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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaporative cooling of sows for the first five to seven days post breeding

Munson, Maynard Dean, 1946- January 1972 (has links)
No description available.
2

Lowering production cost by increasing group size and the effects thereof on pig performance post weaning to 70 days

Louw, Nicolaas Everhardus 03 1900 (has links)
Thesis (MPhil)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The primary objective of today's pig producer is to maximize profit received per unit of pig space provided in a given facility. There are certain management strategies that a farmer can implement to ensure this. The goals of such strategies include maximizing performance and implementing proper pig flow schedules and to make sure current facilities are performing at maximum capacities or are better utilized. Labour in South Africa is still relatively inexpensive, but time is money. Feeding and cleaning small pens are time consuming and expensive to maintain (more feeders and water nipples, gates, walls and heating). Proper management of facility space is vital to remain competitive in today's pig industry. The amount of floor and feeder space provided within an animal's environment could vastly influence pig performance and profitability. Crowding pigs has a negative effect on Average Daily Gain (ADG) and overall performance. Conversely, facility cost per pig increases as additional space is provided, therefore, in the interest of pen efficiency, the space that allows for maximum individual performance may not be optimal for maximizing profit. Factors such as cleaning and cleaning time also have an effect on profitability. Another concerning factor associated with maximizing performance and maintaining the pig flow of a facility is that of Body Weight (BW) variation. Having uniform pigs at 70 day, post-weaning has been a major goal to ensure maximum performance in finishers. Numerous contradictions regarding the growth of piglets post-weaning (especially the effect of group size and floor space allowance) still exist in literature. Also, in South Africa, the majority of pig producers still believe that individual litters or small groups of pigs in the growers perform better and are the most economical production method. Therefore, this trial was performed to investigate the raising of large groups (200-450 pigs/group) compared to small groups (10-20 pigs/group) on their performance until 70 days when they were moved to growers. Over a period of two years, data was collected on a commercial 1200 sow unit in the Western Cape, South Africa. Crossbred pigs (n=14657; Landrace x Large White; both gilts and barrows) weaned at 19 to 24 days with average weaning weight of 5.11 kg were randomly divided into different group sizes. Groups of 10, 20, 200 and 450 were grouped together and were all given the same feed ration. The groups were housed in different buildings naturally ventilated with no artificial heating and with solid flooring. Pelleted diets were formulated (Startrite followed after two weeks with Expresweaner) by Meadows Feed Mills (Paarl, Western Cape) for weaned piglets and fed to all the piglets. The animals received the diets and water ad lib. All the piglets were weighed before being placed into the different pens (initial weight). After 69 - 72 days the piglets were weighed again (final weight). The pigs were weighed as a group and not individually. The data was statistically analysed by determining averages and standard deviations for each house. The results of this trial clearly indicate that raising piglets in larger groups does not negatively affect the performance of the piglet in terms of ADG and mortality. In larger groups, the less time (labour time) spent cleaning and the fewer feeders needed, also results in lower production costs. In