The optimum valine: lysine ratios on performance and carcass traits of male broilers based on different regression approaches.

Three different regression approaches were applied to determine the optimal digestible (d.) and analyzed Val:Lys ratios for broiler performance and carcass yield. One-day-old male Cobb 500 broilers (n = 960) were assigned to 1 of 8 diets, with 6 pens/diet and 20 birds/pen, for 42 days.

Comparison of methionine sources around requirement levels using a methionine efficacy method in 0 to 28 day old broilers.

The addition of methionine in the poultry feed industry is still facing the relative efficacy dilemma between DL-methionine (DLM) and hydroxy-methionine (HMTBA). The aim of this study was to compare the effect of dietary DLM and HMTBA on broiler performance at different levels of total sulfur amino acids (TSAA). The treatments consisted of a basal diet without methionine addition, and 4 increasing methionine doses for both sources resulting in TSAA/Lysine ratios from 0.

Influence of a gonadotropin-releasing hormone vaccine and dietary standardized ileal digestible lysine level on growth performance and carcass quality of grower-finisher pigs.

The aim of this study was to assess the effect of standardized ileal digestible (SID) Lys levels of the diet on the growth performance, carcass characteristics, and meat quality of entire males (EM), surgical castrates (SC), and males vaccinated with a gonadotropin-releasing hormone (GnRH) vaccine (GV). In total, 252 crossbred pigs were fed 6 different experimental diets consisting of 3 sexes (EM, SC, and GV pigs) and 2 dietary SID Lys levels (2008 CVB standard SID Lys recommendation [Std] or 15% extra SID Lys [+15]) according to a 3-phase feeding scheme (d 0 to 35, 35 to 70, and 70 to 105 of experiment) with 6 pens per treatment and 6 pigs per pen. To determine if dietary SID Lys could be reduced for GV males after the second vaccination, an additional dietary treatment was included (GV+15-Std).

Insoluble nonstarch polysaccharides in diets for weaned piglets.

To examine the effect of inclusion insoluble nonstarch polysaccharides (iNSP) in weaned diets on postweaning piglet performance, intestinal activity, and microbial composition 2 experiments were designed. In Exp. 1, 180 piglets were weaned at 28 d of age and divided over 3 treatments: positive control (PC; highly digestible protein), negative control (NC; standard cereal-based diet), and an experimental diet {iNSP; standard + 15% iNSP [wheat straw and oat (Avena sativa) hull]}.

The effect of low-density diets on broiler breeder performance during the laying period and on embryonic development of their offspring.

The effect of low-density diets on bird performance, egg composition, and embryonic development was studied with 2,100 female and 210 male Cobb broiler breeders from 25 to 60 wk of age. The experiment included 5 treatments. These included a control group with a normal density diet (ND, 2,800 kcal of AME/kg).

The effect of low-density diets on broiler breeder development and nutrient digestibility during the rearing period.

Low-density diets might help to reduce hunger feeling in restricted-fed broiler breeders. Effects of low-density diets on nutrient digestibility and bird development were studied in Cobb 500 broiler breeder hens from 4 wk of age until the onset of the lay (wk 26). The experiment included 4 treatments.

The effect of low-density broiler breeder diets on performance and immune status of their offspring.

Effects of low-density broiler breeder diets on offspring performance and mortality were studied using 2,100 female and 210 male Cobb 500 breeders. Breeder treatments involved 4 experimental groups and a control group with normal density diets (ND, 2,600 kcal of AME/kg during rearing and 2,800 kcal of AME/kg during laying). In treatment 2, nutrient densities were decreased by 12% (LD12) and 11% (LD11) during the rearing and laying periods, respectively, whereas in treatment 3, nutrient densities were decreased by 23% (LD23) and 21% (LD21) during the rearing and laying periods, respectively.

In vitro starch digestion correlates well with rate and extent of starch digestion in broiler chickens.

Current feed evaluation systems for poultry are based on digested components (fat, protein and nitrogen-free extracts). Digestible starch is the most important energy source in broiler chicken feeds and is part of the nitrogen-free extract fraction. Digestible starch may be predicted using an in vitro method that mimics digestive processes in the gastrointestinal tract of broiler chickens.

Starch digestion rate in the small intestine of broiler chickens differs among feedstuffs.

Dietary starch is the major energy source for broiler chickens, and knowledge about its digestive behavior can be important. In a digestibility trial with 720 broiler chickens, site, rate and extent of starch digestion were measured for 12 feedstuffs. Starch digestion was determined using the slaughter technique, which involves removal of the small intestine from the recently killed chicken, with manual collection of the contents.

Effects of phosphoglycerate kinase overproduction in Saccharomyces cerevisiae on the physiology and plasmid stability.

In this report the effects of phosphoglycerate kinase (PGK) overproduction on the physiology and plasmid stability in baker's yeast Saccharomyces cerevisiae containing the PGK1 gene on an episomal plasmid are described. This examination reveals that there is a preferred intracellular level for this enzyme, amounting to 10-15% of the total soluble protein. Strains containing the plasmid and the host strain were grown in non-selective batch cultures and continuous culture, under different growth conditions.

High-copy-number integration into the ribosomal DNA of Saccharomyces cerevisiae: a new vector for high-level expression.

Yeast vectors suitable for high-level expression of heterologous proteins should combine a high copy number with a high mitotic stability under non-selective conditions. Since high stability can best be assured by integration of the vector into chromosomal DNA we have set out to design a vector that is able to integrate into the yeast genome in a large number of copies. The rDNA locus appeared to be an attractive target for such multiple integration since it encompasses 100-200 tandemly repeated units.

Growth of rearing calves in relation to lysine contents of milk replacer and calf starter and feeding frequency of milk replacer.

In two factorial feeding experiments with 90 and 102 rearing calves the effect of addition of extra lysine to the milk replacer in combination with a low and high lysine content of the calf starter on dry matter intake and weight gain was studied. Once or twice daily milk feeding was also compared. The calves received milk replacer up to the age of 8 weeks and calf starter and hay ad libitum from the 3rd week on.

Proteolysis of alcohol-treated soybean meal proteins by Bacteroides ruminicola, Bacteroides amylophilus, pepsin, trypsin, and in the rumen of steers.

Sodium dodecyl sulfate-gel electrophoresis and cation exchange chromatography were used to examine degradation of treated and untreated soybean meal protein fractions by Bacteroides amylophilus H18(1), Bacteroides ruminicola B(1)4, pepsin, trypsin, and intraruminally. Soybean meal treatments consisted of 30% vol/vol isopropanol, 40% propanol, or 50% ethanol at 22 degrees C or 70% ethanol at 80 degrees C. Water-soluble protein fractions were applied to a hydroxylapatite column and eluted with a discontinuous phosphate gradient of .

Effects of lasalocid and monensin on nutrient digestion, metabolism and rumen characteristics of sheep.

Two experiments were conducted to evaluate metabolism and rumen fermentation responses of lambs fed either monensin or lasalocid (33 mg/kg level) in an alfalfa-corn diet. Experiment 1 was a lamb metabolism trial where rumen samples were taken at the end of each excreta collection period. In Exp.

Effects of dietary fibers on mineral status of chicks.

We investigated the effects of replacing dietary starch with dietary fibers of various types and particle sizes on utilization of bivalent cations by chicks. Inclusion of polyethylene powder, alfalfa cell walls, corn bran, oat bran and wheat bran into diets resulted in lower serum and tibia Zn levels. However, addition of pectin, cellulose and a xylose:gum arabic (50:50) mixture did not affect tissue Zn levels, whereas addition of 4% lignin increased serum Zn level from 2.