Metabolism and Nutrition, Amino Acids
259 Bioavailability of methionine sources. Letícia Soares*1,
Fernando Andres Prado Antayhua1, Nilva Kazue Sakomura1, Ariane
Helmbrecht2, and Nei André Arruda Barbosa3, 1Universidade
Estadual Paulista, Jaboticabal, São Paulo, Brazil, 2Evonik Industries, Hanau, Wolfgang, Germany, 3Evonik Industries, São Paulo, São
Paulo, Brazil.
The importance of the biological efficacy (BE) of methionine sources
has been the subject of debate among nutritionists, because its precise estimation can optimize growth and economic parameters of the
animals. This study aimed to determine the bioavailability 2-hydroxy4methylthio-butanoic acid 84% (MHA-Ca) in relation to dl-Methionine
(dl-Met). Two trials were conducted, the first from 1 to 21d and the
second from 22 to 42d, using 1890 birds in each trial. The animals were
distributed in a complete randomized block design with 9 treatments
and 7 replicates each, totalizing 63 pens each with 30 birds. The treatments consisted on a basal diet (Met+Cys deficient), and 4 levels of each
methionine source (dl-Met, MHA-Ca). Body weight gain (BWG), feed
intake, and feed conversion ratio (FCR) were measured at 21 and 42 d.
Furthermore, carcass yield (CY), breast yield (BY) and abdominal fat
(AF) was also evaluated at 42 d. By means of multi-exponential regression, the BE MHA-Ca was determined relative to dl-Met 99%. These
analyses were performed for the BWG and FCR for both growth stages,
while CY, BY and AF only for the latter phase. Data for the different
phases were regressed separately and are presented in Table 1.
Table 1 (Abstract 259). Bioefficacy for each variable for exponential regression analysis
BE dl-Met
(%)
Variable
Model
1 to 21 d
BWG
FCR
Y = 593.70 + 277.80 × (1 – e – (28.075 × DLM + 15.952 × MHA-Ca))
Y = 1.45 – 0.2154 × (1 – e – (16.218 × DLM + 10.956 × MHA-Ca))
BE MHA-Ca
(%)
100
100
IC
(%)
56.82
67.52
46–67
53–81
22 to 42 d
100
59.58
17–101
BWG
Y = 1833.1 + 279.6 × (1 – e – (11.132 × DLM + 6.632 × MHA-Ca))
FCR
Y = 1.844 + 0.247 × (1 – e – (9.878 × DLM + 6.452 × MHA-Ca))
100
65.32
48–82
CY
Y = 74.914 + 2.592 × (1 – e – (8.218 × DLM + 3.976 × MHA-Ca))
100
48.38
5–91
BY
Y = 23.508 + 5.460 × (1 – e – (5.546 × DLM + 3.131 × MHA-Ca))
100
56.47
29–84
AF
Y = 2.246 + 0.573 × (1 – e – (8.063 × DLM + 7.813 × MHA-Ca))
100
96.89
3–191
Significant differences in BE of MHA-Ca compared with dl-Met were apparent for productive variables of highest economic importance: FCR,
CY, and BY.
Key Words: methionine, bioefficacy, dl-methionine, MHA-Ca,
broiler
260 A comparison of equations to depict and predict nutritional kinetics. Runlian L. Wang*1,2, Rashed A. Alhotan2, Lynn
Billard2, and Gene M. Pesti2, 1Department of Animal science, Guangdong Ocean University, Zhanjiang, Guangdong, China, 2Departments
of Poultry Science and Statistics, The University of Georgia, Athens,
GA.
The objective of the study was to compare 9 different models for depicting nutritional response kinetics using lysine dose-response data from
53 experiments originating from 17 publications over the past 12 years.
