Abbreviations - Evaluierung ernährungsbedingter Effekte auf die Kinematik und die Telomerlänge

4. Ergebnisse

4.2 Studie 2

4.2.7 Abbreviations

BCS: Body condition score GRF: Ground reaction force

GRF↑: Side with higher vertical ground reaction force GRF↓: Side with lower vertical ground reaction force kbp: Kilo base pairs

MAX: Maximum joint angle MIN: Minimum joint angle OC: Old group with control diet OE: Old group with enriched diet ROM: Range of motion

ROS: Reactive oxygen species TRF: Terminal restriction fragment YC: Young group with control diet YE: Young group with enriched diet

4.2.8 Declarations

Ethics approval and consent to participate

As stated in the section “Animals and Experimental Design”, all measurements were performed in accordance with the relevant statutory provisions. The study was reported to the Lower Saxony State Office for Consumer Protection and Food Safety in Olden-burg, Germany (reference number 33.9-42502-05-13A369). Consent was obtained from all owners.

Consent for publication Not applicable.

Availability of data and materials

The datasets supporting the conclusions of this article are included within the article and its additional files.

Competing interests

The authors declare that they have no competing interests.

Funding

This study was funded by Hill’s Pet Nutrition, Inc. – Division of Colgate-Palmolive Eu-rope Sàrl (Therwil, Switzerland) and they provided both diets used in this study. How-ever, they did not have any additional role in the study design, data collection and analysis or preparation of the manuscript.

Authors’ contributions

HME, KL and IN designed the study. ML and MW collected the data. ML and JTS performed the telomere length analysis. ML processed the kinematic data. MB carried out the statistical analysis and helped with interpreting the data. ML drafted the manuscript, PW, HME; KL and IN revised it critically. All authors contributed with expert opinion and read and approved the final manuscript.

Acknowledgements

The authors wish to thank Alexandra Anders for her assistance with the kinematic re-cordings and the telomere length analysis as well as Saskia Willenbrock and Florenza Lüder Ripoli for their help with establishing the methodology for telomere length analysis. Furthermore, the authors wish to thank Frances Sherwood-Brock for proof-reading the translation.

4.2.9 References

1. Kraft W. Einführung. In: Kraft W, editor. Geriatrie bei Hund und Katze. 2nd ed.

Stuttgart: Parey Verlag; 2003. p. 23-31.

2. Hoskins JD. Geriatrics & gerontology of the dog and cat. 2nd ed. St. Louis:

Saunders; 2004.

3. Galis F, Van der Sluijs I, Van Dooren TJ, Metz JA, Nussbaumer M. Do large dogs die young? J Exp Zool B Mol Dev Evol. 2007;308:119-26.

4. Michell AR. Longevity of British breeds of dog and its relationships with sex, size, cardiovascular variables and disease. Vet Rec. 1999;145:625-9.

5. Kealy RD, Lawler DF, Ballam JM, Mantz SL, Biery DN, Greeley EH, Lust G, Segre M, Smith GK, Stowe HD. Effects of diet restriction on life span and age-related changes in dogs. J Am Vet Med Assoc. 2002;220:1315-20.

6. McKevitt TP, Nasir L, Devlin P, Argyle DJ. Telomere lengths in dogs decrease with increasing donor age. J Nutr. 2002;132:1604S-6S.

7. Aubert G, Lansdorp PM. Telomeres and aging. Physiol Rev. 2008;88:557-79.

8. Cawthon RM, Smith KR, O'Brien E, Sivatchenko A, Kerber RA. Association between telomere length in blood and mortality in people aged 60 years or older.

Lancet. 2003;361:393-5.

9. Wu X, Amos CI, Zhu Y, Zhao H, Grossman BH, Shay JW, Luo S, Hong WK, Spitz MR. Telomere dysfunction: a potential cancer predisposition factor. J Natl Cancer Inst. 2003;95:1211-8.

10. Fitzpatrick AL, Kronmal RA, Gardner JP, Psaty BM, Jenny NS, Tracy RP, Walston J, Kimura M, Aviv A. Leukocyte telomere length and cardiovascular disease in the cardiovascular health study. Am J Epidemiol. 2007;165:14-21.

