Sulfur amino acid requirement and foot pad dermatitis in turkey poults

Retrospective Broiler Health Survey: Scope, Parameters, and Overall Trends

A retrospective analysis encompassing 18 yr (1999-2016) of broiler chicken health surveys from broiler production complexes throughout the United States was conducted to identify trends and areas of opportunity. The analysis used necropsy data from 19,577 broiler chickens considered to be "healthy" or "clinically normal" by visual assessment. The very low incidence of dehydrated (0.01%) or undersized (0.02%) broilers is evidence that the objective of examining "healthy" birds was achieved. The results of the correlation analysis were what was expected for "healthy" broilers, with these birds having positive correlations with skin color and size of the bursa of Fabricius. The average age of broilers included in this analysis ranged from 26.2 days in 2008 to 33.7 days in 2013. The percentage of "normal" broilers (those without visible lesions or abnormalities) varied from 5.63% in 2012 to 28.33% in 1999. The results of this study identified four areas of opportunity for improving poultry health: 1) coccidiosis, 2) oral lesions and gizzard erosions, 3) retained yolks, and 4) pododermatitis.

Differential Effects of Dietary Methionine Isomers on Broilers Challenged with Acute Heat Stress

In this study, we investigated the effect of methionine isomers (D- and L-methionine) on growth performance, blood metabolite levels, nutrient digestibility, intestinal morphology, and foot pad dermatitis in broilers challenged with acute heat stress. In total, 240 broilers were randomly allocated in a 2×2 factorial arrangement consisting of two dietary treatments (D- vs. L-methionine) and two thermal environmental conditions (thermo-neutral vs. acute heat stress). Methionine isomers were added to the diet as an ingredient according to the diet formulation. The broilers were exposed to acute heat stress at 33°C for 5 h on day 14. The average daily gain and feed conversion ratio of birds fed L-methionine were higher than those fed D-methionine (P<0.05) from the time of hatching till 21 days. Induced acute heat stress impaired (P<0.05) the daily gain and feed intake of the broilers on day 21. Furthermore, the blood urea nitrogen levels of birds subjected to acute heat stress on days 14 and 21 were higher (P<0.05) than those of their counterparts. Longer villi (P<0.05) were observed in broilers fed L-methionine-supplemented diet than in those fed D-methionine-supplemented diet on day 14, irrespective of thermal environmental conditions. Heat stress reduced (P<0.01) nutrient digestibility of the broilers on days 14 and 21. Higher incidence and severity of foot pad dermatitis were observed (P<0.05) in broilers fed diet containing D-methionine than in those fed L-methionine-supplemented diet. In conclusion, L-methionine-supplemented diet improved growth performance, overcame growth depression, and reduced the incidence of foot pad dermatitis when broilers were exposed to acute heat stress in the starter period.

Footpad dermatitis in poultry

Footpad dermatitis (FPD) is a condition that causes necrotic lesions on the plantar surface of the footpads in growing broilers and turkeys. This condition not only causes downgrades and condemnations of saleable chicken paws, the portion of the leg below the spur, but is also an animal welfare concern in both the United States and in Europe.. Revenue from chicken paws in 2008 alone was worth $280 million. Harvesting large, unblemished paws has become a priority to poultry companies all over the world. Research on this subject has been ongoing since the 1940s and has looked into many different areas including nutrition, environment, and genetics. Early research looked at nutritional deficiencies such as riboflavin and biotin mainly in turkey poults. This early research was most likely looking at a separate form of dermatitis than what is being investigated now. Recent findings have suggested that there is a myriad of interacting factors that lead to FPD. Litter moisture appears to be the most likely culprit in the onset of this condition. Research has also shown a possible genetic link in the susceptibility to development of FPD lesions. Current chicken paw prices have skyrocketed due to a large export market in Asia. To produce unblemished paws for both increased profit and comply with current animal welfare recommendations, further research is needed to understand how the condition develops and what strategies can be used to prevent it.