The models compared were linear regression (LR), quadratic regression (QP), broken line with linear (BLL) or quadratic (BLQ) ascending
portions, saturation kinetics (SK), a 3-parameter logistic (Log 3), a
4-parameter logistic (Log 4), a sigmoidal (Robbins, Norton and Baker;
RNB 1) and an exponential (RNB 2) model. The workbook NRM.xls
(http://pubs.caes.uga.edu/caespubs/ES-pubs/RB440/RB-440.htm) was
chosen as the statistical framework to model weight gain responses
and the chi-squared value (Qm) statistics, coefficients of determination
(R2) and the sum of total residuals squared (SSR) were used as bases to
compare the models. All data sets could be best described by nonlinear
response effects. There was little difference in R2, SSR or Qm between
the models for most data sets. The highest average R2 was 87.45% for QP,
followed by 86.33% for Log 4 and 85.58% for the SK model.The lowest
88
SSR was for the Log 4 (1521.7), followed by RNB 1 and the SK models
(1551.8 and 1632.1, respectively). The lowest Qm was found for RNB1,
SK, BLL and QP models (1.61, 1.77, 1.91 and 1.91, respectively). If the
number of data sets best fit (or tied for best) by the models R2 values, the
RNB 1 model was superior for 17 data sets, followed by the QP (14),
SK (13), BLL and Log 4 (11), BLQ (10), Log 3 (2), LR and RNB 2(0).
There was no clear advantage to fitting any particular model to all the
data sets, while the LR and RNB 2 were the least well-fitting models
for nutritional response data. Most responses could be best described
by models with a smooth transition from ascending segment to plateau.
Key Words: broiler, lysine, requirement, model, comparison
261 Comparative efficacy of 2-hydroxy-4-methylthio-butanoic
acid (HMTBA) relative to dl-methionine for laying hens fed on
medium or low nutrient under ad libitum feeding regimen. Jian
M. Wan*, Xue M. Ding, Jian P. Wang, Shi P. Bai, Huan W. Peng, Yu
H. Luo, Zhuo W. Su, Yue Xuan, and Ke Y. Zhang, Animal Nutrition
Institute, Sichuan Agricultural University, Chengdu, Sichuan, China.
In practice, practical diets are usually used to compare dl-methionine
(DLM) with dl-2-hydroxy-4-methylthio-butanoic acid (HMTBA) in
field conditions. For this reason, this study using practical diets were
carried out to investigate the effect of relative efficacy of HMTBA for
laying hens provided with a medium or low nutrient level diet on egg
production and quality. A total of 1,500 Lohmann Layers (31-wk-old)
Poult. Sci. 95(E-Suppl. 1)
were assigned to 10 treatments in a completely randomized design, with
10 replicate per treatment and 15 hens per replicate. The efficacy of
HMTBA relative to DLM was set at 80, 84, and 88% (wt/wt), therefore
0, 0.118, 0.112, 0.107% of HMTBA and 0.094% of DLM were added
to a low nutrient level basal diet (AMEn 10.3 MJ/kg, Dig Lys 0.61%,
Dig Met 0.19%) and 0, 0.130, 0.124, 0.118% of HMTBA and 0.104%
of DLM were added to a medium nutrient level basal diet (AMEn 11.3
MJ/kg, Dig. Lys 0.67%, Dig. Met 0.22%). During the experiment period
(31 to 43 wk), hens were fed ad libitum. All data were analyzed using
the GLM procedures of SAS (SAS Institute Inc., Cary, NC) as a 2-way
ANOVA (2 dietary nutrient levels × 5 methionine supplementation
levels). Contrast statements were used to test the significance between
HMTBA and DLM within each dietary nutrient level. Egg production
rate, ADFI, egg weight, egg mass and feed conversion ratio significantly
declined due to methionine deficiency (P < 0.01). There was no difference (P > 0.05) between HMTBA treatment and DLM on egg production
and egg quality parameters (eggshell weight, eggshell thickness, eggshell
strength, yolk color, eggwhite height or Haugh unit) within each dietary
nutrient level. In conclusion, HMTBA supplementation (as efficacy
of 88% relative to DLM on weight basis) can be used as an effective
methionine source in field condition regardless of dietary nutrient level.