11. Minamino T, Komuro I. Role of telomere in endothelial dysfunction in atherosclerosis. Curr Opin Lipidol. 2002;13:537-43.

12. Guan JZ, Maeda T, Sugano M, Oyama J, Higuchi Y, Suzuki T, Makino N. A percentage analysis of the telomere length in Parkinson's disease patients. J Gerontol A Biol Sci Med Sci. 2008;63:467-73.

13. Panossian LA, Porter VR, Valenzuela HF, Zhu X, Reback E, Masterman D, Cummings JL, Effros RB. Telomere shortening in T cells correlates with Alzheimer's disease status. Neurobiol Aging. 2003;24:77-84.

14. Fick LJ, Fick GH, Li Z, Cao E, Bao B, Heffelfinger D, Parker HG, Ostrander EA, Riabowol K. Telomere length correlates with life span of dog breeds. Cell Rep.

2012;2:1530-6.

15. Pang LY, Argyle D. Cancer stem cells and telomerase as potential biomarkers in veterinary oncology. Vet J. 2010;185:15-22.

16. Pang LY, Argyle DJ. Using naturally occurring tumours in dogs and cats to study telomerase and cancer stem cell biology. Biochim Biophys Acta. 2009;1792:380-91.

17. Nasir L, Devlin P, McKevitt T, Rutteman G, Argyle DJ. Telomere lengths and telomerase activity in dog tissues: a potential model system to study human telomere and telomerase biology. Neoplasia. 2001;3:351-9.

18. Egenvall A, Bonnett BN, Olson P, Hedhammar A. Gender, age, breed and distribution of morbidity and mortality in insured dogs in Sweden during 1995 and 1996. Vet Rec. 2000;146:519-25.

19. Hutchinson D, Sutherland-Smith J, Watson AL, Freeman LM. Assessment of methods of evaluating sarcopenia in old dogs. Am J Vet Res. 2012;73:1794-800.

20. Pagano TB, Wojcik S, Costagliola A, De Biase D, Iovino S, Iovane V, Russo V, Papparella S, Paciello O. Age related skeletal muscle atrophy and upregulation of autophagy in dogs. Vet J. 2015;206:54-60.

21. Francuski JV, Radovanovic A, Andric N, Krstic V, Bogdanovic D, Hadzic V, Todorovic V, Lazarevic Macanovic M, Sourice Petit S, Beck-Cormier S, Guicheux J, Gauthier O, Kovacevic Filipovic M. Age-related changes in the articular cartilage of the stifle joint in non-working and working German Shepherd dogs. J Comp Pathol. 2014;151:363-74.

22. Schofield JD, Weightman B. New knowledge of connective tissue ageing. J Clin Path. 1978;31 Suppl (Roy Coll Path) 12:174-90.

23. Morgan JP, Pool RR, Miyabayashi T. Primary degenerative joint disease of the shoulder in a colony of beagles. J Am Vet Med Assoc. 1987;190:531-40.

24. Richter T, von Zglinicki T. A continuous correlation between oxidative stress and telomere shortening in fibroblasts. Exp Gerontol. 2007;42:1039-42.

25. Brioche T, Lemoine-Morel S. Oxidative stress, sarcopenia, antioxidant strategies and exercise: molecular aspects. Curr Pharm Des. 2016;22:2664-78.

26. Regan EA, Bowler RP, Crapo JD. Joint fluid antioxidants are decreased in osteoarthritic joints compared to joints with macroscopically intact cartilage and subacute injury. Osteoarthr Cartil. 2008;16:515-21.

27. Altindag O, Erel O, Aksoy N, Selek S, Celik H, Karaoglanoglu M. Increased oxidative stress and its relation with collagen metabolism in knee osteoarthritis.

Rheumatol Int. 2007;27:339-44.

28. Halliwell B. Oxidative stress and cancer: have we moved forward? Biochem J.

2007;401:1-11.

29. Hwang O. Role of oxidative stress in Parkinson's Disease. Exp Neurobiol.

2013;22:11-7.

