We present the third data release from the Australia Telescope Large Area Survey. These data combine the observations at 1.4 GHz before and after upgrades to the Australia Telescope Compact Array ...reaching a sensitivity of 14 μJy beam−1 in 3.6 deg2 over the Chandra Deep Field South (CDFS) and of 17 μJy beam−1 in 2.7 deg2 over the European Large Area ISO Survey South 1 (ELAIS-S1). We used a variety of array configurations to maximize the uv coverage resulting in a resolution of 16 by 7 arcsec in CDFS and of 12 by 8 arcsec in ELAIS-S1. After correcting for peak bias and bandwidth smearing, we find a total of 3034 radio source components above 5σ in CDFS, of which 514 (17 per cent) are considered to be extended. The number of components detected above 5σ in ELAIS-S1 is 2084, of which 392 (19 per cent) are classified as extended. The catalogues include reliable spectral indices (Δα < 0.2) between 1.40 and 1.71 GHz for ∼350 of the brightest components.
The objective of this study was to determine the effects of high-starch or high-fat diets formulated to be isoenergetic on energy and N partitioning and utilization of energy. Twelve multiparous ...Jersey cows (mean ± standard deviation; 192 ± 11 d in milk; 467 ± 47 kg) in a crossover design with 28-d periods (24-d adaptation and 4-d collection) were used to compare 2 treatment diets. Treatments were high starch (HS; 30.8% starch, 31.8% neutral detergent fiber, and 1.9% fatty acids) or high fat (HF; 16.8% starch, 41.7% neutral detergent fiber, and 4.1% fatty acids). Diets were formulated to have net energy for lactation (NEL) content of 1.55 Mcal/kg of dry matter according to the National Research Council (2001) dairy model. Nutrient composition was varied primarily by replacing corn grain in HS with a rumen-inert fat source and cottonseed hulls in HF. Gross energy content was lower for HS (4.43 vs. 4.54 ± 0.01 Mcal/kg of dry matter), whereas digestible (2.93 vs. 2.74 ± 0.035 Mcal/kg of dry matter) and metabolizable energy (2.60 vs. 2.41 ± 0.030 Mcal/kg of dry matter), and NEL (1.83 vs. 1.67 ± 0.036 Mcal/kg of dry matter) content were all greater than for HF. Tissue energy deposited as body fat tended to be greater for HS (4.70 vs. 2.14 ± 1.01 Mcal/d). For N partitioning, HS increased milk N secretion (141 vs. 131 ± 10.5 g/d) and decreased urinary N excretion (123 vs. 150 ± 6.4 g/d). Compared with HF, HS increased apparent total-tract digestibility of dry matter (66.7 vs. 61.7 ± 1.06%), organic matter (68.5 vs. 63.2 ± 0.98%), energy (66.0 vs. 60.4 ± 0.92%), and 18-carbon fatty acids (67.9 vs. 61.2 ± 1.60%). However, apparent total-tract digestibility of starch decreased for HS from 97.0 to 94.5 ± 0.48%. Compared with HF, HS tended to increase milk yield (19.7 vs. 18.9 ± 1.38 kg/d), milk protein content (4.03 vs. 3.93 ± 0.10%), milk protein yield (0.791 vs. 0.740 ± 0.050 kg/d), and milk lactose yield (0.897 vs. 0.864 ± 0.067 kg/d). In addition, HS decreased milk fat content (5.93 vs. 6.37 ± 0.15%) but did not affect milk fat yield (average of 1.19 ± 0.09 kg/d) or energy-corrected milk yield (average of 27.2 ± 1.99 kg/d). Results of the current study suggest that the HS diet had a greater metabolizable energy and NEL content, increased partitioning of N toward milk secretion and away from urinary excretion, and may have increased partitioning of energy toward tissue energy deposited as fat.
