Within-Litter Birth Weight Variation in the Domestic Pig and its Relation to Pre-Weaning Survival, Weight Gain, and Variation in Weaning Weights

To determine the relationship between within-litter birth weight variation and pre-weaning survival and weight gain, and to provide practical guidance on fostering low-birth-weight piglets, we analyzed piglet survival and weight gain in litters of piglets from 52 sows followed through eight consecutive parities. Litters with high variation in birth weight had more deaths, especially if the litter’s mean birth weight was low. High variation in birth weight was also associated with high variation in weaning weight, but was not significantly related to mean weaning weight. Piglets with birth weights well below the range of most of the litter (‘low-birth-weight piglets’) were more likely to die than their litter-mates, but their weight gains were normal for their birth weight if they survived. These piglets experienced particularly low survival in larger litters and litters from sows of sixth parity or older. Litters containing low-birth-weight piglets started, on average, with more piglets born alive and had a lower pre-weaning survival (with the majority of deaths being low-birth-weight piglets), but did not wean significantly more piglets than litters without low-birth-weight piglets. The majority of litters had a negatively skewed distribution of birth weights, with more piglets well below the mean than well above it. Our data are consistent with the hypothesis that high variation in birth weight contributes to reduced survival, at least for litters of low mean birth weight, and to variable weaning weights. Our data also support the hypothesis that in terms of survival, small piglets have a competitive disadvantage compared to their heavier litter-mates, a disadvantage that is exacerbated in large litters and litters from older sows. Our data suggest that selection for increased litter size that results in more low-birth-weight piglets per litter may not be beneficial unless measures are undertaken to improve the survival of low-birth-weight piglets

The Effect of Littermate Weight on Survival, Weight Gain, and Suckling Behavior of Low-Birth-Weight Piglets in Cross-Fostered Litters

Objective: To determine whether low-birth-weight piglets show better survival, weight gain, and suckling behavior when grouped with other small piglets by cross-fostering. Methods: We manipulated the number and size of foster littermates for low-birth-weight piglets in 31 small (eight or nine piglets) and 22 large (11 or 12 piglets) litters. Experimental litters were composed of four to six piglets of lowest birth weight and either four to six slightly heavier or four to six much heavier piglets from two combined litters. Results: Low-birth-weight piglets raised with much heavier littermates had somewhat lower survival rates, but showed no tendency towards lower weight gains or less successful suckling behavior than low-birth-weight piglets raised with slightly heavier littermates. The somewhat higher survival rate of low-birth-weight piglets raised with slightly heavier littermates was largely offset by more deaths in the foster littermates, so there was no overall reduction in total losses. Low-birth-weight piglets fought more when raised with slightly heavier piglets than with much heavier piglets, and they missed more nursing episodes and had smaller weight gains than littermates, regardless of littermate weight. Implications: Cross-fostering low-birth-weight pigs into litters with other small pigs, compared to fostering into litters with high-birth-weight pigs, slightly improved their survival, but did not affect their weight gain or ability to suckle successfully, nor overall litter survival, even in litters as large as 11 or 12 piglets. Cross-fostering low-birth-weight pigs to litters of similar birth weight increased the level of fighting

Within-Litter Birth Weight Variation in the Domestic Pig and its Relation to Pre-Weaning Survival, Weight Gain, and Variation in Weaning Weights

To determine the relationship between within-litter birth weight variation and pre-weaning survival and weight gain, and to provide practical guidance on fostering low-birth-weight piglets, we analyzed piglet survival and weight gain in litters of piglets from 52 sows followed through eight consecutive parities. Litters with high variation in birth weight had more deaths, especially if the litter’s mean birth weight was low. High variation in birth weight was also associated with high variation in weaning weight, but was not significantly related to mean weaning weight. Piglets with birth weights well below the range of most of the litter (‘low-birth-weight piglets’) were more likely to die than their litter-mates, but their weight gains were normal for their birth weight if they survived. These piglets experienced particularly low survival in larger litters and litters from sows of sixth parity or older. Litters containing low-birth-weight piglets started, on average, with more piglets born alive and had a lower pre-weaning survival (with the majority of deaths being low-birth-weight piglets), but did not wean significantly more piglets than litters without low-birth-weight piglets. The majority of litters had a negatively skewed distribution of birth weights, with more piglets well below the mean than well above it. Our data are consistent with the hypothesis that high variation in birth weight contributes to reduced survival, at least for litters of low mean birth weight, and to variable weaning weights. Our data also support the hypothesis that in terms of survival, small piglets have a competitive disadvantage compared to their heavier litter-mates, a disadvantage that is exacerbated in large litters and litters from older sows. Our data suggest that selection for increased litter size that results in more low-birth-weight piglets per litter may not be beneficial unless measures are undertaken to improve the survival of low-birth-weight piglets

Consumption of Solid Food by Suckling Pigs: Individual Variation and Relation to Weight Gain