today's economical environment, the producer that can lower his production cost while maintaining production standards has a significant advantage. Therefore, it is believed that by grouping pigs in larger groups, labor time (in terms of cleaning) can be reduced, and will lower production cost without reducing production standards. / AFRIKAANSE OPSOMMING: Die hoofdoel van vandag se varkprodusente is om maksimum wins per eenheid vark spasie te maak. Daar is sekere produksietegnieke wat 'n produsent kan volg om dit te verseker. Die doel van die tegnieke is om te verseker dat maksimale produksienorme en doeltreffende vark vloei gehandhaaf word asook dat huidige fassiliteite optimum benut word. Arbeid is nog relatief goedkoop in Suid-Afrika (SA), maar tyd is geld. Die voeding en skoonmaak van klein hokke is tydrowend en duur om te onderhou (meer voerbakke, waternippels, hekke, mure en verhitting). Om koste-effektief te boer, moet goeie bestuur van oppervlakte toegepas word. Die hoeveelheid oppervlakte en voerspasie beskikbaar, het 'n groot invloed op die produksievermoë en winsgewendheid van die varkies. Om te veel varkies per area aan te hou, het 'n negatiewe effek op die Gemiddelde Daaglikse Toename (GOT) en algehele prestasie. Soos die vloerspasie per varkie vergroot, neem die produksiekoste ook toe en is die area wat benodig word om varkies maksimaal te laat produseer, nie altyd die winsgewenste nie. Skoonmaak en skoonmaaktyd het ook 'n invloed op winsgewendheid. Die ideaal is om uniforme varkies op 70 dae te produseer. 'n Variasie in gewig is rede tot kommer, aangesien dit die produksie in die groeiafdeling beïnvloed. Verskeie teenstrydighede aangaande die groei van varkies naspeen (veral die effek van goepgrootte en vloerspasie) bestaan steeds in die literatuur. In SA is die meeste produsente ook nog onder die indruk dat klein groepe varkies beter presteer as groot groepe en die mees ekonomiese metode is om te boer. Daarom is 'n proef geloods om vas te stel hoe die produksie verskil tussen klein groepe (10 - 20 varkies per groep) teenoor groot groepe (200 - 450 varkies per groep) tot 70 dae ouderdom wanneer hulle na die groeiafdeling skuif. Oor 'n periode van twee jaar is data gekollekteer op In kommersiële 1200 sog-eenheid in die Wes-Kaap, Suid-Afrika. Kruisgeteelde varke (n=14657; Landras x Groot Wit; beide beertjies en soggies) is gespeen tussen 19 en 24 dae, met 'n gemiddelde speen gewig van 5.11 kg en ewekansig verdeel in verskillende groepgroottes. Groepe van 10, 20, 200, en 450 varkies was saamgegroepeer en het almal dieselfde dieet ontvang. Die groepe is in verskillende geboue gehuisves en al die geboue het soliede vloere gehad en was natuurlik geventileerd met geen kunsmatige verhitting nie. 'n Verpilde dieet is deur Meadows Voermeule (Paarl, Wes-Kaap) geformuleer (Startrite vir twee weke en dan Expresweaner vir die res van die proef). Die varke het die dieet en water ad lib ontvang. AI die varkies is geweeg voordat hulle in die verskillende hokke geplaas is (aanvangsmassa). Na 69 - 72 dae is die varkies weer geweeg (eindmassa). Die varkies is as 'n goep en nie individueel geweeg nie. Die data is statisties verwerk deur gemiddeldes en standaard-afwykings vir elke huis te bepaal. Die resultate van hierdie proef het duidelik aangetoon dat die grootmaak van varkies in groter goepe nie die produksie van die varkies (i.t.v. GOT of mortaliteit) nadelig beïnvloed het nie. In groter goepe is minder tyd nodig om die hokke skoon te maak en is minder voerders nodig. Dit lei tot 'n verlaging in produksiekoste. Deesdae het die produsent wat sy produksie koste kan verlaag, sonder om produksiestandaarde in the boet, 'n aansienslike voorsprong. Die gevolgtrekking word dus gemaak dat deur varkies in groter groepe aan te hou, arbeid (in terme van skoonmaak) verminder kan word en dus kan produksiekoste verminder sonder dat produksie self afneem.
3