Metabolic pathway analysis for rational design of L-methionine production by Escherichia coli and Corynebacterium glutamicum

Metabolic pathway analysis was carried out to predict the metabolic potential of Corynebacterium glutamicum and Escherichia coli for the production of L-methionine. Based on detailed stoichiometric models for these organisms, this allowed the calculation of the theoretically optimal methionine yield and related metabolic fluxes for various scenarios involving different mutants and process conditions. The theoretical optimal methionine yield on the substrates glucose, sulfate and ammonia for the wildtype of C. glutamicum is 0.49 (C-mol) (C-mol)(-1), whereas the E. coli wildtype exhibits an even higher potential of 0.52 (C-mol) (C-mol)(-1). Both strains showed completely different optimal flux distributions. C. glutamicum has a high flux through the pentose phosphate pathway (PPP), whereas the TCA cycle flux is very low. Additionally, it recruits a metabolic cycle, which involves 2-oxoglutarate and glutamate. In contrast, E. coli does minimize the flux through the PPP, and the flux through the TCA cycle is high. The improved potential of the E. coli wildtype is due to its membrane-bound transhydrogenase and its glycine cleavage system as shown by additional simulations with theoretical mutants. A key point for maximizing methionine yield is the choice of the sulfur source. Replacing sulfate by thiosulfate or sulfide increased the maximal theoretical yield in C. glutamicum up to 0.68 (C-mol) (C-mol)(-1). A further increase is possible by the application of additional C1 sources. The highest theoretical potential was obtained for C. glutamicum applying methanethiol as combined source for C1 carbon and sulfur (0.91 (C-mol) (C-mol)(-1)). Substrate requirement for maintenance purposes reduces theoretical methionine yields. In the case of sulfide used as sulfur source a maintenance requirement of 9.2 mmol ATP g(-1) h(-1), as was observed under stress conditions, would reduce the maximum theoretical yield from 67.8% to 47% at a methionine production rate of 0.65 mmol g(-1) h(-1). The enormous capability of both organisms encourages the development of biotechnological methionine production, whereby the use of metabolic pathway analysis, as shown, provides valuable advice for future strategies in strain and process improvement.

Evaluation of National Research Council amino acid recommendations for large white turkeys

Two trials of identical experimental design were conducted to evaluate the NRC (1994) amino acid requirements for growing turkeys. Diets were formulated for 4-wk age intervals using intact ingredients and amino acid supplements to provide 85, 90, 95, 100, 105, 110, 115, and 120% of the suggested requirements. Formulation was done in a manner to minimize excess levels of as many essential amino acids as possible. Day-old male poults of a commercial Large White strain were grown to 20 wk on the test diets with body weight and feed conversion determined at intervals throughout the test; representative samples of birds were processed to determine carcass composition and parts yield. Results suggested that diets formulated to provide 105% of the suggested NRC requirements were needed to provide maximum body weight gain, feed conversion, and breast meat yield. Ambient temperatures in the present study frequently exceeded 27 C and may have contributed to the need for somewhat greater amino acid needs than the present NRC (1994) suggestions.

A cage-related foot pad dermatitis in dwarf and normal-sized single comb white Leghorn layers

Studies were conducted to determine if wire cage floors were involved in producing a foot pad dermatitis in dwarf and normal-sized Single Comb White Leghorn layers. Dermatitis scores were found to be higher for dwarf birds reared in cages versus litter floors. The use of plastic-coated cage floor inserts and wooden perches reduced the incidence of dermatitis in caged dwarf birds. Normal-sized layers consistently exhibited a lower incidence of dermatitis than did dwarf hens.

Effect of several dermatitis preventing agents on foot pad dermatitis in dwarf and normal sized single comb white Leghorn layers

Studies were conducted to determine the effects of increased dietary levels of vitamin and trace mineral mixtures, methionine, meat and bone meal, fish meal, and safflower oil on foot pad dermatitis in dwarf and normal size Single Comb White Leghorn layers. All layers were maintained in individual wire cages throughout a 40-week experiment period. Individual birds were scored for the incidence of foot pad dermatitis and production parameters were recorded. No significant decrease in the incidence of dermatitis was observed from the following dietary supplements: a 50% increase in a vitamin or a complete trace mineral mixture; a 50% increase in an iron, copper, iodine, and cobalt or a manganese and zinc mixture; .05% methionine; 5% meat and bone meal; 3% herring fish meal; or 2% safflower oil. It was concluded that these mixtures or supplements containing such dermatitis preventative agents as pantothenic acid, zinc, and linoleic acid appeared without effect in minimizing expression of the condition in dwarfs.

