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Dietary energy manipulation on fat deposition and metabolism in broilersZhong, Cheng 07 December 1990 (has links)
The objective of this work was to define the effects of
dietary energy intake on broiler fat deposition and
metabolism. Fatty broilers are one of the major problems in
the broiler industry.
The effects of changing calorie to protein (Cal/Pr)
ratios, and the addition of cellulose or dried distiller's byproduct
(DDBP) in the diet, on abdominal fat deposition, liver
lipogenesis and glucose oxidation and broiler performance
indicated that the mean body weight of broilers fed narrower
Cal/Pr ratio diets (124 and 143 for starter and grower,
respectively) were lower (P<.01) than broilers fed diets with
mid-Cal/Pr ratios (138 and 160) and wide Cal/Pr ratios (147
and 171). Feed conversion was better (P<.01) for broilers fed
the diet with wide Cal/Pr ratio than the broilers fed the diet
with narrow Cal/Pr ratio. Abdominal fat deposition increased
(P<.001) with wide Cal/Pr ratio than narrow Cal/Pr ratio. No
significant differences were found in in vitro liver
lipogenesis and glucose oxidation when Cal/Pr ratio was
widened. Mean body weight, feed conversion and abdominal fat
levels of broilers fed 5% cellulose or 10% DDBP diets were not
different when compared to broilers fed diets with the same
Cal/Pr ratio without these two feed ingredients.
The time-course of the deposition of abdominal fat
fitted a negative exponential growth curve. The data also
indicated that the highest potential for abdominal fat
deposition was during the first two weeks of age. When the
feed intakes of broilers were restricted for a 6 day period
beginning at 1, 2, 3 and 4 weeks of age, the feed efficiencies
of all the restricted broilers were significantly improved
compared with broilers fed ad libitum. No significant
differences were observed in mean body weight between the
different treatments. The percentage of abdominal fat in
broilers restricted-fed starting either at 1 or 2 weeks old
for a 6-day period were lower (P<.05) than broilers fed ad
libitum. Feed restriction from days 7 to 12 reduced the
adipocyte size but not the number. Feed restriction decreased
(P<.05) lipogenesis at 2 and 8 weeks of age. No significant
effects were found in lipolysis between the restricted and ad
libitum-fed broilers. These studies demonstrate that early
feed restriction (days 7 to 12) reduced abdominal fat
deposition which is attributed to the reduction in the
adipocyte size. Smaller size adipocyte resulted from
decreased activity of lipogenesis. / Graduation date: 1991
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Actual and predicted performance of broiler chickensVan Niekerk, S. J. (Sarel Johannes) 03 1900 (has links)
Assignment (MPhil)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The aim of this study was to evaluate the performance and profitability of different dietary specifications for
broiler chickens slaughtered at 35 days of age. Two trials were performed to evaluate different production
parameters. The results of these trials were compared to the predicted results of the EFG broiler model. No
carcass data were available for the two trials mentioned above. Therefore, in order to evaluate the accuracy
of the broiler model when predicting carcass characteristics, two published data sets (Leeson et al., 1996a)
were used. Predicted and actual values were compared, evaluated and discussed.
Two broiler trials were performed. In Trial One the amino acid density decreased throughout the range of
three treatments from prestarter to finisher diets. In Trial Two the amino acid density decreased only in the
four finisher diets. The main difference between predicted and actual results was the response to body
weight. The model predicted a steady increase in feed intake to compensate for the lower dietary
specifications while body weight did not change significantly. This increase in feed intake seems to be
enough to maintain body weight. Trial birds also increased their feed intake as dietary amino acid density
decreased, but this compensation seemed to be too low to maintain body weight compared to the control diet.
The birds may find it easier to compensate when they have time to adapt to the specification.
There is evidence in the literature that birds need seven days to adapt their feed intake to a lower feed
specification (Leeson et al., 1996a). It can be speculated that the trial birds started to loose body weight due
to a lower amino acid intake in this period. The model seems to adapt feed intake immediately after a
change in diet specification.
