Metabolic and anatomical adaptations of heavy-bodied chicks to intermittent feeding. 2. Pancreatic digestive enzymes.

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.     

Bioavailability of threonine in soybean meal for rats and chicks.

The bioavailability of threonine in soybean meal and the effects of the excess amino acids in soybean meal on the estimate were measured using rats and chicks in slope-ratio assays. In Exp. 1, a corn-based diet containing .23% threonine was supplemented with 0 to 45% L-threonine in .05% increments. The growth rate of weanling rats fed these diets increased quadratically (P less than .001) with L-threonine addition, the increase being essentially linear up to the .10% addition. In Exp. 2, the basal diet was supplemented with 0, .025, .050, .075, or 100% threonine from L-threonine, simulated soybean meal (a mixture of crystalline amino acids with a pattern designed to simulate soybean meal), or soybean meal. Regressions of partitioned weight gain and body N gain of rats vs supplemental threonine intake were calculated for each source using multiple regression. Slope ratios (soybean meal:L-threonine) were .91 for weight gain and .92 for body N gain. The additional amino acids in simulated soybean meal did not affect the estimate. For Exp. 3, a corn-soybean meal-based diet containing .48% threonine was supplemented with 0 to 60% L-threonine in .10% increments. The growth rate of broiler chicks fed the diets increased quadratically (P less than .001) with L-threonine addition. The increase was essentially linear up to the .10% addition. In Exp. 4, the basal diet was supplemented as in Exp. 2. Regressions of partitioned weight gain of chicks vs supplemental threonine intake were calculated for each source. The slope ratio for soybean meal:L-threonine was 1.03; however, the model exhibited fundamental invalidity and therefore the estimate should be interpreted with caution. The additional amino acids in the simulated soybean meal did not affect the value.     

Humoral, hormonal and behavioral correlates of feeding in ponies: the effects of meal frequency

The effect of meal frequency on body fluid, glucose, triiodothyronine (T3), heart rate and behavior was measured in 10 ponies. A simple reversal design was used in which each pony received one meal/day (1X) for 2 wk and six meals/day (6X) for 2 wk. The total intake/day was held constant. Feeding was followed by a rise in plasma levels of glucose, T3, protein and osmolality. One large meal was followed by significantly greater changes in all of the variables than was a meal one-sixth the size. Plasma T3 rose from 41 +/- 5 (SE) ng/liter before feeding to 43 +/- 5 ng/liter following a small meal, but rose significantly higher, from 39 +/- 4 to 60 +/- 10 ng/liter, following a large meal. Glucose rose from 84 +/- 3 to 109 +/- 7 mg/dl following a small meal and rose significantly higher, from 83 +/- 3 to 154 +/- 11 mg/dl, after a large meal. Plasma protein rose from 6.55 +/- .14 to 6.62 +/- .16 g/dl following a small meal and from 6.45 +/- .14 to 6.99 +/- .11 g/dl following a large meal. Osmolality rose from 227 +/- 1 mosmol/liter before to 279 +/- 1 mosmol/liter following a small meal and significantly higher from 278 +/- 2 to 285 +/- 1 mosnol/liter following a large meal. Heart rate rose from 42 beats/min in the absence of feed to 50 beats/min when food was visible to the ponies and did not rise higher when eating began. There were no significant differences in the cardiac response to one large meal and that to a small meal.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bioavailability to chicks of selenium in barley, oats and meat meal

Day-old White Leghorn chicks deficient in selenium (Se) were fed a low Se basal diet (containing adequate level of vitamin E) for 2 weeks depletion period before they were given the experimental diets containing different levels of Se for 4 weeks. Dietary treatments contained 0.03, 0.06, 0.09 or 0.12 mg Se/kg as sodium selenite, barley, oats, meat meal or their extracted counterparts. Plasma GSH-Px activity was observed at weekly intervals, while the Se concentration of plasma and liver were determined at the end of the study. The biological availability of Se in the test ingredients was measured by the induction of plasma GSH-Px activity. In comparison to sodium selenite (100 %) it was: 77 % for barley, 80 % for extracted barley, 37 % for oats, 62 % for extracted oats, 20 % for meat meal, and 26 % for extracted meat meal. Using the retention of Se in plasma as a criterion, the following biological availability of Se was observed: barley 151 %; extracted barley 102 %; oats 90 %; extracted oats 107 %; meat meal 40 %; and extracted meat meal 47 %. Similarly, the efficiency of the test ingredients in increasing the Se concentration in liver was: barley 82 %; extracted barley 90 %; oats 67 %; extracted oats 98 %; meat meal 26 %; and extracted meat meal 31 %. The greater biopotency of the natural Se sources for increasing the Se concentration of the chick tissues than for inducing the plasma GSH-Px activity in comparison to sodium selenite, indicated that proportionally less amounts of the Se retained in the chick plasma from the natural sources were incorporated into the metabolic active form of Se, i.e., GSH-Px. Therefore, the plasma GSH-Px activity was suggested as the more reliable criterion to be used for the evaluation of the bioavailability of Se.     

Benefits to foals of feeding soybean meal to lactating broodmares

In order to test the hypothesis that an improvement in the quality of the dietary protein fed lactating mares would improve the growth of their nursling foals, Thoroughbred mares were fed approximately isonitrogenous diets differing slightly in their amino acid compositions during the last 2 weeks of gestation and the first 7 weeks of lactation. The differences in the diets resulted from the substitution of a portion of the complete pelleted feed with soybean meal (SBM). The crude protein content of mares' milk was significantly increased by SBM substitution during the first 5 weeks of lactation. However, SBM did not prevent the gradual decline in protein content typical of mares' milk during the course of lactation. The relative amino acid composition of mares' milk was not changed by SBM substitution, suggesting that more growth-limiting amino acids were provided to the foals suckling from SBM-supplemented mares. The plasma concentrations of lysine, methionine, leucine, phenylalanine, histidine and valine were significantly greater in the foals of SBM-supplemented mares. Those foals grew in withers height about 10% more rapidly during their first 7 weeks of life. These findings indicate that the growth of nursing foals is responsive to the amino acid composition of their dams' diets.     

The effect of feeding Hydrogel-95 to emu chicks at hatch

Very little research has been conducted on emu (Dromaius novaehollandiae) in comparison to other types of poultry. Much of the information that is available to producers is very conflicting. Feed restriction for the emu chick for the first 4 d of life is a common practice among the emu industry; however, scientific research has not supported this practice. To the best of our knowledge, the effects of hydration supplements have not been investigated in the emu. Therefore, weights were recorded on emus fed Hydrogel-95 and were compared with emus that were not fed any supplements to determine if the supplement had any effect on the growth parameters of emu chicks. From these 2 field trials, we conclude that feeding Hydrogel-95 significantly decreases weight loss in emu chicks during the first week of life.     

双低油菜籽粕的饲用价值

1　双低油菜籽粕的加工双低油菜籽粕是榨油的副产品 ,一般系通过溶剂提取油脂后而生成的。高含油量的双低油菜籽在加工时 ,籽中水分含量应保持在 6 %～ 1 0 %之间 ,蒸煮温度必需尽可能迅速增加到 80～ 90℃ ,不要超过 1 1 0℃ ,否则不仅使油菜籽中的蛋白质受损 ,而且温度会分解其中的配糖体糖苷酶。一般加热到 1 0 3～ 1 0 7℃ ,通过蒸汽和高温的作用 ,芥子酵素即完全失去了活性。2　双低油菜籽粕的营养价值双低油菜籽粕蛋白质含量高 ,氨基酸平衡 ,适用于所有家畜饲料。双低油菜籽粕的优点 ,是硫代葡萄糖苷含量低 ,而一般油菜籽粕硫代葡萄糖…     

The effect of feeding hemp seed meal to laying hens

Seed of the hemp cultivar Unika-b was cold-pressed to obtain hemp seed meal (HSM) containing 307 g/kg crude protein and 164 g/kg ether extract (60 g/kg linoleic acid, 120 g/kg alpha-linolenic acid, 160 g/kg oleic acid, lesser amounts of palmitic, stearic, and gamma-linolenic acids). For 4 weeks, 102 43-week-old DeKalb Sigma hens were fed on isonitrogenous and isoenergetic diets containing 0, 50, 100 or 200 g/kg HSM. Eggs were collected for fatty acid analysis during the fourth week of feeding these diets. No significant differences were found between feed treatments for egg production, feed consumption, feed efficiency, body weight change or egg quality. Increasing dietary inclusion of HSM produced eggs with lower concentrations of palmitic acid and higher concentrations of linoleic and alpha-linolenic acids.     

Influence of rapeseed meal on productivity and health of broiler chicks

Research was focussed on investigating the influence of different quantities (0, 10, 20 and 30%) of rapeseed meal (RM), 00-cultivar Silvia on production results, as well as on the morphological and pathohistological changes in the internal organs of chicks during the course of the experiment, measured on the 21st and 42nd days of the 42-day experiment. The experiment involved 120 chicks divided into four groups: a control group (C) and three experimental groups (E1-3). It was found that chicks in Groups C, E1 and E2 realised significantly (P < 0.05) higher gains than those in Group E3, both after the test period and at the end of the experiment. No significant differences with regard to feed conversion were found between groups of chicks. Throughout the experiment chicks in Groups E1-3 were found to have a significantly (P < 0.05) heavier liver. Compared to Groups E1-3, Group C chicks had a significantly (P < 0.05) heavier gizzard after 21 days, but following the finisher diet Group E3 had a significantly (P < 0.05) lighter gizzard. Compared with birds in Group C, those in Groups E2-3 had significantly heavier (P < 0.05) unevacuated intestines when fed the starter diet, and those in Groups E1-2 showed a similar result when fed the finisher diet. Chicks in Group E3 had a significantly lower grill weight than those in Groups C, E1 and E2, both in the first half of the experiment and at the end. The starter diet did not result in any differences in the quantity of abdominal fat among groups, but following the finisher diet Groups E2-3 showed significantly less abdominal fat in comparison to Groups C and E1 (P < 0.05). Group C showed a significantly higher carcass yield than Groups E1-3 (P < 0.05) in the first half of the experiment and at the end. Groups E1-3 manifested a slight to medium hypertrophy of thyroid epithelial tissue as well as slight thymus hypertrophy and slight atrophy of the cloacal bursa follicles.     

