Maternal nutrition and growth hormone (GH) treatment during early-to mid-pregnancy can each alter the subsequent growth and differentiation of muscle in progeny. We have investigated the effects of varying maternal nutrition and maternal treatment with porcine (p) GH during the second quarter of pregnancy in gilts on semitendinosus muscle cross-sectional area and fibre composition of progeny, and relationships between maternal and progeny measures and progeny muscularity. Fifty-three Large White £ Landrace gilts, pregnant to Large White £ Duroc boars, were fed either 2·2 kg (about 35 % ad libitum intake) or 3·0 kg commercial ration (13·5 MJ digestible energy, 150 g crude protein (N £ 6·25)/kg DM)/d and injected with 0, 4 or 8 mg pGH/d from day 25 to 50 of pregnancy, then all were fed 2·2 kg/d for the remainder of pregnancy. The higher maternal feed allowance from day 25 to 50 of pregnancy increased the densities of total and secondary fibres and the secondary:primary fibre ratio in semitendinosus muscles of their female progeny at 61 d of age postnatally. The densities of secondary and total muscle fibres in semitendinosus muscles of progeny were predicted by maternal weight before treatment and maternal plasma insulin-like growth factor-II during treatment. Maternal pGH treatment from day 25 to day 50 of pregnancy did not alter fibre densities, but increased the cross-sectional area of the semitendinosus muscle; this may be partially explained by increased maternal plasma glucose. Thus, maternal nutrition and pGH treatment during the second quarter of pregnancy in pigs independently alter muscle characteristics in progeny.

Treatment of pigs with porcine ST (pST) in early to mid-pregnancy increases body weight and length of their fetuses by mid-pregnancy, but this increased weight may not persist to birth. We investigated the effects of short- (25 d) and long-term (75 d) treatment with pST, and interactions between long-term pST treatment and crude protein content of diet, in restricted-fed gilts. In both experiments, Large White x Landrace gilts were bred at first estrus to Large White x Duroc boars and allowed to farrow naturally. In the first experiment, gilts were fed 1.8 kg/d of a diet containing 13.5 MJ DE/kg of DM and 15.05% CP (as-fed basis) throughout pregnancy, and were injected daily with 0, 2, or 4 mg pST from d 25 to 50 of pregnancy. Maternal treatment with pST from d 25 to 50 of pregnancy did not affect the number of piglets born per litter or progeny size at birth. In the second experiment, gilts were injected daily with 0 or 2 mg of pST and fed 2.2 kg/d of a diet containing 14.5 MJ DE/kg and either (as-fed basis) 16.6% (0.81% lysine) or 22.2% CP (1.16% lysine) from d 25 to 100 of pregnancy. All gilts were then fed 3.0 kg/d of the lower protein diet from d 100 of pregnancy to farrowing. Treatment with 2 mg pST/d from d 25 to 100 of pregnancy increased live weight of all gilts during the treatment period (P = 0.016), but the change in maternal live weight from d 25 to 100 of pregnancy was only increased (P = 0.001) by pST in gilts fed the higher protein diet. Live weight of gilts 1 d after farrowing was increased by pST treatment (P = 0.007), but was not altered by protein content of diet during pregnancy. In gilts fed the lower protein diet, but not in those fed the higher protein diet, pST treatment decreased maternal backfat depth during treatment (P < 0.020) and 1 d after farrowing (P = 0.002). Treatment with pST during pregnancy did not affect the number of piglets born per litter but independently increased body weight by 11.6% (P < 0.001) and length by 3.4% (P = 0.005) of progeny at birth and decreased (P < 0.01) the negative effect of litter size on body weight at birth. We conclude that in feed-restricted gilts, fetal weight gains in response to 25 d of pST treatment before mid-pregnancy are not maintained to term but that treatment with pST during most of pregnancy increases progeny size at birth and reduces maternal constraint of fetal growth.

Antidiuretic activity has been assayed by intravenous injection of the test fluid into unanaesthetized mice to which three doses of water had been given by stomach tube. The method seems to be suitable for doses of the approximate range of 10 to 50 \g=m\U.vasopressin 10 g./ body weight.

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Adult rats kept for eleven weeks on a diet deficient in protein lost weight and some developed scrotal oedema. The retention of bromsulphthalein was increased, but the thymol turbidity test was unaffected; the apparent plasma volume was increased.Water diuresis in the protein deficient animals was impaired. There was no apparent delay in the mean rate of water absorption from the whole gastro-intestinal tract although a delayed absorption of water from the intestine was found in some animals. The concentrations of total plasma proteins and plasma albumin were low as compared with normal animals, but the plasma sodium levels were within normal limits. The inulin clearance (glomerular filtration rate) of the animals on the protein-deficient diet was significantly lower than that of the controls.In normal rats, aminophylline and acetazolamide were diuretic. Caffeine and sodium benzoate did not increase the urine output and mersalyl was antidiuretic. In the protein deficient rats, cortisone acetate increased the water diuresis. Caffeine and sodium benzoate, aminophylline and acetazolamide did not significantly increase this response, mersalyl had an antidiuretic effect. Cortisone acetate increased the food and water intake of the protein deficient rats; it also increased the glomerular filtration rate.It is now well established that animals kept on low protein diets have an impaired water diuresis (Dicker, Heller, and Hewer, 1946;Heller and Dicker, 1947;Leslie and Ralli, 1947; Guggenheim and Hegsted, 1953;Schnieden and Blackmore, 1955a). Rats kept on a protein deficient diet also have an increased total body water and are oedematous (Haigh and Schnieden, 1956). We have investigated the effects of diuretics on such animals to see whether water diuresis could be restored. In addition to the conventional drugs (mercurial and xanthine diuretics), cortisone and corticotrophin were also tested because these hormones have a diuretic effect in nephrosis (Luetscher, Deming, Harvey, Lew, and Poo, 1950; Luetscher, Deming and Johnston, 1951 Bergeim, 1942) 4.5, cod liver oil 3.0, supplemented by 50 mg. vitamin B complex powder (Crookes Laboratories/100 g. diet. It contained 0.4% thiamine, 0.5% riboflavine, 0.18% pyridoxine, 4% nicotinamide, and 0.0014% pantothenic acid. 3 mg. tocopherol acetate/100 g. diet was also added. This diet provided approximately 300 cal./100 g. and 0.2 protein/100 cal.Measurement of Food Intake.-The daily intake of food was estimated by placing groups of 6 rats in suspended cages. Weighed amounts of food in excess of the daily requirement were provided. Some scattering of food could not be prevented, so the cages were suspended over a tray lined with filter paper and the scattered food separated from the faeces each morning and added to food not consumed.Measurement of Water Intake.-Rats were placed in individual metabolism cages fitted with graduated drinking tubes. The amount of water drunk by each animal in 24 hr. was noted.Plasma Prateins.-A biuret method was employed for estimation of total plasm...