Methionine requirement of kittens given amino acid diets containing adequate cystine

Smalley, Katherine A.; Rogers, Quinton R.; Morris, James G.

doi:10.1079/bjn19830050

Cited by 19 publications

(13 citation statements)

References 18 publications

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“…Indeed methionine was undetectable (<10 μmol/L) in plasma from one in-contact cat, while 2 other in-contact cats had only 11 μmol/L methionine which equates to the plasma methionine concentration of kittens fed diets lacking methionine [20,25]. Methionine is an essential amino acid for cats, although cysteine may supply approximately 50% of this requirement [28]. Many of the FD cats in this study were young growing cats which have a higher SAA requirement than adults [20].…”

Section: Discussionmentioning

confidence: 99%

Alterations in amino acid status in cats with feline dysautonomia

McGorum

Symonds

Knottenbelt³

et al. 2017

PLoS ONE

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Feline dysautonomia (FD) is a multiple system neuropathy of unknown aetiology. An apparently identical disease occurs in horses (equine grass sickness, EGS), dogs, rabbits, hares, sheep, alpacas and llamas. Horses with acute EGS have a marked reduction in plasma concentrations of the sulphur amino acids (SAA) cyst(e)ine and methionine, which may reflect exposure to a neurotoxic xenobiotic. The aim of this study was to determine whether FD cats have alterations in amino acid profiles similar to those of EGS horses. Amino acids were quantified in plasma/serum from 14 FD cats, 5 healthy in-contact cats which shared housing and diet with the FD cats, and 6 healthy control cats which were housed separately from FD cats and which received a different diet. The adequacy of amino acids in the cats’ diet was assessed by determining the amino acid content of tinned and dry pelleted foods collected immediately after occurrences of FD. Compared with controls, FD cats had increased concentrations of many essential amino acids, with the exception of methionine which was significantly reduced, and reductions in most non-essential amino acids. In-contact cats also had inadequate methionine status. Artefactual loss of cysteine during analysis precluded assessment of the cyst(e)ine status. Food analysis indicated that the low methionine status was unlikely to be attributable to dietary inadequacy of methionine or cystine. Multi-mycotoxin screening identified low concentrations of several mycotoxins in dry food from all 3 premises. While this indicates fungal contamination of the food, none of these mycotoxins appears to induce the specific clinico-pathologic features which characterise FD and equivalent multiple system neuropathies in other species. Instead, we hypothesise that ingestion of another, as yet unidentified, dietary neurotoxic mycotoxin or xenobiotic, may cause both the characteristic disease pathology and the plasma SAA depletion.

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Section: Discussionmentioning

confidence: 99%

Alterations in amino acid status in cats with feline dysautonomia

McGorum

Symonds

Knottenbelt³

et al. 2017

PLoS ONE

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“…Specialized diets have resulted in a number of physiological, biochemical, and morphological adaptations. In carnivores, several key diet-related physiological traits have been identified, including differences in digestive enzymes [7], shortened digestive tracts [8], changes in amino acid dietary requirements [9, 10], and alterations to taste bud sensitivities (including a heightened response to amino acids and a loss of response to many mono- and di-saccharides) [11, 12], to name a few. In addition to these characteristics, the morphology of cats is highly adapted to hunting and includes flexible bodies, fast reflexes, and strong muscular limbs.…”

Section: Introductionmentioning

confidence: 99%

Comparison of carnivore, omnivore, and herbivore mammalian genomes with a new leopard assembly

