratio) compared with LB chickens. This may also explain why the breast muscle of LB chickens was less sensitive to intermittent feeding than that of HB chickens.

1. Heavy-breed (HB) chicks differed from light-breed (LB) ones in their propensity to be overfed. Whereas in the LB chicks the amount by which they could be overfed reached 70 % more than the food consumed daily by thead lib.-fed chicks, in the HB chicks the maximal excess was only 13 %.2. Overfeeding caused a slight but statistically significant increase in the linear growth rate (shank length) of the LB chicks, with an opposite effect in the HB chicks.3. Overfeeding increased the weight of the crop, proventriculus, small intestine, pancreas, liver and adipose tissue but had no such effect on the heart, cerebrum or cerebellum.4. Overfeeding had no effect on the specific activities of the pancreatic digestive enzymes, liver xanthine dehydrogenase, or tryptophan oxygenase (EC1.13.1.12). The increase in the total activities was due entirely to organ hypertrophy.5. Obesity induced in young chicks had no residual effects on the adult LB chicks, but reduced the linear growth of the adult HB chicks.6. An explanation for the difference between breeds in response to overfeeding at an early age is discussed.

The relative weights of the gastro-intestinal segments and of some other internal organs from light and heavy breed chicks from hatching to 21 days of age were compared. 2. The relative weight of the duodenum and jejunum was higher in the light breed than in the heavy one, the reverse relationship was found for the ileum and caecum. 3. The relative growth of the pancreas, heart, cerebrum and cerebellum was greater in the light breed.

1. Force-feeding of young chicks for 15 d increased kidney arginase (EC3·5·3·1) activity threefold. Fasting for 30 h decreased this activity by 50%.2. Liver xanthine dehydrogenase was slightly increased after force-feeding and decreased following fasting.3. The specific activities of two pentose-phosphate-cycle enzymes were not significantly affected by force-feeding, but glucose-6-phosphate dehydrogenase (EC1.1.1.49) decreased following fasting.4. The over-all secretion of digestive enzymes increased parallel to the increase in food consumption. Therefore, despite an increased absolute weight of the pancreas and intestinal chyme, specific activities were the same in the force-fed andad lib.-fed groups, except for a higher activity in intestinal amylase.5. Fasting did not affect the pancreatic enzymic activities.

1. Chicks of a light‐bodied strain were deprived of food on alternate days from 15 to 46 d of age. 2. Hyperphagia, amounting to twice the intake of control birds early in the experiment, occurred on the repletion day. 3. Final body weight attained 80% of that of the controls. 4. Body fat concentration decreased at first but returned to that of controls after 3 weeks. 5. A consistent hyperlipaemia was observed after food deprivation or restoration. 6. There was a marked increase in the digestive enzymes found in the small intestine, but not in the pancreas during the repletion day. 7. These responses may be considered as mechanisms to reduce the physiological manifestations of starvation.

Rats were fed diets containing 15, 30, 45, or 60% casein for 30 days. The weight gains of rats fed diet containing 30% casein were higher (P

BORCHERS (1958) and Fisher and Johnson (1958) showed that when raw soybean meal (RSM) was fed at different levels, the higher level supported better growth of animals. They concluded, therefore, that the RSM does not contain any toxic factors. Saxena et al. (1962) found that chick growth rate and the feed efficiency decreases, and pancreatic hypertrophy increases, with increasing proportions of RSM in the ration. It has been shown (Alumot and Nitsan, 1961) that raw soybean inhibits the proteolytic activity in the small intestine of young chicks. It was the purpose of the present work to study how and to what extent the proportion of RSM in rations of constant protein level affects the proteolytic activity in the chick’s small intestine and the pancreatic hypertrophy, and to find out whether these two factors are related to the low growth rate and feed efficiency. EXPERIMENTAL One-day-old White Leghorn male chicks were…

Heated soybean diet, supplemented with Birk-Bowman trypsin and chymotrypsin inhibitor from soybean or with chicken ovomucoid, caused pancreas enlargement in chicks but did not affect significantly their growth rate. The effect of the two inhibitors upon the enzymatic activities in the intestinal tract was tested and found to be quite similar.

The protein value of raw, heated and shelled Vicia faba beans (VFB) was compared with that of heated soyabean meal (HSB) when fed at 10 and 15% protein levels to rats of both sexes. While females grew equally well on VFB and HSB diets containing 15% protein, males fed VFB grew more slowly than those fed HSB at the two levels of protein in the diets (the difference being smaller on the 15% protein diet). The lower N utilisation of VFB seems to be the main reason for the differences in the growth response. Shelling improved the nutritive value of VFB, while autoclaving affected it adversely. The trypsin inhibitors of the VFB were not destroyed by autoclaving.

