Guinea Pig Breeding and Sustainable Food Security: A Comprehensive Review

Guinea Pig Breeding and Sustainable Food Security

Introduction

• Guinea pig (Cavia porcellus) breeding is gaining importance in South America due to economic, cultural, and nutritional reasons.
• Guinea pigs are easy to manage and have short reproductive cycles (16 days), making them valuable for meat production.
• Peru leads in guinea pig breeding due to a significant number of specimens and advanced research.
• Annual guinea pig consumption:
  • Peru: 65 million
  • Ecuador: 47 million
  • Bolivia: 6 million
  • Colombia: 2.8 million
• Guinea pig breeding is increasing in South America due to its role in gastronomy and culture in Peru, Ecuador, Bolivia, and Colombia.
• Profit margins in guinea pig production are around 40%.
• Guinea pig farming is crucial for food security in Africa, sustaining numerous families.
• This review explores guinea pig production systems in South America, focusing on economic impact, food security, and future trends.

Description of the Guinea Pig

Morphological Description

• Scientific classification: Class Mammalia, order Rodentia, family Caviidae.
• Males are generally larger than females.
• Females have one pair of inguinal mammae and give birth to 2-4 offspring (gazapos) per parturition.
• Average weight of gazapos: 0.10 to 0.16 kg; they are born fully developed.
• Females start mating at a minimum weight of 0.75 kg (90 days of life).
• Males start mating at a weight greater than 1.20 kg (90-105 days after birth).
• Estrous cycle: 16.1 \pm 0.2 days.
• Gestation period: 63 to 70 days.
• Gestation period compared to other species:
  • Pigs: ~115 days
  • Sheep: ~152 days
  • Goats: ~150 days
  • Rabbits: 31 days
  • Chickens: 30 days
• Herbivorous mammal with a stocky, short-legged body and no external tail.
• Weight ranges from 0.5 kg to 1.5 kg.
• Fur varies in color (brown, white, black, gray) and length; rosettes may be present.
• Short, non-pointed nose; short, rounded ears; large, wide-set eyes.

Digestive System

• Molars for grinding rough plant materials; monogastric herbivore with cecal post-gastric fermentation.
• Single-compartment stomach lined with glandular epithelium.
• Large cecum, holding up to 65% of gastrointestinal contents.
• Microbial activity in the cecum is crucial for nutrient digestion and absorption.
• Guinea pigs can obtain more energy from cellulose than most domestic non-ruminant species due to hind-gut fermentation.
• The intestine harbors a complex microbial content that performs metabolic, trophic, and protective functions.
• Gut structure and function facilitate interactions between the host and microorganisms, playing a fundamental role in digestion.

Breeds for Meat Production

• Several lines and breeds in South America have been selected and bred for meat production.
• Both males and females are used for meat production.
• Examples: Andean commercial line, Inti commercial line, Peru commercial line, Ecuadorian native guinea pig, Peruvian native guinea pig, Bolivian native guinea pig, and Colombian native guinea pig.
• These breeds have undergone genetic selection and specialized breeding to optimize their suitability for meat production.
• Creole breeds have significant genetic diversity but are less suitable for large-scale meat production due to their size and body weight.
• In Peru, four breeds are particularly relevant for meat production:
  • Peru: 73% carcass yield
  • Andean: 70% carcass yield
  • Inti and Mantaro: 76% carcass yield

Exotic Breeds

• The American Cavy Breeders Association (ACBA) recognizes 13 exotic guinea pig breeds in the pet industry.
• Examples: Abyssinian, Abyssinian satin, American, American satin, crown, Peruvian, Peruvian satin, silkie, silk satin, teddy bear, teddy satin, texel, and white crested.
• Continuous experimentation and crossbreeding result in new breed variations.
• Creole breeds are also in demand as pets due to their exotic coats and wide variety of colors.

Systems and Facilities for Guinea Pig Breeding

• Three main systems in South America: family system, family-commercial system, and commercial system.
• These breeding systems use both native and improved lines.

Family Guinea Pig Breeding System

• Uncontrolled breeding; guinea pigs raised in wooden cages, pits on dirt floors, or kitchens.
• No control over reproduction or separation of litters, leading to inbreeding.
• Inbreeding affects offspring number, size, weight, and fur color.
• Feed consists of kitchen waste, crops, and forages like kikuyo (Pennisetum clandestinum).
• Used for family consumption, with 3-10 animals per family.

Family-Commercial System

• More organized; families have dedicated spaces for raising guinea pigs.
• Metal cages installed in external areas, with planted pastures for feed.
• Robust outdoor cages made of galvanized steel and PVC roofs, elevated 0.9 m above ground with mesh size of 1.3 cm \times 3.8 cm.
• Protection from wind and sun to avoid extreme climatic variations.
• Manages 100-500 animals, depending on forage availability.
• Guinea pigs grouped by sex, age, and breed to avoid inbreeding, resulting in better yields.