Key Words: laying hen, methionine, 2-hydroxy-4-methylthio-butanoic acid, egg quality
262 Evaluation of the tryptophan requirement of small-framed
first cycle laying hens. Jinlei Wen*1, Ariane Helmbrecht2, Michael
Elloit3, John E. Thomson2, and Michael E. Persia1, 1Virginia Tech,
Blacksburg, VA, 2Evonik, Kennesaw, GA, 3A&E Nutrition Services
LLC, Lancaster, PA.
Tryptophan is an essential amino acid, required for protein synthesis,
and several metabolic processes in laying hens. Although required, the
literature is mixed if tryptophan is considered the third or fourth limiting
amino acid for laying hens and research on the tryptophan requirement
in laying hens has been limited. The purpose of this experiment was to
evaluate the tryptophan requirement of first cycle laying hens from 41 to
60 wk of age. In total, 270 Hy-line W36 laying hens were randomly allocated to 6 treatments with 15 replicates of 3 birds for each experimental
unit. Hens were maintained 3 to a cage (72 sq in/bird) in a multi-teared
A-frame cage system within an environmentally controlled building.
Hens were provided a 16:8 light schedule and 70 to 80°F temperature
program. A tryptophan deficient basal diet was formulated with corn,
corn gluten meal and soybean meal with determined tryptophan, lysine
and crude protein concentration of 0.096, 0.873, and 15.0%, respectively.
Synthesized l-tryptophan was supplemented to the basal diet in 0.020%
increments to generate experimental diets containing 0.096, 0.116,
0.136, 0.156, 0.176, and 0.196% tryptophan respectively. Hens were
provided a controlled amount of feed daily resulting in approximately
95g/hen/d. The diet containing the lowest concentration of tryptophan
resulted in reduced egg production and was halted at 45 weeks due to
low performance with all other dietary treatments reaching the conclusion of the experiment at 60 weeks of age. Hen-housed egg production
(HHEP) and mortality were monitored daily. Eggs were collected on 2
continuous days each week for feed conversion ratio (FCR) calculations
and egg quality analysis. Single-slope broken line, multi-slope broken
line and quadratic regression were used to estimate tryptophan requirement based on HHEP of the remaining 5 dietary treatments. Based on
HHEP, optimum tryptophan requirement was 154.0, 142.8 and 193.7
mg/hen/d (single-slope broken line regression: Y = 80.86 + 0.4871(X
− 154.02), R2 = 0.85; multi-slope regression: Y = 3.127 + 0.5135X −
Poult. Sci. 95(E-Suppl. 1)
0.3997(X − 142.8), R2 = 0.85; quadratic regression: Y = −0.003046X2
+ 1.1802X − 32.33, R2 = 0.85).
Key Words: laying hen, tryptophan, egg production, first cycle
263 Effect of dietary leucine supplementation on growth and
muscle mass in broilers. Johanna O. Zeitz1, Behnam Saremi*2,
Stella C. Käding1, and Klaus Eder1, 1Justus-Liebig University
Giessen, Institute of Animal Nutrition and Nutritional Physiology,
Giessen, Hessen, Germany, 2Evonik Nutrition & Care GmbH, HanauWolfgang, Hessen, Germany.
Leucine can exert positive effects on body muscle mass by stimulating protein synthesis and/or reducing protein degradation as shown in
newborn animals and human patients. We aimed to evaluate effects of
Leu on growth and muscle mass in broilers. Male Cobb 500 broilers (n
= 240, 39 ± 3.3g) were allocated to 30 cages and 3 groups. Basal diets
(group L0) were corn-soybean meal-based and met Evonik (AMINOChick 2.0) requirements for Leu, Ile and Val during d 1–10, 11–21 and
22–35. Leu was supplemented to exceed requirements by 40% (group
L1) and 70% (group L2), and Ile and Val concentrations were increased
accordingly to keep Leu:Ile and Leu:Val ratios. After 10, 21 and 35 d,
body weight and feed intake were recorded, and 15 birds per group
were slaughtered and carcass and breast meat yields were recorded.