Summary
Small intestine mass and cellularity were previously associated with cattle feed efficiency. The small intestine is responsible for the digestion of nutrients and absorption of fatty acids, ...amino acids and carbohydrates, and it contributes to the overall feed efficiency of cattle. The objective of this study was to evaluate transcriptome differences among the small intestine from cattle with divergent gain and feed intake. Animals most divergent from the bivariate mean in each of the four phenotypic Cartesian quadrants for gain × intake were selected, and the transcriptomes of duodenum, jejunum and ileum were evaluated. Gene expression analyses were performed comparing high gain vs. low gain animals, high intake vs. low intake animals and each of the phenotypic quadrants to all other groups. Genes differentially expressed within the high gain–low intake and low gain–high intake groups of animals included those involved in immune function and inflammation in all small intestine sections. The high gain–high intake group differed from the high gain–low intake group by immune response genes in all sections of the small intestine. In all sections of small intestine, animals with low gain–low intake displayed greater abundance of heat‐shock genes compared to other groups. Several over‐represented pathways were identified. These include the antigen‐processing/presentation pathway in high gain animals and PPAR signaling, starch/sucrose metabolism, retinol metabolism and melatonin degradation pathways in the high intake animals. Genes with functions in immune response, inflammation, stress response, influenza pathogenesis and melatonin degradation pathways may have a relationship with gain and intake in beef steers.
The optimal roughage concentration required in feedlot diets changes continuously for many reasons such as source, availability, price, and interaction with other ingredients in the diet. Wet ...distillers grains and solubles (WDGS) are common in finishing diets and they contain relatively high amounts of fiber compared with other grains they replace. Therefore, concentration of roughage could be altered when WDGS are included in feedlot diets. There has been very little data published regarding the effects of roughage concentration on energy metabolism and nutrient balance in beef steers. Therefore, the effects of roughage concentration in dry-rolled corn (DRC)-based diets containing 25% WDGS were evaluated in 8 steers (BW = 362 ± 3.71 kg) using a replicated Latin square. Data were analyzed with the fixed effects of dietary treatment and period and random effects of square and steer within square were included in the model. Diets consisted of 25% WDGS and the balance being DRC and coarsely ground alfalfa hay (AH) replacing corn at 2% (AH-2), 6% (AH-6), 10% (AH-10), and 14% (AH-14) of dietary dry matter. As a proportion of GE intake, fecal energy loss increased linearly (P = 0.02), and DE decreased linearly (P = 0.02) as dietary level of AH increased. Methane energy loss, as a proportion of GE intake, increased linearly (P < 0.01) and ME decreased linearly (P < 0.01) as dietary concentration of AH increased. Heat production tended (P = 0.10) to decrease reaching a minimum of 10% AH and increased from 10 to 14% AH inclusion. Moreover, as a proportion of GE intake, retained energy (RE) decreased (P < 0.01) as AH level increased in the diet. Reasons for the decrease in RE are 1) the increase in fecal energy loss that is associated with decreased ruminal digestibility of NDF when AH replaced DRC and the shift in ruminal VFA produced, 2) the decreased energy available for animal retention when NDF increased linearly as AH increased in the diet, and 3) the methane and heat energy associated with digestion of the fibrous portion of the AH. Neutral detergent fiber and OM excretion also increased linearly (P < 0.01) with increasing AH in the diet. The increased NDF and OM excretion were likely caused by the difference in digestibility of AH and DRC.
The use of coproducts as an alternative feed source is a common practice when formulating dairy rations. A study using 12 multiparous (79 ± 16 d in milk; mean ± standard deviation) lactating Jersey ...cows was conducted over 5 mo to evaluate the effects of dried distillers grains with solubles (DDGS) or canola meal on milk and gas production. A replicated 4 × 4 Latin square design was used to compare 4 dietary treatments. Treatments comprised a control (CON) containing no coproducts, a treatment diet containing 10% (dry matter basis) low-fat DDGS (LFDG), a treatment diet containing 10% high-fat DDGS (HFDG), and a 10% canola meal (CM) treatment. The crude fat content of the LFDG, HFDG, and CM treatments was 6.05 ± 0.379, 10.0 ± 0.134, and 3.46 ± 0.085%, respectively. Coproducts were included in partial replacement for corn and soybean meal. Indirect headbox-style calorimeters were used to estimate heat production. Dry matter intake and milk yield were similar between all treatments, averaging 17.4 ± 0.56 kg/d and 24.0 ± 0.80 kg, respectively. Milk urea N was affected by treatment and was highest in CON (20.6 mg/dL; 18.0, 19.9, and 18.1 ± 0.62 mg/dL in LFDG, CM, and HFDG, respectively). Heat production per unit of metabolic body weight tended to be affected by treatment and was lowest for CON, and diets containing coproducts were not different (192, 200, 215, and 204 ± 5.91 kcal/kg of metabolic body weight for CON, LFDG, CM, and HFDG, respectively). The concentration of metabolizable energy was affected by dietary treatment; specifically, HFDG did not differ from CON but was greater than LFDG and CM (2.58, 2.46, 2.29, and 2.27 ± 0.09 Mcal/kg for HFDG, CON, LFDG, and CM, respectively). The concentration of net energy balance (milk plus tissue) tended to be affected by dietary treatment; HFDG did not differ from either CON or LFDG, but it was higher than CM (1.38, 1.36, 1.14, and 1.06 ± 0.11 Mcal/kg for HFDG, CON, LFDG, and CM, respectively). Results of this study indicate that milk production and dry matter intake were not affected by feeding common coproducts and that differences may result in whole-animal energy use; fat content of DDGS is a major factor affecting this.
