Genetic variability in the humoral immune response to bovine herpesvirus-1 infection in dairy cattle and genetic correlations with performance traits

Bovine herpesvirus-1 (BoHV-1) is a viral pathogen of global significance that is known to instigate several diseases in cattle, the most notable of which include infectious bovine rhinotracheitis and bovine respiratory disease. The genetic variability in the humoral immune response to BoHV-1 has, to our knowledge, not ever been quantified. Therefore, the objectives of the present study were to estimate the genetic parameters for the humoral immune response to BoHV-1 in Irish female dairy cattle, as well as to investigate the genetic relationship between the humoral immune response to BoHV-1 with milk production performance, fertility performance, and animal mortality. Information on antibody response to BoHV-1 was available to the present study from 2 BoHV-1 sero-prevalence research studies conducted between the years 2010 to 2015, inclusive; after edits, BoHV-1 antibody test results were available on a total of 7,501 female cattle from 58 dairy herds. National records of milk production (i.e., 305-d milk yield, fat yield, protein yield, and somatic cell score; n = 1,211,905 milk-recorded cows), fertility performance (i.e., calving performance, pregnancy diagnosis, and insemination data; n = 2,365,657 cows) together with animal mortality data (i.e., birth, farm movement, death, slaughter, and export events; n = 12,853,257 animals) were also available. Animal linear mixed models were used to quantify variance components for BoHV-1 as well as to estimate genetic correlations among traits. The estimated genetic parameters for the humoral immune response to BoHV-1 in the present study (i.e., heritability range: 0.09 to 0.16) were similar to estimates previously reported for clinical signs of bovine respiratory disease in dairy and beef cattle (i.e., heritability range: 0.05 to 0.11). Results from the present study suggest that breeding for resistance to BoHV-1 infection could reduce the incidence of respiratory disease in cattle while having little or no effect on genetic selection for milk yield or milk constituents (i.e., genetic correlations ranged from ?0.13 to 0.17). Moreover, even though standard errors were large, results also suggest that breeding for resistance to BoHV-1 infection may indirectly improve fertility performance while also reducing the incidence of mortality in older animals (i.e., animals >182 d of age). Results can be used to inform breeding programs of potential genetic gains achievable for resistance to BoHV-1 infection in cattle.     

Effect of an intramammary teat seal and dry cow antibiotic in relation to dry period length on postpartum mastitis

Infusion of either a long-acting antibiotic preparation (cefalonium) or the same antibiotic preparation combined with an internal teat sealant (bismuth subnitrite) were compared for the effect on new intramammary infections at calving and clinical mastitis in the first 100 d of lactation, in relation to dry period length. For all cows, a significant reduction in the incidence of new infections in quarters at calving (3.7 vs. 7.3%) was found for the combination treatment group (150 cows) compared with the antibiotic-alone treatment (133 cows). With a dry period of 10 wk or longer, significantly fewer new quarter infections (3.8 vs. 11.4%) were found in those cows receiving the combination treatment compared with antibiotic treatment alone. When the dry period was less than 10 wk, the incidence of new infections in quarters treated with the combination treatment was lower than for the antibiotic treatment alone (3.7 vs. 6%) but this was not a statistically significant difference. Fewer infections caused by Streptococcus uberis and coagulase-negative staphylococci were found in cows receiving the combination treatment compared with the antibiotic treatment alone (not significant). Coliform isolates were less likely in cows receiving the combination treatment with the longer dry period but the numbers of new intramammary coliform infections were low for both dry period categories. Few infections were caused by coagulase-negative staphylococci. The incidence of clinical mastitis in the first 100 d of lactation in quarters infected at calving was significantly lower (4 vs. 15 cases) for the combination treatment than for the antibiotic treatment alone for both dry period lengths. The clinical incidence in quarters in which a pathogen was not detected in either of the samples taken after calving was comparable between groups. No significant difference was found in the total clinical incidence after calving for both groups irrespective of dry period length.     

