C9orf72 ablation causes immune dysregulation characterized by leukocyte expansion, autoantibody production, and glomerulonephropathy in mice

The expansion of a hexanucleotide (GGGGCC) repeat in C9ORF72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Both the function of C9ORF72 and the mechanism by which the repeat expansion drives neuropathology are unknown. To examine whether C9ORF72 haploinsufficiency induces neurological disease, we created a C9orf72-deficient mouse line. Null mice developed a robust immune phenotype characterized by myeloid expansion, T cell activation, and increased plasma cells. Mice also presented with elevated autoantibodies and evidence of immune-mediated glomerulonephropathy. Collectively, our data suggest that C9orf72 regulates immune homeostasis and an autoimmune response reminiscent of systemic lupus erythematosus (SLE) occurs in its absence. We further imply that haploinsufficiency is unlikely to be the causative factor in C9ALS/FTD pathology.

Effect of crude glycerin on feed manufacturing, growth performance, plasma metabolites, and nutrient digestibility of growing-finishing pigs

Three experiments were conducted to determine the effects of dietary addition of crude glycerin on pellet production efficiency and to evaluate its effect on growth performance and digestibility in growing-finishing pigs. Three dietary treatments were created by addition of 0, 2.5, or 5% crude glycerin to barley-soybean meal-based diet, and 4 batches of each dietary treatment (2 each for grower and finisher diets) were prepared. In the manufacturing process, crude glycerin supplementation linearly increased the feeder speed and production rate (P < 0.05), resulting in a 20 to 29% improvement in the feed production rate compared with the control. Production efficiency (kg/kWh) increased linearly (P < 0.05) as the level of crude glycerin in feed increased. A growth experiment was performed with 240 barrows (30 ± 1 kg initial BW) using a 2-phase feeding program over a 12-wk period with 4 pens per treatment and 20 pigs per pen. On the last day of the growth experiment, blood samples were collected to determine circulating glucose, fructosamine, and IGF-1 concentrations. Overall growth performance was not affected (P > 0.05) by dietary treatment, and there was no effect (P > 0.05) of dietary treatment on any plasma metabolite measured. A digestibility experiment involving 9 male pigs housed in metabolic cages was used to determine the coefficients of apparent fecal digestibility and N and mineral balances. Pigs were assigned to 1 of the 3 diets in each feeding period using a 3 × 3 Latin square arrangement of treatments (43 ± 3 and 74 ± 3 kg initial BW in the growing and finishing periods, respectively). In both feeding periods, fecal digestibility of OM and ether extract were affected by dietary treatment, increasing linearly (P < 0.05) with increasing crude glycerin levels. However, neither CP digestibility nor N retention was affected by the glycerin content in either the growing or finishing period. Digestibilities and balance of Ca and P showed opposite tendencies with the variations in crude glycerin content, which either decreased or increased depending on the feeding period. In conclusion, adding crude glycerin to the diet before pelleting improved feed mill production efficiency. The addition of crude glycerin up to 5% in the diet of growing-finishing pigs had no effect on growth performance, blood metabolites, nutrient digestibility, and N balance, but more studies are needed to determine how crude glycerin affects mineral metabolism and balance.

Effects of low protein diets on growth performance, carcass traits and ammonia emission of barrows and gilts

The aim of the present research was to determine the effect of low protein diets on growth performance, carcass traits and ammonia emission from barrows and gilts during the growing and finishing periods. For each period, three diets were formulated. A control diet (C) with 160 and 155 g crude protein (CP)/kg for the growing and finishing, respectively, a medium level diet (M) and a low level diet (L) with 10 and 20 g CP/kg less than the C, respectively. All the diets were supplemented with crystalline amino acids on an ideal protein basis. Barrows (90) and gilts (90) were sorted by bodyweight and sex and housed in three identical manually ventilated chambers. No significant effects of diet on pig performance were observed. In the finishing period, barrows were heavier (P < 0.001) and had higher average daily gain (P < 0.01) and average daily feed intake (P < 0.01) than gilts. Pigs fed the L diet had higher backfat thickness than those fed the other diets in the growing period (P < 0.05). Backfat thickness was higher (P < 0.01) in barrows than in gilts. Muscle depth decreased in pigs fed the L diet in the finishing period. Muscle depth was not affected (P > 0.05) by sex. Average ammonia emissions during the last 6 days were 117.7, 94.2 and 85.5 mg ammonia/kg pig.day for pigs fed the C, M and L diets, respectively. The results show that a reduction in dietary CP of 10 g/kg, accompanied by supplementation with crystalline amino acid reduced ammonia emission by 19.9% with no detrimental effects on growth performance and carcass characteristics, and a reduction of 20 g/kg reduced ammonia emission by 27.3% with no detrimental effects on growth performance but reduced muscle depth at slaughter.

