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1998

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Articles 241 - 270 of 422

Full-Text Articles in Animal Sciences

Erythrocyte Sizes Of Some Urodeles From Turkey, Mehmet K. Atatür, H. Arikan, A. Mermer Jan 1998

Erythrocyte Sizes Of Some Urodeles From Turkey, Mehmet K. Atatür, H. Arikan, A. Mermer

Turkish Journal of Zoology

This study is on the erythrocyte sizes of some urodeles ( Salamandra salamandra, Triturus vulgaris, Triturus karelinii, Tri-turus vittatus, Mertensiella luschani, Mertensiella caucasica) living in various localities of Turkey. Blood smears stained with Wright's stain were utilized.


A New Subspecies Of Jerboa From Turkey;Allactaga Euphratica Kivanci Subsp. N., Ercüment Çolak, Nuri Yi̇ği̇t Jan 1998

A New Subspecies Of Jerboa From Turkey;Allactaga Euphratica Kivanci Subsp. N., Ercüment Çolak, Nuri Yi̇ği̇t

Turkish Journal of Zoology

In this study, 42 specimens of Allactaga euphratica from Urfa (Turkey) were examined based on morphological, cranial, external and karyological characters. A comparison of specimens from Urfa with those from Syria, Jordan, Kuwait and Iraq showed that specimens from Urfa, Syria and Jordan, Kuwait and Iraq showed that specimens from Urfa, Syria and Jordan differ from those from Kuwait and Iraq. Thus, specimens from Urfa (Turkey), Syria and Jordan were included in a new subspecies, Allactaga euphratica kivanci subsp. n.


Comparative Efficacy Of Bromadiolone, Cholecalciferol And Zinc Phosphideagainst Short -Tailed Mole Rat Nesokia Indica In Captivity, Amjad Pervez, Syed M. Ahmad, S. Waqar, A. Rizvi Jan 1998

Comparative Efficacy Of Bromadiolone, Cholecalciferol And Zinc Phosphideagainst Short -Tailed Mole Rat Nesokia Indica In Captivity, Amjad Pervez, Syed M. Ahmad, S. Waqar, A. Rizvi

Turkish Journal of Zoology

We conducted no-choice and paired choice feeding trials with individually caged Nesokia indica to evaluate the efficacy of Bromadiolone, Cholecalciferol and Zinc phosphide baits. Under no-choice test (1 day and 3 day) male rats consumed less bromadiolone bait. However, sex-wise difference was observed non-significant. Under choice feeding test, difference between bromadiolone bait intake and sex was observed non-significant. Under cholecalciferol bait, treated bait was consumed more than plain bait. Among the baits tested, cholecalciferol appeared promising for controlling short-tailed mole rat, Nesokia indica.


An Investigation On The Reproduction Properties Of Chub ( Leuciscus Cephalusl., 1758) In Lake Tödürge (Zara/Sivas)*, Bülent Ünver Jan 1998

An Investigation On The Reproduction Properties Of Chub ( Leuciscus Cephalusl., 1758) In Lake Tödürge (Zara/Sivas)*, Bülent Ünver

Turkish Journal of Zoology

In this study, the reproductive properties of the chub population ( Leuciscus cephalusL., 1758) in lake Tödürge, Zara/Sivas, were investigated. A total of 674 specimens were caught between April and November 1994. The age and sex distributions and the age of sexual maturity were determined. The reproduction period of the population was determined. Fecundity was determined and the relationships between the fecundity and body weight, length and age were investigated. The age composition of specimens of the population consisting of 68.25% female and 31.75% male, was found to be between I and VII. Males reached maturity in their second or …


Incidence Of Mealy Bug Dismycoccus Brevipes (Cockrell) On Pineapple, Akhlaq Ahmed Khan, Ghulam Mustafa Avesi, Syed Zafar Masud, Syed Waqar Ali Rizvi Jan 1998

Incidence Of Mealy Bug Dismycoccus Brevipes (Cockrell) On Pineapple, Akhlaq Ahmed Khan, Ghulam Mustafa Avesi, Syed Zafar Masud, Syed Waqar Ali Rizvi

Turkish Journal of Zoology

The pineapple mealy bug ( Dismycoccus brevipes) infestation is reported for the first time from Pakistan, Ratoon, crownlet, slip and sucker plants were found infested by this bug. A total of 3464 bugs were collected from these plants with a mean value of 43.3 bugs/plant. Two-third (2291) of the bug population was found on the roots while one-third (1173) were recovered from the leaf base of the pineapple.


