Introduction of rabbits to other countries

Transcription

1 Dietary advice for healthy and sick rabbits Origin of the domestic rabbit (Oryctolagus cuniculus) Originated in Iberian peninsula hot, dry and arid for some of year Rabbits can exist in these conditions Introduction of rabbits to other countries Worldwide distribution of Oryctolagus cuniculus Domesticated and kept in captivity for meat and fur Spread around the world by settlers who took and released them in new countries Wild rabbits in Europe are descended from introduced rabbits Effects of rabbits on landscape In Australia Eat virtually everything Destroy natural habitat Happened in UK Even worse in Australia Killed all rabbits on one side Trapped, shot, poisoned 1

2 Or biological control Chemical poisons Dropped by helicopters or planes in baited food Did they use poisonous plants? Is plant toxicity a problem? Lots of plants are meant to be toxic for rabbits None were used to kill rabbits in Australia Cannabis No- they are either resistant to toxin or they don t eat the plant Correlation between plants that rabbis leave alone and poisonous plants What rabbits like to eat Do wild rabbits eat hay? and shoots?? Dried leaves Tulips (meant to be poisonous) Ground Elder Or would they prefer grass 2

3 Food for pet rabbits Commercial rabbit foods Lots of brands of commercial rabbit foods for pet rabbits Lots of claims Big variation in quality and suitability for pet rabbits Competition between companies Information about nutritional requirements is taken from data about growth and reproductive performance of farmed rabbits Muesli mixes Many brands Cheap, convenient and available Palatable Store well Well marketed and advertised Formulated from data tables Analysis of whole mix is balanced Nutritional value of each ingredient Many ingredients are unbalanced. For example: High in carbohydrate Low in fibre Low in calcium Low in Vitamin A Low in Vitamin D Inverse Ca:P ratio Using calcium as an exampledietary requirement is 0.6-1% Calcium content of ingredients Selective feeding Vitamin and mineral supplement added to pellet or extrusions Food Alfalfa 1.5% Barley 0.07% Beans Calcium (Dry matter analysis) 0.14%` Pellets/ extrusions???? (0.5-1%) Maize (sweetcorn) 0.04% Oats 0.03% Peas 0.12% Wheat 0.16% Rabbits will pick out favourite ingredients Leave most unpalatable behind Often part with vitamin and mineral supplement in it Caring owner throws it away and replenishes bowl 3

4 Weaning rabbits on to muesli mixes Muesli mixes are never a good idea Selective feeding is a problem when weaning a litter of babies Dominant rabbits will pick out low calcium palatable ingredients Calcium requirement is high because they are growing Go on to develop dental disease Burgess have stopped making them Supreme haven t Pellets Nuggets Easy to change analysis for life stages Give control of cost and efficiency of production Easy to store Convenient Can be medicated Are the way that most commercial rabbits are fed May get hay as well if they are lucky Really started in UK by Burgess In response to problems with selective feeding Cooked, palatable biscuit Stores well Can incorporate long fibre strands- partially denatured by cooking Meant to be fed alongside hay Harcourt-Brown F.M.(1996) Calcium deficiency, diet and dental disease in pet rabbits. Veterinary Record for rabbits Lots of choice If the rabbit eats it, then it is Ok Grazing outside is perfect for rabbits Expensive to provide secure space Have to sacrifice any idea of growing flowers or veg Not an option for most people 4

5 Alternative option Some examples of plants that rabbits enjoy: Lots of free food, including grass on verges and alongside foot paths Won t have been sprayed May be mowed, which is inconvenient More details about foraging and illustrations on website Plants from veg garden Books Available from RWAF shop What about probiotics? What are probiotics Probiotics are defined as live micro organisms which, when administered in adequate amounts, confer a health benefit on the host A successful probiotic strain is expected to Tolerate gastric acid and bile tolerance Adhere to the intestinal epithelium and colonise Produce antimicrobial substances 5

