Validated procedures play an important role to obtain accurate information about individual amino acid requirement data. The aim of the present study was to assess lysine (Lys) requirement of growing chicken both by c...Validated procedures play an important role to obtain accurate information about individual amino acid requirement data. The aim of the present study was to assess lysine (Lys) requirement of growing chicken both by classical supplementation technique and principles of diet dilution technique as applied with “Goettingen approach”. During the starter period (1 - 21 d), a growth study with male meat type chicken (Ross 308) was conducted making use of five graded dietary Lys-levels (3 repetition boxes with 3 birds/box). L-Lys×HCl was gradually added to a diet based on wheat, soybean protein concentrate, wheat gluten and fishmeal to yield 80%, 87.5%, 95%, 102.5% and 110% of the expected requirement level (13 g Lys/kg as fed). Diets were iso-energetic (12.8 MJME/kg) and iso-nitrogenous (21.65% crude protein). Birds were fed on free choice level also to assess the feed intake (FI) effects as important factor on traditional response criteria. Analyzed body composition at start and end of the growth study yielded N deposition (ND) data for further data assessment using exponential approximations depending on dietary Lys content or observed Lys intake. The results indicated significant differences (p < 0.05) in response on body weight gain (BWG) and observed dietary protein quality with unexpected consequences for the derived Lys requirement data. According to the independent variable (Lys in % of diet versus daily Lys intake) and aimed level of daily ND, the needed in-feed content of Lys varied between 1.24% and 1.46%. Application of the exponential modelling by “Goettingen approach” overcame these misleading conclusions by modelling the relationship between required Lys intake and observed response data (BWG, ND) taking also into account the expected real feed intake to formulate the needed in-feed concentration.展开更多
[Objective] To investigate the relationship between perinatal diseases and contents of superoxide dismutase (SOD) and malondialdehyde (MDA) in serum of dairy cows. [Method] A total of 38 dairy cows including 22 health...[Objective] To investigate the relationship between perinatal diseases and contents of superoxide dismutase (SOD) and malondialdehyde (MDA) in serum of dairy cows. [Method] A total of 38 dairy cows including 22 healthy cows, five cows with ketosis, four cows with fatty liver and seven cows with retained fatal placenta in perinatal period were selected. The contents of SOD and MDA in serum were respectively determined at different times ante partum and post partum. [Result] In the dairy cows with perinatal diseases, the SOD activity is lower and the MDA content was higher than that in the healthy dairy cows during perinatal period. [Conclusion] The antioxidant activity of dairy cows with perinatal diseases is lower than that of healthy dairy cows during perinatal period.展开更多
A total of 480 day-old Cobb 500 broilers were used to investigate the effects of different levels of digestible amino acids(DAA; 100%, 107% and 114% of Cobb recommendations) and ME(3,000 or2,900 kcal/kg) of prestarter...A total of 480 day-old Cobb 500 broilers were used to investigate the effects of different levels of digestible amino acids(DAA; 100%, 107% and 114% of Cobb recommendations) and ME(3,000 or2,900 kcal/kg) of prestarter diet on mixed sex broilers performance, enzyme activity, small intestine morphology, and serum metabolites. Broilers were randomly allotted to 6 treatments, where each treatment applied to 4 pens with 20 birds in each. The birds were subjected to their respective treatment diets from 1 to 10 days of age. This was followed by feeding common starter and finisher diets for the last29 days. The enzyme activity of the pancreas was measured at 10 days of age. Morphometric indexes of jejunum were measured at 10 days of age and the end of the feeding period. Our results showed that the body weight(BW) increased as the DAA density of the prestarter diet increased from 100% to 114% over the first 10 days and the entire period of the study. Birds fed 114% DAA presented a better feed conversion ratio on day 10(P < 0.05). At day 39, carcass weight and breast yield increased as the DAA levels increased from 100% to 114%(P < 0.05). The whole intestine length, small intestine length, and weights of the pancreas were lower in birds fed 100% DAA-diets at 10 days of age(P < 0.05). Increasing the dietary DAA and ME did not affect serum amylase, lipase, and protease concentrations and pancreatic amylase and lipase activity(P > 0.05); however, the activity of pancreatic protease increased as the DAA level increased from 100% to 114%(P < 0.05). The villus width and villus surface area(VSA) increased as the DAA level increased from 100% to 114% on day 10(P < 0.05). At 10 days of age, crypt depth was the lowest in the birds fed plenty DAA prestarter diets(P < 0.05). It was found that dietary treatments at 39 days of age did not affect intestinal morphology. The results of the present work indicate that DAA level of 114% of Cobb recommendations and energy level of 2,900 kcal/kg diet may be recommended for starting broiler chicks.展开更多