The simulation on literature data lead to the following conclusions:
1) Broilers posses the capacity to increase their feed intake with at least 65% should finisher diets with
lower amino acid and energy concentrations be supplied. If only the energy concentration of finisher
diets were decreased, the increase in feed intake will be around 30%. (see Table 16 and 23)
2) The accurate prediction of feed intake from the given dietary specification has a major influence on
the accuracy of the prediction of broiler performance.
3) Amino acid density and DLys:ME ratio plays a significant role in the control and prediction of feed
intake.
The EFG broiler model is based on sound scientific principles. The model is comprehensive and can be
used for a wide range of environmental and management conditions as well as dietary conditions. The
nutritionist can use the model with confidence to assist in practical feed formulation. The actual strength of
the model lies in the time and money being saved compared to practical trials. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om die prestasie en winsgewendheid van braaikuikens te bepaal wanneer voere
met verskillende digthede tot op 35 dae gevoer word. Twee eksperimente is uitgevoer om produksieresultate
te evalueer. Die resultate van hierdie eksperimente is met die voorspelde waardes uit die EFG
simulasie-model vergelyk. Aangesien geen karkasdata vir bogenoemde eksperimente beskikbaar was nie, is
twee gepubliseerde datastelle gebruik om hierdie deel van die model te evalueer (Leeson et al., 1996a).
Twee braaikuiken eksperimente is uitgevoer. Eksperiment Een het uit drie behandelings bestaan waarvan die
aminosuur-konsentrasie vanaf dag een tussen behandelings verskil het. In Eksperiment Twee het die
aminosuur-konsentrasie net in die vier afrondingsdiëte verskil. Liggaamsmassa op 35 dae het die grooste
verskil tussen voorspelde- en werklike waardes getoon. Beide voorspelde en werklike innames het in albei
eksperimente verhoog soos wat aminosuur-konsentrasie afgeneem het. Voorspelde liggaamsmassa het egter
konstant gebly terwyl werklike data 'n afname in liggaamsmassa getoon het. Dit bleik dat die voorspelde
toename in innames voldoende was om massa te onderhou terwyl die voëls in werklikheid nie genoeg
gekompenseer het nie. Leeson et al., 1996a het tot die gevolgtrekking gekom dat braaikuikens minstens
sewe dae benodig om hul voeriname by 'n nuwe spesifikasie aan te pas. So 'n stadige aanpassing kan
daartoe lei dat energie- en aminosuur-inname daal indien 'n dieet met laer spesifikasie gevoer. Dit sal
daartoe lei dat die kuikens liggaamsmassa verloor.
Uit die literatuur simulasies is die volgende afleidings gemaak:
1) Braaikuikens besit die vermoeë om voerinname in die afrondingstyd met minstens 65% te verhoog
indien 'n afrondingvoer met laer amiosuur- asook energiekonsentrasie gevoer word. Indien net die
energiekonsentrasie verlaag word, sal die inname met sowat 30% verhoog.
2) Die akkurate voorspelling van inname is krities vir die akkurate voorspelling van produksieparameters.
3) Aminosuur-digtheid en DLys:ME speel 'n belangrike rol in die beheer en voorspelling van
voerinname by braaikuikens.
Die EFG braaikuikenmodel is op suiwer wetenskaplike beginsels geskoei. Die model is omvattend en kan
vir 'n wye reeks van omgewings- en bestuurstoestande asook dieet-spesifikasies gebruik word. Die
voedingkundige kan die model met vertroue gebruik om met praktiese voerformulering by te staan. Die
model kan die formuleerder baie tyd spaar aangesien praktiese eksperimente ingeperk kan word.
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Possible involvment of carbohydrate and lipid metabolism in the incidence of sudden death syndrome in broiler chickensAttamangkune, Seksom 29 October 1992 (has links)
Seven experiments were carried out to investigate the
involvement of carbohydrate and lipid metabolism on the
incidence of Sudden Death Syndrome (SDS) in broiler
chickens.
