[Evaluation of nutritional characteristics of commercial canned cat diets]

OBJECTIVE

To evaluate commercial complete canned cat foods according to their composition, labeling and nutritional characteristics.

MATERIALS AND METHODS

A total of 21 commercial complete canned compound feeds for adult cats were analyzed for crude nutrients, minerals, vitamins, selected amino acids and taurine. The analyzed parameters were compared to the internal set of standards of the European Pet Food Industry Federation (FEDIAF). The energy content was calculated and compared with the labeled recommendations regarding the amounts of diet that should be fed. Analyzed nutrients were compared with the labeled nutrients according to the regulations of the EU food and feed law (directive EU regulation 767/2009).

RESULTS

In many cases, the labeled feeding protocols did not match the calculated daily energy requirements. In eight complete foods, the recommended daily feed amounts were underestimated and four recommendations exceeded energy requirements of adult cats. In 12 complete foods, the calcium and phosphorus contents were threefold higher than the respective requirement. In 16 of 21 complete foods, substantial discrepancies were observed between the recommendations and the analyzed trace elements. In particular, selenium contents exceeded the selenium requirement more than threefold. The vitamin, arginine and taurine contents showed no significant discrepancies to the recommendations. With respect to the labeled nutrients, there were only minor deviations from the regulations of the European law.

CONCLUSION AND CLINICAL RELEVANCE

In general, healthy adult cats are adequately supplied with energy and nutrients when feeding commercial canned complete diets for cats. In cases of body weight loss or gain, the labelled feed amounts should be questioned. The high phosphorus contents are an issue of concern, because a high phosphorus intake can potentially increase the risk for urinary stones and particularly for older cats the risk for renal insufficiency. Furthermore, it is recommended to decrease the high selenium levels by the reduction of selenium-rich feed materials such as offal.

Der BARF-Trend in der Hundeernährung – Eine Herausforderung für den Tierarzt?

Das Füttern von sog. BARF-Rationen ist ein aktueller Ernährungstrend bei Hunden. Der Übersichtsartikel beschreibt das tierärztliche Spannungsfeld zwischen Motivation und Kenntnisstand der Hundebesitzer auf der einen Seite und den wesentlichen Nachteilen der BARF-Fütterung auf der anderen Seite. Bei vielen Hundebesitzern besteht der Wunsch nach einer „natürlichen und gesunden Fütterung“, wohingegen die Nachteile der BARF-Fütterung maßgeblich durch Imbalancen in der Nährstoffzufuhr und der Kontamination mit Salmonellen hauptsächlich durch rohes Geflügelfleisch gekennzeichnet sind.

[Effects of a supplementation on sodium chloride or ammonium chloride on urolithic potential in the rabbit]

AIM

Reduction of urolithic potential by means of increased water intake and urine dilution through supplementation of sodium chloride (NaCl) or decrease of urine pH by supplementation of ammonium chloride (NH4Cl) in rabbits.

MATERIALS AND METHODS

Sixteen female, 6-month-old dwarf rabbits received the following three feeding regimens in a random order: complete feed without supplements = control; complete feed + 10 g NaCl/kg feed = NaCl; complete feed + 2.5 g NH4Cl/kg feed = NH4Cl. The diets were fed ad libitum over a period of 27 days without roughage. Water was provided ad libitum by a drinker. A 14-day wash-out-period (hay feeding) was performed between the different diets. Blood, faeces, and urine were collected at the beginning of each feeding period, after 21-day adaptation to the respective diet, and after the 3-day collection period. The following parameters were analysed: water and food intake as well as acid-base balance and mineral content in blood, urine, and faeces.