30. Bonomini F, Tengattini S, Fabiano A, Bianchi R, Rezzani R. Atherosclerosis and oxidative stress. Histol Histopathol. 2008;23:381-90.

31. Pohanka M. Alzheimer s disease and oxidative stress: a review. Curr Med Chem.

2014;21:356-64.

32. Kudryavtseva AV, Krasnov GS, Dmitriev AA, Alekseev BY, Kardymon OL, Sadritdinova AF, Fedorova MS, Pokrovsky AV, Melnikova NV, Kaprin AD, Moskalev AA, Snezhkina AV. Mitochondrial dysfunction and oxidative stress in aging and cancer. Oncotarget. 2016;7:44879-905.

33. Sies H. Oxidative stress: oxidants and antioxidants. Exp Physiol. 1997;82:291-5.

34. Mirabello L, Huang WY, Wong JY, Chatterjee N, Reding D, Crawford ED, De Vivo I, Hayes RB, Savage SA. The association between leukocyte telomere length and cigarette smoking, dietary and physical variables, and risk of prostate cancer.

Aging Cell. 2009;8:405-13.

35. Marcon F, Siniscalchi E, Crebelli R, Saieva C, Sera F, Fortini P, Simonelli V, Palli D. Diet-related telomere shortening and chromosome stability. Mutagenesis.

2012;27:49-57.

36. Xu Q, Parks CG, DeRoo LA, Cawthon RM, Sandler DP, Chen H. Multivitamin use and telomere length in women. Am J Clin Nutr. 2009;89:1857-63.

37. Wang Y, Smith S, Teichtahl AJ, Hodge AM, Wluka AE, Giles GG, Cicuttini FM.

Association between dietary intake of antioxidants and prevalence of femoral head cartilage defects and bone marrow lesions in community-based adults. J Rheumatol. 2016;43:1885-90.

38. Hsu DZ, Chu PY, Jou IM. Daily sesame oil supplement attenuates joint pain by inhibiting muscular oxidative stress in osteoarthritis rat model. J Nutr Biochem.

2016;29:36-40.

39. Costell M, O'Connor JE, Grisolia S. Age-dependent decrease of carnitine content in muscle of mice and humans. Biochem Biophys Res Commun. 1989;161:1135-43.

40. Hagen TM, Liu J, Lykkesfeldt J, Wehr CM, Ingersoll RT, Vinarsky V, Bartholomew JC, Ames BN. Feeding acetyl-L-carnitine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress. Proc Natl Acad Sci U S A. 2002;99:1870-5.

41. Ferrucci L, Cherubini A, Bandinelli S, Bartali B, Corsi A, Lauretani F, Martin A, Andres-Lacueva C, Senin U, Guralnik JM. Relationship of plasma polyunsaturated fatty acids to circulating inflammatory markers. J Clin Endocrinol Metab.

2006;91:439-46.

42. Kiecolt-Glaser JK, Epel ES, Belury MA, Andridge R, Lin J, Glaser R, Malarkey WB, Hwang BS, Blackburn E. Omega-3 fatty acids, oxidative stress, and leukocyte telomere length: A randomized controlled trial. Brain Behav Immun. 2013;28:16-24.

43. Farzaneh-Far R, Lin J, Epel ES, Harris WS, Blackburn EH, Whooley MA.

Association of marine omega-3 fatty acid levels with telomeric aging in patients with coronary heart disease. JAMA. 2010;303:250-7.

44. Sechi S, Chiavolelli F, Spissu N, Di Cerbo A, Canello S, Guidetti G, Fiore F, Cocco R. An antioxidant dietary supplement improves brain-derived neurotrophic factor levels in serum of aged dogs: preliminary results. J Vet Med. 2015;2015:412501.

45. Milgram NW, Head E, Muggenburg B, Holowachuk D, Murphey H, Estrada J, Ikeda-Douglas CJ, Zicker SC, Cotman CW. Landmark discrimination learning in the dog: effects of age, an antioxidant fortified food, and cognitive strategy.

Neurosci Biobehav Rev. 2002;26:679-95.