Hepatic arachidonate level decreased after 1 h postmortem.
The decreased level of hepatic arachidonate
previously observed in SDS birds was, therefore, associated
with the post-mortem aging.
Broiler chickens fed diets high in glucose monohydrate
(cerelose) were more susceptible to SDS mortality than
broilers fed diets high in corn starch or corn-soy. Feeding
broilers a high cerelose diet increased the levels of plasma
calcium, total protein, triacylglycerol, and uric acid
compared to broilers fed corn starch diet. Broilers fed
cerelose diet also showed the higher incidence of leg
abnormality than broilers fed corn starch or corn-soy diets.
Daily intraperitoneal injection with 0.25 ml of L(+)
lactic acid solution (100 mg lactic acid/ml) to broilers
over a 7-d period failed to reproduce the SDS incidence,
whereas intravenous injection of 40% lactic acid solution
(200 mg lactic acid/kg body weight) resulted in 100%
incidence of SDS-type mortality. No SDS-type mortality was
observed with the intravenous injection of 40% sodium
lactate solution (200 mg sodium lactate/kg body weight).
Disturbance of physiological acid-base balance might be a
factor in the SDS-type mortality.
Suboptimal thiamin level in broilers fed cerelose diets
was observed. Thiamin supplementation to cerelose diet
improved the thiamin status of the broilers. Mortality due
to SDS was decreased when thiamin hydrochloride was
supplemented to cerelose diet at the level of 0.6 and 2.8 mg
thiamin hydrochloride/kg diet, respectively. Thiamin
supplementation, however, did not change the liver pyruvate
dehydrogenase activity and the proportion of pyruvate
dehydrogenase in the active form.
Disturbance of acid-base balance was postulated to be
associated with the incidence of SDS. Other genetic,
nutritional, and environmental factors are likely to modify
the incidence by affecting the acid-base status of the
chicken. / Graduation date: 1993
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Nutritional implications in broilers fed single or a combination of feed ingredients during feed shortages in the Republic of YemenModhish, Abdulmalek M. 07 February 1991 (has links)
Most of the feed required for poultry production in
the Republic of Yemen is imported from Europe. Sometimes,
feed shipments arrive later due to lack of hard currencies
to pay for the feed or to pay the freight charges. Yemeni
broiler producers in such cases feed their birds a single
feed ingredient or a mixture of ingredients until feed
arrives.
Five experiments were conducted to simulate feed
shortage situations. As a single ingredient, barley is the
grain of choice in case of feed shortages. When broilers
were switched to corn-soy after the single ingredient
diets, the compensatory growth was correlated with the
severity of reduced growth.
Feeding diets with a mixture of faba beans + sorghum
grain with or without 7% herring meal for 21 and 49 days,
respectively, reduced significantly (P<.05) mean body
weight, total feed consumed, feed efficiency and apparent
protein efficiency ratio.
Feeding wheat bran at 10-15% with adjustment for protein
and energy from day-old to 49 days of age resulted in
significantly (P<.05) improved mean body weights compared to
the control broilers. Increasing wheat bran levels further
gradually reduced body weight and feed consumption.
Abdominal fat increased significantly (P<.05) when wheat
bran inclusion exceeded 20 percent.
Cellulase supplementation did not show any significant
interaction with wheat bran in all the measured parameters.
Supplementing protease to wheat bran diets significantly
(P<.05) reduced mean body weight, feed consumption and the
feed conversion in broilers. These dramatic effects were
proportionally ameliorated by increasing the levels of wheat
bran. / Graduation date: 1991
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Natural development and dietary regulation of body and intestinal growth in broiler chickensIji, Paul Ade. January 1998 (has links) (PDF)
Corrigenda inserted behind title page. Bibliography: leaves 275-306. The pattern of body growth and intestinal development of an Australian strain of broiler chicken, the Steggles x Ross (F1) in response to different diets was studied. Five experiments were designed to examine the pattern of growth and mechanisms involved. In four other experiments, the mechanisms underlying the gross response of the broiler chicks to dietary ingredients, anti-nutritive factors and growth enhancers were examined. Results indicated that a rapid development of the small intestine preceded significant overall body growth. Body growth would, however, depend more on the various physiological events such as those related to mucosal growth and renewal, digestive enzyme function, and nutrient transport. Some of the differences observed in productivity of broiler chickens on different diets were traced to events at the intestinal level.
