Genetic parameters for automatically-measured vaginal temperature, respiration efficiency, and other thermotolerance indicators measured on lactating sows under heat stress conditions.

Background: Genetic selection based on direct indicators of heat stress could capture additional mechanisms that are involved in heat stress response and enable more accurate selection for more heat-tolerant individuals. Therefore, the main objectives of this study were to estimate genetic parameters for various heat stress indicators in a commercial population of Landrace × Large White lactating sows measured under heat stress conditions. The main indicators evaluated were: skin surface temperatures (SST), automatically-recorded vaginal temperature (T), respiration rate (RR), panting score (PS), body condition score (BCS), hair density (HD), body size (BS), ear size, and respiration efficiency (R).

Evaluation of essential fatty acids in lactating sow diets on sow reproductive performance, colostrum and milk composition, and piglet survivability.

Mixed parity sows (n = 3,451; PIC, Hendersonville, TN; parities 2 through 9) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. Our hypothesis, like observed in earlier research, was that increasing linoleic acid (LA) and α-linolenic acid (ALA) would improve sow and litter performance. At approximately day 112 of gestation, sows were randomly assigned within parity groups to 1 of 4 corn-soybean meal-wheat-based lactation diets that contained 0.

Proposed multidimensional pain outcome methodology to demonstrate analgesic drug efficacy and facilitate future drug approval for piglet castration.

Castration of male piglets in the United States is conducted without analgesics because no Food and Drug Administration (FDA) approved products are labeled for pain control in swine. The absence of approved products is primarily due to a wide variation in how pain is measured in suckling piglets and the lack of validated pain-specific outcomes individually indistinct from other biological responses, such as general stress or inflammation responses with cortisol. Simply put, to measure pain mitigation, measurement of pain must be specific, quantifiable, and defined.

Effects of group-size-floor space allowance during the nursery phase of production on future litter size and retention of sows through three parities.

We previously reported that reduced floor space allowance caused by increasing the number of gilts per pen decreased growth and affected blood chemistry and immunology. The current objective was to determine effects of nursery group-size-floor space allowance on future litter sizes and retention in the breeding herd through three parities in sows. A 3 × 3 factorial arrangement of treatments was employed with 2,537 gilts classified as large (6.

Effect of suckling intensity of primiparous sows on production performance during current and subsequent parities1.

This study was conducted to evaluate the effects of suckling intensity (litter size and lactation length) to primiparious sows on production performance during current and subsequent parities. Upon farrowing, 115 primiparous sows (farrowing weight: 222.7 ± 20.

Effect of feeding three lysine to energy diets on growth, body composition and age at puberty in replacement gilts.

This study evaluated the effect of diets differing in standard ileal digestible (SID) lysine on lysine intake, growth rate, body composition and age at puberty on maternal line gilts. Crossbred Large White×Landrace gilts (n=641) were fed corn-soybean diets differing in SID lysine concentration (%, g SID lysine:Mcal ME); diets were not isocaloric. Gilts received three grower, finisher diet combinations: low (0.

Effects of group-size-floor space allowance during the nursery phase of production on growth, physiology, and hematology in replacement gilts.

The objective was to determine effects of nursery group-size-floor space allowance on growth, physiology, and hematology of replacement gilts. A 3 × 3 factorial arrangement of treatments was used wherein gilts classified as large, medium, or small ( = 2537; BW = 5.6 ± 0.

Wider stall space affects behavior, lesion scores, and productivity of gestating sows.

Limited space allowance within the standard gestation stall is an important welfare concern because it restricts the ability of the sow to make postural adjustments and hinders her ability to perform natural behaviors. Therefore, we evaluated the impacts of increasing stall space and/or providing sows the freedom to access a small pen area on sow well-being using multiple welfare metrics. A total of 96 primi- and multiparous crossbred sows were randomly assigned in groups of 4 sows/treatment across 8 replicates to 1 of 3 stall treatments (TRT): standard stall (CTL; dimensions: 61 by 216 cm), width-adjustable stall (flex stall [FLX]; dimensions: adjustable width of 56 to 79 cm by 216 cm), or an individual walk-in/lock-in stall with access to a small communal open-pen area at the rear of the stall (free-access stall [FAS]; dimensions: 69 by 226 cm).