Individual daily consumption of supplementary solid food (\u27creep feed\u27) was measured from Day 10 to weaning at Day 28 for 39 piglets in four litters, and its relationship to body weight and weight gain up to Day 42 was investigated. Individual consumption was measured by combining the weight of the feed removed from the dispensers (monitored electronically) and a video image of piglet activity at the feeder. Creep feed consumption varied greatly, both between and within litters. On average, pigs began feeding on Day 12 (range Day 10-28), intake was relatively low (usually \u3c 5 g day ‒1) until Day 20 but increased considerably in the week before weaning, with a mean intake of 63 g day ‒1 (range 2-205 g day ‒1) during that week. Over the entire creep-feeding period, total feed consumption ranged from 13-1911 g per pig. Within litters, intake was positively correlated with birth weight (P \u3c 0.05) and the correlation with weight gains to Day 20 tended to be positive rather than negative. This suggests that greater creep feed intake was typical of the larger and more mature piglets, rather than serving as compensation for poor milk intake among the more deprived litter-mates. However, one exceptional pig began, on Day 14 after several days of weight loss, to eat more creep feed than any other piglet studied, suggesting that compensatory creep feeding can occur at a young age in exceptional cases. In a multiple regression analysis, creep feed intake accounted for 37% of the variation in weight gain in the week before weaning (P \u3c 0.001) and 7% of the variation in gain from Day 10 to weaning (P \u3c 0.01) after variation attributable to antecedent variables had been taken into account. Within-litter differences in weight gain during the 2 weeks after weaning were correlated with weight at birth and weight gain before weaning (P \u3c 0.05), but not with pre-weaning creep feed intake. Hence, creep feed intake appeared to contribute to pre-weaning gains and these in turn were correlated with post-weaning gains; however, a more direct effect of pre-weaning creep feed intake on post-weaning gain could not be detected

New Pulsars from an Arecibo Drift Scan Search

We report the discovery of pulsars J0030+0451, J0711+0931, and J1313+0931 that were found in a search of 470 square degrees at 430 MHz using the 305m Arecibo telescope. The search has an estimated sensitivity for long period, low dispersion measure, low zenith angle, and high Galactic latitude pulsars of ~1 mJy, comparable to previous Arecibo searches. Spin and astrometric parameters for the three pulsars are presented along with polarimetry at 430 MHz. PSR J0030+0451, a nearby pulsar with a period of 4.8 ms, belongs to the less common category of isolated millisecond pulsars. We have measured significant polarization in PSR J0030+0451 over more than 50% of the period, and use these data for a detailed discussion of its magnetospheric geometry. Scintillation observations of PSR J0030+0451 provide an estimate of the plasma turbulence level along the line of sight through the local interstellar medium.Comment: 21 pages, 4 figures, Accepted for Publication in Ap

Bostonia: The Boston University Alumni Magazine. Volume 12

Founded in 1900, Bostonia magazine is Boston University’s main alumni publication

Tensile Fracture of Welded Polymer Interfaces: Miscibility, Entanglements and Crazing

Large-scale molecular simulations are performed to investigate tensile failure of polymer interfaces as a function of welding time $t$. Changes in the tensile stress, mode of failure and interfacial fracture energy $G_I$ are correlated to changes in the interfacial entanglements as determined from Primitive Path Analysis. Bulk polymers fail through craze formation, followed by craze breakdown through chain scission. At small $t$ welded interfaces are not strong enough to support craze formation and fail at small strains through chain pullout at the interface. Once chains have formed an average of about one entanglement across the interface, a stable craze is formed throughout the sample. The failure stress of the craze rises with welding time and the mode of craze breakdown changes from chain pullout to chain scission as the interface approaches bulk strength. The interfacial fracture energy $G_I$ is calculated by coupling the simulation results to a continuum fracture mechanics model. As in experiment, $G_I$ increases as $t^{1/2}$ before saturating at the average bulk fracture energy $G_b$. As in previous simulations of shear strength, saturation coincides with the recovery of the bulk entanglement density. Before saturation, $G_I$ is proportional to the areal density of interfacial entanglements. Immiscibiltiy limits interdiffusion and thus suppresses entanglements at the interface. Even small degrees of immisciblity reduce interfacial entanglements enough that failure occurs by chain pullout and $G_I \ll G_b$

BMQ

BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals

Developing Telemental Health Partnerships Between State Medical Schools and Federally Qualified Health Centers: Navigating the Regulatory Landscape and Policy Recommendations

BackgroundFederally Qualified Health Centers (FQHCs) deliver care to 26 million Americans living in underserved areas, but few offer telemental health (TMH) services. The social missions of FQHCs and publicly funded state medical schools create a compelling argument for the development of TMH partnerships. In this paper, we share our experience and recommendations from launching TMH partnerships between 12 rural FQHCs and 3 state medical schools.ExperienceThere was consensus that medical school TMH providers should practice as part of the FQHC team to promote integration, enhance quality and safety, and ensure financial sustainability. For TMH providers to practice and bill as FQHC providers, the following issues must be addressed: (1) credentialing and privileging the TMH providers at the FQHC, (2) expanding FQHC Scope of Project to include telepsychiatry, (3) remote access to medical records, (4) insurance credentialing/paneling, billing, and supplemental payments, (5) contracting with the medical school, and (6) indemnity coverage for TMH.RecommendationsWe make recommendations to both state medical schools and FQHCs about how to overcome existing barriers to TMH partnerships. We also make recommendations about changes to policy that would mitigate the impact of these barriers. Specifically, we make recommendations to the Centers for Medicare and Medicaid about insurance credentialing, facility fees, eligibility of TMH encounters for supplemental payments, and Medicare eligibility rules for TMH billing by FQHCs. We also make recommendations to the Health Resources and Services Administration about restrictions on adding telepsychiatry to the FQHCsâ Scope of Project and the eligibility of TMH providers for indemnity coverage under the Federal Tort Claims Act.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149739/1/jrh12323_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149739/2/jrh12323.pd

Evaluation Research and Institutional Pressures: Challenges in Public-Nonprofit Contracting

This article examines the connection between program evaluation research and decision-making by public managers. Drawing on neo-institutional theory, a framework is presented for diagnosing the pressures and conditions that lead alternatively toward or away the rational use of evaluation research. Three cases of public-nonprofit contracting for the delivery of major programs are presented to clarify the way coercive, mimetic, and normative pressures interfere with a sound connection being made between research and implementation. The article concludes by considering how public managers can respond to the isomorphic pressures in their environment that make it hard to act on data relating to program performance.This publication is Hauser Center Working Paper No. 23. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers