Estimation of genetic parameters and effects of cytoplasmic line on scrotal circumference and semen quality traits in Angus bulls.

The purpose of this study was to estimate the heritability of scrotal circumference (SC) and semen traits, genetic correlations between SC and semen quality traits, and the effect of cytoplasmic line on SC and semen traits. Breeding soundness exam (BSE) data were collected on registered Angus bulls at 4 ranches over 7 yr. The American Angus Association provided historical pedigree information to estimate the effect of cytoplasmic line on SC and semen quality traits. After editing, the evaluated data set contained 1,281 bulls with breeding soundness exam data that traced back to 100 founder dams. Data were analyzed using a 2-trait animal model to obtain heritability, genetic correlation between SC and semen quality traits, as well as the effect of cytoplasmic line as a random effect for SC, percent motility (MOT), percent primary abnormalities (PRIM), percent secondary abnormalities (SEC), and percent total abnormalities (TOT) using multiple-trait derivative-free REML. Fixed effects included source ranch and collection year, and test age was used as a covariate. Estimates of heritability for SC, MOT, PRIM, SEC, and TOT were 0.46, 0.05, 0.27, 0.23, and 0.25, respectively. Genetic correlations between SC and MOT, PRIM, SEC, and TOT were 0.36, -0.19, -0.11, and -0.23, respectively. The proportions of phenotypic variance accounted for by cytoplasmic line for SC, MOT, PRIM, SEC, and TOT were <0.001, 0.013, 0.023, 0.002, and <0.001, respectively. Genetic correlations between SC and semen quality traits were low to moderate and favorable. Cytoplasmic line may have a marginal effect on MOT and PRIM, but is likely not a significant source of variation for SC, SEC, or TOT.

Integrated genomic and proteomic analyses of a systematically perturbed metabolic network.

We demonstrate an integrated approach to build, test, and refine a model of a cellular pathway, in which perturbations to critical pathway components are analyzed using DNA microarrays, quantitative proteomics, and databases of known physical interactions. Using this approach, we identify 997 messenger RNAs responding to 20 systematic perturbations of the yeast galactose-utilization pathway, provide evidence that approximately 15 of 289 detected proteins are regulated posttranscriptionally, and identify explicit physical interactions governing the cellular response to each perturbation. We refine the model through further iterations of perturbation and global measurements, suggesting hypotheses about the regulation of galactose utilization and physical interactions between this and a variety of other metabolic pathways.

Final-week performance of straight-run broilers as affected by early coccidiostat withdrawal followed by increased dietary salt.

Three experiments were conducted to evaluate elevated dietary NaCl levels as a means of offsetting industry-observed reductions of growth, feed intake, and feed efficiency associated with early (35-d) coccidiostat withdrawal. In the first experiment, monensin (100 ppm) was withdrawn and dietary salt levels of 0.33, 0.48, 0.63, 0.78, or 0.93% provided from 35 to 42 d of age. Experiments 2 and 3 involved lasalocid (110 ppm) withdrawal and slat amounts of 0.33, 0.53, 0.73, or 0.93%. In all studies, a positive control of 0.33% salt and the coccidiostat was also given. Monensin withdrawal reduced body weight gain, which was not overcome by slat addition. Feed efficiency during the 1-wk period was improved to the level of the group receiving continued medication by salt amounts of 0.78% or above. In contrast to industry field observations, removal of lasalocid did not reduce body weight gain, feed intake, or water consumption, and elevation of salt levels resulted in no consistent improvements of weight gain, feed intake, or feed conversion. Water intake increased proportionally as salt concentration increased. Elevated salt levels do not appear to be a reliable means of offsetting reduced performance related to early coccidiostat withdrawal, nor were such performance problems demonstrable for lasalocid in these trials.

The performance of commercial broilers when fed various levels of rendered whole-hen meal.

In each of two experiments, approximately 1200 straight-run broiler chicks were fed 0, 4, 8, or 12% rendered whole hen meal (RHM) to determine its effectiveness and acceptability as a nutrient source from hatch to 6 wk of age. Approximately 2,275 kg of commercial laying hen mortality losses were collected, frozen, and stored over a 3-wk period. The birds were rendered at a commercial facility, stabilized, sampled, analyzed, dried, and stored again by freezing. Based on sample analysis and moisture content, diets were computer-formulated to be isocaloric and equivalent in as many nutrients as possible. Fat, fiber, arginine, and tryptophan levels varied slightly within age-related diet groups. The diets were consumed ad libitum from hatch to either 41 (Experiment 1) or 42 (Experiment 2) d. In both experiments, the addition of RHM at any level resulted in equal or greater body weight than that observed with control diets that contained no RHM. The effect of RHM on body weight was not significant in the first experiment; however, it was significant in the second experiment. Feed intake generally increased relative to body weight. Feed intake differences were significant in both studies, but in Experiment 2 did not parallel body weight patterns. Contrasting results were obtained with feed efficiency with control birds being most efficient in one trial and least efficient in the other. Rendered whole-hens were acceptable and highly utilizable as a protein and nutrient substitute in the diets of the commercial broiler. The RHM was found to be pathogen-free upon analysis, with no resulting differences in mortality due to either presence or level of the material.

Research note: the performance of spring- and summer-reared broilers as affected by precision beak trimming at seven days of age.

In each of two duplicate trials approximately 2,500 day-old Peterson x Arbor Acres straight-run broiler chicks were equally divided between two treatments of three pens each. Treatment 1 was maintained as controls (C), and Treatment 2 birds were precision beak-trimmed (PBT) at 7 days of age. Feed and water were supplied for ad libitum consumption to both groups. Trials 1 and 2 were initiated in March and June, respectively. Performance of spring-reared broilers were comparable regardless of beak trimming procedure, except that PBT broilers experienced slightly higher mortality after PBT. Final body weights of the summer-reared broilers were 15% lower than those reared in the spring. Additionally, PBT resulted in significantly reduced final body weights and feed intake. There were no significant differences in mortality or feed conversion due to PBT.

Common ocular problems of Shin Tzu dogs.

In recent years the Shih Tzu has become a popular breed of dog. It has a number of serious diseases of the eye which are not being recognized by breeders, owners, and sometimes veterinarians. The purpose of this communication is to assist veterinarians in recognizing and treating, where possible, some of the common ocular problems of this breed, including medial canthal entropion, various trichiasis problems, dermoids, third eyelid gland prolapse, chronic keratitis and corneal ulcers, progressive retinal atrophy, vitreal syneresis, and retinal detachment. Because most of the problems are inherited or of suspected genetic origin, breeders should receive genetic counselling from their veterinarian.

Management of chemical burns of the canine cornea.

Significant clinical signs and general principles of treatment for chemical burns of the canine cornea are presented using three typical case studies for illustration. Alkali burns are more common in dogs than acid burns. The sources of alkali in this study were soap, cement, and mortar dust. Common signs of chemical burns are ocular pain, corneal ulceration, tear film inadequacy, corneal edema, and marked corneal neovascularity. Successful treatment requires thorough ocular lavage, treatment for corneal ulceration, and adequate anti-inflammatory therapy when the corneal epithelium becomes intact.

Effect of energy on the performance of broiler chicks fed various levels of monensin.

A total of 768 female broiler chicks in two experiments was fed diets containing 0, 100, or 120 mg monensin/kg of diet with and without added animal fat, in a 2 X 3 factorial design. Chicks were grown in electrically heated battery brooders and supplied feed and water ad libitum for 21 days. Animal fat fed at 6.8% of the diet consistently improved body weight, daily feed intake, and feed conversion regardless of monensin level. Monensin at 100 and 120 mg/kg of diet, in general, decreased these performance criteria progressively. Daily monensin intake was related to the concentration of monensin in the diet. Intake per unit of body weight was increased by reducing fat or increasing monensin.

Evaluation of supplemental niacin for turkeys fed corn-soy diets from four to twelve weeks of age.

A corn-soy basal diet, which was calculated to contain 21 mg of niacin/kg diet, was used to investigate the niacin needs of turkey poults from 4 to 12 weeks of age. Poults had been fed a diet that contained 80.6 mg niacin/kg of feed until 4 weeks of age. Supplemental niacin was added at 0, 10, 20, and 50 mg/kg. There were no significant differences in mortality, leg disorders, or 12-week weight gains due to amount of niacin of the diet. These data indicate that 21 mg/kg niacin is adequate for optimum growth of turkeys from 4 to 12 weeks of age when they are fed a corn-soy diet.

The postrest performance of laying hens subjected to early or late water restriction during the feed withdrawal period.

