Summary. Gastrointestinal transit in the pig : measurement using radioactive lanthanides and comparison with sheep.A technique to characterize the transit time of digesta through the gastrointestinal tract of the sheep has been described by François and Compere (1971). In the present paper, the authors present an adaptation of the method to the pig. On the first day of the experiment, each animal was given a diet uniformly labelled with 144 Ce as an unabsorbable marker. The feces were collected at 1 or 2-hour intervals at progressively extended periods for the remainder of the collection period. The fecal concentration of the marker rose rapidly to a maximum, then decreased following a simple exponential law. Data were also expressed as a cumulative excretion curve of 144 Ce. The mean retention time in the pig digestive tract could be calculated by concentration curves using either the m t parameter of Debouche (1974) or the t parameter proposed by Levenspiel (1974)

The dose related effects of recombinant porcine somatotropin (rpST) on growth, carcass characteristics, muscle properties, and meat quality were investigated in lean Belgian Landrace finishing pigs. Ninety-six pigs (48 barrows and 48 gilts) were injected daily with either vehicle, 1.5, 3, or 6 mg of rpST from 60 to 97.5 kg live weight. Each treatment group consisted of six pens of four pigs each (two of each sex). Pigs were given ad libitum access to a high-protein (20.4% CP) cereal-based diet. Administration of rpST increased (P less than .05) growth rate (16.3 to 25.4%) and improved (P less than .05) feed efficiency (16.9 to 29.4%). Feed consumption was reduced (12%; P less than .05) only in the 6 mg of rpST group. Liver, kidney, and heart weights were increased (P less than .05) in the 3 and 6 mg of rpST groups. Although the Belgian Landrace pigs are bred for superior carcass quality, rpST further improved (P less than .05) carcass composition at all dose levels as evidenced by a reduction (10 to 50%) in a number of subcutaneous fat depth measurements, an increase (10 to 20%) in longissimus muscle area, and an improvement in the lean cut:fat cut ratio. Rate of pH decline in the gluteus and longissimus muscles was similar, but rapid, in all groups (pH after 30 min = 5.74 to 5.94); the ultimate (24 or 72 h) pH was .15 to .2 pH units higher (P less than .05) in the pigs that received the 3 and 6 mg of rpST doses.(ABSTRACT TRUNCATED AT 250 WORDS)

caractéristique est exigée tant pour les études de digestibilité que pour celles visant à déterminer l'ingestion au pâturage. En outre, ils doivent rester associés aux constituants de la phase marquée, au cours du transit. Cette exigence est particulièrement importante pour les études de digestion menées sur des animaux munis de fistules simples. L'oxyde de chrome proposé par E DIN (101 8) comme indicateur inerte a été fort utilisé, principalement en vue de la détermination de digestibilité des rations par de nombreux auteurs, pour de nombreuses espèces animales (S CHUR C H , I,r,oYD

No abstract

Summary. Absorption and secretion of total and phospholipid phosphorus in the gastrointestinal tract of the sheep : A quantitative study.Quantitative aspects of the absorption and the secretion of total and lipid phosphorus were studied in adult wethers fed chopped meadow hay using radiocerium and chromium sesquioxide-paper as unabsorbable reference markers. Radiocerium was administered with the hay uniformly labelled in its totality, whereas identical doses of chromium sesquioxide-paper were distributed reliably and simply by incorporation into alfalfa pellets (mode of preparation to be described in another publication). The chopped labelled hay and chromium sesquioxide pellets were fed twice a day. High P secretion was found in the reticulo-rumen, ranging from 2.5 to 10 g a day and consisting mainly (90 p. 100) of mineral P. The organic P, probably of microbial origin, represented a daily secretion of 15 g of phospholipids. Considerable total and phospholipid P secretion occurred in the first part of the small intestine (ranging from 6.2 to 48.6 g of total P and 1.8 to 3.4 g of phospholipid P a day). Biliary phospholipids amounted to 30 p. 100 of total P secretion, and phosphates to the remainder. This secretion of total and lipid P was followed in all subjects by absorption of comparable intensity in the small intestine. As far as the present experimental conditions are concerned, these conclusions are not compatible with the existence of a saturable process for P absorption.Introduction.