Call number: LD2668 .T4 1978 C38 / Master of Science

The occurrence and concentration of substances like glycosides, alkaloids, certain amino acids, and, especially, phenolics in vegetation has been seen as a defense against environmental perturbations. Whether this phenomenon is associated with the disruptive effect of man, herbivore predation or the invasion of arthropods and microorganisms remains to be ascertained by ecologists. However, contemporary research shows that most so-called secondary metabolites in plants render them less sensitive to adverse factors in the natural environment. Likewise, herbivores that adapted to chemical defense in plants were rewarded with wider food source and might have been able to more efficiently exploit rapidly changing foraging environments. This study focuses on relationships between goats, their ruminal microbes and tannin-rich plants in a central Arizona chaparral vegetation type dominated by shrub live oak (Quercus turbinella). The study tested hypotheses involving goat dietary selection, estimated through microhistological analysis of feces; phenolic profile of shrub live oak, expressed as condensed and hydrolyzable tannins, protein binding capacity of oak leaves extract, expressed as bovine serum albumin (BSA) precipitation; and apparent dry matter digestibility of mature and immature oak leaves by goat ruminal microbes measured at 6, 12, 24 and 48 hours. Findings of this research indicated that goats prefer leaf and shoot ends of shrubs, mainly shrub live oak, despite the constant high concentration of tannins in that plant. Hydrolyzable tannins in oak are synthesized during summer/fall and late spring, and the synthesis of condensed tannins is mostly restricted to winter and early spring. Precipitation of BSA by extract of oak leaves, apparently associated with hydrolyzable tannins, did not discourage oak consumption by goats. The digestibility of younger and older oak leaves was more influenced by time of incubation than level of phenolics in plant tissue. This research emphasizes the adaptability of goats to ecological zones where presence of toxins and digestion reducing compounds in plants adversely affects survival and fitness of non-adapted herbivores.

No description available.

Citocinas são pequenas moléculas de sinalização celular que desempenham um papel muito importante no sistema imunológico e atuam na comunicação intracelular. Escolheu-se cinco genes pertencentes a essa família com o objetivo de se estudar SNPs que possam estar associados com a resistência à verminose gastrintestinal em caprinos. São eles: IL2, IL4, IL13, IFNg e TNFa. Para isso foi estudada uma população de 229 caprinos. Estes animais foram produzidos na Embrapa Caprinos e Ovinos (Sobral, CE) a partir de animais das Raças Saanen, raça considerada susceptível a endoparasitas gastrintestinais e Anglo-nubiana, raça considerada resistente aos mesmos endoparasitas. Após dois cruzamentos a terceira geração de animais, considerada F2, possuía 229 animais. Foram coletadas amostras de sangue para posteriores etapas de extração de DNA e quantificação; foram coletadas também amostras de fezes para contagem de ovos por grama de fezes (OPG). Os dados foram transformados em log10(n+1), onde n é número de ovos por grama de fezes, e analisados usando o procedimento dos modelos mistos do SAS (2002/2003). Os efeitos fixos incluídos no modelo foram sexo, coleta e idade a coleta e a variável animal foi utilizada como efeito aleatório. Com base no resultado dessa análise escolheu-se 44 animais com fenótipos extremos para resistência. Visando a prospecção de SNPs foram sequenciadas duas regiões do gene IL2, uma região do gene IL4, duas regiões do gene IL13, três regiões do gene IFNg e quatro regiões do gene TNFa. Foram encontrados dois SNPs no gene IL2 (intron 1 e intron 2), um SNP no gene IL4 (intron 3), um SNP no gene IL13 (intron 1), seis SNPs no gene IFNg (dois no exon 1, um no intron 1, um no intron 2, um no exon 3 e um no exon 4) e dez SNPs no gene TNFa (dois deles na região promotora do gene, dois no intron 2 e seis no exon 4). Verificou-se que há alteração de aminoácido na sequência de apenas um dos SNPs encontrados em regiões codificadoras de proteínas. A troca ocorre no segundo SNP localizado no exon 1 do gene IFNg (A/C), onde há alteração do aminoácido asparagina (considerando o alelo A) para treonina (alelo C). O estudo da associação entre as amostras extremos para resistência e os marcadores tipo SNP foi realizado com o teste de Fisher e observou-se que, dentre os vinte SNPs encontrados, oito deles apresentaram um valor de P ≤0,05, o que indica que os SNPs são potenciais marcadores moleculadores para resistência à verminose gastrintestinal, ou seja, provavelmente associados ao fenótipo estudado. Para essa associação ser validada é necessário estudar o efeito desses SNPs na população completa e em outras populações. / The cytokines are small cell-signaling proteins that play important role in immunologic system acting in intracellular communication. Five genes from cytokine family, i.e., IL2, IL4, IL13, IFNg, and TNFa were selected to search for SNPs, which may be associated with goat gastrointestinal endoparasites resistance. A population of 229 goats was produced in Embrapa Caprinos (Sobral, CE, Brazil). This population was an F2 offspring from a F1 intercross, which was in turn produced by crossing Saanen pure breed considered to be susceptible to gastrointestinal endoparasites with Anglo-nubiana pure breed considered to be resistant. Blood samples were collected for DNA extraction and fecal samples were collected for parasite egg counting. The data were transformed in log10(n+1), where n is the number of eggs per gram of feces, and analyzed by using the mixed model procedure of SAS (2002/2003). The fixed effects included were sex, sampling and age at sampling. The animal variable was used as random effect. After data analyses, forty four phenotypic extremes for endoparasite resistance were selected. Two regions of the gene IL2, one region of each gene IL4 and IL13, three regions of IFNg, and four regions of TNFa were sequenced in the search for SNPs. Two SNPs were found in the gene IL2 (intron 1 and intron 2), one SNP was found in IL4 (intron 3) one SNP in IL13 (intron 1) six SNPs in IFNg (two in the exon 1, one in the intron 1, one in the intron 2, one in the exon 3, and one in the exon 4) and ten SNPs were found in the gene TNFa (two in the promoter region, two in the intron 2 and six in the exon 4). Among all the SNPs found within exons only the second SNP of the IFNg exon 1 changes the amino acid. This SNP replaces an asparagine (allele A) by a threonin (allele C). The association study between the extremes and SNPs was performed using the Fisher exact test. A number of eight of the twenty described SNPs presented significant P value (P ≤0.05) indicating association with gastrointestinal endoparasite resistance and thus, the potential applicability as molecular markers for genetic improvement efforts involving this disease. To validate the associations, however, is necessary to study the effect of SNPs in a great number of animals and also in a variety of breeds.