Productivity Enhancement Of Rice Crop Yield Through Prevention Of Losses Due To Wild Boars In Pakistan, Abdul Rauf Khokhar, Syed Waqar Ali Rizvi Jan 1998

Productivity Enhancement Of Rice Crop Yield Through Prevention Of Losses Due To Wild Boars In Pakistan, Abdul Rauf Khokhar, Syed Waqar Ali Rizvi

Turkish Journal of Zoology

The wild boar control trials were conducted in rice fields in the districts of Sheikhupura, Sialkot, Faisalabad and Gujrat, covering an overall area of 3000 hectares. Zinc phosphide encapsulated bait was used resulting in 80-100% reductions in wild boar activity. In addition, the impact of the boar control work on the crop productivity was evaluated by interviewing 391 farmers selected randomly from the trial areas. The average farm size of the sampled farmers was 426.30 hectares. The average yield loss due to wild boars was estimated at 22.75%. By applying newly developed zinc phosphide capsular technology, 502.17 mt. of rice …


The Effect Of Salinity On Larval Growth And Survival Of Penaeus Indicus (Decapoda: Penaeidae), Metin Kumlu Jan 1998

The Effect Of Salinity On Larval Growth And Survival Of Penaeus Indicus (Decapoda: Penaeidae), Metin Kumlu

Turkish Journal of Zoology

This study was conducted to determine optimum salinity for the larval growth, survival and development of Penaeus indicus. For this, PZI (protozoea 1) larvae were stocked in 2-L round bottom glass flasks in two replicates at 20, 25, 30 and 35 ppt salinities and were reared on live diets until PL (postlarvae) stages. Highest survival (91%) and greatest growth (6.48 mm) at postlarval stages (PLI/2) were obtained with the larvae cultured at 25 ppt (P


A New Species Of The Genus Orculella From East Anatolia (Mollusca: Pulmonata: Pupilloidea), Hartwig Schütt, Rıdvan Sesen Jan 1998

A New Species Of The Genus Orculella From East Anatolia (Mollusca: Pulmonata: Pupilloidea), Hartwig Schütt, Rıdvan Sesen

Turkish Journal of Zoology

A new land snail Orculella garzanensis which is evidently the largest species of this genus was described from East Anatolia Siirt Province.


A Report On Reptiles Collected From Kumluca-Kalkan (Antalya), Turkey, Abidin Budak, Cemal Varol Tok, Ahmet Mermer Jan 1998

A Report On Reptiles Collected From Kumluca-Kalkan (Antalya), Turkey, Abidin Budak, Cemal Varol Tok, Ahmet Mermer

Turkish Journal of Zoology

9 species of lizards and 2 species of snakes, belonging to a total of seven families were collected from Kumluca-Kalkan between 8 and 10 April 1997.


The Herpetofauna Of The Ordu-Giresun Region, Yusuf Kumlutaş, Varol Tok, Oğuz Türkozan Jan 1998

The Herpetofauna Of The Ordu-Giresun Region, Yusuf Kumlutaş, Varol Tok, Oğuz Türkozan

Turkish Journal of Zoology

In this study, 17 reptile and amphibian species were recorded from 19 different localities in the Ordu-Giresun region. Of these, 3 belong to the urodelans species group, 6 belong to anurans, 4 belong to lizards and 4 belong to snakes.


The Behavioural Abilities Of Meteorus Versicolor Wesm. And Rogas Rossicuskok. (Hymenoptera, Branconidae) Parasitoids Of Tephrina Arenacearia Den.Et Schiff. (Lepidoptera, Geometridae), Ilhama Gudrat Gizi Kerimova Jan 1998

The Behavioural Abilities Of Meteorus Versicolor Wesm. And Rogas Rossicuskok. (Hymenoptera, Branconidae) Parasitoids Of Tephrina Arenacearia Den.Et Schiff. (Lepidoptera, Geometridae), Ilhama Gudrat Gizi Kerimova

Turkish Journal of Zoology

This paper concerns with the behavioural abilities of Meteorus versicolor Wesm. and Rogas rossicus Kok. (Hymenoptera, Braconidae)-internal parasitoids of Thephrina arenacearia Den. et Schiff. (Lepidoptera, Geometridae) as well. Periods of development phases and searching, ovipositional and mating behaviour of both parasitoids have been investigated.