A comparison of three strains of Holstein-Friesian cows grazed on pasture: growth, development, and puberty

With the introduction of a protein milk payment system in New Zealand in 1988, there was an influx of North American (NA) Holstein-Friesian (HF) genetics into New Zealand (NZ) dairy herds, leading to an increase in the average percentage of NA genetics in NZ HF cows—from 2% in 1980 to 38% in 1999. Of interest has been the effect this change has had on farm profitability and on the management required for these animals, as well as the phenotypic changes that have occurred within the national herd under the breeding programs operated in NZ from 1970 to 1990. The objective of this study was to quantify differences in body dimensions, body weights, and puberty-related parameters among 3 strains of HF, representing animals of NZ origin representative of the genetics present in 1970 and 1990 and of NA origin with 1990s genetics. A total of 172 animals born in 1999 were compared. The strains were 1) NZ70, a strain of NZ Friesian (average 7% NA genetics) equivalent to high-genetic-merit (high Breeding Worth) cows farmed in the 1970s; 2) NZ90, a strain of HF of NZ origin (average 24% NA genetics) typical of the animals present in the 1990s; and 3) NA90, a strain of HF of NA origin (average of 91% NA genetics) typical of animals present in the 1990s. The differences in BW among all strains were significant at 6 and 12 mo of age. At 15 and 24 mo, the 2 NZ strains were significantly lighter than the NA90 animals. At 24 mo of age (i.e., prior to first calving), the NA90 strain animals (BW = 515 kg) were 22 and 34 kg heavier than the NZ90 and NZ70 strains. The body length of the NA90 strain was greater than either of the 2 NZ strains; the differences among the NA90 strain and the 2 NZ strains varied from 2 to 6 cm, with the differences generally being greater at older ages. The trend in heart girth difference among strains was similar to that observed for body length. The wither height of the NA90 animals was greater than that of the NZ strains by 1 to 7 cm, although there was no significant difference between the NA90 and NZ90 strains at birth. At puberty the NA90 heifers were 20 d older and 20 kg heavier than the NZ90 heifers, which in turn were 25 kg and 25 d older than the NZ70 heifers. The NA90 strain had a heavier mature body weight, and their older age at puberty suggested either that they mature later or that, under pastoral conditions, their growth rate is limited by their inability to consume sufficient metabolizable energy as grazed pasture, with a consequent delay in puberty. Results from this study will be useful in revising target BW in growing heifers of different germplasm.     

A test of metabolically efficient coding in the retina

We tested the hypothesis that aspects of the neural code of retinal ganglion cells are optimized to transmit visual information at minimal metabolic cost. Under a broad ensemble of light patterns, ganglion cell spike trains consisted of sparse, precise bursts of spikes. These bursts were viewed as independent neural symbols. The noise in each burst was measured via repeated presentation of the visual stimulus, and the energy cost was estimated from the total charge flow during ganglion cell spiking. Given these costs and noise, the theory of efficient codes predicts an optimal distribution of symbol usage. Symbols that are either noisy or costly occur less frequently in this optimal code. We found good qualitative and quantitative agreement with the measured distribution of burst sizes for ganglion cells in the tiger salamander retina.     

Deep levels in bulk LEC single crystal IxGa1-xAs

Bulk single crystals of In_xGa_1-xAs (0.01 <x < 0.12) were successfully grown by the Liquid Encapsulated Czochraski (LEC) technique. These crystals are of high quality and can provide tunable substrate material for epitaxial application, since the lattice constant may be adjusted by varying the composition. Nominally undoped crystals were semi-insulating as grown ifx is less than about 0.05. Semi-insulating crystals with higher In composition can be obtained by chromium doping during crystal growth. The asgrown crystals were studied by 4.2 K photoluminescence spectroscopy (PL) and thermally stimulated current spectroscopy (TSC). Results from PL measurements indicate good crystal quality and impurity control. TSC spectra reveal several bulk traps in undoped and Cr doped semi-insulating samples. The activation energies of these traps decrease as In composition is increased. The amount of change in activation energy is about one third of the bandgap shrinkage due to increased In concentration.     

Refusal to eat in the elderly

Refusal to eat by the elderly, and subsequent malnutrition, occurs in both institutional and community settings. Causes include physiologic changes associated with aging, mental disorders such as dementia and depression, and medical, social, and environmental factors. Treatment approaches call for management of these causes while considering the roles that medicine, ethics, and culture play in the process.