Decline In Feed Intake Research Articles

Effectiveness of Low Sodium Diets for Recycling of Egg Production Type Hens

Egg type hens were recycled by the use of low sodium diet treatments compared to a conventional forced-molt procedure and an unrecycled control. Use of a low sodium diet containing .02 to .06% sodium for 6 weeks with reduction in daily photoperiod resulted in improvements in egg production, egg specific gravity, and albumen thickness similar to those of a forced-molt group in three separate experiments. Egg production was increased 11 to 13%, egg specific gravity was increased by .002 to .004, and albumen thickness was increased by 2 to 8 Haugh units over the 32-week posttreatment period for both treatments. Hens fed the low sodium diet for 3.5 or 4 weeks did not respond as favorably as hens fed this diet for 6 weeks. Eight weeks on the low sodium diet did not further improve performance. Results comparable to the forced-molt procedure were achieved with a decline in egg production at .03 to .07% sodium in the diet, a decline in feed intake at .03 to .07% sodium, a loss in body weight at .03 to .10% sodium, and an increase in molt score at .03 to .11% sodium during the experimental period. During the posttreatment period, results comparable to the forced-molt procedure were obtained for egg production increase at .03 to .08% sodium, for egg specific gravity increase at .03 to .12% sodium, and for egg albumen thickness increase at .03 to .12% dietary sodium. Mortality was unchanged.

Short- and long-term effects of eating on blood composition in free-feeding goats

SUMMARYAdult goats provided with permanent jugular and portal vein catheters were used to study the relation between spontaneous meals and blood composition in free-feeding goats in order to determine which constituents might fulfil a feedback signal function in the control of feed intake. Animals were fed ad libitum concentrates, supplemented with a small amount of hay. Blood samples were collected before, during and after spontaneous meals by means of a remote sampling system and were analysed for volatile fatty acids, glucose, insulin, glucagon and growth hormone.In a preliminary experiment the relationship between body weight, voluntary feed intake, blood glucose and plasma insulin was examined in goats fed ad libitum concentrates and hay for 18 weeks. The data indicate a regulation of energy balance through control of feed intake. Since an increased glucose and insulin concentration was observed concomitantly with a decline in feed intake, glucose and/or insulin may fulfil a signal function in the control of energy balance.Spontaneous meals were not preceded by a systematic change of any of the above blood constituents. Therefore, it is unlikely that meal initiation is governed by one of those. In contrast, spontaneous meals resulted in a rapid increase of insulin during eating (P < 0·025) whereas no clear changes were observed for the other substances. Thus, insulin might be a candidate for a feedback function in the control of meal duration.

High Dietary Zinc or Magnesium as Forced-Resting Agents for Laying Hens

Abstract Ninety caged Single Comb White Leghorn hens, 58 weeks of age, were randomly assigned to 5 treatment groups of 18 birds each and either a) molted conventionally by removal of water for 48 hr and feed for 9 days followed by ad libitum intake of a 10% crude protein ration; or force-rested by the inclusion of b) 1.0% zinc as zinc acetate; c) 1.0% zinc as zinc oxide; d) 2.0% magnesium, as magnesium acetate; or e) 2.0% magnesium, as magnesium oxide into the laying ration for 14 days. One percent dietary zinc, as either the acetate or oxide, resulted in a rapid decline in feed intake and cessation of egg production (within 6 days), with subsequent rate of lay, egg Haugh units, specific gravity, and shell thickness during the 24 weeks following forced-rest similar to the hens molted conventionally. Neither magnesium treatment was effective as a dietary treatment for the induction of forced-rest as reduction in feed intake and cessation of egg production during the forced-rest period was incomplete. Following forced-rest, the eggs from both magnesium treated groups had significantly lower Haugh units and the magnesium oxide treatment also resulted in significant reduction in egg specific gravity and shell thickness. The results indicate that 1.0% zinc, as either the acetate or oxide, may be an effective dietary agent for the induction of forced-rest.