RESULTS

NaCl supplementation numerically increased the daily water intake from 40.5 ± 14.4 ml/kg body weight (BW) (control) up to 49.5 ± 14.3 ml/kg BW and significantly increased the daily urine volume from 16.9 ± 7.8 ml/kg BW (control group) to 21.1 ± 7.4 ml/kg BW. The specific gravity of urine samples from NaCl supplementation decreased from 1.060 ± 0.008 to 1.044 ± 0.008. NH4Cl supplementation did not induce significant changes in urine pH, blood acid-base parameters, or calcium retention. Relative supersaturations (RSS) for calcium oxalate and calcium phosphate showed no significant changes after treatment. RSS for struvite increased from 360 ± 735 (after hay feeding) to 3312 ± 6188 on control feeding, 2910 ± 4913 with NaCl supplementation, and 3022 ± 6635 with NH4Cl supplementation (p < 0.05).

CONCLUSIONS

NaCl supplementation significantly increased the urine volume and decreased its specific gravity. Therefore, NaCl supplementation might be an additional dietary treatment to increase the elimination of urine crystals in rabbits. NH4Cl supplementation did not induce acidification of the urine.

Mapping QTL for growth and muscling traits in three connected porcine F₂ crosses

Abstract. QTL experiments in pigs are often analysed separately, although similar or same founder breeds are frequently used to establish the experimental design. The aim of the present study was to jointly analyse three porcine F2-crosses for six growth and four muscling traits. The crosses were a Meishan × Pietrain cross, a Wild Boar × Pietrain cross, and a Wild Boar × Meishan cross. In some cases, same founder animals were used to establish the crosses. 966 F2-individuals were genotyped for 242 genetic markers (mostly microsatellites) and phenotyped for birth weight, 21 and 35 day weight, slaughter weight, carcass length, food conversion ratio, ham meat weight, shoulder meat weight, loin and neck meat weight, and meat area. A multi-allele multi-QTL model was applied that estimated an additive QTL effect for each founder breed and parental origin (either paternally or maternally derived), and a dominant QTL effect for each cross. This model was previously introduced in plant breeding. Numerous QTL were mapped on the autosomes. Most QTL were localised on SSC1, 2, 3, 4, 6 and 8, and no QTL were on SSC9, 11, 13, 15, 17 and 18. The confidence intervals were short in many cases. QTL with an exceptionally high test statistic were found for carcass length on SSC1, 4, 7 and 17. The coefficient of variation was remarkably small for this trait, which suggests that carcass length is affected by only a few genes with large effects. Positional and functional candidates underlying promising QTL are suggested for further study.

A two-step approach to map quantitative trait loci for meat quality in connected porcine F(2) crosses considering main and epistatic effects

The aim of this study was to map QTL for meat quality traits in three connected porcine F(2) crosses comprising around 1000 individuals. The three crosses were derived from the founder breeds Chinese Meishan, European Wild Boar and Pietrain. The animals were genotyped genomewide for approximately 250 genetic markers, mostly microsatellites. They were phenotyped for seven meat quality traits (pH at 45 min and 24 h after slaughter, conductivity at 45 min and 24 h after slaughter, meat colour, drip loss and rigour). QTL mapping was conducted using a two-step procedure. In the first step, the QTL were mapped using a multi-QTL multi-allele model that was tailored to analyse multiple connected F(2) crosses. It considered additive, dominance and imprinting effects. The major gene RYR1:g.1843C>T affecting the meat quality on SSC6 was included as a cofactor in the model. The mapped QTL were tested for pairwise epistatic effects in the second step. All possible epistatic effects between additive, dominant and imprinting effects were considered, leading to nine orthogonal forms of epistasis. Numerous QTL were found. The most interesting chromosome was SSC6. Not all genetic variance of meat quality was explained by RYR1:g.1843C>T. A small confidence interval was obtained, which facilitated the identification of candidate genes underlying the QTL. Epistasis was significant for the pairwise QTL on SSC12 and SSC14 for pH24 and for the QTL on SSC2 and SSC5 for rigour. Some evidence for additional pairwise epistatic effects was found, although not significant. Imprinting was involved in epistasis.

