Size-selective assessment of airborne particles in swine confinement building with the UVAPS

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Feasibility and Costs of Phosphorus Application Limits on 39 U.S. Swine Operations

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An Assessment of Nitrogen-Based Manure Application Rates on 39 U.S. Swine Operations

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Épandage des déjections du bétail

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Les odeurs, la poussière due à la circulation routière et la contamination potentielle du sol et des eaux sont fréquemment associées à l’épandage des déjections. Ces problèmes peuvent être souvent réglés de façon efficace en utilisant des techniques de gestion appropriées et en tenant compte des pratiques culturales et des règlements en matière d’environnement.

Enzyme Supplementation and Feed Processing Solutions Provide Solutions for Low-Quality Grains

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The nutritional quality of wheat or barley can vary substantially (see previous Centre of Swine Volume 10 Number 3). Ignoring the existing variation may cause lower finished feed quality and thereby impact the swine producer economically through reduced growth performance.

For wheat and barley, reduced nutritional quality usually means a reduced digestible energy (DE) content. The reduction in DE content is almost completely caused by a reduction in energy digestibility, not by a reduction in the total amount of energy in the ingredient sample (or gross energy = GE content). The reduction in energy digestibility is usually related to an increase in fibre content of the grain.

Solutions for the use of low quality grains in diet formulations while maintaining growth performance should focus on two aspects: (1) correcting diet formulations to achieve the formulated diet DE content or (2) enzyme supplementation or feed processing to overcome to reduction in energy digestibility of the grain. For either solution, correct prediction of DE content of individual wheat and barley samples may be critical, but the impact of correct prediction of DE content on further decision making regarding enzyme supplementation or feed processing to improve energy digestibility is poorly understood. Equations to predict DE content of wheat and barley are presently being evaluated using the 2002-harvest.

To study whether a specific wheat sample would impact the beneficial effects of enzyme supplementation or feed processing, three samples of wheat were collected from the 2002-harvest. The three wheat samples (W1, W2, and W3) had a similar content of crude protein (18.8 to 19.7% DM) but had a wide range in neutral detergent fibre (NDF) content (W1, 20.1; W2, 29.3; and W3, 35.7% DM).

Results of a digestibility study with grower pigs indicate that the increased fibre content for samples W1 to W3 indeed resulted in decreased energy digestibility (Figure 1) and reduced DE content from 3,680 to 3,320 kcal/kg DM, confirming the importance of ingredient evaluation and that an increase in fibre (NDF) coincides with a decrease in energy digestibility and DE content. The range in wheat DE content also reflects a range in economic value of more than $15 per tonne of wheat used for swine feed.

Wheat diets were supplemented with a carbohydrase enzyme (xylanase). The enzyme should help the pig to digest energy, because negative effects of fibre fractions (or arabinoxylans) on energy digestibility will be alleviated. Indeed, enzyme supplementation improved energy digestibility for wheat samples W2 and W3, but not for wheat sample W1 (Figure 2), indicating that the beneficial effect of enzymes is dependent on the wheat sample in the diet. This result further stresses the importance of ingredient evaluation, or the importance of enzyme supplementation to alleviated expected differences in energy digestibility. The underlying reason for the positive response for W2 and W3 to enzyme supplementation and the lack thereof for W1 will be related to the content of fibre fractions in the wheat, specifically the fraction called xylan. Therefore, the wheat samples are presently being analysed for these fractions to further related wheat characteristics to prediction of an enzyme response.

Wheat samples were ground across three hammer mill screens to achieve a predicted particle size of 900, 650, and 400 mm (microns). Particle size reduction should help the pig to digest energy, because a finer particle size means that the ratio of surface area to volume of the particles is increased. In other words, digestive enzymes of the pig or microbes of the pig have better access to the nutrients with a finer particle size. Indeed, enzyme supplementation improved energy digestibility for wheat samples W2 and W3, but not for wheat sample W1 (Figure 3), indicating that the beneficial effect of particle size reduction is dependent on the wheat sample in the diet.

Xylanase and phytase supplementation on growth performance of grower pigs

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The nutritional value of wheat millrun with xylanase and (or) phytase supplementation in wheat based diets for growing pigs was evaluated. Wheat millrun inclusion depressed energy and P digestibility and also ADG, but had no effect on ADFI and G: F. Xyalnase and phytase reduced ADFI and improved nutrient digestibility. However, the improved nutrient digestibility did not result in improved growth performance.

The Delicate Nursery Environment

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The optimal nursery environment encompasses temperature, physical, and social components. Big Sky Farms are worried about temperature control (they go from 29.0 to 19.0 degrees C) and ventilation (pigs start off with 1.5 to 1.7 cubic feet per minute up to 1.7 to 2.0 cfm). Day one is important for the piglets due to the weaning stress. To minimize this stress, it is ensured that temperatures are comfortable for the piglets, piglets are sorted by size for equal competition, they are creep fed adequately, feeders are set correctly, and provide a night light. Nursery pigs are to not be stocked at less than 2.8 square feet per pig from 5 to 24 kg, and no less than 3.2 square feet per pig from 25 to 32 kg. High standards of hygiene (washing and disinfection) are enforced to avoid a build-up of pathogenic bacteria. The piglets are fed 4 different rations throughout the nursery phase in order to increase the piglet quality that is coming out of the nursery.