6 What is in probiotics for rabbits Any evidence of efficacy? Lactobacillus? Enterococcus faecium Saccharomyces cerevisiae Not always easy to find out Some evidence that they improve performance (i.e. growth) in farmed rabbits One study showed a 50% reduction in losses from enteritis in farmed rabbits fed on yeast probiotic Inconclusive about effect on gut flora No hard evidence that they make a difference to pet rabbits, but many people find them beneficial Prebiotics According to Wikipaedia Definition: A non-digestible food ingredient that promotes the growth of beneficial microorganisms in the intestines. Example- Fructooligosaccharides Should increase the number or activity of beneficial bacteria. In a variety of foods Top 10 Foods Containing Prebiotics Food Prebiotic Fiber Content by Weight Gum Arabic 85% Raw, Dry Chicory Root 64.6% Raw, Dry Jerusalem Artichoke 31.5% Raw, Dry Dandelion Greens 24.3% Raw, Dry Garlic 17.5% Raw, Dry Leek 11.7% Raw, Dry Onion 8.6% Raw Asparagus 5% Raw Wheat bran 5% Whole Wheat flour, Cooked 4.8% Raw Banana 1% Vitamin and mineral supplements and blocks Not necessary if rabbit is on a good diet Caecal microflora synthesise many vitamins Amount of calcium that is in them could be a problem for rabbits with urinary tract disease Recommended diet for healthy rabbits Tiny amount pellets or nuggets Small amount fruit & root vegetables 6

7 Diet for rabbits with no incisors- Tiny amount pellets or no nuggets Small amount fruit & root vegetables Shred or grate food Diet for rabbits with early dental disease (apical elongation) Tiny amount pellets or no nuggets Small amount fruit & root vegetables Rabbits with apical elongation may not be able to, or won t, eat hay Corrective dentistry or dietary modification for early dental disease? Case Example- early stages of PSADD Coronal reduction is limited to selected cases in which malocclusion is minimal, has been diagnosed early, and proper occlusion of both incisor and cheek teeth can be restored Capello. V. (2016) Vet Clin Exot Anim My rabbit- Earl Earl- 2 years later after dietary modification only Effects of dietary modification on incisors Ridges grown out 7

8 Diet for rabbits with advanced dental disease Fruit & root vegetables Rabbits with deformed crowns can t chew fibrous foods- could shred it Rabbits with apical elongation can t won t eat hay Diet for rabbits with advanced dental disease Fruit & root vegetables Rabbits with deformed crowns can t chew fibrous foods- could shred it Rabbits with apical elongation can t won t eat hay End stage Obesity Fruit & root vegetables Rabbits with no crowns struggle to eat at all Rabbits with deformed crowns can t chew fibrous foods- could shred it Rabbits with apical elongation can t won t eat hay Have to convince owners that there is a problem Try to get the to feel about feeding the rabbit instead of not feeding it If it has good teeth, it won t starve on a diet of hay/grass and leafy greens If it has bad teeth, it might Situation even worse if they don t eat caecotrophs Diet for weight loss Fruit & root vegetables Diet for to improve caecotroph ingestion Fruit & root vegetables 8

9 Rabbits with endstage dental disease Very difficult Can be obese Struggle to eat fibre- can choke Live on soft foods Toast, banana, nuggets, muesli, biscuits Obese rabbits with end stage dental disease Fruit & root vegetables Rabbits with no crowns struggle to eat at all Rabbits with deformed crowns can t chew fibrous foods- could shred it Rabbits with apical elongation can t won t eat hay Outcome for rabbits with endstage dental disease Accept they will be obese Can try Low Calorie foods Shred greens etc. Diet and urinary tract disease Too much calcium in diet is blamed for too much calcium in urine Hypercalciuria is cited as a cause of urinary tract problems Extrapolated that too much dietary calcium causes urinary tract disease Not so simple Large amounts of sediment are in urine of: Rabbits on a high calcium diet Rabbits with adequate amount of dietary calcium but a low demand Rabbits with concentrated urine Urine concentration Natural diet is leafy green plants that are mostly water High water intake dilutes urine So sediment is diluted if rabbit eats lots of leafy green veg Sediment not diluted if rabbit eats lots of dry foodincluding hay 9