Age at puberty, ovulation rate, and uterine length of developing gilts fed two lysine and three metabolizable energy concentrations from 100 to 260 d of age.

The objective of this study was to determine the effect of ad libitum feeding diets differing in standard ileal digestible (SID) lysine and ME concentrations that bracket those fed to developing gilts in U.S. commercial settings.

Optimal dietary energy and amino acids for gilt development: Growth, body composition, feed intake, and carcass composition traits.

The objective of this study was to determine if body composition of developing gilts could be altered at the onset of estrus by ad libitum feeding diets differing in standard ileal digestible (SID) lysine and ME using levels that are within those used in practice by pig producers in the United States. Crossbred Large White × Landrace gilts ( = 1,221), housed in groups, were randomly allotted to 6 corn-soybean diets in a 2 × 3 factorial arrangement formulated to provide 2 SID lysine and 3 ME levels. Gilts received grower diets formulated to provide 0.

Space allowance and high fiber diet impact performance and behavior of group-kept gestating sows.

Identifying and optimizing housing and management systems that improve the well-being of the gestating sow is essential to sustaining animal agriculture. Therefore, the impact of 2 floor-space allowances and a high-fiber gestation diet on dry group-housed sows were evaluated using multiple measures of well-being. Groups of 10 multiparous sows/pen (n = 221) were assigned randomly to treatments in a 2 × 2 factorial arrangement to either a corn-soybean meal diet (CTL) or corn-soybean meal diet supplemented with soybean hulls and wheat middlings (FBR), and floor-space allowance of either 1.

Space allowance for gestating sows in pens: behavior and immunity.

Different floor space allowances for dry, pregnant sows in pens were evaluated to determine the impacts of space on sow behavior, immune, and cortisol measures. The experiment consisted of 6 replications (blocks 1 to 6; n = 20 sows/group), and within each replicate, physiological measurements were recorded for 2 consecutive pregnancies. A total of 152 sows were measured at 1 gestation, and 65 of those sows were measured at the successive gestation (n = 217).

Application of artificial neural network models to analyse the relationships between Gammarus pulex L. (Crustacea, Amphipoda) and river characteristics.

This study aimed at analysing the relationship between river characteristics and abundance of Gammarus pulex. To this end, four methods which can identify the relative contribution and/or the contribution profile of the input variables in neural networks describing the habitat preferences of this species were compared: (i) the "PaD" ("Partial Derivatives") method consists of a calculation of the partial derivatives of the output in relation to the input variables; (ii) the "Weights" method is a computation using the connection weights of the backpropagation Artificial Neural Networks; (iii) the "Perturb" method analyses the effect of a perturbation of the input variables on the output variable; (iv) the "Profile" method is a successive variation of one input variable while the others are kept constant at a fixed set of values. The dataset consisted of 179 samples, collected over a three-year period in the Zwalm river basin in Flanders, Belgium.

Development of river ecosystem models for Flemish watercourses: case studies in the Zwalm river basin.

Only recently, modelling has been accepted as an interesting and powerful tool to support river quality assessment and management. The 'River Invertebrate Prediction and Classification System' (RIVPACS), based on statistical modelling, was one of the first and best known systems in this context. RIVPACS was developed to classify macroinvertebrate community types and to predict the fauna expected to occur in different types of watercourses, based on a small number of environmental variables.

Overview and quantification of the factors affecting the upstream and downstream movements of Gammarus pulex (Amphipoda).

Human activities have severely deteriorated the Flemish river systems, and many functions such as drinking water supply, fishing, ...

Comparison of Artificial Neural Network (ANN) Model Development Methods for Prediction of Macroinvertebrate Communities in the Zwalm River Basin in Flanders, Belgium.

Modelling has become an interesting tool to support decision making in water management. River ecosystem modelling methods have improved substantially during recent years. New concepts, such as artificial neural networks, fuzzy logic, evolutionary algorithms, chaos and fractals, cellular automata, etc.