46. Hall JA, MacLeay J, Yerramilli M, Obare E, Yerramilli M, Schiefelbein H, Paetau-Robinson I, Jewell DE. Positive impact of nutritional interventions on serum symmetric dimethylarginine and creatinine concentrations in client-owned geriatric dogs. PLoS One. 2016;11:e0153653.

47. Cotman CW, Head E, Muggenburg BA, Zicker S, Milgram NW. Brain aging in the canine: a diet enriched in antioxidants reduces cognitive dysfunction. Neurobiol Aging. 2002;23:809-18.

48. Head E, Rofina J, Zicker S. Oxidative stress, aging, and central nervous system disease in the canine model of human brain aging. Vet Clin North Am Small Anim Pract. 2008;38:167-vi.

49. Snigdha S, de Rivera C, Milgram NW, Cotman CW. Effect of mitochondrial cofactors and antioxidants supplementation on cognition in the aged canine.

Neurobiol Aging. 2016;37:171-8.

50. Laflamme D. Development and validation of a body condition score system for dogs. Canine Pract. 1997;22:10-5.

51. Göhring J, Fulcher N, Jacak J, Riha K. TeloTool: a new tool for telomere length measurement from terminal restriction fragment analysis with improved probe intensity correction. Nucleic Acids Res. 2014;42:e21.

52. Goldner B, Fuchs A, Nolte I, Schilling N. Kinematic adaptations to tripedal locomotion in dogs. Vet J. 2015;204:192-200.

53. Drüen S, Böddeker J, Meyer-Lindenberg A, Fehr M, Nolte I, Wefstaedt P.

Computer-based gait analysis of dogs: evaluation of kinetic and kinematic parameters after cemented and cementless total hip replacement. Vet Comp Orthop Traumatol. 2012;25:375-84.

54. Böddeker J, Drüen S, Meyer-Lindenberg A, Fehr M, Nolte I, Wefstaedt P.

Computer-assisted gait analysis of the dog: comparison of two surgical techniques for the ruptured cranial cruciate ligament. Vet Comp Orthop Traumatol.

2012;25:11-21.

55. Galindo-Zamora V, Dziallas P, Wolf DC, Kramer S, Abdelhadi J, Lucas K, Nolte I, Wefstaedt P. Evaluation of thoracic limb loads, elbow movement, and morphology in dogs before and after arthroscopic management of unilateral medial coronoid process disease. Vet Surg. 2014;43:819-28.

56. Helmsmüller D, Anders A, Nolte I, Schilling N. Ontogenetic change of the weight support pattern in growing dogs. J Exp Zool A Ecol Genet Physiol. 2014;321:254-64.

57. Bockstahler B, Müller M, Henninger W, Mayrhofer E, Peham C, Podbregar I.

Kinetische und kinematische Analyse der Bewegung (Ganganalyse) der Vorderextremitaten bei gesunden Militarhunden - Erhebung von Basiswerten.

Wien Tierärztl Monatsschr. 2008;95:127-38.

58. Bockstahler BA, Henninger W, Müller M, Mayrhofer E, Peham C, Podbregar I.

Influence of borderline hip dysplasia on joint kinematics of clinically sound Belgian Shepherd dogs. Am J Vet Res. 2007;68:271-6.

59. Kadaba MP, Ramakrishnan HK, Wootten ME, Gainey J, Gorton G, Cochran GV.

Repeatability of kinematic, kinetic, and electromyographic data in normal adult gait.

J Orthop Res. 1989;7:849-60.

60. Frenck RW, Jr., Blackburn EH, Shannon KM. The rate of telomere sequence loss in human leukocytes varies with age. Proc Natl Acad Sci U S A. 1998;95:5607-10.

61. Hemann MT, Strong MA, Hao LY, Greider CW. The shortest telomere, not average telomere length, is critical for cell viability and chromosome stability. Cell.

2001;107:67-77.

62. Zou Y, Sfeir A, Gryaznov SM, Shay JW, Wright WE. Does a sentinel or a subset of short telomeres determine replicative senescence? Mol Biol Cell. 2004;15:3709-18.

63. Rae DE, Vignaud A, Butler-Browne GS, Thornell LE, Sinclair-Smith C, Derman EW, Lambert MI, Collins M. Skeletal muscle telomere length in healthy, experienced, endurance runners. Eur J Appl Physiol. 2010;109:323-30.

