Forms and retention of phosphorus in an illite-clay soil profile with a history of fertilisation with pig manure and mineral fertilisers

Posted in: Environment by admin on January 1, 2007 | No Comments

Effect of Nitrification on Phosphorus dissolving in a Piggery Effluent treated by a Sequencing Batch Reactor

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Trials using modified sequencing batch reactors were performed to study the influence of the amount of nitrified nitrogen on pH (and thus solubility of the phosphorus) and determine whether the pH was the main cause of the increased phosphorus dissolving. It was determined that the modified sequencing batch reactor process management (hydraulic retention time and anaerobic/aerobic step duration) did allow the control of the amount of nitrogen nitrified in one cycle and hence the amount of the phosphorus dissolved.

Productivity and aggression at grouping of grower-finisher pigs in large groups

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A total ofeight 11-wk trials were conducted to evaluate the productivity and aggression at
grouping ofgrower-f inisher pigs [initial body weight (BW)= 31.8 ± 5.4 kg (mean ± SD), n=2304] in two group size
treatments (18 and 108 pigs pen-1). Pigs were housed on fully-slatted floors, provided one wet/dry feeder space for every
nine pigs, and a floor space allowance of 0.76 m2 pig-1 in both group sizes. The level ofaggression at grouping was
recorded for 2 h starting 0, 24 and 48 h following grouping into small and large groups. Pigs were weighed on weeks 0, 2, 5,
7 and 11, and average daily gain (ADG) was obtained. Average daily feed intake (ADFI) was recorded during two periods
(weeks 2 to 5 and 7 to 11). There was no difference in percentage of time spent on aggression between two group sizes up to
48 h following grouping. ADG for the entire 11-wk trial was affected (2 %) by large group size (0.971 and 0.955 kg d-1 for
groups of 18 and 108, respectively; P<0.05). However, the greatest effect on ADG was observed during the first 2 wk following grouping (0.919 and 0.833 kg d-1 for groups of 18 and 108, respectively; P<0.001). There were no significant effects due to group size on ADFI, feed efficiency, variability in final BW within a pen, carcass traits or mortality and morbidity (P>0.05). In summary, the overall productivity and aggression at grouping did not differ substantially between
group sizes of 18 and 108 pigs pen-1.

Application of a Biological Treatment Approach to Control Gaseous Emissions from Swine Operations

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Swine barn workers may be exposed to potentially hazardous levels of gases, especially hydrogen sulphide (H2S), generated during in-barn manure handling tasks. This study demonstrated that adaptation of measures developed in another industry with similar environmental concerns (i.e., oil industry) could lead to successful control of gas emissions generated from swine operations. First, the activity of microbial species which are responsible for the generation of undesirable gases and odour precursor compounds in the manure are diminished using a balanced mixture of specific inhibitors, namely nitrite (NO2) and molybdate (Mo). The second mechanism involved stimulation of the catalytic activity of sulphide-oxidizing bacteria that are either indigenous in the raw swine manure or those which are isolated and enriched from the manure in the laboratory and subsequently added to raw swine manure during treatment. These preliminary results indicate the potential for isolation and enrichment of indigenous sulphide-oxidizing bacteria present in the manure. A more detailed study is being conducted to verify the possibility of enriching a sulphide-oxidizing culture from the manure and to assess the activity of the enriched culture in reducing the emission of sulphide from manure slurries. The effect of this treatment on manure nutrient properties will also be examined to determine the possible environmental impact of subsequent land application of the treated manure. This is necessary information to formulate guidelines for pork producers on the proper application of the treatment in actual swine barns.

