Effects of spray-dried animal plasma in calf milk replacer on health and growth of dairy calves

Male Holstein calves (n = 120) purchased from local dairy farms were fed one of three calf milk replacers for 42 d. Experimental milk replacers were formulated to contain whey protein concentrate (WPC) as the primary protein source or WPC plus 5% spray-dried bovine plasma (SDBP) or spray-dried porcine plasma (SDPP). The SDPP was heated to remove heat-insoluble materials and provide products with similar IgG content. Calves were also fed commercial calf starter and water for ad libitum consumption. Intake, change in body weight (BW), feed efficiency, morbidity and mortality were determined. Mortality was 10, 3, and 2 in calves fed WPC, SDBP, and SDPP treatments, respectively. Morbidity, measured as the number of days that calves had diarrhea was reduced by 30% when SDBP or SDPP were fed. Calves had diarrhea for 6.9, 3.9, and 4.7 d during the 42-d study when fed commercial calf milk replacer containing WPC, SDBP, and SDPP, respectively. Fecal scores tended to be reduced and feed efficiency tended to be improved when SDBP or SDPP were fed. Mean intakes of total dry matter during the 42-d study were greater when calves were fed SDBP or SDPP and were 661, 710, and 684 g/d for calves fed WPC, SDBP, and SDPP, respectively. Mean BW gains from d0 to 42 were 231,261, and 218 g/d, respectively. Calves fed SDPP tended to have lower BW gain during the first 28 d of the study. However, difference in daily BW gain from d 1 to 28 was only 39 g/d. Inclusion of SDBP or SDPP in milk replacer reduced morbidity and mortality of milk-fed dairy calves.     

Clinical and ultrastructural ocular histopathologic studies of adult-onset metachromatic leukodystrophy

A twin brother and sister with adult-onset metachromatic leukodystrophy developed progressive central acuity loss and optic disk pallor. Both had normal electroretinograms and fluorescein angiography. Postmortem examination of the sister's eyes by histochemistry and electron microscopy revealed ganglion cell loss and optic atrophy. Cerebroside sulfate had accumulated in optic nerve glial cells. Optic atrophy was more advanced than in previously reported cases of infantile-onset metachromatic leukodystrophy. The pathologic process seemed to be retrograde optic nerve degeneration due to abnormal myelin metabolism.     

Characterization of a colostrum replacer and a colostrum supplement containing IgG concentrate and growth factors

The objective of this study was to characterize absorption of colostrum replacer (CR) or supplement (CS) containing fractions of bovine plasma. Immunoglobulin concentrate (IGC) was prepared from bovine blood to a final purity of approximately 90% IgG. Blood was also processed to produce a fraction containing elevated concentrations of IGF-I and TGF-beta (GF). Both IGC and GF were spray-dried and blended with other ingredients to produce CR (30% IgG) or CS (15% IgG) containing 0 or 5% GF. Holstein bull calves were assigned to one of five treatments: 1) Pooled colostrum (MC)--1.9 L of pooled colostrum at 1 and 8 h of age to provide over 150 g of IgG; 2) Low supplement (LC)--1.9 L of CS at 1 and 8 h of age to provide 150 g of IgG; 3) Low supplement + GF (LG)--1.9 L of a CS with GF at 1 and 8 h of age to provide 150 g of IgG; 4) High supplement (HC)--1.9 L of CR at 1 h of age to provide 150 g of IgG and 1.9 L of a commercial milk replacer (MR) at 8 h of age; and 5) High supplement + GF (HG)--1.9 L of a CR with GF at 1 h of age to provide 150 g of IgG and 1.9 L of MR at 8 h of age. Apparent efficiency of IgG absorption was higher for calves fed HC and HG compared with those fed LC and LG and was lower for calves fed LG and HG compared with those fed LC and HC. IgG concentrations at 24 h were highest in calves fed MC compared with other calves and were higher in calves fed HC and HG compared to LC and LG. Calves fed LG and HG had lower IgG concentrations at 24 h of age compared with those fed LC and HC. These results indicate that 150 g of IgG provided in one dose soon after birth is superior to 150 g of IgG fed in two doses 7 h apart. Also, addition of a plasma fraction containing elevated concentrations of IGF-I and TGF-beta decreased IgG absorption in the neonatal calf.     