The effect of level of nutrition on thyroid activity in beef cattle

Four experiments were conducted to determine the effect of different nutritional levels on thyroid activity in beef cattle. In experiment 1, plasma protein-bound iodine (P.B.I.) levels in eight steers on poor pasture increased by over 50% 24 hr after supplying a supplement of 20 lb good quality lucerne hay per animal per day. In experiment 2, 17 grazing spayed heifers given a supplement of 2 lb peanut meal per day over a 4-month period also had higher P.B.I.'s than 24 controls. In experiment 3,10 growing steers given a constant amount of lucerne hay throughout the year showed decreases in P.B.I. and thyroid secretion rate consistent with a decline in feed intake per unit of metabolic body weight. A Latin square design was used in experiment 4, to study the effects of ad libitum feeding of three different rations: lucerne hay, non-legume hay, and ground sorghum plus non-legume hay to 18 steers. All rations caused sharp first-day increases in P.B.I., the magnitude of which depended on the quality of the ration. As feeding continued the P.B.I.'s decreased somewhat. At the end of 5 weeks, P.B.I.'s and thyroid secretion rates were similar in steers fed on lucerne or sorghum plus non-legume hay, but significantly lower (P < 0.05) in those fed on non-legume hay alone. The failure of intramuscular injections of vitamin A to increase P.B.I. in animals on low-carotene pasture and hay ruled out the carotene content as a source of the nutritional effect. These studies indicate that various types of improved nutrition can have pronounced effects on the thyroid, and that seasonal and animal differences in thyroid activity could result from differences in quality or quantity of pasture intake.

Studies on the carbohydrate metabolism of sheep. XVIII. The metabolism of glucose, free fatty acids, ketones, and amino acids in late pregnancy and lactation

The metabolism of glucose, free fatty acids (FFA), ketone bodies, and amino acids in late pregnancy and lactation was studied at three levels of feeding in an experiment designed to measure the increase in nutrient requirements of ewes with advancing pregnancy.The plasma FFA level is a more sensitive criterion of undernutrition during pregnancy than the level of blood glucose or ketones. In ewes on a constant feed intake and in medium body condition approaching late pregnancy, the rate of mobilization of fat reserves necessary to maintain caloric homeostasis, as indicated by plasma FFA level, was closely correlated with total foetal weight in late pregnancy and with the level of milk production in the first month of lactation. However, these ewes were unable to maintain blood glucose levels in the normal range in late pregnancy; severe hypoglycaemia was present in twin-bearing ewes. Caloric homeostasis was best maintained in fat ewes fed ad libitum; variation in blood glucose and FFA levels during late pregnancy and early lactation was minimal, in spite of a marked and variable decline in feed intake in twin-bearing ewes in late pregnancy. Reduction of foetal demand for nutrients may prevent or defer the breakdown of homeostatic meohanisms, but appears to play a minor role in the maintenance of caloric homeostasis in the undernourished pregnant ewe. However, reduction in the level of milk production is a major factor in the undernourished lactating ewe; severe hypoglycaemia and hyperketonaemia are thus prevented. The metabolic effects of high foetal requirements of amino acids are discussed in relation to observed variations in plasma amino acid Level in late pregnancy.

The Use of Malt Sprouts in the Bacon Hog Ration

The results of these feeding trials indicated a remarkable similarity between the effects of malt sprouts and antibiotic supplements when added to the hog ration. Malt sprouts appeared to be partially effective in preventing at least one type of scours. The inclusion of malt sprouts in the growing ration of the pig resulted in a stimulation of growth and a significant increase in feed efficiency.The growth stimulation was not as great as that obtained with terramycin. When malt sprouts was included in the hog finishing ration, a growth stimulating effect was observed for one lot of pigs. The feed efficiency of the ration also showed an upward trend as the malt sprouts fraction of the ration was increased. However, the introduction of malt sprouts into the finishing ration neither stimulated growth nor increased feed efficiency for a second lot of pigs. These opposing results cannot be reconciled, and point to the necessity of further research into the growth-stimulating properties of malt sprouts during this period of growth in the pig. The withdrawal of malt sprouts from the ration when pigs reached a weight of 115 lb., resulted in a decrease in growth rate, presumably due to the decline in feed intake. Such a decrease in growth rate was not observed with the withdrawal of malt sprouts from a ration previously supplemented with terramycin. The crude fiber introduced into the ration by the use of malt sprouts apparently in no way decreased the value of the ration for pigs. It was not, however, effective in improving the grade of carcass produced.