Mapping quantitative trait loci for metabolic and cytological fatness traits of connected F2 crosses in pigs

In the present study 3 connected F(2) crosses were used to map QTL for classical fat traits as well as fat-related metabolic and cytological traits in pigs. The founder breeds were Chinese Meishan, European Wild Boar, and Pietrain with to some extent the same founder animals in the different crosses. The different selection history of the breeds for fatness traits as well as the connectedness of the crosses led to a high statistical power. The total number of F(2) animals varied between 694 and 966, depending on the trait. The animals were genotyped for around 250 genetic markers, mostly microsatellites. The statistical model was a multi-allele, multi-QTL model that accounted for imprinting. The model was previously introduced from plant breeding experiments. The traits investigated were backfat depth and fat area as well as relative number of fat cells with different sizes and 2 metabolic traits (i.e., soluble protein content as an indicator for the level of metabolic turnover and NADP-malate dehydrogenase as an indicator for enzyme activity). The results revealed in total 37 significant QTL on chromosomes 1, 2, 4, 5, 6, 7, 8, 9, 14, 17, and 18, with often an overlap of confidence intervals of several traits. These confidence intervals were in some cases remarkably small, which is due to the high statistical power of the design. In total, 18 QTL showed significant imprinting effects. The small and overlapping confidence intervals for the classical fatness traits as well as for the cytological and metabolic traits enabled positional and functional candidate gene identification for several mapped QTL.

Role of the ssu and seu genes of Corynebacterium glutamicum ATCC 13032 in utilization of sulfonates and sulfonate esters as sulfur sources

Corynebacterium glutamicum ATCC 13032 was found to be able to utilize a broad range of sulfonates and sulfonate esters as sulfur sources. The two gene clusters potentially involved in sulfonate utilization, ssuD1CBA and ssuI-seuABC-ssuD2, were identified in the genome of C. glutamicum ATCC 13032 by similarity searches. While the ssu genes encode proteins resembling Ssu proteins from Escherichia coli or Bacillus subtilis, the seu gene products exhibited similarity to the dibenzothiophene-degrading Dsz monooxygenases of Rhodococcus strain IGTS8. Growth tests with the C. glutamicum wild-type and appropriate mutant strains showed that the clustered genes ssuC, ssuB, and ssuA, putatively encoding the components of an ABC-type transporter system, are required for the utilization of aliphatic sulfonates. In C. glutamicum sulfonates are apparently degraded by sulfonatases encoded by ssuD1 and ssuD2. It was also found that the seu genes seuA, seuB, and seuC can effectively replace ssuD1 and ssuD2 for the degradation of sulfonate esters. The utilization of all sulfonates and sulfonate esters tested is dependent on a novel putative reductase encoded by ssuI. Obviously, all monooxygenases encoded by the ssu and seu genes, including SsuD1, SsuD2, SeuA, SeuB, and SeuC, which are reduced flavin mononucleotide dependent according to sequence similarity, have SsuI as an essential component. Using real-time reverse transcription-PCR, the ssu and seu gene cluster was found to be expressed considerably more strongly during growth on sulfonates and sulfonate esters than during growth on sulfate.

Antagonistic and Agonistic GnRH Analogue Treatment of Precocious Puberty: Tracking Gonadotropin Concentrations in Urine

BACKGROUND

The pharmacodynamics of gonadotropin-releasing hormone (GnRH) agonists includes an initial 'flare-up' of the pituitary-gonadal axis, followed by reduced luteinizing hormone (LH) secretion. The question is if combining a short-acting antagonist with a long-acting agonist can diminish gonadotropin flare-up.

METHODS

To achieve quick downregulation in patients with recently diagnosed central precocious puberty (CPP, 7 patients) or short stature with short predicted final height (3 patients), we combined the GnRH antagonist cetrorelix (3 subcutaneous injections every 72 h) at the beginning of GnRH agonist treatment (leuprorelin or triptorelin) in 6 patients and compared the effect to 4 patients treated solely with GnRH agonist. To monitor effects, we measured LH and FSH concentrations in urine collected from initial morning urination during the first month of treatment.