POUSSIÈRES

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POUSSIÈRES DANS LES BÂTIMENTS D’ÉLEVAGE: SOURCES, COMPOSITION ET TYPE
La poussière est normalement considérée comme un des contaminants présents dans les bâtiments
d’élevage. La poussière est générée par la ration, la litière, le fumier/lisier séché, les débris de peau et les
matériaux du bâtiment (Maghirang et al., 1995). Selon Zhang et al. (1994), d’autres formes de partic ules
aériennes aussi appelés bioaérosols incluent des bactéries, endotoxines et moississures. En effet, Butera
et al. (1991), ont trouvé que les moississures représentaient moins de 1% du total des microorganismes
dans la poussière des porcheries de croissance-finition. Les bactéries gramme positive représentent
jusqu’à 72% de toutes les bactéries isolées. Martin et al. (1996) ont démontré que la poussière peut être
composée de plusieurs éléments car ils ont trouvé six espèces différentes de bactéries ou fongus dans la
poussière provenant d’une pièce où il n’y avait pas de porc et 22 différents microorganismes ont été
détectés dans la poussière provenant d’une pièce où des porcs étaient gardés.
La poussière respirable est définie comme étant composée de particules ayant un diamètre aérodynamique
moyen de moins de 5 mm (Pearson and Sharples, 1995). Elles peuvent être inhalées profondément dans
les poumons des humains ou des animaux où elles peuvent se loger dans les alvéoles. Les particules plus
petites que 0.5 mm demeurent normalement en suspension et sont expulsées lorsque la personne ou
l’animal expire. Les particules totales de poussières sont très souvent définies comme de la poussière
inhalable.
Les concentrations massiques de poussières totales ont été mesurées dans la section pouponnière d’une
porcherie ventilée mécaniquement durant la saison chaude. L’échantillonnage s’est effectué sur 13 jours
durant une période de six semaines (Maghirang et al., 1997). La fraction de poussière respirable a varié
de 2 à 30% de la poussière totale avec une valeur moyenne de 11%. Si on considère la quantité d’énergie
nécessaire pour produire de la poussière provenant de la ration, Jansen et Feddes (1995) ont conclu que
les matières fécales sont probablement la source majeure de poussières respirables provenant de bâtiments
d’élevage. Pickrell et al. (1993) ont aussi observé que les petites particules en suspension dans les
porcheries ont des concentrations quatres fois plus élevées en endotoxines que les particules plus grosses,
suggérant ainsi qu’elles contiennent une plus grande concentration de matières fécales. Par conséquent,
particulièrement dans les porcheries, les poussières respirables proviennent du fumier/lisier séché. Parce
que ces particules sont biologiquement actives et qu’elles pénètrent dans les poumons, la poussière
respirable peut avoir des effets néfastes sur la santé des animaux et des travailleurs.

Restaurant oil, corn silage and vegetable waste all grist for the Ridgetown digester

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Until now, researchers making biogas from the
anaerobic digester at the University of Guelph’s
Ridgetown Campus have been using liquid manure to
feed the operation. Their next step is to add other materials,
such as used oil or grease from fast-food restaurants or
food processing activities. In Ontario, there is currently only one operating anaerobic
digester on a farm, while in Germany there are almost 4,000. In
several European countries, farmers are allowed to add other
materials to the manure in their anaerobic digesters. For example,
some farmers are permitted to put up to 20 per cent of
organic materials obtained outside the farm into their digesters.
Adding this amount of these materials might lead to a doubling
in the output of methane, Fleming notes.
Products like spent oil from restaurants can’t be digested on
their own. However, blending the oil with pig manure should
result in a boost in gas production. This small addition of product
could result in double or triple the gas output, depending
on the material being added.
Along with mixing the pig manure with fats and oils,
researchers will try using corn silage or vegetable waste from
crops high in sugar, such as sugar beets or sweet potatoes

Scale and Access Issues Affecting Smallholder Hog Producers in an Expanding Peri-Urban Market

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The study offers a new way of conceptualizing the problems that lead to the exclusion of
smallholders from live hog and pork markets, explaining why some smallholders participate
successfully, while others do not. Determinants are identified using limited-dependent variable
models based on the hypothesis that transaction costs, such as access to credit and market
information, affect market participation. The report also presents a contemporary approach to
measuring profit efficiency in hog production for the case of Southern Luzon, Philippines.
Although the findings of this study are specific to the Philippine context, many of the
issues confronted are common to the challenges of participation, upscaling processes, and
policy interventions across the developing world. The research has generated solid empirical
perspectives of the changing situation of poor smallholder producers in a high-value market
situation. IFPRI thus continues to examine the effect of mechanisms like contract farming on
collective action as a means of increasing smallholder participation in high-value markets,
particularly in developing countries in Asia and Africa, where small farms continue to dominate
the landscape.