The Taxonomy And Karyology Of Rattus Norvegicus (Berkenhout, 1769) Andrattus Rattus (Linnaeus, 1758) (Rodentia: Muridae) In Turkey, Nuri Yi̇ği̇t, Ercüment Çolak, Mustafa Sözen, Şakir Özkurt Jan 1998

The Taxonomy And Karyology Of Rattus Norvegicus (Berkenhout, 1769) Andrattus Rattus (Linnaeus, 1758) (Rodentia: Muridae) In Turkey, Nuri Yi̇ği̇t, Ercüment Çolak, Mustafa Sözen, Şakir Özkurt

Turkish Journal of Zoology

In this study, the Turkish population of Rattus norvegicus and Rattus rattus were studied with regard to external, cranial, phalli, bacula and tooth crown morphology and karyotype. External, internal and karyologic characteristics of R. norvegicus were found to be consistent with previously published results. Additionally, it was determined that there are striking color variations in the dorsal and ventral fur of R. rattus and that crown morphology is not a definitive characteristic distinguishing these species because of connected lobes in old specimens. According to the karyological studies, the diploid chromosome numbers and fundamental numbers of R. norvegicus and R. rattus …


Some Observations On Gastric Emptying In The Black Sea Whiting,Merlangius Merlangus Euxinus, (N. 1840) Fed On Natural Prey, Kadir Seyhan, N. Selda Başçinar, Ertug Düzgüneş Jan 1998

Some Observations On Gastric Emptying In The Black Sea Whiting,Merlangius Merlangus Euxinus, (N. 1840) Fed On Natural Prey, Kadir Seyhan, N. Selda Başçinar, Ertug Düzgüneş

Turkish Journal of Zoology

In this study a new perspective on the feeding physiology of whiting, Merlangius merlangus euxinus, N. 1840 was investigated. The effects of the skin of the prey, double feeding and prey type on the gastric emptying rate (GER) of whiting fed on natural prey, namely anchovy ( Engraulis encrasicholus) and mussels ( Mytilus galloprovincialis), were investigated. Return of appetite was also studied. It was found that in laboratory conditions, whiting (48.0±8.30 g, n=12) had consumed about 10.2% of its body weight in mussels and return of appetite was found to be approximately 30 h. The effect of the skin of …


The Short-Term Toxicity Of Two Toxicants To Artemia Nauplii, Melahat Toğulga Jan 1998

The Short-Term Toxicity Of Two Toxicants To Artemia Nauplii, Melahat Toğulga

Turkish Journal of Zoology

In this study, the short-term toxicities of sodium lauryl sulphate (an anionic detergent) and potassium dichromate on instar I and mixed instar II-III nauplii populations of Artemia were investigated. The comparisons between our results and the ARC-test (Artemia Reference Center) protocol show our experiments to be acceptable for acute toxicity standardization.


Toxicity Of Neem Leaves Extract (Nlx) Compared Withmalathion (57 E.C.) Against Late 3rd Instar Larvaeof Culex Fatigans(Wild Strain) By Who Method, Mohammad Arshad Azmi, Syed Naeemul Hassan Naqvi, Imtiaz Ahmad, Rahila Tabassum, Bushra Anb Jan 1998

Toxicity Of Neem Leaves Extract (Nlx) Compared Withmalathion (57 E.C.) Against Late 3rd Instar Larvaeof Culex Fatigans(Wild Strain) By Who Method, Mohammad Arshad Azmi, Syed Naeemul Hassan Naqvi, Imtiaz Ahmad, Rahila Tabassum, Bushra Anb

Turkish Journal of Zoology

Among the filariaris causing mosquitoes Culex fatigans is considered an important intermediate host in South-East Asia. Toxicity of ethanolic extract of neem leaves (NLX) is compared with an organophosphate pesticide malathion (57 E.C.). The LC 50 value of malathion (Sisthion) determined presently is 0.45 ppm against late 3rd instar larvae of Culex fatigans (wild strain) and of neem fraction (NLX) is 390 ppm by standard WHO method.