RESULTS

In both treatment groups, gonadotropin flare-up could be detected in urine levels increased due to the flare-up phenomenon which was of short duration (<5 days) in the majority (5 of 6) of combined-treated patients and in the minority (1 of 4) of patients treated by agonist alone. During the first 10 days of treatment, mean LH concentration measured in urine was significantly lower in 4 CPP patients treated by the combined therapy compared to 3 CPP patients treated by the agonist only (mean LH combined therapy: 10.4 +/- 2.8 vs. 20.1 +/- 11.0 mU/ml in the agonist-only group, mean +/- SEM, p < 0.05). Significant correlations between stimulated serum LH in GnRH test prior to treatment and maximum urine LH after initiating GnRH analogue treatment (r = 0.547, p = 0.043), as well as basal serum LH and basal urine LH (r = 0.685, p = 0.014) were found.

CONCLUSION

Combined GnRH agonist and antagonist treatment led to rapid gonadotropin suppression. Also, urine measurements of LH and FSH seemed suitable for monitoring gonadotropin-inhibiting or -stimulating properties of GnRH analogues in individual patients. However, a controlled trial of a larger patient cohort is required to decide which treatment is the most effective.

Genome-wide analysis of the L-methionine biosynthetic pathway in Corynebacterium glutamicum by targeted gene deletion and homologous complementation

The genome sequence of Corynebacterium glutamicum, a gram-positive soil bacterium widely used as an amino acid producer, was analyzed by a similarity-based approach to elucidate the pathway for the biosynthesis of L-methionine. The functions of candidate ORFs were derived by gene deletion and, if necessary, by homologous complementation of suitable mutants. Of nine candidate ORFs (four of which were known previously), seven ORFs (cg0754 (metX), cg0755 (metY), cg1290 (metE), cg1702 (metH), cg2383 (metF), cg2536 (aecD), and cg2687 (metB)) were demonstrated to be part of the pathway while two others (cg0961 and cg3086) could be excluded. C. glutamicum synthesizes methionine in three, respectively four steps, starting from homoserine. C. glutamicum possesses two genes with similarity to homoserine acetyltransferases but only MetX can act as such while Cg0961 catalyzes a different, unknown reaction. For the incorporation of the sulfur moiety, the known functions of MetY and MetB could be confirmed and AecD was proven to be the only functional cystathionine beta-lyase in C. glutamicum, while Cg3086 can act neither as cystathionine gamma-synthase nor as cystathionine beta-lyase. Finally, MetE and MetH, which catalyze the conversion of L-homocysteine to L-methionine, could be newly identified, together with MetF which provides the necessary N(5)-methyltetrahydrofolate.

[The effect of anesthesia on kidney scintigraphy in the dog]

Renal scintigraphy is one of the diagnostic devices in the upper urinary tract. In 24 dogs of different age, sex and breed that--according to the usual laboratory tests--were considered healthy with respect to renal function, a renal scintigraphy with the tubular excreted tracer 99mTc-MAG3 was performed. The dogs were grouped according to three different anaesthetic regimens in order to estimate the influence of anaesthesia--which is necessary for this investigation--onto function of the normal kidney. Eight dogs were scintigraphed twice using different anaesthesia protocols. In group A (n = 22), anaesthesia was performed with a combination of atropine/diazepam/ketamine/xylazine. The reference range determined was for the period of maximal activity accumulation (Tmax) 3.2 +/- 0.8 min and for the elimination half-time (Tmax/2) 6.3 +/- 1.4 min. MAG3-clearance was 7.5 +/- 1.8 ml/min/kg. Group B (n = 5) received thiopental as a continuous intravenous infusion. Tmax was measured with 2.9 +/- 1.1 min, Tmax/2 with 4.7 +/- 1.2 min and the MAG3-clearance was 6.8 +/- 1.6 ml/min/kg. In group C (n = 5), the dogs were given propofol and halothane, and the values determined for Tmax and Tmax/2 were 4.8 +/- 2.7 and 4.8 +/- 1.4 min, respectively. The MAG3-clearance was 10.0 +/- 2.3 ml/min/kg. It is concluded that the anaesthetic regime used has a distinct influence on the reference values.