Crossbreeding parameters for growth and feed consumption traits from a five diallel mating scheme in rabbits

Twenty-five genetic groups of young rabbits originated from a diallel-crossbreeding scheme among 5 selected lines: 3 maternal and 2 terminal sire lines belonging to 2 Spanish research institutions. A sample of 2,773 young rabbits from 525 litters was controlled during the fattening period lasting from 5 to 9 wk. Growth and feed consumption traits were evaluated throughout different biweekly batches. A Bayesian approach was used for inference from an animal model with common litter effects. On average, genetic groups coming from lines selected for growth rate were heavier (+58.9 g at 32 d and +315.5 g at 60 d), had greater growth rate (9.24 and 8.15 g/d from individual or cage analysis, respectively) and feed intake (+13.24 g/d), and showed better feed conversion ratio (-0.21 g of intake/g of gain), than the genetic groups originated from crosses among lines selected for litter size. Crossbreeding parameters were estimated from the samples of the marginal posterior distribution of the genetic group effect according to the Dickerson model. Maternal genetic and individual heterosis effects were null or very low. Direct genetic effects mainly regulated the expression of growth traits.

Effect of formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens

1. The effect of dietary formic acid on performance, digestibility, intestinal histomorphology and plasma metabolite levels of broiler chickens was studied. 2. An experiment with 120 Ross male broiler chickens was conducted from 1 to 42 d of age at the laboratory. There were 4 treatment groups: control (C), 10 mg/kg feed avilamycin (AV) and formic acid at two concentrations, 5 and 10 g/kg feed (FA5 and FA10, respectively). 3. No differences in weight gain, feed intake or feed conversion ratio were observed in male broiler chickens fed on the different diets. 4. An effect of the additives on ileal dry matter (DM) digestibility at 42 d of age was detected with the finisher diets; AV and 10 g/kg of feed formic acid slightly improved ileal DM digestibility compared to the other treatment groups. 5. Jejunum pH was not affected when 5 or 10 g/kg formic acid was added, and the results do not clearly show a positive effect of formic acid on the intestinal histomorphology. 6. No differences were noticed for blood metabolites in the different diets, and the levels of calcium and phosphorus in the plasma were not altered by formic acid addition. 7. In conclusion, when using broiler chickens under conditions of good hygiene, dietary formic acid did not have a clear positive effect on performance, intestinal histomorphology or plasma metabolite levels; however, there was a slight positive effect on the ileal digestibility of nutrients.

Crossbreeding parameter estimation for functional longevity in rabbits using survival analysis methodology

A complete diallel cross involving 3 maternal lines of rabbit was performed to estimate cross-breeding parameters for functional longevity. This trait was defined as the ability to delay involuntary culling. The lines considered, A, V, and Prat, had all been selected by litter size at weaning for a long period. Data were related to a total of 653 does belonging to the 9 genetic types from the diallel cross; does were reared and bred on the same commercial farm. Survival analysis was performed using a Cox proportional hazard model. The model incorporated time-dependent factors, such as year-season, litter size, and the interaction between cycle and physiological status of the female; time-independent factors, such as the genetic type of the doe; and sire and dam random factors. Crossbreeding parameters were estimated from the solutions obtained for the type of doe and its estimated variance-covariance matrix, using a generalized least squares procedure. The estimated parameters were the differences between lines in direct genetic effects and maternal genetic effects and individual heterosis. Relevant differences were observed in direct genetic effects between lines A and Prat but not in any maternal effects. Heterosis was found to be significant and favorable between lines A and Prat, and between the lines V and Prat. The magnitude of this effect was variable but important, especially in the first cross. Results stress the importance of using crosses between specialized lines to produce does for intensive meat rabbit production.

Influence of two plant extracts on broilers performance, digestibility, and digestive organ size

A 42-d trial was conducted to study the influence of 2 plant extracts on performance, digestibility, and digestive organ weights in broilers. The feeding program consisted of a starter diet until 21 d and a finisher diet until 42 d. There were 4 treatment groups: control; 10 ppm avilamycin (AB); 200 ppm essential oil extract (EOE) from oregano, cinnamon, and pepper; and 5,000 ppm Labiatae extract (LE) from sage, thyme, and rosemary. No differences in feed intake or feed conversion were observed. From 14 to 21 d of age, broilers fed the LE diet grew faster than the broilers fed the control or EOE feeds (68.8 vs. 63.9 and 61.6 g/d, respectively). Antibiotic and plant extract supplementation improved apparent whole-tract and ileal digestibility of the nutrients. For starter feed, LE supplementation improved apparent fecal digestibility of DM (P < 0.01), and all additives increased ether extract digestibility (P < 0.001). However, no effect was detected for CP digestibility (P > 0.1). At the ileal level, the AB, EOE, and LE supplementation of the starter feed increased DM and starch (P < 0.01) digestibility but not CP digestibility (P > 0.1). All additives improved apparent fecal digestibility of DM and CP of the finisher diet. No differences were observed for proventriculus, gizzard, liver, pancreas, or large or small intestine weight. In the present study, both plant extracts improved the digestibility of the feeds for broilers. The effect of different additives on digestibility improved the performance slightly, but this effect was not statistically significant.