The data were analyzed by ANOVA with experimental group as fixed
effect. Body weights at d 35 (2,298 ± 150, 2,326 ± 168, and 2,251 ± 177
g for L0, L1, and L2) and daily gains did not differ between groups (P
> 0.1). Likewise, daily feed intake was similar in all groups during the
35 d-period (90.6 ± 4.4, 91.7 ± 3.2 and 91.7 ± 3.9 g/d for L0, L1, and
L2, P = 0.90), and during all 3 feeding phases (P > 0.1). The feed:gain
ratio was similar during the 35-d growth period (1.44, 1.43 and 1.45 in
L0, L1 and L2) (P = 0.56), and during d 1–10 (P = 0.30) and d 21–35
(P = 0.95). During d 10–21, the feed:gain ratio in group L1 was lower
(1.24 ± 0.03) compared with L0 (1.28 ± 0.02) and L2 (1.28 ± 0.03) (P =
0.024). After 10 d, carcass weights and dressing percentage were lower
in L2 compared with L1 and L0 (P < 0.05). At d 35, carcass weights were
higher (P < 0.1) in L1 (1,675 ± 101 g) compared with L2 (1594 ± 75g),
and L0 was intermediate (1,657 ± 32 g), however, dressing percentage
was similar in all groups (P = 0.80). Breast meat (% of carcass weight)
at d 35 was higher (P < 0.1) in L1 (28.6 ± 1.1%) than in L2 (26.3 ±
2.6%), and L0 (27.6 ± 2.1%) was intermediate. In conclusion, a positive
effect on growth and muscle mass due to moderate Leu supplementation
could be demonstrated.
Key Words: leucine, branched-chain amino acids, growth performance, muscle growth, chickens
264 Dietary methionine deficiency is associated with the bone
remodeling in meat-type chickens. Samuel E. Aggrey1, Marie C.
Milfort1, Romdhane Rekaya1, and Behnam Saremi*2, 1Poultry Science Department, University of Georgia, Athens, GA, 2Evonik Nutrition & Care GmbH, Hanau-Wolfgang, Hessen, Germany.
Methionine is a sulfur-containing essential amino acid that plays many
significant roles in the body including protein biosynthesis, immune
modulation, antioxidant levels and wellbeing. In a typical poultry
corn-soy diet, methionine is the first limiting amino acid and needs to
be supplemented in the diet. Even though methionine use in poultry
diets is extensive, the molecular control of dietary methionine remains
to be elucidated. We used RNA-Seq to study global transcriptomics in
the pectoralis (P.) major of meat-type chickens from hatch until 10 d
89
of age (starter phase). Cobb 500 male chickens (n = 900) were fed a
diet deficient in Met+Cys (0.77% in starter phase) or the deficient diet
supplemented with either LMET, DLMET or MHA-FA (equimolar
comparison). Fold change of ≥1.5 and false discovery rate of ≤0.05
were used as criteria for differentially expressed genes (DEGs). In the
P. major at d 10, there were 287, 384 and 283 DEGs in the group fed
MET deficient diet compared with the LMET, DLMET and MHA-FA
groups, respectively. A major pathway that was activated when all 3
methionine isomers were compared with the deficient group was the
osteoclast differentiation pathway. Among the differentially expressed
genes were FHL2, PPARG, CSF1R, CYBA, PIK3CD, SP11, TNFSF11,
BTK, and SLP76, SQSTM1, NCF1, and FOSL2. It is thought that dietary
methionine deficiency elicit inflammatory reaction that activate the
osteoclast differentiation pathway. Osteoclasts originates from the hematopoietic monocyte-macrophage lineage responsible for bone resorption.
Increased osteoclast resorption can affect bone quality leading to bone
fractures, which has animal welfare implications.
Key Words: methionine, HMTBA, RNA-Seq, chicken
265 Dietary methionine deficiency is associated with the
inflammatory bowel disease pathway in meat-type chickens.
Samuel E. Aggrey1, Marie C. Milfort1, Romdhane Rekaya1, and
Behnam Saremi*2, 1Poultry Science Department, University of Georgia, Athens, GA, 2Evonik Nutrition & Care GmbH, Hanau-Wolfgang,
Hessen, Germany.