64. Kadi F, Ponsot E, Piehl-Aulin K, Mackey A, Kjaer M, Oskarsson E, Holm L. The effects of regular strength training on telomere length in human skeletal muscle.

Med Sci Sports Exerc. 2008;40:82-7.

65. Bellows J, Colitz CM, Daristotle L, Ingram DK, Lepine A, Marks SL, Sanderson SL, Tomlinson J, Zhang J. Common physical and functional changes associated with aging in dogs. J Am Vet Med Assoc. 2015;246:67-75.

66. Marcellin-Little DJ, Levine D, Canapp SO, Jr. The canine shoulder: selected disorders and their management with physical therapy. Clin Tech Small Anim Pract. 2007;22:171-82.

67. DeCamp CE. Kinetic and kinematic gait analysis and the assessment of lameness in the dog. Vet Clin North Am Small Anim Pract. 1997;27:825-40.

68. LaRocca TJ, Seals DR, Pierce GL. Leukocyte telomere length is preserved with aging in endurance exercise-trained adults and related to maximal aerobic capacity. Mech Ageing Dev. 2010;131:165-7.

69. Osthus IB, Sgura A, Berardinelli F, Alsnes IV, Bronstad E, Rehn T, Stobakk PK, Hatle H, Wisloff U, Nauman J. Telomere length and long-term endurance exercise:

does exercise training affect biological age? A pilot study. PLoS One.

2012;7:e52769.

70. Torres BT, Whitlock D, Reynolds LR, Fu YC, Navik JA, Speas AL, Sornborger A, Budsberg SC. The effect of marker location variability on noninvasive canine stifle kinematics. Vet Surg. 2011;40:715-9.

71. Schwencke M, Smolders LA, Bergknut N, Gustås P, Meij BP, Hazewinkel HA. Soft tissue artifact in canine kinematic gait analysis. Vet Surg. 2012;41:829-37.

72. Kim SY, Kim JY, Hayashi K, Kapatkin AS. Skin movement during the kinematic analysis of the canine pelvic limb. Vet Comp Orthop Traumatol. 2011;24:326-32.

4.2.10 Tables and Figures

Table 1

Major ingredients of the control diet C and the enriched diet E

Ingredient Diet C (control)

Diet E (enriched)

Moisture (%) 10.1 8.5

ME (kJ / 100g) 1624 1650

ME (kcal / 100g) 388 395

Crude protein (%) 24.0 19.3

Crude fat (%) 10.8 14.4

Crude fiber (%) 2.4 5.1

Crude ash (%) 8.6 5.2

All contents of ingredients are on a dry matter basis and were measured by the Institute for Animal Nutrition (University of Veterinary Medicine Hannover, Foundation, Ger-many).

ME = Metabolizable energy

Table 2

Composition of the four groups and their body weight, BCS and training phase duration during the study

Young group with

Weight 1 (kg) 31.4 ± 5.0 28.2 ± 5.0 32.2 ± 6.5 32.9 ± 5.6

Weight 2 (kg) 31.4 ± 4.5 28.5 ± 5.1 32.4 ± 6.9 32.6 ± 5.5

Weight 3 (kg) 31.8 ± 4.7 28.9 ± 5.2 33.4 ± 6.6 31.6 ± 5.2

BCS 1 4.5 ± 0.9 4.6 ± 0.9 4.7 ± 0.7 5.2 ± 0.9

BCS 2 4.2 ± 0.8 4.5 ± 1.0 4.8 ± 1.0 5.1 ± 0.9

BCS 3 4.3 ± 0.7 4.8 ± 0.9 4.7 ± 0.9 4.8 ± 0.9

Training 1 (min) 16.2 ± 10.4 19.6 ± 9.1 14.1 ± 6.1 17.1 ± 9.6

Training 2 (min) 6.6 ± 3.6 8.1 ± 5.3 5.6 ± 3.3 7.9 ± 8.1

Training 3 (min) 5.1 ± 3.2 4.8 ± 1.6 3.4 ± 1.7 3.9 ± 1.4

Number, breed, sex and average age of the dogs of the four groups as well as average treadmill speed during recordings are depicted.