The effects of handling and group size on welfare of pigs in lairage and their influence on stomach weight, carcass microbial contamination and meat quality

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Slaughtering animals with a full stomach is considered a high risk factor for meat safety, as spillage of gut contents, due to more frequent inadvertent puncture of the stomach during the dressing process, can lead to microbial cross-contamination between carcasses (Miller et al. 1997). To reduce the risk of puncturing the stomach, a feed withdrawal of 16 to 24 h before slaughter has been recommended to reduce stomach size (Chevillon 1994). However, industry reports and some studies have revealed a high variability in stomach weights at slaughter, even among pigs that were subjected to the same fasting interval before slaughter (Guise et al. 1995; Turgeon 2003). According to Enck et al. (1989), stress increases intestinal motility, resulting in a greater evacuation of the caecum and large intestine. It also increases the pH of the stomach contents, favouring the survival, proliferation and release of faecal bacteria (such as Salmonella), both towards the internal organs and the surrounding environment (Gregory 1998). Hence, the individual difference in the pig response to preslaughter stress might contribute to stomach weight variation at slaughter. The use of electric prods must be limited in pig handling given their detrimental effects on welfare (flight behaviour, higher heart rate and salivary cortisol level) and meat quality (Brundige et al. 1998; D’Souza et al. 1998; Jongman et al. 2000). Mixing unfamiliar pigs inevitably causes some fighting, which causes skin bruises and poor pork quality (Jones et al. 1994; Warriss 1996). To limit fighting and help pigs rest and recover from transport stress, the current recommendations are either to keep pigs in small groups (10 to 15 pigs) or to mix very large groups (up to 200 pigs) in the lairage pen prior to slaughter (Grandin 1990; Christensen and Barton-Gade 1997). Turner et al. (1999) showed that group size influences drinking behaviour, pigs in large groups (60) spending significantly less time drinking than pigs in smaller groups (20). Hence, it may be hypothesized that the difference in drinking rate between groups of pigs varying in size may contribute to stomach weight variation at slaughter. The aim of this experiment was thus to determine, under commercial conditions, the effects of gentle vs. rough handling practices and large vs. small group size in lairage on behaviour, stomach weight, microbial carcass contamination and meat quality variation of pigs. At unloading and on the way to stunning, 800 barrows were exposed to either gentle handling (GH: slowly with a plastic board or whip) or rough handling (RH: quickly with an electric prod). Pigs were kept in large or small groups (30 or 10 pigs) during lairage. Compared with GH, RH increased climbing, slipping and turning around behaviours during unloading, and climbing on the way to stunning. RH also reduced drinking behaviour during lairage. Pigs kept in large groups were observed more often standing and fighting than pigs kept in small groups, but, in contrast, had a slightly lower level of urinary cortisol at slaughter. Stomach weight and microbial contamination at slaughter were not affected by treatments. RH tended to increase skin bruise score on the carcass and produced more exudative meat. In conclusion, the response of pigs to the two specific stressors applied prior to slaughter in this study did not seem to contribute to stomach weight variation at slaughter, but it did influence pork quality.

Effect of “Skip-a-Heat” Breeding on Subsequent Reproductive Performance in First Parity Sows

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Recent work at the University of Alberta has shown that the performance of contemporary dam-line first parity sows is truly amazing! Even when primiparous sows are induced to lose large amounts of body tissues through imposed feed restriction during peak lactation, there is a relative lack of effect on many measures of post-weaning fertility. However, a second parity “dip” or lack of an increase in second litter size, is often observed in production. First and second parity sows subjected to “skip-a-heat” breeding (bred at the 2nd estrus after weaning, or “skipped”) exhibited an increase of two pigs born compared to sows bred at first post-weaning estrus but this increase in litter size also resulted in an accumulation of 21 non-productive days (NPD) and a 9% chance of sows not standing to be bred at 2nd estrus. Recent data on the changing reproductive characteristics of contemporary commercial sows suggested that the response to skip-a-heat breeding in first parity sow needs to be re-evaluated. This trial re-assessed the effect of breeding sows at 1st vs. 2nd post-weaning estrus on follicular development, size of the largest ovulatory follicle, ovulation rate and embryonic survival to day 30 in contemporary commercial sows. Results confirmed that under good management practices, high production performance is achievable: 95% of sows returned to estrus within 10 days; 98% of sows bred; 100% of sows “skipped” sows detected in heat; and a 92% conception rate. However, litter size at d 30 appeared to be limited because of lower embryonic survival in sows bred at first post-weaning estrus. The present study also confirmed that breeding first parity weaned sows at 2nd post-weaning estrus will negate the effects of the “second parity dip.” Alternative methods to increase second parity litter size without the accumulation of the 22 NPD associated with “skip-a-heat” merits further investigation.

Livestock sector development and implications for rural poverty alleviation in India

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