Methionine (MET) is the first limiting amino acid in a typical poultry
diet. Restriction of dietary MET affects protein biosynthesis, feed efficiency and body composition. The molecular mechanisms that underlie
such restrictions remains to be elucidated. We studied the molecular
mechanisms that underlie dietary MET restrictions in broiler chickens
from hatch until 10 d of age in the Pectoralis major muscle using next
generation sequencing. Cobb 500 male chickens (n = 900) were fed a diet
deficient in Met+Cys (0.77% in 0–10 d starter phases) or the deficient
diet supplemented with either LMET, DLMET or MHA-FA (equimolar
comparison). Fold change of ≥1.5 and false discovery rate of ≤0.05 were
used as criteria for differentially expressed genes (DEGs). The major
biological processes were immune response, regulation of immune
response and regulation of T cell activity. The gene ontology molecular
functions were signal receptor activity, transmembrane signaling, and
receptor activity. Most significant cellular component was related to
extracellular matrix, collagen type IX trimer, proteinaceous extracellular matrix and components of membrane. Among the major pathways
inhibited or activated during dietary MET deficiency in chickens were
inflammatory bowel disease (IBD), hematopoietic cell lineage, T cell
receptor signaling pathway, Cytokine-cytokine receptor interaction,
and B cell receptor signaling pathways. Inflammatory bowel disease is
characterized by chronic inflammation of the gastrointestinal tract due
the dysregulated immune system. Differential expression of TLR and
ILs, STAT4, and AP1 elicit cascade of events that leads to IBD. When
the LMET was compared with either DLMET or MHA-FA isomers,
the differential pathways were dilated cardiomyopathy, hypertrophic
cardiomyopathy and adrenergic signaling in cardiomyocytes. Among
the differentially expressed genes between DLMET and HMA-FA were
NFA1P2, HMGB2, DCP1B, glycoprotein Ib, and GP1BB. Suboptimal
dietary MET compromises the immune function of birds that leads to
inflammation in the digestion system.
Key Words: methionine, HMTBA, RNA-seq, chicken
90
266 Effect of dietary supplementation of either dl-methionine
or dl-methionine hydroxy analogue on the antioxidant system in
broilers. Johanna O. Zeitz1, Behnam Saremi*2, Sarah Mohrmann1,
Lukas Fehse1, and Klaus Eder1, 1Justus-Liebig University Giessen,
Institute of Animal Nutrition and Nutritional Physiology, Giessen,
Hessen, Germany, 2Evonik Nutrition & Care GmbH, Hanau-Wolfgang, Hessen, Germany.
Methionine (Met), a precursor of the antioxidant glutathione (GSH), may
influence the animal’s antioxidant defense. Therefore, the question was if
different dietary Met concentrations and 2 Met sources, dl-Met (DLM)
and dl-2-hydroxy-4-(methylthio) butyric acid (DL-HMTBA), modify
oxidative stress-related parameters in broilers. Male Cobb 500 broilers
(n = 336) were allocated to 42 cages and 7 groups. Wheat and soybean
meal-based basal diets deficient in Met+Cys (0.76, 0.64, and 0.58%
during d 0–10, 11–21 and 22–35, respectively) were either not supplemented (Control group) or supplemented with DLM or dl-HMTBA at
0.1, 0.25 and 0.4% (equimolar comparison). After 10, 21 and 35 d, body
weight and feed intake were recorded and plasma and liver samples were
collected (n = 6 per group) and analyzed for GSH, thiobarbituric acid
reactive substances (TBARS) (photometry) and tocopherol (HPLC).
Tocopherol and TBARS concentrations were related to triglycerides.
The data were analyzed by ANOVA (fixed factors: Met source, Met
concentration, interaction). Feed intake and weight gain increased and
the feed:gain ratio improved in response to Met supplementation. The
relative efficacy of dl-HMTBA for feed:gain ratio was 86% of that
of DLM (regression analysis). Overall, concentrations of tocopherol,
TBARS and GSH were not influenced by Met source, but by Met concentration. Plasma tocopherol concentrations in Met-supplemented groups
were similar (d 10), partly higher (d 21), or higher (d 35) compared with
the Control. Plasma TBARS were similar after 21 and 35 d, but lower
in all Met-supplemented groups compared with the Control at d 10. In
liver, GSH was higher in the groups receiving 0.25 and 0.4% Met and
tocopherol was partly higher in Met-supplemented groups compared
with the Control, whereas TBARS concentrations were similar in all
groups. In conclusion, the dietary Met level, but not the source, may
influence the antioxidant defense system in healthy broilers.