Potato starch depressed the growth rate of chicks significantly when it was the main source of carbohydrates. Whether fed alone or together with glucose at a ratio of 1:1, it adversely affected feed efficiency in general, and the utilization of dietary nitrogen, fat and nitrogen-free extract (N.F.E.) in particular. The addition of α-tocopheryl acetate to diets low in vitamin E and containing potato starch and oxidized safflower oil, improved the retention of nitrogen, fat and NFE, but did not affect efficiency. Pronounced differences in α-amylase activity between chicks fed corn and potato starch were observed only when the latter supplied the major part of the dietary carbohydrate. Under these conditions pancreatic α-amylase activity was higher in chicks fed potato starch, but was lower in the chyme obtained from various parts of the intestinal tract.

1. The effect of methionine supplementation upon pancreatic trypsin, chymotrypsin, pancreatopeptidase E and amylase of chicks given raw and heated soya-bean diets (RSD and HSD) was studied before and after fasting.2. Statistical analysis of the ratios of amylase to pancreatopeptidase E, trypsin and chymotrypsin in each individual chick revealed that methionine supplementation consistently increased the ratio of amylolytic to proteolytic enzymes. This phenomenon was most marked in the fasted RSD group, less in the fed RSD and fasted HSD groups and least in the fed HSD group.3. The results are discussed in relation to methionine metabolism in chicks given RSD and HSD supplemented with trypsin inhibitors.

1. Excessive amounts of food (70% greater thanad lib. intake) introduced into the gastrointestinal tract of young chicks were efficiently digested and caused increased growth resulting mainly from lean body substance and partially from fat deposition, more efficient energy utilization than thead lib.-fed controls, increased relative weights of the crop, proventriculus, intestine, liver and abdominal adipose tissue. Pancreas relative weight was not changed and that of the gizzard was reduced.2. The treatment also caused changes in blood plasma composition. Free fatty acid, trigly-ceride, α2-, β- and γ-globulin and pre-β-lipoprotein concentrations increased.3. Fasting for 30 h caused higher body fat losses and lower body protein losses in the force-fed chicks than in thead lib.-fed chicks.4. The effects of over-feeding on body and blood plasma composition and differences found in these measurements during starvation are discussed.

Trypsin, chymotrypsin and amylase levels were determined in the pancreas, all along the intestinal tract, and in the feces of rats fed raw or heated soy flour diets. The levels of all enzymes measured in the pancreas in the non-fasted state were lower in the raw than in the heated soy flour-fed rats. Fasting equalized these levels. Trypsin and amylase tended to be lower, and chymotrypsin was significantly higher in the intestinal tracts of raw soy flour-fed rats than in the group fed heated soy flour; the greatest differences were found in the ileum. Trypsin and chymotrypsin levels in the feces were higher in the group fed raw soy flour than in the group fed heated soy flour. Amylase in the feces of the raw soy flour-fed rats was higher at the beginning of the experiment and dropped sharply to be even lower than in the heated soy flour-fed rats at days 13 to 14 of the experiment. It was concluded that measuring the enzymic levels in the feces is a very sensitive method for determining whether a test diet induces hypersecretion of digestive enzymes in rats. This method can be used from the start of feeding the experimental diet. As the animal need not be killed, the effect of the test diet upon enzymic secretion can be studied as a function of time, and it might be suitable to studies with large animals.

The relationship between water intake and water concentration in the body and in the gastrointestinal contents was studied in meat-type chickens fed either intermittently or ad libitum, as controls. In experiment 1, male broilers were reared from 12 to 33 d of age and were fed every second day or ad libitum. The water consumption of the intermittently-fed birds on days of food removal was 31% of the consumption of the control group. On days of food restoration their water consumption exceeded that of the controls, by 27%. No significant differences in water:food ratios were found between birds fed intermittently or the controls on days of food restoration. The restricted birds had a lower fat and a higher protein concentration in the body. No relationship was found between water:food ratio and body composition. In experiment 2, birds were kept on the same feeding regimes from 12 to 46 d of age. The water content of the pancreas increased after food restoration compared with ad libitum feeding or food deprivation. The amount of water in the gastrointestinal contents increased progressively from crop to ileum. The feeding regimens had no effect on the water content of the intestine.