Commercial System

• Implements programs for controlling the reproductive system, health management, and feeding.
• Metal cages similar to the family-commercial system, housed in a concrete and brick shed.
• Shed divided into sections to group guinea pigs by sex, age, breed, and purpose.
• Manages over 500 animals.

Reproductive Indexes

• Family system: native population, poor management, productive indexes less than 0.2.
• Family-commercial system: precocious lines (Peru and Inti) crossed with native animals, productive indexes up to 0.8.
• Commercial breeding: selected, precocious, prolific, and efficient feed converters, productive index of 1.

Food Sources and Nutritional Requirements

• Gazapos do not eat or nurse in their first 12-24 hours but are born with the ability to feed themselves; offer fiber-rich foods.
• Feeding is based on robust plant sources: grasses like kikuyo, vicia, crop residues, alfalfa, forage corn, ryegrass.
• Feeds are deposited on the cage floor or through feeders.
• Feeding occurs twice a day using forages, forage mixtures, and balanced feed.
• Green forages provide necessary water; if balanced feed and dry forages are used, drinking water is essential.
• Protein concentration of 18-20% required during growth and lactation to provide essential amino acids.
• Minimum crude fiber level of 10% recommended.
• Deficient diet can cause reproductive delays, embryonic death, abortions, weak offspring, low carcass yields, low weight, and high mortality.
• Vitamin C is essential; guinea pigs cannot synthesize it due to lack of L-gulonolactone oxidase.
• Must obtain vitamin C from external sources, mainly green forages.
• Recommended ascorbic acid doses: 10 mg/kg daily for non-breeding adults, 30 mg/kg daily for growing or pregnant guinea pigs.
• Vitamin C deficiency can cause rough fur, anorexia, diarrhea, teeth grinding, joint swelling, gastrointestinal stasis, and increased susceptibility to bacterial infections.

Feeding Alternatives in Guinea Pig Breeding

• Feeding represents approximately 40% of production costs in commercial systems.
• Costs include labor, fodder transportation, feed preparation, and distribution.

Grazing System

• Guinea pigs graze directly on forage crops, reducing transportation costs.
• Mamani et al. (2015) showed similar weight and carcass yields compared to conventional feeding.
• Requires initial investment for adapting transportable cages and installing barriers to protect guinea pigs from environmental conditions and predators.

Supplementing Conventional Diets

• Barley and sunflower seeds improve weight gain at a similar cost to traditional feed.
• Erythrina (a tree with abundant foliage and high protein content) used in silvopastoral systems.
• A diet of 50% concentrate and 50% Erythrina sp. leaves and petioles improves live weight gain and carcass yield compared to 100% Erythrina sp.
• Euphorbia heterophylla (though poisonous to humans) can be used to increase n-3 polyunsaturated fatty acids in tissues.

Fish Silage

• Increases weight gain due to better utilization of amino acids and energy from fatty acids.
• Improves feed conversion due to pre-availability of nutrients.
• Affects meat flavor; recommended to use a maximum of 20% fish silage in the diet.

Mineral Supplementation

• Sodium butyrate (200-300 mg) can improve productive performance by modifying intestinal characteristics, increasing villi size, and reducing crypt depth.
• Copper sulfate (100-300 ppm) has negative effects on liver tissue, villi size, and crypt depth, and does not improve productive performance.

Supply of Probiotic Strains to Guinea Pigs

• Probiotic bacteria supplementation can contribute to safe guinea pig meat production and improve breeding.
• Benefits include prevention of infectious diseases, reduction in antibiotic use, and improvement of productive parameters.
• Wasson et al. (2000) showed that Lactobacillus plantarum, Lactobacillus casei, Lactobacillus acidophilus, and Streptococcus faecium at 10^7 CFU/g can eliminate or reduce antibiotic-induced disease effects.
• Massi (2006) evaluated the effect of strains and cell fractions of various probiotic bacteria on guinea pig intestinal motility in vitro.
• Torres et al. (2013) supplemented diets with probiotic bacterial species isolated from guinea pig intestinal mucosa, showing improvements in productive parameters.
• Ranasinghe et al. (2013) found that feeding 5 mL of L. bulgaricus and S. thermophilus (1.76 × 109 CFU/mL and 1.5 × 108 CFU/mL, respectively) reduced total serum cholesterol.
• Guevara et al. (2016) evaluated replacing growth-promoting antibiotics with probiotic strains.
• Cano et al. (2016) evaluated the impact of a commercial suspension containing several probiotic strains on growth and feed conversion, indicating improvements in weight gain and feed conversion.
• Jurado-Gámez et al. (2017) analyzed productive parameters and the efficacy of commercial probiotic strains as a dietary supplement.
• Several studies suggest that probiotic inclusion may not improve feed intake, weight gain, or carcass yield if strains are not protected against adverse factors in the gastric environment.