A Study On Ecology And Biology Of Microtus Guentheridanford And Alston,1880 (Mammalia: Rodentia) In Turkey, Ercüment Çolak, Mustafa Sözen, Nuri Yi̇ği̇t, Şakir Özkurt Jan 1998

A Study On Ecology And Biology Of Microtus Guentheridanford And Alston,1880 (Mammalia: Rodentia) In Turkey, Ercüment Çolak, Mustafa Sözen, Nuri Yi̇ği̇t, Şakir Özkurt

Turkish Journal of Zoology

In this study, ecology and biology of Microtus guentheriwere investigated based on both field and laboratory observations along with its effects on agricultural crops. It was determined that this vole has a shallow burrow with numerous entrances and does not store food in its burrow. In captivity, M. guentherigave litters from September to June and a female produced 42 pups, being seven litters during a reproduction season. The duration of pregnancy varied 20 to 21 days. The average litter size was 5.5 and young were born in an average weight of 3.3 g. The fur developed at an age of …


Comparative Toxicological Studies Of Rb-A (Neem Extract) And Coopex(Permethrin+Bioallethrin) Against Sitophilus Oryzae With Reference Totheir Effects On Oxygen Consumption And Got, Gpt Activity, Mohammad Arshad Azmi, Syed Naimul Hasan Naqvi, Muhammed Farhanullah Khan, Kahkashan Akhtar, Farah Younus Khan Jan 1998

Comparative Toxicological Studies Of Rb-A (Neem Extract) And Coopex(Permethrin+Bioallethrin) Against Sitophilus Oryzae With Reference Totheir Effects On Oxygen Consumption And Got, Gpt Activity, Mohammad Arshad Azmi, Syed Naimul Hasan Naqvi, Muhammed Farhanullah Khan, Kahkashan Akhtar, Farah Younus Khan

Turkish Journal of Zoology

The toxicity of a neem extract RB-a in comparison with a pyrethroid, Coopex, was studied along with their effects on GPT and GOT activities and oxygen consumption in S. oryzae. The LD 50 value of Coopex was found to be 6.128 \mug/cm 2 whereas RB-a was found not to be an acute contact poison. Even at a dose of 1257 \mug/cm 2 it could cause 34% mortality of S. oryzae. The oxygen consumption under the effects of Coopex was found to decline less i.e. at 6.12 \mug/cm 2 from 0.0005191 to 0.0006589, as compared to RB-a where the rate of …


Influence Of Sediment On Heavy Metal Uptake By The Polychaete Arenicola Marina, Levent Bat Jan 1998

Influence Of Sediment On Heavy Metal Uptake By The Polychaete Arenicola Marina, Levent Bat

Turkish Journal of Zoology

In this study, the suitability of the polychaete Arenicola marina as a test organism using clean intertidal sediment contaminated with copper, zinc and cadmium was evaluated. Metal levels in casts were significantly lower than in unworked sediment indicating that the bioturbatory activity of lugworms might be significant in the distribution of the pollutants. This study showed that sediments contaminated with specific pollutants affected the uptake of these pollutants by Arenicola in a predictable and dose–dependant way and gave further justification for the use of this species in sediment toxicity tests.


Ultrastructural Study On The Ovarian Wall And The Oviduct Of The Asellus Aquaticus (Crustacea: Isopoda), B. Melike Erkan Jan 1998

Ultrastructural Study On The Ovarian Wall And The Oviduct Of The Asellus Aquaticus (Crustacea: Isopoda), B. Melike Erkan

Turkish Journal of Zoology

In this study the ovarium, ovarian wall and oviduct of Asellus aquaticus ( A. aquaticus) (Crustacea: Isopoda) were investigated by stereomicroscopy, phase contrast microscopy and light microscopy. Long, tube-shaped, separate ovaries of A. aquaticus are located dorsolateral to the gut. The germinal zone is confined to the ventral region of the ovary as a thin band. The ovarian wall is composed of a few fibrous layers. The oviduct is located in the anterior one-third of the ovary, not in the central part. The sheath of the oviduct was found to possess some muscle cells, a feature first noted in this …


Drought-Induced Shift Of A Forest–Woodland Ecotone: Rapid Landscape Response To Climate Variation, Craig Allen, David D. Breshears Jan 1998

