Abstract: The quality of a protein is defined as the total amount of limiting amino acids and the ratio between these amino acids, which affects the growth of broilers and the intermediate metabolic processes associated with lipid synthesis.

It is well known that the amount of dietary protein (concentration of crude protein (CP)) and the quality (amino acid composition associated with the desired equilibrium pattern) affect the body composition of the chicken (Rhalil et al., 1968). For example, diets with low energy protein values ​​increase the lean percentage of broiler carcasses (Donaldson et al., 1956; Thomas and Combs, 1967), whereas diets with high energy protein values ​​not only increase the rate of fat synthesis in vitro (Rosebr - Oug and Steele, 1985) and the rate of resynthesis of fat in the liver has also accelerated (Donal-dson, 1985).

We studied the energy-protein ratio and made possible different interpretations of the test results (Rosebrough and Steele, 1985). For example, when the CP in the organism is expressed as a percentage of dry matter, the leanness of the diet with an energy-protein ratio of 10 is significantly better than that of the diet with an energy-protein ratio of 17. On the other hand, when the steroid protein is expressed in grams of protein deposition in a certain period of time, the effect of the high-energy protein group is better. Overall, it may be due to the fact that diets with low energy-to-protein ratios limit energy intake, which leads to an increase in carcass leanness (Bartov, 1979). From this perspective, it is important to understand that, unlike human pathological obesity, apparent fat synthesis in poultry only occurs when the diet meets the requirement for the maximum rate of synthesis of muscle tissue.

We studied the regulation of dietary restriction amino acids on somatic protein synthesis. From this perspective, the first limiting amino acid is considered as the "final redistribution agent." The provision of this amino acid causes some of the energy used in the diet to synthesize fat to be transferred to the desired muscle tissue. This problem is described as the combination of amino acids in feed and their relationship to the first limiting amino acid.

The protein quality in the diet reflects the maximum growth and balance of amino acids required for muscle tissue synthesis. For example, it has been suggested that "available protein content" can be used to describe the degree to which a protein satisfies a limiting amino acid (Fisher et al., 1959). The effective protein content can be calculated from the relative ratio of lysine to CP in the diet, assuming 60 grams of lysine per kilogram of completely effective protein (Yeh and Leveille, 1969). Although dietary effective protein levels (the first limiting essential amino acid content in the diet) may regulate fat synthesis, it is not known whether this is due to the role of limiting amino acid content at the ribosome level or due to excess amino acids. Decomposition causes changes in the intracellular metabolism. The latter mechanism is obviously based on the fact that when the excess amino acid carbon skeleton is converted to glucose, the content of acetyl groups needed to re-synthesize the fat will be reduced, and the synthesis of fat may lack the substrate.

method:

The purpose of our experiment was to study the metabolism of fat and carbohydrates in broilers when dietary supplementation with a restricted lysine (supplemented with lysine hydrochloride or increased soymeal usage) was performed. Based on this experiment, the broiler broilers were then studied feeding low-level CP but adding the first five limiting amino acids. The 0 hypothesis in the trial was that the low-protein diet supplemented with amino acids and the CP-rich diet had similar effects on metabolism.

Table 1 Dietary CP Levels and Lysine Additions for 35 Days Broiler A Growth In Vitro Fat Synthesis (IVL)

And plasma hormone levels

Diet

body weight

Weight gain/consumables

IVLb

IGF-Ic

T3c

T4 c

15% CP-8.0g Lysine/Kg

896

0.43

43.2

16.8

2.1

6.8

17% CP-9.4g Lysine/Kg

960

0.49

36.6

16.8

1.7

8.2

18.3% CP-10.6g Lysine/Kg

1,156

0.50

30.1

19.0

1.6

9.0

20% CP-11.9g Lysine/Kg

1,244

0.59

23.7

21.7

1.4

10.9

15% CP-9.4g Lysine/Kg

913

0.50

48.3

18.6

1.8

8.2

15% CP-10.7g Lysine/Kg

1,116

0.51

53.5

17.4

1.4

10.8

15% CP-12.0g Lysine/Kg

1,136

0.52

59.5

17.5

1.7

7.0

a Seven-day-old chicks with an average body weight of 150 g were assigned to each grain treatment group for a 28-day period, and then some chickens were selected from each treatment to determine the effect of the diet on intermediate metabolism.

b In vitro fat synthesis was determined by in vitro culture of liver tissue in 10 mM 2-14C sodium acetate medium for 2 hours followed by determination of labeled acetic acid in hepatic lipids. The number of micromoles of product going to each gram of liver tissue.

c The number of hormones per milliliter of plasma.