Effects of a nonspecific nitrogen deficiency on growth rate and leg problems in chicks

Five experiments were conducted using crystalline amino acid and semipurified diets containing adequate levels of all indispensable amino acids, vitamins, and minerals to study the effects of dispensable amino acids on growth and the incidence of leg abnormalities of male chicks. Purified diets containing 5% L-glutamic acid as the sole source of nonspecific nitrogen resulted in poor growth and feed efficiency, high mortality, and a high incidence of leg abnormalities with many severe cases of this condition. Increasing the dietary level of L-glutamic acid to 10% of the purified diet or supplementing the 5% L-glutamic acid diet with 2.40% glycine or 1.68% L-serine improved weight gain but did not eliminate the leg conditions. Higher L-serine (3.36%) resulted in a growth depression, indicating that this level was toxic to the birds. It was necessary to increase the dietary L-glutamic acid to 12.5% to reduce the incidence of leg problems to a minimum. Plasma dispensable amino acid levels (aspartic acid, glutamic acid, and alanine) paralleled the levels of L-glutamic acid in the diets fed to the chicks. Plasma serine and glycine levels were increased by adding either serine or glycine, but the magnitude of the increase of either amino acid was greatest with the addition of that amino acid to the diet. Plasma proline concentrations increased when chick diets were supplemented with high levels of glycine (2.4%), serine (3.36%), or glutamic acid (9.7%) in relation to those supplemented with only 5% L-glutamic acid. Feeding an intact protein (isolated soybean protein) diet did not alleviate leg disorders, although it did improve weight gain.

Prevention of foot lesions in broiler breeder hens kept in individual cages

Individually-caged broiler breeder hens were fed allowances of 1.88, 1.61, 1.32 or 1.13 MJ apparent metabolisable energy (AME) per bird d at four different protein intakes (27, 23, 19.5 or 16.5 g crude protein per bird d) from 21 to 60 weeks of age. A system of foot scoring was used to assess the extent and severity of foot damage. Damage increased as energy intake increased but protein intake had little effect on foot condition. Cushion floors or perches introduced into the cages at 27 weeks of age reduced the deterioration in foot condition observed on all dietary treatments during lay. Egg output was not affected by foot condition although severe foot damage was observed in several cases.

Methionine-cystine interrelationships in chicks and rats fed diets containing suboptimal levels of methionine

Studies were continued with both chicks and rats on the previously reported (featherston and Rogler, 1978) growth depression observed when a crystalline amino acid diet adequate in all nonsulfur-containing amino acids and containing .2% DL-methionine and .2% L-cystine was supplemented with an additional .2% L-cystine. In the present investigation, an average growth depression of 37% was observed in chicks fed a diet containing .4% L-cystine and .2% DL-methionine as compared with chicks fed a diet containing .2% L-cystine and the same level of methionine. A comparable depression was noted when cystine was replaced by L-cysteine. In contrast, an additional .2% of another amino acid (L-tryptophan) did not depress growth. When the high and low cystine diets were meal-fed, results obtained were similar to those observed with ad libitum feeding, but the magnitude of the difference was reduced. Foot-pad lesions, similar to those described in turkey poults fed methionine-deficient diets, were observed in two experiments. Factorial analysis of plasma amino acids indicated that the total of all amino acids analyzed was significantly (P < .05) higher in chicks fed the lower cystine or cysteine diets. Plasma methionine was slightly lower (P < .10) but plasma cystine was significantly (P < .05) higher in chicks fed the cystine or cysteine supplemented diets. A study with .2 and .4% L-cystine and 200, 600, and 2000 mg/kg of choline (factorial design) demonstrated a significant (P < .05) depression in weight gain due to the added L-cystine, no significant (P < .05) differences due to choline, and the absence of a cystine-choline interaction. No detrimental effects were observed when weanling rats were fed a crystalline amino acid diet containing .1% DL-methionine and .2% L-cystine supplemented with additional L-cystine.