Drought-Induced Shift Of A Forest–Woodland Ecotone: Rapid Landscape Response To Climate Variation, Craig Allen, David D. Breshears

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

In coming decades, global climate changes are expected to produce large shifts in vegetation distributions at unprecedented rates. These shifts are expected to be most rapid and extreme at ecotones, the boundaries between ecosystems, particularly those in semiarid landscapes. However, current models do not adequately provide for such rapid effects—particularly those caused by mortality—largely because of the lack of data from field studies. Here we report the most rapid landscape-scale shift of a woody ecotone ever documented: in northern New Mexico in the 1950s, the ecotone between semiarid ponderosa pine forest and pinon– juniper woodland shifted extensively (2 km or …


1998 Southeast Nebraska Tallgrass Praire Inventory: Johnson, Gage, And Jefferson Counties, Final Report, Robert F. Steinauer Jan 1998

1998 Southeast Nebraska Tallgrass Praire Inventory: Johnson, Gage, And Jefferson Counties, Final Report, Robert F. Steinauer

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This report is prepared as a requirement of the 1998 Southeast Nebraska Prairie Survey contract between the Platte/Rainwater Basin Project Office of the Nature Conservancy and Robert F. Steinauer. The original contract called for the examination of Johnson County south of Highway 136, and Gage County east of Beatrice. Due to the scarcity of prairies in these areas, the survey region was expanded to include northern Johnson County, and southern Jefferson County.

Prairies in these areas were identified using infrared and black and white photos, driving on county and within grassland roads, and conversations with landowners. Heritage Program “Site Survey …


1997 Inventory For Spiranthes Diluvialis Sheviak In Western Nebraska: A Final Report, Volume Ii, Terri Hildebrand Jan 1998

1997 Inventory For Spiranthes Diluvialis Sheviak In Western Nebraska: A Final Report, Volume Ii, Terri Hildebrand

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This study resulted from an agreement between Nebraska Game and Parks Commission (NGPC) and the United States Fish and Wildlife Service (USFW). After the 1996 discovery of Spiranthes diluvialis, in western Nebraska, NGPC was seeking to determine the extent of the Nebraska population. Information on the wet meadow community of orchid occurrence in Nebraska and eastern Wyoming was needed. This report includes descriptions of communities inventoried, Spiranthes diluvialis populations, and additional species monitored by Nebraska and Wyoming Natural Heritage programs.

Between May and September 1997, potential Spiranthes diluvialis habitat was inventoried for occurrences of the orchid. For all sites …


Caribou Rangifer Tarandus Caribou Jan 1998

Caribou Rangifer Tarandus Caribou

United States Fish and Wildlife Service: Publications

Caribou are the largest members of the reindeer family (Rangifer tarandus) and are native to the arctic and sub-arctic regions of Siberia, North America and Greenland. Reindeer, which are traditionally herded in northern Europe and Eurasia, were introduced into Alaska in 1892. Although some herding of reindeer continues in Alaska today, many of the introduced reindeer interbred with caribou. The four caribou subspecies—barren ground, Peary’s, tundra and woodland—differ greatly in range, size, coloration, behavior, food habits and habitat use.

Caribou are a medium-sized member of the deer family and stand about 31⁄2 feet tall at the shoulder. Females …


Florida Panther Puma [Felis] Concolor Coryi Jan 1998

Florida Panther Puma [Felis] Concolor Coryi

United States Fish and Wildlife Service: Publications

There are only 30 to 50 adult Florida panthers left in the wild, making Florida's official state animal one of the most endangered mammals in the world.  At one time perhaps 3,000 or more Florida panthers ranged throughout Florida, northward through Georgia, parts of South Carolina, and Tennessee, and westward through Alabama, Mississippi, Louisiana, Arkansas, and possibly eastern Texas.  Today, the Florida panther's range is limited to parts of southern Florida, including the Big Cypress Swamp and the Everglades.

Initially, the Florida panter's decline was due to excessive hunting because of an unfounded fear for livestock and human safety.  More …


Sea Turtles Jan 1998

Sea Turtles

United States Fish and Wildlife Service: Publications

Of the six sea turtle species that are found in the U.S. waters or that nest on U.S. beaches, all are designated as either threatened or endangered under the Endangered Species Act.  Endangered status means a species is considered in danger of exinction throughout all or a significant portion of its range; threatened means it is likely to become endangered.