Key Words: dl-methionine, methionine hydroxy analogue, oxidative
stress, antioxidant defense system, chicken
267 Evaluation of the effects of supplementation with methionine and/or betaine on broiler meat quality. Silvana C. Caldas,
Tamara Z. Ferreira, Eveline Berwanger, Vladimir P. Nascimento,
Sergio L. Vieira*, and Liris Kindlein, Universidade Federal do Rio
Grande do Sul, Porto Alegre, RS, Brazil.
The modern poultry sector technologies increased the possibilities of
use alternative agro industrial products to reduce the final cost of diet.
Betaine has been used as a source of sparing methionine in the feed of
broilers because of the price but it also helps in the regulation of cell
function, especially in stress phases. This study aimed to evaluate the
effects of substitution of methionine by betaine supplementation on
meat quality parameters (pH, cooking loss, water-holding capacity,
color [lightness (L*), redness (a*) and yellowness (b*)], shear force
and firmness) of 1,920 Cobb × Cobb 500 male broilers distributed
into 8 treatments with 12 replications of 20 birds each until 35 d old.
The treatments were positive control (77% AA sulfur: lysine), Without
supplementation of sulfur (dl-methionine) and betaine, 80% sulfur: 20%
betaine, 60% sulfur: 40% betaine, 40% sulfur: 60% betaine, 20% sulfur:
80% betaine, 0% sulfur: 100% betaine and 0% sulfur: 120% betaine.
Poult. Sci. 95(E-Suppl. 1)
The general linear model (GLM) procedures of SAS was used to analyze
the data and means were separated by Tukey’s test when significant (P
< 0.05). According to the results, there was not significant difference
for the parameters cooking loss, water-holding capacity, shear force
and firmness. However, the effect of betaine were significant differ in
b* value that presented low values in 60:40 (7.23), 40:60 (7.10), 20:80
(7.09), 0:100 (7.03) and 0:120 (6.24) when compared with positive
control (9.57).
Key Words: betaine, breast meat quality, broiler
268 Replacing supplemental dl-methionine by betaine effects
on the occurrence of breast myopathies. Leticia S. Gross, Tamara
Z. Ferreira, Eveline Berwanger, Vladimir P. Nascimento, Sergio L.
Vieira*, and Liris Kindlein, Universidade Federal do Rio Grande do
Sul, Porto Alegre, Rio Grande do Sul, Brazil.
Studies have been conducted to assess the use of betaine with broilers
with attention on carcass quality issues. This is an osmolyte and methyl
donor frequently used in broiler nutrition. This study aimed evaluate the
effects of replacing supplemental dl-Met by betaine on the occurrence of
wooden breast and white stripping using broilers slaughtered at 35 d of
age. 1,920 Cobb male broilers were randomly assigned into 8 treatments
with 12 replicates of 20 birds each. Treatments were partial replacements of dl-Met by betaine in diets having TSAA ratio to dig. Lys as
0.77 as follow: Positive control – PC 100% supplemented with dl-Met;
a negative control – NC (without dl-Met or betaine supplementation;
80:20–80% dl-Met: 20% betaine; 60:40–60% dl-Met: 40% betaine;
40:60–40% dl-Met: 60% betaine; 20:80–20% dl-Met: 80% betaine;
100–100% betaine and 120–120% betaine. Birds per experimental
unit where randomly taken (12) and breast fillets (pectoralis major)
were macroscopic analyzed for the presence of myopathies. Results
showed the occurrence of breast fillets without WB condition higher in
PC (16.67%) when compared with WB occurrence in other treatments
(without supplementation- 9.09%; 80:20/20:80/0:100/0:120- 8.33% and
60:40/40:60 that was characterized by the absence of normal fillets).