Table 2 Addition of dietary CP and lysine to growth of 35-day-old broiler chick a in vitro fat synthesis (IVL)

And plasma hormone levels

Diet

1

2

3

4

5

6

7

CP,%

12

14.4

17.2

20

12

12

12

Egg + saccharin, g/kg diet

8.3

8.8

9.4

10.8

8.4

8.4

8.4

Lysine, g/kg diet

5.9

7.9

9.9

11.9

7.9

9.8

12.0

Tryptophan, g/kg diet

1.2

1.5

1.9

2.2

1.5

1.8

2.1

Threonine, g/kg diet

4.8

5.9

7.5

8.2

5.0

5.4

5.7

Isoleucine, g/kg diet

5.2

6.8

9.1

10.1

6.0

6.9

7.8

Arginine, g/kg diet

7.3

9.6

12.9

14.3

9.6

11.9

14.2

Weight, g

668

959

930

1,083

894

916

952

Weight gain: Consumption

0.27

0.37

0.43

0.46

0.41

0.46

0.46

IVLb

28.5

24.7

14.6

9.4

17.9

19.6

19.6

IGF-Ic

18.6

20.3

19.5

21.5

18.5

20.1

19.9

T3c

1.9

1.6

1.3

1.2

1.4

1.4

1.5

T4 c

9.1

10.9

12.4

12.9

10.7

9.3

12.0

a Seven-day-old chicks with an average body weight of 150 g were assigned to each grain treatment group for a 28-day period, and then some chickens were selected from each treatment to determine the effect of the diet on intermediate metabolism.

b In vitro fat synthesis was determined by in vitro culture of liver tissue in 10 mM 2-14C sodium acetate medium for 2 hours followed by determination of labeled acetic acid in hepatic lipids. The number of micromoles of product going to each gram of liver tissue.

c The number of hormones per milliliter of plasma.

In the first trial, a corn-soybean basal diet containing all essential amino acids except lysine was prepared and then lysine hydrochloride was added to achieve the desired level. In the second trial, a basic diet deficient in essential amino acids (12% CP) was prepared first, followed by mixing with diets containing CP 20% in different proportions or adding amino acids to their respective contents. Considering that arginine may be related to the utilization of lysine, arginine corresponding to the amount of lysine is also added to the diet.

Several indexes related to production (weight change and feed conversion rate) were measured in the test, and the levels of some metabolic hormones (triiodothyronine [T3], thyroxine [T4] and Insulin-like growth factor-I [IGF-I] Insulin-like growth factor is one of a class of hormones that acts as an active agent under the control of somatotropin or somatotropin.We are particularly interested in IGF-I on poultry because it Control muscle growth.Finally, we used improved tissue culture method to test the effect of different diets on fat metabolism in broilers.

result:

The logical study of the protein pair's mechanism of metabolic regulation remains to be carried out in future experiments on protein quality (amino acid composition). In the current preliminary trial, the concept of using lysine as a limiting factor for proteins was invoked.

In the first trial, we found that the weight of broiler fed with 15% CP-8.0g lysine/Kg group and the lysine containing 17% CP group or 15% CP but adding lysine to 17% CP group There was no significant difference in acid levels. We also found that when low-protein dietary lysine was added to the lysine level of the 18.3% CP group, its production performance was similar to that of the group fed with the higher-protein diet. Conversely, when the lysine level in the low-protein diet was increased to 20% CP, the production performance could not be similar to that in the 20% CP group. The lowest CP content was the worst in feed conversion, while the highest CP content was the best in feed conversion. Feed conversion efficiency at different levels of lysine supplementation was similar and was lower than that of the highest protein content group.

Analyzing the metabolic hormone levels in the treatment groups, we noticed some effects of increasing dietary CP levels or adding lysine to the 15% CP group. For example, the highest levels of plasma IGF-I and T4 protein were found in broilers. The addition of lysine does not affect IGF-I in plasma but affects T4 levels.