Six of the seven sea turtles species are listed as endangered or threatened: green, Kemp's ridley, olive ridley, hawksbill, loggerhead and leatherback sea turtles.  Only one species, the flatback sea turtle, is not considered threatened with extinction at this time. …


1998 Nebraska Swine Report Jan 1998

1998 Nebraska Swine Report

Nebraska Swine Reports

Reproduction
Efficacy of Once (1x) vs Twice (2x) Daily Physical or Fence-line Contact with Boars for Stimulating Earlier Puberty in Gilts
Follicular Development in Gilts Selected for High Ovulation Rate and Embryo Survival Vs Randomly Selected Control Line Gilts

Genetics
The Effects of Genetic Line and Diet Regimen on Attainment of Puberty in Gilts
Effects of Gestation Housing System on Productivity of Three Genetic Lines of Sows
Responses to 14 Generations of Selection for Components of Litter Size

Health
Activity of Four Antimicrobial Agents Against Porcine Serpulina Pilosicoli Isolates From the Midwestern United States

Nutrition
Protein Sources for Segregated Early …


The Pig Pro Decision, Networking, And Environmental Protection: The Public Policy Challenge, J. David Aiken Jan 1998

The Pig Pro Decision, Networking, And Environmental Protection: The Public Policy Challenge, J. David Aiken

Nebraska Swine Reports

On August 29, 1997, the Nebraska Supreme Court issued its first decision interpreting the provisions of Initiative 300 (I300), Nebraska’s family farm constitutional amendment. In its Pig Pro decision, a unanimous court ruled five Dawson county farmers who sought to form a non-profit cooperative corporation would violate article XII §12 of the Nebraska Constitution (I300). The decision means Nebraska farmers cannot network their operations and receive limited liability protection under I300.


Properties And Applications Of Pork Trim Obtained From An Advanced Meat Recovery System, Christi M. Calhoun, Roger W. Mandigo Jan 1998

Properties And Applications Of Pork Trim Obtained From An Advanced Meat Recovery System, Christi M. Calhoun, Roger W. Mandigo

Nebraska Swine Reports

Automated mechanical systems are being utilized by the pork industry to efficiently and economically recover meat remaining on bones after fabrication. The recovered meat, referred to as pork trim-finely textured (PTFT), has unique properties which must be understood to best use this lean meat source. This research characterized the chemical and physical properties of PTFT, determined incorporation levels in ground pork and studied the storage and shelf-life-stability of products containing PTFT. Chemical and physical properties of PTFT were compared to knife trimmed meat (KT) and 80 percent lean ground pork (GP). PTFT had higher iron, calcium, total pigment and cholesterol …


The Effect Of Protein Intake On Growth Performance, Plasma Urea Concentration, Liver Weight, And Arginase Activity Of Finishing Barrows And Gilts, Hsin-Yi Chen, Phillip S. Miller, Austin Lewis Jan 1998

The Effect Of Protein Intake On Growth Performance, Plasma Urea Concentration, Liver Weight, And Arginase Activity Of Finishing Barrows And Gilts, Hsin-Yi Chen, Phillip S. Miller, Austin Lewis

Nebraska Swine Reports

An experiment was conducted to evaluate the effects of dietary protein concentration on growth performance, plasma urea concentration, liver weight and liver arginase activity of finishing (138 lb) barrows and gilts. Average daily feed intake, arginase activity and plasma urea concentration were greater in barrows than in gilts, whereas liver weight was lighter in barrows than in gilts. These data suggest gilts are affected more negatively by high protein diets than barrows. We believe the changes in liver weight and urea cycle enzymes (arginase) are related to these feed intake differences.


Explanation Of Statistics Used In This Report Jan 1998

Explanation Of Statistics Used In This Report

Nebraska Swine Reports

Pigs treated alike vary in performance, due to their different genetic makeup and to environmental effects we cannot completely control. When a group of pigs is randomly allotted to treatments it is nearly impossible to get an “equal” group of pigs on each treatment. The natural variability among pigs and the number of pigs per treatment determine the expected variation among treatment groups due to random sampling.