Effects of Low Protein Diets Supplemented with Ami-no Acids on Production Performance,Carcass Qual-ity and Input-output Ratio of Pigs

[ Objectives ] To study the effects of low-protein diets supplemented with amino acids on the production performance, carcass quality and input-output ratio of fattening pigs and growing-finishing pigs. [ Methods] Two studies were conducted on fattening pigs and growing pigs respectively. Pigs in two experimental groupswere fed with low-protein diets supplemented with amino acids and normal diets respectively, and the initial weight, final weight, feed consumption and car- cass index of the tested pigs were measured. [ Results] The average final weight of fattening pigs in test group was 2.4 kg lower than that in control group, while the difference was not significant （P 〉 0.05 ）. The average daily gain of fattening pigs in test group was 60 g lower than that in control group, indicating that low protein diets had a tendency to decrease the growth rate （P 〉 0.05 ）, and reduction of daily weight gain in low protein diet pigs reached 7.6%. The development of pigs in low protein diet group was poor, however, the difference was not significant. Carcass backfat thickness in low-protein diet group was slightly higher than that in control group, the difference was significant （ P 〈 0.05 ）. There was no significant difference in input-output ratio between low-protein diet group and control group. Finalweight of growing-finishing pigs in low-protein diet group was 3.22 % lower than that in control group, the average daily weight gainwas 6.91% lower than that in control group, feed intake in test group was 5.48% lower than that in control group, and difference between the two treatments was significant （P 〈 0.05 ）. Feed meat ratio in low-protein diet group improved, however, the difference was not significant（P 〉0.05）. [ Conclusions] Production performance of the pigs would be decreasedand the input-output ratio could not be improvedwhen the adding contents of crude protein in diets was reduced 3% -4%. Therefore, it is recommended that the crude protein level should be enough when pigs were fed with low-protein diets.

Dietary stimulation of the endogenous somatotropic axis in weaner and growerfinisher pigs using medium chain triglycerides and cysteamine hydrochloride

Background： Three experiments were conducted to examine the overall hypothesis that addition of medium chain triglycerides（MCT） and cysteamine hydrochloride（CSH） into the diets of young and growing pigs would stimulate the endogenous somatotropic axis to improve growth and performance.Results： In Experiment 1, weaner pigs were given either a 5 d dietary supplement of 5 % MCT（n = 8） or a control diet（n = 8）. MCT increased the plasma concentration of growth hormone（GH; P ＆lt; 0.05） and the GH secretagogue,ghrelin（P ＆lt; 0.05）. Additionally, the MCT treatment reduced scouring（P ＆lt; 0.05）, maintained villous height in the small intestine（P ＆lt; 0.05） and stabilised daily weight gain（P ＆lt; 0.05）, compared to the controls. Experiment 2compared the effects of 4 levels（0, 1, 3 and 6 % v/v） of MCT supplementation in grower-finisher male pigs, of approximately 35 kg live weight（n = 15 per treatment）. Blood samples taken after 7 wk of treatment showed that the MCT supplementation increased circulating ghrelin（P ＆lt; 0.001）, GH（P ＆lt; 0.01） and insulin（P ＆lt; 0.05）concentrations in a dose-dependent manner. Daily weight gain, feed intake and feed conversion ratio were not affected by the MCT diets. In Experiment 3, 64 female pigs of approximately 60 kg live weight were allocated to one of three dietary treatments： control（n = 20）; 6 % MCT（n = 21）; and 70 mg/kg CSH（n = 21）. After 3 wk of supplementation, the MCT treated pigs had a higher plasma concentration of ghrelin compared to the control and CSH pigs（P ＆lt; 0.05）. Plasma concentrations of GH and weight were not affected by any of the dietary treatments.Conclusions： Evidence is provided in Experiment 1 to support the use of dietary MCT supplements, perhaps acting via stimulation of somatotropic endocrine pathways, to minimise weaning-associated disorders such as slowing of growth and diarrhoea. In Experiments 2 and 3, although there was no effect on weight gain or feed conversion ratio in either experiment, MCT and CSH increased endocrine components of the somatotropic axis.