Furthermore, average body weight, BCS and duration of training phase at the three measuring dates.

The number of dogs which participated in the study and were measured at least at the first two measuring dates is indicated without brackets. In brackets is the number of dogs which completed the study and were measured at all three measuring dates.

In cases of age, body weight, BCS, duration of training phase and speed of treadmill the mean ± standard deviation is presented.

Table 3

Positions of the joint determining markers (bold) and the additional markers

Forelimb Hindlimb Back

Margo dorsalis scapulae Crista iliaca ossis ilii Cervicothoracic transition Scapula Tuber ischiadicum ossis ilii Throracolumbar transition Tuberculum majus humeri Trochanter major ossis femoris Os sacrum

Humerus Femur

Epicondylus lateralis humeri Epicondylus lateralis ossis femoris

Radius Tibia

Processus styloideus ulnae Malleolus lateralis fibulae distal at Os metacarpale quintum distal at Os metatarsale quintum

Table 4

Average changes in the four groups after three and six months of feeding

Young group with control diet – YC

Young group with enriched diet – YE

Old group with control diet – OC

Old group with enriched diet – OE

→ 3 mo → 6 mo → 3 mo → 6 mo → 3 mo → 6 mo → 3 mo → 6 mo

Shoulder joint MIN GRF↑ +3.8 ± 14.2 +3.0 ± 20.1 −1.3 ± 23.2 +7.5 ± 27.5 −10.4 ± 13.6 −9.2 ± 14.9 −2.8 ± 12.2 +3.8 ± 17.8 GRF↓ −3.6 ± 17.2 −5.4 ± 19.1 −5.0 ± 17.1 −2.1 ± 26.4 −1.4 ± 15.7 −4.5 ± 14.2 −8.9 ± 21.0 −1.0 ± 15.9 MAX GRF↑ +7.2 ± 22.9 +7.2 ± 21.6 +11.8 ± 24.2 +10.6 ± 26.8 −2.6 ± 23.6 −5.1 ± 18.9 +7.9 ± 31.6 +17.9 ± 36.2

GRF↓ +6.5 ± 16.9 +3.9 ± 18.6 +3.9 ± 14.3 −1.1 ± 14.1 +0.3 ± 21.4 +0.8 ± 23.0 +3.1 ± 15.4 +13.3 ± 25.1 ROM GRF↑ +5.6 ± 17.4 +4.8 ± 17.2 +6.2 ± 20.1 +9.1 ± 26.3 −6.5 ± 14.4 −7.5 ± 13.8 +3.2 ± 19.6 +12.0 ± 26.4 GRF↓ +2.6 ± 15.1 0.0 ± 16.3 0.0 ± 12.5 −2.1 ± 15.8 −0.8 ± 16.5 −1.5 ± 18.2 −1.9 ± 15.3 +7.0 ± 16.2

Elbow joint MIN GRF↑ −0.2 ± 7.0 −1.4 ± 7.2 −0.9 ± 8.1 +0.7 ± 8.9 +0.8 ± 7.6 +2.2 ± 7.2 −1.4 ± 6.8 −1.0 ± 7.4 GRF↓ +3.3 ± 6.4 +3.2 ± 9.3 −1.6 ± 7.6 +2.5 ± 7.0 +0.5 ± 7.4 +0.1 ± 6.4 +0.1 ± 6.0 +0.7 ± 9.7 MAX GRF↑ −1.3 ± 6.2 −0.3 ± 10.6 +1.6 ± 10.2 +1.0 ± 6.7 +1.6 ± 9.4 +2.1 ± 11.4 −3.2 ± 12.1 0.0 ± 7.6

GRF↓ +2.6 ± 10.3 −0.6 ± 10.2 +0.4 ± 13.1 +3.3 ± 10.0 −0.7 ± 8.5 +1.9 ± 13.8 −2.9 ± 9.9 +0.3 ± 9.2 ROM GRF↑ −0.7 ± 6.2 −1.1 ± 6.7 0.0 ± 7.7 +0.7 ± 6.8 +1.0 ± 6.3 +2.1 ± 7.8 −2.5 ± 7.3 −0.8 ± 5.9 GRF↓ +2.9 ± 7.6 +1.5 ± 8.8 −0.8 ± 9.1 +2.8 ± 7.1 −0.2 ± 6.2 +0.6 ± 6.9 −1.3 ± 6.5 +0.4 ± 8.9