Assessing dominance in sheep in a competitive situation: level of motivation and test duration

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The dominance structure in an established group of sheep is often difficult to determine in the field, because of the low frequency of agonistic interactions. One solution to this problem is to test each pair separately in a competitive situation. The most frequently used test involves competition for food after a specific period of food deprivation, but to date, there is no agreement as to the optimum length of time the animals should go without food. The present experiment compared competitive behaviour of sheep at different lengths of time after a meal. The experimental animals were a group of 10 1- year old female Scottish Blackface sheep (45 dyads). The animals had access to dry grass daily, from 07:00 to 08:00 h and from 19:00 to 20:00 h. They were tested in pairs for 5 minutes immediately after and 2, 4, 6 and 8 h after the end of the morning meal. In the test arena a feed hopper provided access to feed to only one sheep at a time. Aggressive interactions such as blocking, threats and butts, as well as non-aggressive interactions (nudges), the time spent at the feeder, and the number and type of displacements (aggressive or non-aggressive) were recorded. The number of displacements was also recorded in the home pens during ten 45-minute periods of group feedings. Blocking behaviour showed the clearest difference between the two sheep in a pair and was therefore, used as the main indicator of dominance. Its occurrence increased as the time since the morning meal was increased and decreased in the course of the 5 minute tests. Consistency between pair-tests and group observations was greatest in the test 8 h after the previous meal, but the difference in consistency between the 2 and 8 h tests was small. This experiment suggest that a period of at least 2 h of food withdrawal is necessary to generate sufficient motivation for a competition test and to mask differences in feeding motivation between individuals. While the performance of dominance-relevant behaviour increased with time since the last meal, a period of 4 h may be sufficient to provide high-quality data. We also suggest that the test duration can be reduced to 2 minutes.

The effect of early colour preference and of a colour exposing procedure on the choice of nest colours in laying hens.

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Hens at the start of lay prefer nests in the corners and at the ends of rows, which leads to overcrowding in the nest and more aggression as a result. Increased aggression leads to cracked and mislaid eggs. The current study was designed to verify whether nest colour could be used to increase their attractiveness in order to counter-balance the aforementioned positional effects. Tests were also conducted to determine whether early colour preference could be demonstrated, whether early colour preference could affect nest colour preference, and whether exposing chicks to specific colours at an early age could influence nest colour preference later on. In the first group, chicks were exposed to one of four colours (blue, green, yellow and red) during the first 12 days of life. In two additional groups, individuals showing high preference for these colours were identified. 50.5 % of chicks chose yellow most often, 32.1 % chose red, but only 7.1 and 2.2 % chose green and blue, respectively. 8.1 % of chicks did not show a preference for a single colour, but showed preference for two or three colours equally. As adult hens, they were tested for their choice of nest colour at the start of lay (weeks 19-22) from the following eight categories: those that had been exposed to blue, green, yellow or red during the first 12 days of life, those that had been selected at the same age for their preference of yellow, red, or yellow and red, and those that had been selected because they had shown no preference to any particular colour during the first 12 days of life. There were not enough birds showing a preference for blue or green at an early age to be tested later on as hens. Groups of four were created, and each bird of a group originated from a different category. Each group had a choice of four double nests, with each nest painted in one of the four colours. Hens that were exposed to blue, green or red at an early age did not prefer corresponding nest colours when in lay. The same was true for hens showing preference for red or red and yellow at an early age. All hens showed a significant preference for yellow nests when in lay, and were indifferent to blue, green, and red nests. However, birds selected for their preference of the colour yellow at an early age, as well as those exposed to yellow at that age, did not show this general preference of yellow nests. Instead, they were indifferent to all four nest colours offered. So, in systems where nests are arranged in rows, it should be possible to distribute hens more evenly among available nests, and thus avoid overcrowding, by painting the mid-third of nest rows yellow. The nests should be painted in a way as to reduce aggression between the hens and decrease the number of cracked and mislaid eggs at the start of lay.

Factors influencing bruises and mortality of broilers during catching, transport, and lairage

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The risk factors associated with mortality and bruises occurring between catching and slaughter were identified and quantified using a multilevel analysis. Some the data collected indicated that the mean percentage of dead on arrival was 0.46. After correcting the percentage of bruises for economic value, the percentage of bruises was 2.20. Bruises were associated with season, moment of transport, and ambient temperature. Factors associated with the percentage of dead on arrival were ambient temperature, moment of transport, catching company, breed, flock size, mean body weight, lairage time, and the interaction term transport time x ambient temperature. Stocking density, transport time, and lairage time were the most important factors associated with deads on arrival. These factors can be improved relatively easily and therefore increase animal welfare and profitability.