This is the first of two papers describing the second data release (DR2) of the Australia Telescope Large Area Survey at 1.4 GHz, which comprises deep wide-field observations in total intensity, ...linear polarization, and circular polarization over the Chandra Deep Field-South and European Large Area Infrared Space Observatory
Survey-South 1 regions. DR2 improves upon the first data release by maintaining consistent data reductions across the two regions, including polarization analysis, and including differential number counts in total intensity and linear polarization. Typical DR2 sensitivities across the mosaicked multipointing images are 30 μJy beam−1 at approximately 12 arcsec × 6 arcsec resolution over a combined area of 6.4 deg2. In this paper we present detailed descriptions of our data reduction and analysis procedures, including corrections for instrumental effects such as positional variations in image sensitivity, bandwidth smearing with a non-circular beam, and polarization leakage, and application of the blobcat source extractor. We present the DR2 images and catalogues of components (discrete regions of radio emission) and sources (groups of physically associated radio components). We describe new analytic methods to account for resolution bias and Eddington bias when constructing differential number counts of radio components.
The growing ethanol industry in the Southern Great Plains has increased the use of wet distillers grains with solubles (WDGS) in beef cattle (Bos taurus) finishing diets. Few studies have used ...steam-flaked corn (Zea mays L.; SFC)-based diets to evaluate the effects of WDGS in finishing cattle diets, and a reliable estimate of the net energy value of WDGS has yet to be determined. Effects of corn processing method and WDGS on energy metabolism, C and N balance, and enteric methane (CH(4)) production were evaluated in a short-term study using 8 Jersey steers and respiration calorimetry chambers. A 2 by 2 factorial arrangement of treatments was used in a Latin square design. The 4 treatment combinations consisted of: i) SFC-based diet with 0% WDGS (SFC-0); ii) SFC-based diet with 30% WDGS (SFC-30); iii) dry-rolled corn (DRC)-based diet with 0% WDGS (DRC-0); and iv) DRC-based diet with 30% WDGS (DRC-30). Diets were balanced for degradable intake protein (DIP) and ether extract (EE) by the addition of cottonseed (Gossypium hirsutum L.) meal and yellow grease. As a proportion of GE, grain processing method did not affect (P ≥ 0.12) fecal, digestible, urinary, and ME, or heat production. Steers consuming SFC-based diets produced less (P < 0.04) CH(4) than steers consuming DRC-based diets. Retained energy tended to be greater (P = 0.09) for cattle consuming SFC- than DRC-based diets. Inclusion of WDGS did not affect (P ≥ 0.17) fecal, digestible, urinary, metabolizable, and retained energy, or heat production as a proportion of GE. Furthermore, neither inclusion of WDGS or grain processing method affected (P ≥ 0.17) daily CO(2) production. Due in part to greater N intake, cattle consuming diets containing 30% WDGS excreted more (P = 0.01) total N and excreted a greater (P < 0.01) quantity of N in the urine. From these results, we conclude that cattle consuming SFC-based diets produce less CH(4) and retain more energy than cattle fed DRC-based diets; however, dietary inclusion of WDGS at 30% seems to have little effect on CH(4) production and energy metabolism when diets are balanced for DIP and EE. Cattle excrete a greater amount of C when fed DRC compared with SFC-based diets, and dietary inclusion of 30% WDGS increases urinary N excretion. Finally, we determined the NE(g) values for WDGS were 1.66 and 1.65 Mcal/kg in a SFC or DRC-based diet, respectively, when WDGS replaced 30% of our control (SFC-0 and DRC-0) diets.