et al. 2016

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BackgroundThere are three main dietary groups in mammals: carnivores, omnivores, and herbivores. Currently, there is limited comparative genomics insight into the evolution of dietary specializations in mammals. Due to recent advances in sequencing technologies, we were able to perform in-depth whole genome analyses of representatives of these three dietary groups.ResultsWe investigated the evolution of carnivory by comparing 18 representative genomes from across Mammalia with carnivorous, omnivorous, and herbivorous dietary specializations, focusing on Felidae (domestic cat, tiger, lion, cheetah, and leopard), Hominidae, and Bovidae genomes. We generated a new high-quality leopard genome assembly, as well as two wild Amur leopard whole genomes. In addition to a clear contraction in gene families for starch and sucrose metabolism, the carnivore genomes showed evidence of shared evolutionary adaptations in genes associated with diet, muscle strength, agility, and other traits responsible for successful hunting and meat consumption. Additionally, an analysis of highly conserved regions at the family level revealed molecular signatures of dietary adaptation in each of Felidae, Hominidae, and Bovidae. However, unlike carnivores, omnivores and herbivores showed fewer shared adaptive signatures, indicating that carnivores are under strong selective pressure related to diet. Finally, felids showed recent reductions in genetic diversity associated with decreased population sizes, which may be due to the inflexible nature of their strict diet, highlighting their vulnerability and critical conservation status.ConclusionsOur study provides a large-scale family level comparative genomic analysis to address genomic changes associated with dietary specialization. Our genomic analyses also provide useful resources for diet-related genetic and health research.Electronic supplementary materialThe online version of this article (doi:10.1186/s13059-016-1071-4) contains supplementary material, which is available to authorized users.

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“…The minimum requirement of CP of growing kittens was determined (Smalley et al., 1985) using dietary EAA concentrations well in excess of each minimal requirement and the EAA requirements of kittens were determined (Hardy et al., 1977; Costello et al., 1980; Titchenal et al., 1980; Schaeffer et al., 1982; Hargrove et al., 1983, 1984; Smalley et al., 1983; Quam et al., 1987; Williams et al., 1987; Hammer et al., 1996; Morris et al., 2004) using diets with an excess of CP. After completion of these studies, a free amino acid diet containing the minimum requirement of EAA and CP was offered to kittens.…”

Section: Introductionmentioning

confidence: 99%

Increasing dietary crude protein does not increase the essential amino acid requirements of kittens*

Strieker

Morris

Rogers

2006

Animal Physiology Nutrition

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Essential amino acid (EAA) requirements of omnivores and herbivores (e.g. chicks, lambs, pigs and rats) are directly related to the concentration of dietary crude protein (CP). When an EAA is limiting in the diet, addition of a mixture of EAA lacking the limiting one (which increases dietary CP) results in a decrease in food intake and weight gain. This interaction has been referred to as an AA imbalance and has not been studied in depth in strict carnivores. The objectives of these experiments were to examine the effects on growing kittens (2-week periods) of the addition to diets of a mixture of AA lacking the limiting one. The control diets were at the requirement of the respective limiting EAA (or about 85% of the 1986 National Research Council requirement). In experiment 1, with the dietary EAAs at the minimally determined requirements, the concentration of the essential or dispensable amino acids was increased to determine if CP or an EAA was limiting. Results of growth rates (n = 12) and plasma AA concentrations indicated that tryptophan was limiting, but increased body weight gain also occurred when the concentration of CP was increased as dispensable amino acids without additional tryptophan. Experiment 1 was repeated in experiment 2 using a crossover design. Again, when tryptophan was limiting additional concentrations of dispensable AAs increased body weight gain. This response is the opposite of that in herbivores and omnivores. Experiment 3 consisted of 10 separate crossover trials, one for each of the 10 EAA and examined the effect of two concentrations of dietary CP (200 and 300 g CP/kg diet) on body weight gain of kittens (n = 8) offered diets limiting in each respective EAA. Body weight gain was numerically greater when diets contained 300 g CP/kg than 200 g CP/kg for eight of 10 EAAs (p < 0.05 for only isoleucine and threonine) when each amino acid was limiting. This response is the reverse of that which occurs in chicks, lambs, pigs and rats when an EAA is limiting and dietary CP lacking the limiting EAA is increased. These results indicate that the EAA requirements of kittens are not positively correlated with dietary CP concentrations.

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Methionine requirement of kittens given amino acid diets containing adequate cystine

Cited by 19 publications

References 18 publications

Alterations in amino acid status in cats with feline dysautonomia

Alterations in amino acid status in cats with feline dysautonomia

Comparison of carnivore, omnivore, and herbivore mammalian genomes with a new leopard assembly

Increasing dietary crude protein does not increase the essential amino acid requirements of kittens*

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