Articulating a social-ecological resilience agenda for urban design

In an era of change and uncertainty, the need for resilience is high on urban agendas. To date, multiple resilience concepts have been adopted into urban design with minimal substantiation. Resilience theory can potentially improve practice by rebalancing contemporary discourses in order to better value procedural aspects of urban design. The paper establishes theoretical links between urban design and resilience, where the integration of social and ecological systems, and the ability to enable adaptability and transformability, are key. In pursuit of shared principles between the two fields, a literature review identifies cross-cutting themes of diversity, social capital, innovation and learning.     

Agglomeration and the spatial distribution of creativity

Abstract.  This article analyses the spatial distribution of "creativity"– the production of new knowledge. We analyse commercial patents granted in Sweden between 1994 and 2001 using a panel of 100 labour market areas that encompass the entire country. We relate patent activity to measures of localisation and urbanisation, to the industrial composition and size distribution of firms, and to the regional distribution of human capital. Our analysis confirms the importance of human capital and research facilities in stimulating regional patent output. Our results document the importance of agglomeration and spatial factors in influencing creativity: patent activity is increased in larger and more dense labour markets and in regions in which a larger fraction of the labour force is employed in medium-sized firms. Our results also indicate that creativity is greater in labour markets with more diverse employment bases and in those which contain a larger share of national employment in certain industries, thus confirming the importance of urbanisation and localisation economies in stimulating creativity. Our quantitative results suggest that the urbanisation of Sweden during the 1990s had an important effect upon the aggregate level of patent activity in the country, leading to increases of up to 15 percent in aggregate patents.     

Short communication: Use of fecal starch concentration as an indicator of dry feed digestion in preweaned dairy calves

Fecal starch (FS) has been used as a tool to evaluate starch and diet digestibility in lactating dairy cows and feedlot steers. Some on-farm advisors also use FS to evaluate calf starter digestibility in preweaned dairy calves. Our objective was to evaluate the influence of starter intake (SI), starch and organic matter digestibility, milk replacer (MR) feeding rate, and age on FS concentrations in preweaned dairy calves. Male Holstein calves (43 ± 2.9 kg of body weight; n = 35) from a single farm were fed different amounts of MR ranging from 0.44 to 1.10 kg of dry matter (DM) daily (27% crude protein, 17% fat) and weaned by 7 wk of age. Starter ingredient composition was 37% whole corn, 20% whole oats, 35% protein pellet, and 3% molasses and contained 43 ± 1.9% starch. Fecal grab samples were taken at 3 (n = 20), 6 (n = 20), and 8 wk (n = 35) of age. Twelve fecal samples per calf were taken via rectal palpation over a 5-d period each week, frozen daily, combined on an equal wet-weight basis, and subsampled for analysis. Chromic oxide was used as an external digestibility marker at 3 and 6 wk (included in MR), whereas acid-insoluble ash was used as an internal marker at 8 wk. Milk replacer and starter intakes (offered and refused) were recorded daily during collection periods. Multiple and linear regression of organic matter digestibility (% of DM), total-tract starch digestibility (TTSD; % of DM), MR intake (kg/d), SI (kg/d), and age (week) versus FS (% of fecal DM) were determined using PROC REG of SAS (version 9.2, SAS Institute Inc., Cary, NC). Prior to weaning, SI, age, and MR rate explained 89% of the variation in TTSD, where TTSD = [19.7 × SI (±4.25)] + [3.8 × age (±0.79)] – [24.8 × MR (±3.19)] + 56.2 (±3.39). At 3 wk of age, TTSD increased (coefficient of determination = 0.53) and SI decreased (coefficient of determination = 0.20) with increasing FS. At 6 wk of age, TTSD and SI were unrelated to FS. In 8-wk-old calves (with 2 trials), SI, MR rate, FS, and trial explained 92% of the variation in TTSD, where TTSD = –[2.6 × SI (±0.67)] – [2.4 × MR (±0.56)] – [0.6 × FS (±0.04)] + [1.1 × trial (±0.33)] + 100.4 (±1.02). Postweaning, TTSD decreased linearly as FS increased (coefficient of determination = 0.86), whereas FS and SI were unrelated, a relationship in contrast to the previously observed result in calves still consuming milk replacer. In the current study, FS was not a good estimate of TTSD or dry feed intake in the preweaned calf, but has potential for evaluating TTSD in calves after weaning.