In relation to WS, 120 treatment had a higher prevalence (41.67%) of
breast fillets without this myopathy, and better results on the association of WB/WS myopathies with 50% fillets classified with only one of
this myopathies. However, 60:40 and 40:60 treatments had the highest
(100%) occurrence of the association of both myopathies. Analyzing the
occurrence of those myopathies according to the body weight (BW) and
growth rate (GR), the treatment PC had a higher BW/GR (2,494/824)
and better results for fillets without WB. For the occurrence of WS,
better results were in 120% associated with the low BW in this treatment (2.213). According to the results, we can conclude that 120% of
betaine supplementation has shown positive effects in reduction on the
occurrence of WS and in the WB/WS association even with a difference in BW.
Key Words: broiler, betaine, myopathies, supplementation
269 Dietary methionine sources and levels affect sulfur amino
acid metabolism in broiler breeder hens. Jian M. Wan*, Xue M.
Ding, Jian P. Wang, Shi P. Bai, Huan W. Peng, Yu H. Luo, Zhuo W.
Su, Yue Xuan, and Ke Y. Zhang, Animal Nutrition Institute, Sichuan
Agricultural University, Chengdu, Sichuan, P. R. China.
The objective of the study was to investigate the effects of dietary
methionine source and level on plasma free amino acids patterns and
expression of genes involved in hepatic methyl group metabolism in
broiler breeder hens. A total of 2184 Da Hen 699 broiler breeder hens
Poult. Sci. 95(E-Suppl. 1)
(29 wk, a local color-feathered breed in China) were assigned to 13
dietary treatments in a completely randomized design, with 8 replicates
per treatment and 21 hens per replicate. The 13 treatments included 1
diet without any dl-methionine (DLM) or 2-hydroxy-4-(methylthio)
butanoic acid (HMTBA) and 12 additional treatments with 2 methionine
sources (DLM and HMTBA) and 6 supplemental levels of each source
(0.05, 0.10, 0.15, 0.20, 0.25, and 1.00%) in a 2 × 6 factorial arrangements. All data was first subjected to 1-way ANOVA using the GLM
procedures of SAS, then analyzed as a 2-way ANOVA excluding the
basal treatment. Contrast statements were utilized to test the significance
of both linear and quadratic terms for methionine supplemental level. No
differences were observed among dietary treatments for broiler breeder
performance criterion. Higher methionine concentration was measured
in the plasma obtained from DLM supplemented hens compared with
those from HMTBA supplemented. Plasma alanine concentration was
significantly affected by methionine level, and linearly increased as
DLM or HMTBA supplemental level increased. There was a linear
increase in concentrations of proline, tyrosine, phenylalanine, and
serine as dietary DLM supplemental level increased. Plasma aspartate
concentration was higher in hens fed HMTBA diet than those fed DLM
diet. Hens treated with DLM had higher relative expression of ADA
than those fed HMTBA. As methionine supplemental level increased,
relative expression of ADA changed quadratically. There was a linear
increase for GNMT expression as dietary DLM supplemental level
increased. In conclusion, HMTBA and DLM were equivalent sources of
methionine. The effects of HMTBA on plasma free amino acid patterns
and the expression of hepatic genes involved methionine metabolism
are different from DLM.
Key Words: methionine, methionine hydroxyl analogue, sulfur
amino acids metabolism, plasma free amino acid
270 Examining the effect of high dietary calcium on ileal
endogenous amino acid losses and standardized ileal amino
acid digestibility in broilers. Sunday A. Adedokun*1, Anthony J.
Pescatore1, Michael J. Ford1, Jacqueline P. Jacob1, and Tuoying Ao2,
1Department of Animal and Food Sciences, University of Kentucky,
Lexington, KY, 2Alltech Inc., Catnip Pike, Nicholasville, KY.
Previous studies showed that broilers (BR) generally have higher standardized ileal amino acid digestibility (SIAAD) values than laying hen
(LH). In most of these studies, dietary calcium (Ca) was not adjusted to
reflect Ca need for LH. Hence, the objective of this study was to evaluate the effect of adequate (met BR requirement, 1%) and high (met LH
requirement, 3.2%) Ca levels on ileal endogenous amino acid losses
(IEAAL) and SIAAD in 21 d-old BR fed nitrogen-free diet (NFD) and
distillers dried grains with solubles (DDGS)-based diets, respectively.