T3 levels in plasma were lowest in the 20% CP group and highest in the 15% CP group. Adding lysine to a diet of 15% CP to 10.7%/kg diet or 12%/kg diet reduced plasma T3 levels. Increasing dietary CP levels from 15% to 20% also reduced plasma T3 levels.

Table 1 summarizes the in vitro synthesis of lipids in terms of increasing CP or lysine levels. Fat synthesis rates were highest in the 20% CP diet fed group and lowest in the 15% group. We found that with the increase of CP level, the fat synthesis obviously decreased linearly. Conversely, lysine hydrochloride was added to the low CP diet to achieve higher lysine levels in the CP diet and fat synthesis was accelerated. We found that adding lysine also increased feed intake, while increased feed intake increased the rate of fat synthesis.

Table 2 shows the effect of increasing the level of CP in the diet or adding methionine, lysine, tryptophan, threonine and isoleucine to the control group in the original low CP diet.

As expected, increasing dietary CP levels significantly increased body weight, and feed conversion efficiency improved with increasing CP content. In contrast, adding 5 amino acids to the basal diet significantly increased body weight only in group 1 (equivalent to 14.4% CP group) (p

Increasing CP levels from 12% to 17.2% also reduced fat synthesis. In contrast, the addition of five amino acids to the basal diet significantly altered amino acid nutrition but did not significantly reduce fat synthesis.

This particular finding suggests that raising a so-called "ideal protein" with the best amino acid ratio is not a way to reduce body fat in broilers. The key to mastering the composition of amino acids, CPs, and bodies may lie in a thorough understanding of what we previously learned about the concepts of non-essential and essential amino acids.

The second trial included the addition of several amino acids to low protein diets to achieve a reasonable amount and a balanced ratio. There was no significant difference in plasma IGF-I, T4, and T3 levels between the basal diet group and the treatment group that added methionine, lysine, tryptophan, threonine and isoleucine to the control group ( Table 2). The addition of these 5 amino acids in groups 1 and 2 (equivalent to the amino acid levels of 14.4% CP and 17.2% CP, respectively) significantly increased plasma IGF-I levels compared to basal diets (p

The trends of T4 among treatment groups are similar to the above indicators. The addition of these 5 amino acids in groups 1 and 2 (equivalent to the amino acid levels of 14.4% CP and 17.2% CP, respectively) significantly increased plasma IGF-I levels compared to basal diets (p

Although the growth performance can be improved by increasing lysine (test 1) or balancing the limiting amino acids (test 2), the plasma IGF-I is only based on the control value (broilers fed a 20% CP diet) with no added amino acid basis Diets (15% CP, Table 1; 12% CP, Table 2) were only different when compared.

Analysis of plasma IGF-I concentrations as indicators of animal metabolic levels has made some progress. For example, when comparing plasma IGF-I values ​​in different animals, it was found to be lower in broiler chickens (Leung et al., 1986) than in growing rats (Prewitt et al., 1982), although both are on growth trends. similar. Huybrechts et al. (1985) studied plasma IGF-I concentrations in broiler and layer chickens and found that plasma IGF-I concentrations in laying hens decreased as diets increased, but not in broiler chickens. The latter finding is not surprising, because broilers are selected through high-intensity selection of fast-growing traits. Several trials in the 1980s provided evidence that nutritional status regulates plasma IGF-I levels. Lauterio and Scanes (1987) compared the level of IGF-I in plasma of broilers as a function of dietary protein and found that IGF-I levels in plasma of broilers decreased when CP was reduced from 20% to 5%. Increased CP from 5% to 20%. In this trial, changes in plasma IGF-I were attributed to changes in protein nutrition levels.

In a later experiment (Rosebrough et al., 1988) the relationship between protein and energy intake and different growth indicators was studied. In that trial, feed restriction was used, so protein and energy intake were fixed. On the basis of limited energy intake (70% of free feed intake), two levels of CP intake were set, and plasma IGF-I was higher in broiler chickens that consumed more protein. Plasma IGF-I levels were consistent with growth and relative breast muscle size, indicating that this hormone can regulate the growth of lean tissue. This led us to speculate that the acceleration of muscle growth in chickens fed a high-protein diet is associated with IGF-I. From this study it can be concluded that plasma IGF-I concentration is a useful indicator of the adequacy of dietary protein, taking into account the energy intake. Interestingly, in several experiments, injection of IGF-I did not show its pro-growth effect (Huybrechts et al., 1992; Spencer et al., 1996; Tixier Boichard et al., 1992; McGuinness and Cogburn, 1991).