Metabolic and economic efficiency of broiler chicks as affected by dietary protein levels.

1. An experiment was designed to determine if decreasing excess amino acids in the diets of chicks would improve metabolic efficiency, as indicated by growth rate and food efficiency. 2. Semi-purified diets were fed with crude protein contents of 180 or 230 g/kg. The sources of protein were maize gluten meal, groundnut meal, sesame meal or soya-bean meal. Crystalline amino acids were supplemented to meet all amino acid requirements. 3. The dietary crude protein content had no statistically significant effect on weight gain or food consumption. The probability that the higher protein improved gain per food was 0.06. Protein source had a significant effect on all the responses measured. 4. Decreased concentrations of excess amino acids in chick diets had no favourable effects on weight gain or gain per food. Lower protein diets were more expensive per unit of gain.     

Effect of feeding cassava (Manihot esculenta Crantz) root meal on growth performance,hydrocyanide intake and haematological parameters of broiler chicks

The effect of feeding cassava root meal on growth performance, hydrocyanide intake, haematological indices and serum thiocyanate concentration of broiler chicks was investigated using 300-day-old male broilers. There were five dietary treatments arranged in a 2?×?2?+?1 factorial arrangement of two processing methods of cassava root (peeled and unpeeled) included at two levels (100 and 200 g/kg) plus a control diet (maize-based diet, containing no cassava root). Each treatment was replicated six times with ten birds per replicate. The feeding trial lasted for 28 days. Control-fed birds had the highest overall (P?P?P?P?P?P?P?P?P?P?P?P?P?P?相似文献   

Response of broiler chicks to non-steam- or steam-pelleted diets containing raw,full-fat soybean meal

The objective of this study was to evaluate the effects of steam pelleting of diets containing graded levels of raw, full-fat soybean meal (RSBM) on the chemical properties and feeding values of the diets. Samples of diets with steam- or non-steam-pelleted as well as the mash containing varying levels of RSBM were subjected to detailed chemical analysis. As a result of this study, trypsin inhibitor (TI) concentrations in the diets ranged between 4,153 and 10,484 TIU/g. Amino acid concentrations were higher in the non-steam-pelleted and mash diets than the steam-pelleted diets. A 4 × 2 factorial arrangement (RSBM: zero, 10, 20 or 30%, equivalent to zero, 30, 60, and 90 g/kg of diet, respectively, and non-steam- or steam-pelleted diets) was used while feeding broiler chicks (zero to 14 d of age). Each treatment was replicated 6 times with 8 birds per replicate. As a result of this study, there was no difference (P > 0.05) in mortality of birds among the groups. Feed intake (FI) (P < 0.05) and body weight gain (BWG) (P < 0.001) decreased with increasing levels of RSBM. Birds fed on steam-pelleted diets gained less (P < 0.001) weight than birds on the non-steam-pelleted diets, but the FI was not significantly (P > 0.05) different. The FCR was negatively affected (P < 0.05) by increasing levels of RSBM. There was no interaction effect between RSBM and pelleting method on the FI, BWG, or FCR of birds. The weight of the pancreas (P < 0.001) and duodenum (P < 0.01) increased with a rise in the level of RSBM in diets. Non-steam pelleting increased (P < 0.05) the pancreatic protein content, whereas the activity of chymotrypsin was reduced (P < 0.01) when the RSBM level was increased. Birds fed with RSBM-free diets had thicker muscle, longer villi, wider villus surface area, and higher villus to crypt depth ratios than birds on the other diets, but these differences were not significant. It can be concluded that steam pelleting of diets containing RSBM is inadequate to reduce the adverse impact of TI on chicks.     

Processing and feeding value of mango seed kernel for starting chicks

1. De‐oiled mango seed kernel meal (MSK) was found to contain tannins, cyanogenetic glucosides and traces of alkaloids and gums. Treating with 0#lb3 m HCl followed by Ca(OH)₂ suspension removed all of the tannins and much of the cyanogenetic glucosides and gums.

2. Substitution of 141 g MSK/kg diet for maize in a practical diet did not affect performance of chicks, whereas adverse effects occurred with 282 g or more/kg.

3. Processing of MSK improved performance but it was still not equivalent to that achieved with maize.

4. Increasing the protein content of the diet containing processed MSK from 207 to 226 g/kg did not improve performance and replacing ground nut meal with soyabean meal depressed performance.