文摘Validated procedures play an important role to obtain accurate information about individual amino acid requirement data. The aim of the present study was to assess lysine (Lys) requirement of growing chicken both by classical supplementation technique and principles of diet dilution technique as applied with “Goettingen approach”. During the starter period (1 - 21 d), a growth study with male meat type chicken (Ross 308) was conducted making use of five graded dietary Lys-levels (3 repetition boxes with 3 birds/box). L-Lys×HCl was gradually added to a diet based on wheat, soybean protein concentrate, wheat gluten and fishmeal to yield 80%, 87.5%, 95%, 102.5% and 110% of the expected requirement level (13 g Lys/kg as fed). Diets were iso-energetic (12.8 MJME/kg) and iso-nitrogenous (21.65% crude protein). Birds were fed on free choice level also to assess the feed intake (FI) effects as important factor on traditional response criteria. Analyzed body composition at start and end of the growth study yielded N deposition (ND) data for further data assessment using exponential approximations depending on dietary Lys content or observed Lys intake. The results indicated significant differences (p < 0.05) in response on body weight gain (BWG) and observed dietary protein quality with unexpected consequences for the derived Lys requirement data. According to the independent variable (Lys in % of diet versus daily Lys intake) and aimed level of daily ND, the needed in-feed content of Lys varied between 1.24% and 1.46%. Application of the exponential modelling by “Goettingen approach” overcame these misleading conclusions by modelling the relationship between required Lys intake and observed response data (BWG, ND) taking also into account the expected real feed intake to formulate the needed in-feed concentration.
文摘[Objective] To investigate the relationship between perinatal diseases and contents of superoxide dismutase (SOD) and malondialdehyde (MDA) in serum of dairy cows. [Method] A total of 38 dairy cows including 22 healthy cows, five cows with ketosis, four cows with fatty liver and seven cows with retained fatal placenta in perinatal period were selected. The contents of SOD and MDA in serum were respectively determined at different times ante partum and post partum. [Result] In the dairy cows with perinatal diseases, the SOD activity is lower and the MDA content was higher than that in the healthy dairy cows during perinatal period. [Conclusion] The antioxidant activity of dairy cows with perinatal diseases is lower than that of healthy dairy cows during perinatal period.
文摘A total of 480 day-old Cobb 500 broilers were used to investigate the effects of different levels of digestible amino acids(DAA; 100%, 107% and 114% of Cobb recommendations) and ME(3,000 or2,900 kcal/kg) of prestarter diet on mixed sex broilers performance, enzyme activity, small intestine morphology, and serum metabolites. Broilers were randomly allotted to 6 treatments, where each treatment applied to 4 pens with 20 birds in each. The birds were subjected to their respective treatment diets from 1 to 10 days of age. This was followed by feeding common starter and finisher diets for the last29 days. The enzyme activity of the pancreas was measured at 10 days of age. Morphometric indexes of jejunum were measured at 10 days of age and the end of the feeding period. Our results showed that the body weight(BW) increased as the DAA density of the prestarter diet increased from 100% to 114% over the first 10 days and the entire period of the study. Birds fed 114% DAA presented a better feed conversion ratio on day 10(P < 0.05). At day 39, carcass weight and breast yield increased as the DAA levels increased from 100% to 114%(P < 0.05). The whole intestine length, small intestine length, and weights of the pancreas were lower in birds fed 100% DAA-diets at 10 days of age(P < 0.05). Increasing the dietary DAA and ME did not affect serum amylase, lipase, and protease concentrations and pancreatic amylase and lipase activity(P > 0.05); however, the activity of pancreatic protease increased as the DAA level increased from 100% to 114%(P < 0.05). The villus width and villus surface area(VSA) increased as the DAA level increased from 100% to 114% on day 10(P < 0.05). At 10 days of age, crypt depth was the lowest in the birds fed plenty DAA prestarter diets(P < 0.05). It was found that dietary treatments at 39 days of age did not affect intestinal morphology. The results of the present work indicate that DAA level of 114% of Cobb recommendations and energy level of 2,900 kcal/kg diet may be recommended for starting broiler chicks.