10 Dietary advice for rabbits with urinary tract disease Low calcium diets are often recommended to prevent or treat urinary tract disease Recommendation to avoid high calcium veggies It is sensible to restrict calcium but how? Influence of water content on dietary calculations Recommended dietary calcium is 0.6-1% But actual calcium intake depends on how much food is eaten and how much water is in it. Concentrated foods- pellets/nuggets have 5-10% water is 15% water is 80% water Lettuce is 95% water Recommended daily allowance (RDA) of calcium Rather than judging calcium content by its % dry matter (0.6-1%) Think about it as how much calcium a rabbit eats to meet its requirements RDA Recommended Daily Allowance Requirement will depend on whether rabbit is growing, lactating, pregnant or has teeth that are growing In region of 500mg/day Calculating amount of food that provides 500mg calcium Took figures from a variety of books and websites. Figures are on a dry matter basis Found values for dry matter content of food Set up Excel spreadsheet and calculated how much of a food item a rabbit would have to eat to ingest 500mg calcium Food Apples 0.12% Calcium (Dry matter analysis) Bananas 0.03% (0.06%) Broccoli 0.48% Cabbage 0.43% Carrot tops 1.94% Carrots 0.37% Dandelions 1.87% Lettuce 0.86% Maize (sweetcorn) 0.04% Oats 0.03% Watercress 1.2% Amount of food to provides 500mg calcium Amount of food item that provides 500mg calcium 63g Burgess Suparabbit Excel (0.9%Ca) 63g nuggets g Oxbow Bunny Basics ( % Ca) 1.6kg of lettuce 5.63kg of maize i.e. 3 lettuces ~10 cereal packets 10

11 Amount of food item that provides 500mg calcium Amount of food to provides 500mg calcium 2 large pieces broccoli 15 apples 529g spring 631g spinach 1.13kg carrots cabbage ~2 cabbages ~2.5 bags ~10-15 carrots Amount of food item that provides 500g calcium High calcium veggies 20 bananas 152g carrot tops 245g dandelions 256g kale ( 1+ bag) Mineral blocks Weighs 55g Contains 19% calcium and no water Calcium content 55X 19% = 10.45g 1/20 block supplies RDA (500mg) of for calcium Calcium content variable Depends on species of grass and soil type Usually around % 463g of grass if calcium content is 0.54% Seems a lot 11

12 But if you dry it out and separate it.. Water content of grass that provides 500mg calcium Rabbits produce lots of hard faeces ( per day) Have a large caecum that needs to be filled 463g grass contains 350mls water Low calcium nuggets Amount of hay that provides 500mg calcium 63g nuggets Could easily eat two bowlfuls and eat twice RDA of calcium 143g grass hay (85% DM)- contains 21mls water 41g alfalfa hay (1-2.07% calcium)- 6mls water May not be a good idea if rabbit has urinary tract problems. Urine will be concentrated Sipper bottles Rabbits drink less from sipper bottles. More concentrated urine. More sediment Tschudin, A., Clauss, M., Codron, D., Hatt, J.M. (2011). Preference of rabbits for drinking from open dishes versus nipple drinkers. Veterinary Record, 168, 190 Dietary modification for rabbits with urinary tract disease Most useful part of treatment Fluid intake should be increased Water from a bowl not sipper Offer food with high water content Oxalates should be restricted Calcium and phosphorus content should not be high or low Ca: P ratio should be balanced <2:1 Additional vitamin C may be helpful No vitamin or mineral supplements 12

13 Care with hay- not a lot of fluid and may not provide sufficient nutrients for rabbits with CRF that are SMALL struggling to maintain AMOUNTS body weight ONLY: Pelleted or Alfalfa should be avoided extruded food altogether- low in water, Salad high in calcium, protein Fruit and oxalate Diet for rabbits with urinary tract disease Small amount fruit & root vegetables Limited or no dry food Limited or no dry food NO MUESLI MIXES Plenty of leafy green plants and grass Prevents and treats urinary tract disorders Prevents and treats dental disease Colony v. pet THE rabbits END Access to good quality hay is mandatory 13