1. The comparative effects of raw soya beans on food intake, growth, digestive organ weight, and enzyme activities in goslings and chicks were studied.2. Goslings were more affected than chicks by the ingestion of a raw soya-bean diet (RSD) in the following ways: reduction in food intake and growth rate; increase in relative weight of the digestive organs; reduction in specific activities of lipase (EC 3.1.1.3), amylase (EC 3.2.1.1) and chymotrypsin (EC 3.4.4.5) in the pancreas (not affected in chicks); greater inhibition of trypsin (EC 3.4.4.4), chymotrypsin and amylase in the intestinal contents of goslings than of chicks.3. Addition of methionine to the RSD improved food intake and growth rate more in goslings than in chicks.4. The interrelationships between enzyme activities, food passage rate, nutrient absorption and food intake regulation are discussed.

Publisher Summary To explain metabolic differences between fat and lean lines of chickens, most studies have focused on lipid turnover. However, there may be other correlated responses to selection for high or low abdominal fat, which may contribute to the understanding of the differences in adiposity between the lines; the gastrointestinal tract may be one of them. The physical texture of food and supplementation of the diet with antibiotics affect the weight of the digestive organs and the thickness of the intestinal wall. Concurrently, an improved energy retention and increased adiposity may occur. This chapter also presents a study where the relative weight of the digestive organs, the length of the small intestine, and its weight-length ratio were determined in lines of chickens selected for high or low abdominal fat. The chapter also describes the activities of digestive enzymes in the pancreas and intestinal contents.

We delineated in rats, the relationship between trypsin inhibitory activity in the urine and the nephrotoxic effects of gentamicin, eg, proteinuria and deterioration of glomerular filtration rate (GFR), measured by creatinine clearance. Gentamicin, 70 mg/kg per day, was injected intraperitoneally for 6-10 successive days. Serum and urine gentamicin levels were determined by a microbiological test. Trypsin inhibitory activity was assayed by the casein digestion method. The results showed a steady increase in urinary trypsin inhibitory activity starting from the fourth injection day. The increased levels of urinary trypsin inhibitory activity were associated with increased levels of urinary gentamicin excretion (r = 0.36, p less than 0.02, n = 50 after the fourth injection day), and were significantly higher than in control groups (p less than 0.001). The urinary trypsin inhibitory activity was inversely correlated with the GFR (r = -0.45, p less than 0.01, after the second injection day). The serum trypsin inhibitory activity remained unchanged throughout the study period in all groups. These data suggest that increased urinary trypsin inhibitory activity may be involved in the pathogenesis of gentamicin-induced nephrotoxicity.

1. Protein synthesis was estimated in vivo in breast (superficial pectoral) and tibia (gastrocnemius) muscles, liver, kidney, pancreas, crop, duodenum, jejunum and ileum, using L-[U-14C]lysine injection. The effect on incorporation of [14C]lysine 1 and 2 h after injection was examined in five chickens adapted or not adapted to intermittent feeding.2. Incorporation of [14C]lysine into tissue decreased in magnitude in the following descending order: pancreas > jejunum, duodenum > ileum, crop, liver > kidney > tibia, breast muscle and blood plasma.3. The incorporation of [14C]lysine into muscle protein was higher in chicks after 24 h of refeeding than after 24 h of food deprivation. These differences were higher in adapted than in non-adapted birds. On days of refeeding the rate of incorporation exceeded that found in chickens fed ad lib.4. Bound 14C from lysine in the intestinal segments was less than in control birds after food deprivation and greater after refeeding in non-adapted chicks only.5. A negative relation was observed between bound and free 14C in muscles and in other tissues.6. Short- and long-term adaptations to feeding regimens are discussed.

1. Amylase (EC 3.2.1.1) activity found in the intestinal tract of chicks posterior to the stomach is of endogenous origin, as amylase in the food is inactivated by the low pH in the stomachs.2. Ingestion of raw soya-bean diet (RSD) or of heated soya-bean diet (HSD) supplemented with trypsin inhibitors induced higher amylase activities in the lower part of the small intestine and caecum as compared with HSD.3. Ingestion of RSD after ligation at the end of the duodenum, end of the ileum or one of the caeca, or injection of soya-bean trypsin inhibitor into a ligated caecum, indicated that there is no amylase synthesis by the intestinal tract cells or microflora as a response to the presence of RSD or trypsin inhibitors.4. It seems that amylase found in the digestive tract of the chick is of pancreatic origin and that RSD or trypsin inhibitors induce higher pancreatic amylase secretion than HSD which (the additional amylase) accumulates mainly in the caeca.

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