Simulation of a swine nursery to facilitate economical management

Harmon, Jay David January 1989 (has links)
Two deterministic simulation models were developed to assess the economics of swine nurseries. The first model assessed the emergency needs of swine nurseries by simulating the temperature response during a short term power failure. The failure model accounted for heat exchange by conduction, convection, radiation, and air infiltration. An existing sub-model was used to predict swine heat and moisture loss. The failure model was validated using a nursery constructed of concrete block. It performed well for cases with constant solar load, but tended to overpredict temperature changes during periods of no solar load. Validation indicated accurate wall-characteristic and wind velocity estimations were crucial to obtain accurate model results. The second model was developed to describe the normal operation of swine nurseries by predicting pig growth and feed consumption, building fuel consumption, and cost per unit of gain produced. lt was based on an existing swine model that was converted to an hourly basis. An optimization option was incorporated into the operational model to allow minimization of the cost per unit of gain. The operational model was validated and found to accurately predict feed consumption and growth during a one week time frame. Fuel consumption was less accurate. The optimization mode predicted considerable cost savings for operation at lower temperatures. / Ph. D.
4

An investigation of the effects of cool dry breathing air on the respiration rate and rectal temperatures of farrowing sows

McGinty, Ralph Jerry. January 1960 (has links)
Call number: LD2668 .T4 1960 K63
5

Nocturnal cooling of a solar collector-storage unit

Janke, Edward Lee. January 1978 (has links)
Call number: LD2668 .T4 1978 J35 / Master of Science
6

Computerized heat loss evaluation of farrowing houses

George, Herschel C January 2010 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
7

Parent-offspring conflict and its implications for maternal housing systems in domestic pigs

Pajor, Edmond A. January 1998 (has links)
No description available.
8

Parent-offspring conflict and its implications for maternal housing systems in domestic pigs

Pajor, Edmond A. January 1998 (has links)
This thesis compares growth and behaviour of domestic sows and piglets in confined pens versus get-away pens (where sows could leave their fitters at will), to ask whether parent-offspring conflict occurs, whether it increases with offspring age, whether it involves offspring access to the udder, and whether it affects animal production or welfare. Parent-offspring conflict occurs in domestic pigs: piglets of Confined sows suckled more and ate less solid food but grew at the same rate as piglets from Get-away sows, indicating they obtained more milk. Confined sows lost more weight than Get-away sows and returned to oestrus later, indicating a fitness cost of providing the additional milk. Parent-offspring conflict increased with piglet age: as the fitter aged, Get-away sows spent more time away from their young and the differences between Get-away sows and Confined sows in weight loss and nursing frequency increased. In Get-away sows, the reduction in contact with their young occurred rapidly, but its timing varied greatly among individual sows. Behavioural conflict over access to the udder is a plausible mechanism by which conflict is expressed in swine: piglets from Confined pens spent more time nuzzling the udder than piglets of Get-away sows. Piglets from Get-away sows nuzzled the udder a higher proportion of the time when the sow was present than piglets from Confined sows. Get-away sows terminated more nursings than Confined sows thus limiting the amount of contact piglets had with the udder after nursing. Mowing sows to control maternal provisioning improved productivity: there was a slight benefit of reduced time to the next oestrus for Get-away sows. Piglets from Get-away sows gained more weight and consumed more food after weaning than piglets from Confined sows. There was only slight evidence that get-away pens reduced behavioural indicators of post-weaning stress (e.g., movements, vocalizations, response to playback of vocalizations) for either the pi
9

Effects of swine farrowing house air and mineral nutrition on Cucumis sativus, L.

Long, John Edward. January 1979 (has links)
Call number: LD2668 .T4 1979 L65 / Master of Science
10

Groei- en produksievergelyking tussen konvensionele, multi-eenheid, siektegeteisterde varke en hoë gesondheids multi-eenheid varke

Raath, Jacobus Johannes 12 1900 (has links)
Thesis (MPhil (Animal Sciences))--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: A trial was done to determine if there are any differences in the growth performance of finisher pigs in the old conventional type of housing with disease infected pigs, pigs in multi unit housing that were also disease infected and high health pigs in multi unit type of housing. The high health pigs gave the best results when factors like A.D.I., A.D.G., F.C.R., margin over feed cost and carcass weight are compared with the results of the other two treatments. The difference in achievement between the disease infected pigs and the high health pigs were not the same for all the production factors but it was still in favour of the high health pigs. The trial results show just how dynamic pig production has become. From the results it is very clear that there is not any place anymore for the old conventional type of housing in any modern piggery. The time has also come for every pig farmer to look at and evaluate the health status of his piggery and to consider changing over to a high health herd. From a production as well as an economic viewpoint it makes good sense.

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