Methionine and cystine requirements of growing turkeys

Sulfur amino acid requirements of starting, growing, finishing male Large White turkeys were investigated in three experiments using 3000 turkeys. Requirements were determined by least squares analyses of response curves obtained by supplementing methionine and cystine deficient basal diets with graded levels of DL-methionine and/or L-cystine. Experiments were conducted from 1 to 4, 8 to 12, and 16 to 20 weeks of age. Diets included starch, soybean meal, faba beans, and field peas. Requirements for total sulfur amino acids (TSAA) determined with diets marginally deficient in cystine were .95 to 1.01, .70 to .71, and .43 to .48% of the diet for starting (1 to 4 weeks), growing (8 to 12 weeks), finishing (16 to 20 weeks) turkeys, respectively, in different experiments. On the basis of dietary metabolizable energy, the respective TSAA requirement values (in %/therm) were .298 to .332, .205 to .221, and .128 to .134. Minimum methionine requirements (determined with excess dietary cystine) were .46, .30, and .19% of the diet for starting, growing, and finishing turkeys, respectively. Cystine replacement values, calculated by dividing the maximum usable levels of cystine (TSAA requirements minus methionine requirements) by TSAA requirements were 55, 58, and 57% of the TSAA requirement for starting, growing, and finishing turkeys, respectively.

Amino acid digestibility of dehulled soybean meal by adult turkeys

Nine adult Large White male turkeys were fed dehulled soybean meal (DSBM) as the sole dietary component to determine the apparent digestibilities of its dry matter and amino acids. Apparent digestibility was determined by the total excreta collection method. Average apparent dry matter digestibility of DSBM was 53.3%. Amino acid contents of the DSBM and excreta for all except the sulfur amino acids were determined after acid hydrolysis. The sulfur amino acid levels were determined after performic acid oxidation and acid hydrolysis. Apparent amino acid digestibility averaged 87%. Glycine and arginine were the least and most efficiently digested amino acids with values of 80% and 93%, respectively.

Methionine and protein requirements of young turkeys

Nine experiments involving a total of 3697 turkeys divided into 48 pens per experiment were conducted to determine the methionine or total sulfur amino acid and the protein requirements of Medium White turkeys between 0 and 4 weeks and between 4 and 8 weeks of age. In each experiment, 24 diets varying in protein and methionine content in a 4 X 6 factorial design were fed. Body weight gains were found to be more closely related to the total sulfur amino acid content than to the methionine content of practical type corn-soybean meal diets. For the respective age periods between 0 to 4 and 4 to 8 weeks, the total sulfur amino acid requirements of Medium White turkeys were approximately 1.10 and 1.00% or 3.8 and 3.4 mg per kcal metabolizable energy, and the minimum protein requirements were at least 27% and 24% when diets contained sufficient total amino acids.

Effect of dietary methionine status on response of chicks to coccidial infection

Three experiments determined if the methionine requirement of broiler chicks was affected by coccidial infection. Chicks were fed a corn-soy or a corn-soy-pea basal diet containing 0.73% and 0.62% total sulfur amino acids (TSAA), respectively. Levels of 0 to 0.45% DL-methionine were added, with and without 0.01% monensin sodium. In two experiments, the chicks were inoculated at two weeks of age with a mixture of oocysts of E. acervulina, E. maxima, E. tenella, E. necatrix and E. brunetti. Lesion scores on the intestines and ceca, and blood carotenoid levels were determined at three weeks. The experiments were terminated at four weeks. A level of methionine greater than 0.47% and of TSAA greater than 0.83% was necessary to obtain maximum growth rate in uninoculated chicks. No evidence of dermatitis was observed. Growth rate and feed efficiency of chicks infected with coccidiosis were more severly depressed when the diet was not supplemented with methionine. Infections of coccidia and low levels of methionine, which in themselves did not produce any significant change in weight gain, did give a significant weight depression in combination. Adding monensin to the diet prevented a reduction in growth rate and feed efficiency of inoculated chicks fed adequate methionine. Monensin did not completely prevent the adverse effects of a coccidial infection, based on feed efficiency, when chicks were fed diets inadequate in methionine. Blood carotenoid levels were not affected by methionine level, but were significantly lowered by coccidial infection in the absence of monensin. Intestinal and cecal lesions in inoculated chicks were significantly reduced by including monesin in the diet. Although the coccidial infection more severly affected the performance of chicks fed diets deficient in methionine, satistical analysis of pooled data indicated no difference in the quantitative requirement of chicks for methionine. Therefore, a level of methionine and cystine adequate for optimum growth under the coccidial-free conditions should be adequate for chicks when infected with coccidia.