Two experiments initiated in December and April were conducted to determine the effect of water restriction on the performance of force-rested hens. Birds used in this study were housed in cages and were 74 weeks of age at the beginning of each study. Treatment assignments were 1) no water restriction, 2) water restriction on Days 1 and 2 (48 hr), and 3) water restriction on Days 9 and 10 (48 hr). All birds were subjected to identical 10 day feed withdrawal periods, were fed low protein and low calcium recovery diets to Day 35, and then were placed on a standard postrest feeding system for six 28-day production periods. With only three exceptions, within-experiment differences in postrest performance due to water restriction treatment were not significant regardless of criteria evaluated or season of force-rest initiation. When water was restricted on Days 9 and 10 in the experiment initiated in April, hens laid at a significantly lower rate with significantly heavier eggs than others in the same experiment. Hens that experienced either water restriction treatment during the April force-rest had poorer feed conversion when expressed in terms of egg numbers. Feed intake, feed conversion on a weight-for-weight basis, egg specific gravity, and mortality were not affected by water restriction treatment, regardless of season. Water restriction was not necessary for a successful force-rest of laying hens, and, in fact, could be detrimental when instituted in the later part of the feed withdrawal period in warm weather.

The performance of four strains of laying hens subjected to various postrest combinations of calcium and phosphorus after forced rest in winter or summer.

Four strains of laying hens, including one brown egg strain, were force-rested in February at approximately 62 weeks of age. Hens from the same four strains, which were the same age, were also force-tested under similar conditions during August of the same year. In each of the two trials, a total of 2300 hens were housed at the rate of two per 25.4 x 45.7-cm cage. The resting procedure for both studies included feed withdrawal for 9 or 10 days followed by feeding a 8.6% protein diet for 25 days. Water was supplied at all times. After the 35-day resting period, the hens were assigned to four calcium and phosphorus combinations, which varied from the duplication of a first-year pullet phase feeding program to the feeding of a final phase type diet for the entire postrest production period. Nutrient level within each dietary system was adjusted periodically based on daily feed intake. Strain performance differences were observed in both seasons. Rate of return to production and postrest production rates were similar to the patterns observed within the respective strain's performance during the pullet year. This was noted in both studies. Relative strain production performance, however, when compared to the other strains, was not consistent between the two rest seasons. There was no difference in performance due to calcium and phosphorus treatment utilized in either postrest production season.(ABSTRACT TRUNCATED AT 250 WORDS)

The performance of laying hens as affected by copper sulfate and methionine level.

Two strains of White Leghorn hens were subjected to seven copper treatments that included a negative control for the first week of each of five 28-day periods. The hens were approximately 500 days of age when the experiment began. Copper treatments were assigned to simulate the different levels of copper intake that might result from differences in daily feed intake similar to the practice followed with commercial industry. In order to simulate daily dietary intake ranging from a low of 73 to a high of 136 g per bird, levels of 76, 91, 100, 114, 129, and 143 mg of copper sulfate per kilogram were added to each of the basal diets. Treatments were administered across two methionine levels in a corn-soy basal diet. Hen-day egg production, egg weight, daily feed intake, and feed efficiency values were not affected by dietary levels of copper or methionine. Hens fed diets containing low methionine laid eggs with significantly poorer specific gravity.

Dietary and plasma phosphorus in hens with fatty liver syndrome.

Plasma inorganic phosphorus was determined in two experiments in hens that had fatty liver syndrome. In Experiment 1, plasma inorganic phosphorus was determined in twelve strains of hens all fed the same diet. Plasma inorganic phosphorus immediately following oviposition was elevated in all strains. The two strains in the first experiment with the highest as well as the two strains with the lowest plasma inorganic phosphorus were used in the second experiment. Each of the four strains were subdivided into three groups of 60 hens each and fed a practical layer diet containing either .30, .75, or 1.40% total phosphorus and 3.4% calcium. Significant differences were found in plasma inorganic phosphorus between strains fed the three dietary phosphorus levels. Results indicated that plasma inorganic phosphorus is related to dietary phosphorus in hens with an elevated plasma inorganic phosphorus level associated with fatty liver syndrome.

The effect of low protein pullet growing diets on performance of laying hens housed in the fall.

A total of 6000 layer-type pullet chicks were fed either a low protein (9.1%) or a high protein (15.4%) diet from 8 through 18 weeks of the growing period in two experiments. All chicks were fed a commercial starter for the first 8 weeks and the high protein diet from 18 to 21 weeks of age. All chicks were grown in floor pens and were supplied feed and water ad libitum throughout the growing trial. They were placed in either a cage- or floor-laying house and fed a commercial layer diet for 12 periods of 28 days each. The experiment was repeated in the subsequent year. The low protein regimen was found to produce a smaller pullet, delay sexual maturity, delay production peaks, and maintain higher levels of production near the end of the laying period. Pullets fed the low protein grower diet had higher mortality during the growing period, greater feed intake during the laying period, eggs with higher Haugh unit values, and reduced egg production in the laying house.