Carpal joint MIN GRF↑ −0.2 ± 7.7 −0.2 ± 5.6 −4.0 ± 6.2 −4.9 ± 7.1 −2.0 ± 5.5 −1.3 ± 6.2 −3.4 ± 6.7 −3.8 ± 11.0 GRF↓ +2.0 ± 7.9 0.0 ± 5.5 −2.6 ± 6.9 −1.5 ± 6.6 −1.2 ± 9.2 −4.4 ± 6.0 −2.5 ± 8.3 −2.7 ± 6.5 MAX GRF↑ −3.3 ± 7.6 −2.5 ± 7.5 +0.2 ± 8.1 −2.3 ± 6.8 −2.0 ± 7.8 −4.3 ± 11.4 −3.6 ± 7.6 −3.6 ± 8.2 GRF↓ +0.2 ± 6.7 −1.4 ± 6.3 −0.7 ± 7.9 −3.0 ± 9.7 −0.8 ± 10.4 −4.8 ± 9.5 −3.3 ± 7.4 −4.9 ± 7.5 ROM GRF↑ −1.4 ± 6.7 −1.1 ± 5.4 −2.5 ± 5.9 −4.1 ± 5.2 −2.0 ± 5.6 −2.4 ± 7.3 −3.6 ± 5.2 −3.8 ± 9.0 GRF↓ +1.3 ± 6.9 −0.5 ± 4.5 −1.9 ± 6.0 −2.2 ± 6.8 −1.1 ± 9.0 −4.6 ± 5.7 −2.8 ± 7.1 −3.5 ± 6.4

Hip joint

MIN GRF↑ +2.7 ± 9.9 +0.5 ± 10.2 +2.1 ± 9.5 +0.9 ± 10.6 +6.2 ± 10.6 +5.0 ± 11.7 +1.5 ± 13.1 +4.2 ± 14.1 GRF↓ +3.3 ± 15.1 +2.3 ± 5.5 +1.4 ± 9.1 −2.5 ± 9.4 −1.7 ± 13.1 −1.6 ± 14.0 +3.1 ± 11.4 +3.4 ± 13.6 MAX GRF↑ +5.3 ± 9.9 +3.9 ± 11.3 −1.6 ± 11.4 −4.1 ± 8.6 +1.9 ± 9.5 +2.2 ± 13.0 +0.3 ± 16.6 +1.1 ± 9.7

GRF↓ +1.0 ± 8.1 +1.0 ± 8.2 +0.4 ± 12.9 −2.4 ± 11.8 +0.7 ± 10.8 −0.2 ± 10.6 +3.3 ± 10.7 +2.8 ± 12.4 ROM GRF↑ +3.8 ± 8.6 +1.8 ± 6.3 0.0 ± 7.9 −1.8 ± 7.3 +3.8 ± 7.4 +3.5 ± 11.7 +0.7 ± 13.5 +2.3 ± 9.8

GRF↓ +2.0 ± 9.9 +1.4 ± 5.1 +0.8 ± 9.4 −2.6 ± 9.4 −0.7 ± 9.9 −1.1 ± 11.2 +3.0 ± 9.2 +2.9 ± 11.3

Stifle joint

MIN GRF↑ +4.8 ± 6.5 +2.6 ± 6.7 −0.6 ± 5.5 +1.7 ± 8.6 +0.9 ± 5.1 −0.5 ± 8.2 +0.2 ± 10.1 −0.7 ± 5.8 GRF↓ −2.1 ± 6.8 −6.1 ± 7.8 −1.0 ± 6.2 −2.8 ± 5.9 +1.4 ± 10.5 −1.0 ± 8.1 −0.1 ± 7.5 +1.2 ± 9.2 MAX GRF↑ −1.1 ± 13.4 −0.2 ± 13.1 −4.0 ± 11.5 −1.8 ± 11.0 −5.0 ± 10.1 −6.7 ± 11.0 −3.7 ± 10.4 −2.1 ± 12.2