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The effect of intermittent feeding programs and genetic line on adiposity in broiler chickens /Lefebvre, Francois L. January 1987 (has links)
No description available.
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Effects of flaxseed processing on nutrient utilization, fatty acid deposition, performance response of broilers, and on flaxseed hydrogen cyanide contentShen, Yingran, 1964- January 2000 (has links)
A series of experiments were carved out to study the effect of dietary enzyme inclusion or flaxseed processing on feeding value of flaxseed for broilers. The feed enzymes tested containing xylanase activities failed to produce any positive performance response when used in a 10% flaxseed diet with manufacturer recommended dosage for broilers (D 1 to 21). / Autoclaving of flaxseed at 16.5 kg/cm2 and 120°C for 15 min slightly improved the performance of young broilers fed a 10% flaxseed diet. This improvement was not observed at lower temperature and shorter period of autoclaving, but was magnified at higher flaxseed level. Autoclaving, microwave roasting, pelleting significantly (P < 0.05) reduced HCN content in flaxseed. The greatest HCN reduction was observed with repeated pelleting (54.9%) and microwave roasting (83.2%), from its 377 mg/kg of raw flaxseed. / When tested with roosters, flaxseed processing effectively increased ME values, dry matter, and ether extract utilization. The raw flaxseed TME and TMEn of 3343 and 3225 kcal/kg, respectively, was significantly (P < 0.01) increased by repeated pelleting (44%) and microwave roasting (32%). It was the result of significant improvement (P < 0.05) of EE utilization by the relevant processing. These improvements had a similar effect on total FA and linolenic acid utilization. / The processing method and flaxseed level had a very significant effect on deposition of total T-3 FAs in breast and thigh meat (P < 0.001) of 40 days old broilers. The highest level of T-3 FAs in muscle lipids of 23.04% and 26.46% for breast and thigh, respectively, was achieved with the highest flaxseed level (14% in days 1 to 21 days, and 17% in days 22--40) and pellet-then-mash processing, which lead to low T-6/T-3 ratios of 0.81 and 0.80 in breast and thigh muscle lipid, respectively. The proper flaxseed processing allowed more flaxseed (up to 12%) to be included in broiler diets without obvious growth depression, while achieving the higher desired T-3 FAs deposition in meat.
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Natural development and dietary regulation of body and intestinal growth in broiler chickens / Paul Ade Iji.Iji, Paul Ade January 1998 (has links)
Corrigenda inserted behind title page. / Bibliography: leaves 275-306. / xxxv, 306 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The pattern of body growth and intestinal development of an Australian strain of broiler chicken, the Steggles x Ross (F1) in response to different diets was studied. Five experiments were designed to examine the pattern of growth and mechanisms involved. In four other experiments, the mechanisms underlying the gross response of the broiler chicks to dietary ingredients, anti-nutritive factors and growth enhancers were examined. Results indicated that a rapid development of the small intestine preceded significant overall body growth. Body growth would, however, depend more on the various physiological events such as those related to mucosal growth and renewal, digestive enzyme function, and nutrient transport. Some of the differences observed in productivity of broiler chickens on different diets were traced to events at the intestinal level. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1999
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Effects of flaxseed processing on nutrient utilization, fatty acid deposition, performance response of broilers, and on flaxseed hydrogen cyanide contentShen, Yingran, 1964- January 2000 (has links)
No description available.
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The effect of intermittent feeding programs and genetic line on adiposity in broiler chickens /Lefebvre, Francois L. January 1987 (has links)
No description available.
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