ABSTRACT
Carcass composition traits and weights and lengths of organs relative to body weight were measured in females from a broiler-breeder parent stock segregating for early and late-feathering alleles maintained under four feeding regimens. Feeding regimens consisted of ad libitum (AL), ad libitum restricted (ALR, feed restricted daily), and skip-one-day and skip-two-days (SOD and STD, given two or three times ALR allowance on Day 1 and not fed on the next 1 or 2 days, respectively). At 160 days of age, pullets on SOD and STD were changed to ALR feeding; daily feed allowances were increased to 135 g by day 180 and to 138 g on day 250. Organ growth and carcass composition were generally similar for early and late-feathering genotypes. Restricted feeding increased relative weights and lengths of segments of the gastrointestinal tract (GIT) and pancreas and reduced relative weights of the abdominal fat depot (AFD) and lipid contents of the liver, AFD, and total carcass. Relative weights of legs, breast, feathers, heart, and liver and carcass protein composition were not affected by feeding regimen. Relative oviduct and ovary weights were not affected, but number of rapidly developing follicles was higher for AL than restricted-fed hens. Relationships of most organs to total body weight changed little after sexual maturity. Relative weights and lengths of GIT decreased whereas breast, legs, and AFD increased. Feed-restricted chickens adapted to fasts by retaining GIT contents longer. Feeding regimen x age interactions were significant for esophagus, proventriculus, gizzard, shank, breast, legs, feathers, and AFD weights; esophagus, duodenum, jejunum, ileum, and shank lengths; and lipid contents of AFD and liver.
Subject(s)
Chickens/physiology , Food Deprivation/physiology , Animals , Body Weight , Chickens/anatomy & histology , Chickens/genetics , Eating , Feathers/growth & development , Female , Organ Size/veterinaryABSTRACT
Hysterectomy-derived germ-free guineapigs were given colonization-resistant caecal flora from mice (mCRF) or microflora obtained from the caecum of an antibiotic-decontaminated conventional guineapig (gpCRF) and compared with guineapigs raised conventionally with the sow. Body weight and the following intestinal parameters were determined for the groups: colonization resistance (CR) to Escherichia coli, relative caecal weight (RCW), beta-aspartylglycine (faeces), volatile fatty acids (caecum) and bile acids (faeces). mCRF guineapigs showed values quite different from control animals for CR and RCW, indicating the unsuitability of mouse CRF for normalizing guineapigs. In gpCRF guineapigs CR and RCW values were comparable with controls, indicating the suitability of the guineapig flora for normalizing guineapigs. mCRF guineapigs housed with gpCRF guineapigs, showed an improvement in CR and RCW, yielding values found in control animals.
