Invited review: Further progress is needed in procedures for the biological evaluation of dietary protein quality in pig and poultry feeds

Liebert, F.

doi:10.5194/aab-60-259-2017

Cited by 13 publications

(25 citation statements)

References 67 publications

(60 reference statements)

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“…[14], see 2.5. 3 One male bird died within week 4. 4 Final body weight of male birds was determined 1 d earlier (see Table 3).…”

Section: Resultsmentioning

confidence: 99%

“…Over generations, poultry breeding has significantly improved performance data for broiler chickens [1] [2]. However in more recent years, fast selection progress has played an important role for the market meat yield by increasing the body protein deposition potential of present genotypes [3]. As already reported [4] [5], the body composition of recently produced broiler chickens has changed as compared to birds of earlier decades.…”

Section: Introductionmentioning

confidence: 99%

“…15 replications per gender and age group, respectively. 2 Body weight following 24 h feed deprivation 3. One male bird died within week 4 4.…”

mentioning

confidence: 99%

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Age and Gender Dependent Deposition of Crude Nutrients and Energy in Fast Growing Meat-Type Chickens

Wecke¹,

Liebert²

2019

OJAS

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Two consecutive growth studies were conducted to investigate the age-dependent nutrient and energy deposition in male and female meat-type chickens (Ross 308) based on feather and feather-free body fraction data determined according to the comparative slaughter technique. Birds were reared under standardized housing conditions (15 floor pens per gender, 5 birds per pen). Both the starter (day 1 to 22) and grower diets (day 22 to 36) were based on corn, wheat, soybean meal, soybean protein concentrate and crystalline feed amino acids. Diets were formulated to ensure an equal feed protein quality close to the ideal amino acid ratio by adjusting a constant mixture of the feed proteins. Individual body weight (BW) and feed intake per pen were recorded weekly. At the start (day 1) as well as on a weekly basis until the end of the 5th week, 15 birds per gender (each 3 pens of 5 birds) were selected and euthanized following 24 h feed deprivation. Subsequently, the feathers were manually removed and quantified. Crude nutrient analysed in representative samples of both feather and feather-free body fractions. The nutrient and energy deposition in the bodies of both genders were significantly increased with increasing age (p < 0.001). Male birds deposited significantly higher body protein (p < 0.001) and female birds significantly more fat and energy in the whole body (p < 0.001) during the entire growth period. In contrast, no differences were found in protein contents of the BW gain between genders dependent on age (p > 0.05). However, the protein partitioning in the gain of both analyzed body fractions provided oppositional results. Accordingly, male birds yielded relatively more protein in the feather-free body fraction (p < 0.001) and females relatively more feather protein (p < 0.001) as related to the whole body protein gain.

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“…[14], see 2.5. 3 One male bird died within week 4. 4 Final body weight of male birds was determined 1 d earlier (see Table 3).…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Age and Gender Dependent Deposition of Crude Nutrients and Energy in Fast Growing Meat-Type Chickens

Wecke¹,

Liebert²

2019

OJAS

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“…Thus, once the amino acid ideal profile is determined, it is sufficient to determine the requirement of a single amino acid and the others can be calculated (Baker, 2003;Dari et al, 2005). The requirements determined by NRC (1994), Leeson and Summers (2005) and Rostagno et al (2005, 2011, 2017, 2000 were estimated from a compilation of tests conducted with different diets, periods of production of the birds, strains and environmental conditions and then determined the amino acid ideal profile. Similarly, Coon and Zhang (1999) conducted five experiments to determine the amino acid requirements of laying hens and the ideal profile recommended by them is based on the average requirements determined in the five assays.…”