ABSTRACT
Feed costs are a major economic expense in finishing and developing cattle; however, collection of feed intake data is costly. Examining relationships among measures of growth and intake, ...including breed differences, could facilitate selection for efficient cattle. Objectives of this study were to estimate genetic parameters for growth and intake traits and compare indices for feed efficiency to accelerate selection response. On-test ADFI and on-test ADG (TESTADG) and postweaning ADG (PWADG) records for 5,606 finishing steers and growing heifers were collected at the U.S. Meat Animal Research Center in Clay Center, NE. On-test ADFI and ADG data were recorded over testing periods that ranged from 62 to 148 d. Individual quadratic regressions were fitted for BW on time, and TESTADG was predicted from the resulting equations. We included PWADG in the model to improve estimates of growth and intake parameters; PWADG was derived by dividing gain from weaning weight to yearling weight by the number of days between the weights. Genetic parameters were estimated using multiple-trait REML animal models with TESTADG, ADFI, and PWADG for both sexes as dependent variables. Fixed contemporary groups were cohorts of calves simultaneously tested, and covariates included age on test, age of dam, direct and maternal heterosis, and breed composition. Genetic correlations (SE) between steer TESTADG and ADFI, PWADG and ADFI, and TESTADG and PWADG were 0.33 (0.10), 0.59 (0.06), and 0.50 (0.09), respectively, and corresponding estimates for heifers were 0.66 (0.073), 0.77 (0.05), and 0.88 (0.05), respectively. Indices combining EBV for ADFI with EBV for ADG were developed and evaluated. Greater improvement in feed efficiency can be expected using an unrestricted index versus a restricted index. Heterosis significantly affected each trait contributing to greater ADFI and TESTADG. Breed additive effects were estimated for ADFI, TESTADG, and the efficiency indices.
The objective of this experiment was to determine the association of glucocorticoids and markers for immune status in finishing beef steers and heifers with DMI, growth, and efficiency. Steers (n = ...127) and heifers (n = 109) were individually fed a finishing ration for 84 d with BW measured every 21 d. Blood samples were collected via jugular venipuncture for metabolite (glucose and lactate) and cortisol analysis and rectal grab samples of feces were collected for corticosterone analysis on d 83 of the experiment. Plasma cortisol was not correlated to DMI (r = -0.08, P > 0.05) or fractional DMI (g DMI/kg BW; r = -0.03; P > 0.05), but was negatively correlated with ADG (r = -0.17, P < 0.01) and G:F (r = -0.20; P < 0.01) and positively correlated to residual feed intake (RFI; r = 0.14, P < 0.05). Fecal corticosterone was positively correlated to fractional DMI (r = 0.15, P < 0.05) and RFI (r = 0.23, P < 0.01) and negatively correlated to G:F (r = -0.18; P < 0.01). Using a mixed model analysis, none of the metabolites or hormones were associated with DMI (P > 0.05), but fecal corticosterone was positively associated with BW-adjusted DMI in heifers only (P = 0.04). Plasma lactate (P < 0.01) was and plasma cortisol (P < 0.10) tended to be negatively associated with ADG. Plasma cortisol (P < 0.05) and fecal corticosterone tended (P < 0.10) to be negatively associated with G:F. Fecal corticosterone was positively associated with RFI in heifers (P < 0.04). In a mixed model analysis, total leukocyte count was positively associated with ADG (P < 0.04) and tended to be positively associated with G:F (P < 0.06). Amongst leukocyte subtypes, neutrophil count was positively associated with ADG in steers (P < 0.02) and monocytes were positively associated with ADG in heifers (P < 0.03). Lymphocyte counts (LY) in steers were negatively associated with DMI (P = 0.03) and fractional DMI (P < 0.03). In heifers, LY tended to be positively associated with DMI (P < 0.09) and BW-adjusted DMI (P < 0.06). Lymphocyte count was also positively associated with ADG (P < 0.01) and G:F (P = 0.05) in heifers. The association of production traits with immune status seems to be different between steers and heifers. There was a stronger relationship of cortisol than fecal corticosterone to feed efficiency measures, suggesting that an cortisol concentrations could be a better marker for feed efficiency traits than fecal corticosterone concentrations.
PDF