Slaughter of Guinea Pigs

• Guinea pigs can be slaughtered after 90 days of age and with a live weight between 1.1 kg and 1.5 kg.
• Slaughter method should guarantee animal welfare and comply with ethical standards.
• The most used method is cervical dislocation, but Limon et al. (2016) suggest that the captive bolt gun is more effective for immediate desensitization.
• Captive bolt gun placement: midline between the eyes and ears to penetrate the thalamus and midbrain regions.
• Another technique involves anesthesia with sodium pentobarbital or sodium hexobarbital, followed by cardiac exsanguination.
• Injection site: lateral to the midline, near the apex of the bladder and distal to the liver and stomach.

Guinea Pig Breeding as a Guarantee of Sustainable Food Security

• Guinea pig breeding has spread to Asia, Africa, and Europe.
• Ease of handling and docile nature make it an appreciated food source worldwide.
• Guinea pig breeding provides a source of meat protein and generates economic income for rural communities.
• Its prolific nature, easy management, adaptability, low dietary requirements, and ability to be raised without large tracts of land make it an important option for guaranteeing sustainable food security and sovereignty for low-income people.
• Guinea pigs have improved the food security of rural smallholder households in developing countries.
• Guinea pigs breed in a wide range of climates.
• In Ivory Coast, guinea pig breeding reduces poverty and malnutrition; in Cameroon, it guarantees food security.
• The choice to raise guinea pigs for consumption or sale is influenced by socioeconomic level.
• Countries in North America and the European Union are demanding guinea pigs for consumption.
• The export of guinea pig meat has become relevant due to migration from Peru, Ecuador, and Bolivia to the United States and Europe; Peru exports around 20,000 guinea pigs per year to the United States.
• Guinea pig breeding plays a crucial role in the sustainable food security and sovereignty of rural populations by providing a sustainable source of meat protein and income opportunities.

Pathogens and Infections Identified in Guinea Pigs

• Guinea pig breeding exposes animals to pathogens.
• Pathogens identified include Salmonella sp., Escherichia sp., Citrobacter sp., Klebsiella sp., Yersinia sp., and Campylobacter sp.
• Salmonella enterica serovar Typhimurium is a main pathogen in Peru and Ecuador, causing salmonellosis.
• Salmonellosis symptoms: fever, decay, bristly hair, dehydration, and bulging abdomen.
• Exposure to pathogenic strains of E. coli can lead to diarrhea and weakness.
• Pathogen presence varies depending on geographic region and husbandry conditions.
• Control and prevention of infections are fundamental for maintaining guinea pig health and ensuring food safety.

Molecular Methods Used for Pathogen Identification

• Molecular methods detect specific DNA or RNA sequences characteristic of pathogens.
• Samples for isolation: rectal and vaginal scrapings, feces, or organs.
• Methods focus on detecting the genus using exclusive genes and identifying the serovar using specific genes coding for the pathogen serovar.
• Molecular methods offer high sensitivity and specificity.

Antibiotics Used for the Treatment of Infections and as Growth Promoters

• Antibiotic use is highly relevant due to concerns about antimicrobial resistance.
• Prudent use of antibiotics is essential to minimize antimicrobial resistance.
• Antibiotics should be administered under strict observation of clinical signs and severity of the infection.
• Guinea pigs' gastrointestinal tracts are highly sensitive to some antibiotics.
• In southern Colombia, antibiotics are administered by untrained personnel without observing clinical signs, causing resistance.
• Microorganisms adapt through genetic variation (mutations).
• Exposure to low doses of antibiotics can result in antimicrobial-resistant strains.
• Mutations can be transferred through plasmid exchange within the bacterial colony.
• Common antibiotics: trimethoprim/sulfamethoxazole, enrofloxacin, chloramphenicol, gentamicin/amikacin, tetracycline/oxytetracycline, and Tresaderm.
• These antibiotics are also used in human medicine, raising concerns for WHO, as they can enter the human food chain, potentially causing a major pandemic.

Conclusions

• Guinea pig farming is important for sustainable food security and sovereignty in South America and elsewhere.
• Represents an excellent example of indigenous and local knowledge systems.
• Challenges include pathogen infections.
• Identification and management of pathogens are critical.
• Studies highlight common pathogens like Salmonella and Escherichia.
• Feeding strategies include supplementation with barley, sunflower seeds, and forage trees like Erythrina.
• Probiotic strains show potential for improving intestinal health and preventing disease.
• Responsible antibiotic use is important, based on clinical signs and severity of infections, to avoid antimicrobial resistance.
• This work aligns with the One Health concept by addressing intertwined aspects of animal and human health.