Section: 67mentioning

confidence: 99%

Optimal in‐feed amino acid ratio for laying hens based on deletion method

Soares

Sakomura

Dorigam

et al. 2018

Animal Physiology Nutrition

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A total of 56 Hy‐line W‐36 hens from 28 to 30 weeks were used on nitrogen balance (NB) trial to estimate daily N maintenance requirements (NMR) and the genetic potential for daily N retention (NRmaxT). The treatments consisted of six graded levels of nitrogen in the diets (N1 = 8; N2 = 16; N3 = 24; N4 = 32; N5 = 40; and N6 = 48 g N/kg of feed), formulated using the dilution technique. The regression analyses between nitrogen intake and excretion were performed to fit the exponential function and to determine the NMR = 292 mg/BWkg 0.67, which was applied for further calculation of NRmaxT = 1,883 mg/BWkg 0.67. A second NB trial was conducted, and a total of 96 Hy‐line W‐36 hens were used in the same period to estimate the ideal amino acid ratio (IAAR). Twelve treatments with eight replicates and one bird per cage were used. A balanced diet (BD) was formulated to meet the IAAR and the requirement of other nutrients for pullets. The limiting diets were formulated diluting BD with cornstarch and refilled with synthetic AAs and other feed ingredients, except for the AA under study. In each trial, the data of nitrogen intake, excretion, deposition and retention were obtained in a NB trial. The IAAR determined by Goettingen approach was Lys 100, Met+Cys 88, Trp 21, Thr 69, Arg 109, Val 90, Ile 75, Leu 127, Phe+Tir 110, Gly+Ser 73 and His 29%. The IAAR determined by Louvain approach was Lys 100, Met+Cys 88, Trp 21, Thr 69, Arg 104, Val 91, Ile 78, Leu 121, Phe+Tir 119, Gly+Ser 77 and His 29%.

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“…Consequently, body composition data of actual broiler genotypes provide important information for further improvement of optimized dietary protein and amino acid supply. In addition, further minimizing of N excretion according to the future demands is supported [5]. Modern broiler genotypes require significantly higher energy and nutrient concentrations in the diet to optimize both performance data (body weight gain, body protein deposition) and efficiency of protein utilization [6].…”

Section: Introductionmentioning

confidence: 99%

Age and Gender Dependent Nutrient Composition of Feather and Feather-Free Body Fractions in Meat-Type Chickens

Wecke¹,

Khan²,

Sünder³

et al. 2018

OJAS

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The objective of this research was to update current results about the nutrient composition of broiler chickens during the growth period up to market age. Two growth experiments were conducted for assessing the nutrient content of feathers and feather-free body of meat-type chickens (Ross 308). Both male and female birds were reared under uniform management conditions (floor pens; 15 pens per gender; 5 birds per pen). Experimental diets both for the starter (day 1 to 22) and the grower period (day 22 to 36) were based on corn, wheat, soybean meal, soybean protein concentrate and well balanced with feed amino acids. The feed protein quality was adapted to the ideal amino acid ratio and equated within both of the feeding periods by adjusting a constant mixture of the feed proteins. Each 15 birds per gender (3 pens of 5 birds) were selected and subsequently fasted for 24 h before quantitative de-feathering both at start of the experiment and further on weekly up to the end of the 5 th week. Nutrient content was determined in representative samples of the feather and feather-free body fraction. In the feather dry matter (DM) very high crude protein (CP) concentrations (>96%) with low age-dependent and insignificant gender-specific differences were observed. In spite, a relatively high variation of CP content in the DM of feather-free body was found. Depending on age, the body CP significantly decreased with increasing age, but male birds yielded higher (p < 0.001) CP content. The crude lipid content of the feather-free and whole empty body significantly increased with age and was higher in female as compared to male birds (p < 0.001). Depending on age and gender, the crude ash content both in feathers and feather-free body of modern fast-growing chickens was rather low and with very low variation.

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Invited review: Further progress is needed in procedures for the biological evaluation of dietary protein quality in pig and poultry feeds

Cited by 13 publications

References 67 publications

Age and Gender Dependent Deposition of Crude Nutrients and Energy in Fast Growing Meat-Type Chickens

Age and Gender Dependent Deposition of Crude Nutrients and Energy in Fast Growing Meat-Type Chickens

Optimal in‐feed amino acid ratio for laying hens based on deletion method

Age and Gender Dependent Nutrient Composition of Feather and Feather-Free Body Fractions in Meat-Type Chickens

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