GRF↓ −0.4 ± 11.0 −5.0 ± 9.9 −0.6 ± 11.3 −1.2 ± 7.2 −0.5 ± 12.6 −0.8 ± 11.2 −1.7 ± 12.4 −0.5 ± 10.9 ROM GRF↑ +1.9 ± 6.9 +0.9 ± 6.2 −2.1 ± 6.5 −0.1 ± 6.5 −1.8 ± 6.0 −3.2 ± 6.5 −1.6 ± 5.3 −1.4 ± 6.3

GRF↓ −1.7 ± 6.7 −5.8 ± 6.9 −0.9 ± 6.4 −2.3 ± 4.8 +0.5 ± 8.7 −0.8 ± 7.8 −1.0 ± 6.5 +0.2 ± 7.3

Tarsal joint MIN GRF↑ +1.2 ± 7.5 −0.2 ± 9.2 −0.7 ± 8.9 −1.4 ± 12.7 −1.8 ± 9.0 −2.3 ± 8.8 −0.6 ± 10.3 −1.7 ± 7.6 GRF↓ −1.4 ± 7.5 −0.8 ± 8.0 −3.5 ± 7.2 −5.7 ± 12.2 −2.3 ± 8.8 −3.0 ± 10.7 −1.5 ± 9.8 −1.5 ± 10.3 MAX GRF↑ +2.4 ± 10.1 0.0 ± 10.0 +1.5 ± 11.7 −1.5 ± 10.8 +0.4 ± 8.1 +1.3 ± 11.6 +1.4 ± 10.5 +0.1 ± 8.6

GRF↓ +2.4 ± 9.8 +2.7 ± 9.5 +1.2 ± 9.1 −1.2 ± 12.2 −3.7 ± 8.8 −3.1 ± 9.9 +4.7 ± 10.3 +0.6 ± 12.7 ROM GRF↑ +1.7 ± 7.5 −0.3 ± 8.1 +0.3 ± 8.2 −1.5 ± 9.9 −0.6 ± 7.1 −0.4 ± 8.8 +0.4 ± 7.6 −0.9 ± 6.4

GRF↓ +0.4 ± 6.3 +0.8 ± 6.2 −1.0 ± 6.8 −3.3 ±± 11.5 −3.2 ± 7.2 −3.2 ± 9.0 +1.6 ± 8.0 −0.9 ± 8.3 Mean TRF length +0.2 ± 4.9 +4.1 ± 7.2 +1.6 ± 6.1 +2.9 ± 6.7 +2.1 ± 5.3 −0.2 ± 5.2 +4.3 ± 9.7 +4.0 ± 8.3 Min. TRF length −0.5 ± 11.6 +7.7 ± 26.8 +4.9 ± 12.1 +0.7 ± 14.4 +4.1 ± 18.1 −3.0 ± 9.7 +2.2 ± 7.3 +7.0 ±15.2 In each joint percentage changes (mean ± standard deviation) in MIN, MAX and ROM are depicted, each on GRF↑ side and GRF↓

side. Furthermore, percentage changes (mean ± standard deviation) in mean and minimum TRF length are depicted.

A smaller MIN (greater flexion), greater MAX (greater extension), greater ROM, greater mean TRF length and greater minimum TRF length represent an increase.

→ 3 mo = Change between start and after three months of feeding

→ 6 mo = Change between start and after six months of feeding Min. TRF length = Minimum TRF length

Figure 1

TRF distribution of three dogs as an example. In each dog the samples of the three measuring dates were placed alongside one another in the gel. On the left side one canine and one human positive control can be seen. In the middle of the figure is the molecular weight marker, bands from 3.5 to 21.2 kbp can be seen.

Figure 2

Average changes in telomere length of the four groups after three and six months of feeding. Depicted are the percentage changes in mean TRF length (a) and minimum TRF length (b). A greater mean TRF length and a greater minimum TRF length represent an increase. The y-axis ranges from −4 to +8 %.