Each of the diets was fed for 5 d. A total of 384 Cobb 500 BR were
used in this study which was conducted as a completely randomized
design (CRD) with 16 replicate cages of 6 birds/cage. All birds had
access to feed and water on an ad libitum basis. IEAAL and apparent
ileal digestibility (AID) values of AA were analyzed using the GLM
procedure of SAS appropriate for a CRD while the SIAAD values were
analyzed using the GLM procedure of SAS appropriate for a 2 × 2 factorial arrangement of treatments. IEAAL and N losses (mg/kg DMI) were
higher (P < 0.05) when NFD with high Ca level was fed (total AA was
39% higher; N was 35% higher). AID for AA was higher (P < 0.05) in
BR fed DDGS-based semi- purified diet with high Ca level except for
Arg, Lys, Met, Cys, Ser, and Tyr. There was no interaction (P > 0.05)
between dietary Ca level and method of standardization, but high dietary
Ca resulted in higher (P < 0.05) SIAAD for all AA except for Arg, Lys,
Met, Cys, and Tyr. Although SIAAD values were numerically higher
91
when correction was done using IEAAL from birds fed NFD with high
Ca, there was no effect of method of correction on SIAAD values for
all AA. In conclusion, feeding NFD with higher Ca resulted in higher
IEAAL while DDGS diet with high Ca resulted in higher AID values.
Finally, SIAAD values was significantly increased when correction
was done using IEAAL from birds fed NFD containing high Ca level.
Key Words: broiler, endogenous amino acid loss, apparent digestibility, standardized digestibility
271 Comparison of three levels of amino acid density on sex
separate broiler performance and processing characteristics.
Sandro Cerrate*, Kim Walter, Benton Hudson, Alejandro Corzo, and
Bryan Fancher, Aviagen Inc., Huntsville, AL.
The effect of 3 levels of amino acid density on growth performance and
carcass characteristics were studied in female and male Ross YPx708
broilers from 0 to 62 d of age. Six dietary treatments were completely
randomized and arranged as a 2 × 3 factorial with 2 sexes (male and
female) and 3 feeding phases that consisted of control diets based on
Aviagen amino acid recommendations (2014) coded as “A,” diets with
15% less amino acids than diets A (A-15%), and diets with 15% more
amino acids than diets A (A+25%). Each treatment was replicated 24
times and with 12 chicks per replicate. Across all ages, except at 62 d
92
of age, chickens fed diets A or A+15% had higher weights than those
fed diets A-15%, and the increments were more pronounced with males
than with females. At 62 d of age, straight-run chickens fed diet A
were heavier than those fed diet A-15% and birds fed diet A+15% had
intermediate weights. Across all ages, chickens fed diet A or A+15%
had similar weights, and males were heavier than females. During all
periods, the feed conversion ratio was improved as amino acids were
elevated (A-15% > A > A+15%), and the improvements were more
pronounced with males than with females at 24, 39 and 47 d of age.
Males had better cumulative feed conversion than females at 24 d and
thereafter. Livability was not affected due to diets or sex. At 48 d of age,
male birds fed diets A+15% resulted in smaller carcass yield than those
fed diets A, whereas female carcass yield was not influenced by amino
acids. At 55 d, the carcass yield was progressively enhanced by adding
amino acids. At 55 and 62 d, males had better carcass yield than females.
At 48, 55, and 62 d of age, straight-run birds fed diets A or A+15% had
better breast yield than those fed diets A-15%. Males at those ages had
higher thigh and drum yields than females, whereas females had higher
breast and abdominal fat yields than males. The results of this study
suggest that amino acid recommendations for both male and female
chickens might be advised similarly and diets A sufficed for optimizing
performance of most variables evaluated.
Key Words: amino acid, sex, broiler, carcass characteristics
Poult. Sci. 95(E-Suppl. 1)