Evaluating the quality of feed fats and oils and their effects on pig growth performance

Feed fats and oils provide significant amounts of energy to swine diets, but there is large variation in composition,quality, feeding value, and price among sources. Common measures of lipid quality include moisture, insolubles,and unsaponifiables（MIU）, titer, and free fatty acid content, but provide limited information regarding their feeding value. Lipid peroxidation is an important quality factor related to animal growth performance and health, but maximum tolerable limits in various lipids have not been established. Several indicative assays can be used to detect the presence of various peroxidation compounds, but due to the complexity and numerous compounds produced and degraded during peroxidation process, no single method can adequately determine the extent of peroxidation. Until further information is available, using a combination of peroxide value, thiobarbituric acid reactive substances（TBARS）, and anisidine value appear to provide a reasonable assessment of the extent of peroxidation in a lipid at a reasonable cost. However, fatty acid composition of the lipid being evaluated should be considered when selecting specific assays. Predictive tests can also be used to estimate the stability or susceptibility of lipids to peroxidation and include active oxygen method, oil stability index, and oxygen bomb method. A review of 16 published studies with pigs has shown an average decrease of 11.4% in growth rate, 8.8% feed intake fed isocaloric diets containing peroxidized lipids compared to diets containing unperoxidized lipids of the same source.Furthermore, serum vitamin E content was generally reduced and serum TBARS content was increased when peroxidized lipids were fed in these studies, suggesting that feeding peroxidized lipids negatively affects metabolic oxidative status of pigs. However, it is unclear if antioxidants are useful additions to lipids to maintain optimal nutritional value, or if their addition to swine diets is beneficial in overcoming a metabolic oxidative challenge.

The Positive Effects of Proprietary Undenatured B-Glucans on Growing Pigs

Beta-glucan that is typically isolated from the fungi or yeast, by solvent extraction, is a commonly used supplement. However, the solvent extraction of beta-glucan from these sources destroys the tertiary structure of the compound, and reduces the immuno-stimulating efficacy of the denatured beta-glucan when compared to undenatured beta-glucan (UDBG1). The objective of this study was to investigate growth performance of piglets, from weaning, that received diets containing undenatured beta-glucan (UDBG) for the following four weeks (up to an average live weight of 26.4 kg). The study was conducted with 128 Noroc pigs from 24 litters at the experimental pig house of the Norwegian University of Life Sciences. There were four dietary treatments;one group was fed a control diet containing no UDBG, three other groups were fed a diet containing 0.02 mg UDBG/kg, 0.2 mg UDBG/kg;or 2.0 mg UDBG/kg. In week 1 - 2, the pigs fed 2.0 mg UDBG per kg of feed gained 12% faster than the control diet. The numerical increase in weight gain during the first period after weaning is indicative of an improved immune status of the piglets fed the higher inclusion levels of the UDBG diets. Additionally, the piglets fed the highest level of UDBG (2.0 mg/kg) were found to have a better viability compared to the other groups, as determined by the Veterinary staff. No clinical problems related to the dietary treatments were observed. The animals revealed good growth and an average daily gain (ADG) for all pigs were 559 g for the overall experimental period. The growth performance was calculated for the two first weeks of the study, the remaining last two weeks of the study, and for the overall four-week experimental period. Significant effects of UDBG on weight gain and feed intake were found during the early weeks, but diminished later in the trial. The addition of UBDG to diets had a significant positive effect on several blood hematological parameters including the index of anisocytis, neutrophilic granulocytes, and lymphocytes. A significant positive linear effect of increasing dietary levels of UBDG was also found for hemoglobin and hematocrit.

The Positive Effects of Proprietary Undenatured β-Glucans on Stressed Marine Life

The safety of beta-glucans, including undenatured beta-glucan (UDBG), has been exhaustively studied over the recent past and has shown to be safe and efficacious in rodents as well as in humans with less than optimal immune systems. As such, we sought to find the effect of UDBG on certainly stressed crustaceans and fish. The survival of shrimp larvae fed the UDBG and other diets was measured on day 16. The diet containing 11.7% UDBG reduced larvae mortality by 18%;which is almost twice as much as the mortality reduced by the MacroGard diet, and up to 19.5% less than a standard Commercial Diet. In an effort to understand how UDBG protects against stressed marine life, UDBG was given to LPS-challenged trout. The UDBG positively influenced the level of transcription of several genes relevant to the immune system and overall health of the trout. The experimental findings indicated that UDBG: 1) modifies inflammatory responses, 2) makes responses more flexible and versatile, 3) protects from cellular stress, and 4) enhances “effector” mechanisms. Importantly, there was no evidence of immune system over-activity.