Analysis of the test results also showed that thyroid hormone (T3 and T4) levels may play a role in determining protein levels in broiler diets. In this experiment, in order to make the differences between the groups more obvious, the variability among the treatments was greater. Despite the difficulty of hypothesis testing when dietary variation is large, there are still many reports of dietary and hormone levels. Yang et al. (1987) pointed out that although reducing the energy provided by carbohydrates causes weight loss, the levels of T3 and T4 do not change. This study may indicate that thyroid function plays a role in growth, and that the degree of correlation between growth and dietary energy is greater than the correlation with the quality of energy raw materials in the diet.

Changes in diets that generally have a greater impact on growth can cause changes in these hormone levels. Under realistic production conditions, using these indicators as indicators of changes in nutritional status may be difficult. For example, small changes in biological indicators may improve weight and feed rewards, resulting in higher economic benefits. We can see that within the range of dietary CP levels from 12% to 18%, IGF-I concentrations are significantly associated with the growth of broilers. On the contrary, we found that when feeding a diet with more than 18% CP, the result was almost insignificant. There are few studies on the biochemical mechanism of fat synthesis by feeding high-protein diets. Bartov (1979) reported that excessive dietary protein would force broilers to digest energy because excess nitrogen was excreted in the form of uric acid, reducing the energy used in fat synthesis (Buttery and Boorman, 1976). Yeh and Leveille (1969) found a negative correlation between dietary protein levels and in vitro fat synthesis rates. It is possible that the increase in dietary protein levels will inhibit glycolysis and thus reduce the amount of glucose products used in fat synthesis. The hypothesis in the current study is to improve the quality of the protein, both by adding the first limiting amino acid to the diet or by adding several amino acids to the diet where the CP level is critical, which will reduce the energy used in fat synthesis.

The results of this experiment can not provide a basis for the latter hypothesis. The rules of fat synthesis in broilers are complex and cannot be explained simply by satisfying the synthesis of muscle tissue and reducing the energy of fat synthesis.

prompt:

We verified the relationship between CP levels and protein quality and a range of growth and intermediate metabolic parameters. Plasma IGF-I concentrations are positively correlated with growth performance and may modulate and reflect changes in muscle tissue synthesis rates. When the effects of different diets are significant, and energy intake is considered together with the quantity and quality of the protein, plasma IGF-I concentrations may be used as an indicator of protein adequacy. Under current commercial conditions, it seems unrealistic to use hormone levels to predict the growth performance of broilers. We have clearly demonstrated that the changes in body composition caused by dietary energy and protein changes are related to changes in the ability of broilers to use for fat synthesis.

In addition, the difference in energy-protein ratio should be large enough to cause a large enough change in the metabolic rate to overcome the difference in the metabolic rate in the natural state. Protein quality is defined as the absolute value of a limiting amino acid and the ratio between these amino acids, which influences the growth of the intermediate metabolic processes involved in fat synthesis.

2022 New Laser Distance Sensor

At the start of 2022, JRT introduce our customers a batch of new series laser distance measurer sensor(S92-20m, S91, BA6A-150m, BA6A-20Hz, M703A-8Hz, U81-10m etc.). Especially S91(RS485 interface and software Rx Tx protocol) and S92(RS232 interface) ip54 enclosure distance sensor model, custoemrs would like to use it in their industrial automation solutions,according to the ip54 waterproof protection level, well protect laser, Wide Voltage 5~32V(Optimize for industrial using), and easy-to-install.
If you are interested in JRT more laser measuring sensors, or you would like buy qty 2 quotation for trial basis, please welcome to contact us.
Kind regards
JRT Team

Chengdu JRT Main Ranging Modules: Industrial Laser Distance Sensors, Laser Rangefinder Sensor , Tof LiDAR Sensors.


laser measuring,infrared sensor,distance measurers,laser distance measurer,laser sensor

Chengdu JRT Meter Technology Co., Ltd , https://www.irdistancesensor.com