Citocinas são pequenas moléculas de sinalização celular que desempenham um papel muito importante no sistema imunológico e atuam na comunicação intracelular. Escolheu-se cinco genes pertencentes a essa família com o objetivo de se estudar SNPs que possam estar associados com a resistência à verminose gastrintestinal em caprinos. São eles: IL2, IL4, IL13, IFNg e TNFa. Para isso foi estudada uma população de 229 caprinos. Estes animais foram produzidos na Embrapa Caprinos e Ovinos (Sobral, CE) a partir de animais das Raças Saanen, raça considerada susceptível a endoparasitas gastrintestinais e Anglo-nubiana, raça considerada resistente aos mesmos endoparasitas. Após dois cruzamentos a terceira geração de animais, considerada F2, possuía 229 animais. Foram coletadas amostras de sangue para posteriores etapas de extração de DNA e quantificação; foram coletadas também amostras de fezes para contagem de ovos por grama de fezes (OPG). Os dados foram transformados em log10(n+1), onde n é número de ovos por grama de fezes, e analisados usando o procedimento dos modelos mistos do SAS (2002/2003). Os efeitos fixos incluídos no modelo foram sexo, coleta e idade a coleta e a variável animal foi utilizada como efeito aleatório. Com base no resultado dessa análise escolheu-se 44 animais com fenótipos extremos para resistência. Visando a prospecção de SNPs foram sequenciadas duas regiões do gene IL2, uma região do gene IL4, duas regiões do gene IL13, três regiões do gene IFNg e quatro regiões do gene TNFa. Foram encontrados dois SNPs no gene IL2 (intron 1 e intron 2), um SNP no gene IL4 (intron 3), um SNP no gene IL13 (intron 1), seis SNPs no gene IFNg (dois no exon 1, um no intron 1, um no intron 2, um no exon 3 e um no exon 4) e dez SNPs no gene TNFa (dois deles na região promotora do gene, dois no intron 2 e seis no exon 4). Verificou-se que há alteração de aminoácido na sequência de apenas um dos SNPs encontrados em regiões codificadoras de proteínas. A troca ocorre no segundo SNP localizado no exon 1 do gene IFNg (A/C), onde há alteração do aminoácido asparagina (considerando o alelo A) para treonina (alelo C). O estudo da associação entre as amostras extremos para resistência e os marcadores tipo SNP foi realizado com o teste de Fisher e observou-se que, dentre os vinte SNPs encontrados, oito deles apresentaram um valor de P ≤0,05, o que indica que os SNPs são potenciais marcadores moleculadores para resistência à verminose gastrintestinal, ou seja, provavelmente associados ao fenótipo estudado. Para essa associação ser validada é necessário estudar o efeito desses SNPs na população completa e em outras populações. / The cytokines are small cell-signaling proteins that play important role in immunologic system acting in intracellular communication. Five genes from cytokine family, i.e., IL2, IL4, IL13, IFNg, and TNFa were selected to search for SNPs, which may be associated with goat gastrointestinal endoparasites resistance. A population of 229 goats was produced in Embrapa Caprinos (Sobral, CE, Brazil). This population was an F2 offspring from a F1 intercross, which was in turn produced by crossing Saanen pure breed considered to be susceptible to gastrointestinal endoparasites with Anglo-nubiana pure breed considered to be resistant. Blood samples were collected for DNA extraction and fecal samples were collected for parasite egg counting. The data were transformed in log10(n+1), where n is the number of eggs per gram of feces, and analyzed by using the mixed model procedure of SAS (2002/2003). The fixed effects included were sex, sampling and age at sampling. The animal variable was used as random effect. After data analyses, forty four phenotypic extremes for endoparasite resistance were selected. Two regions of the gene IL2, one region of each gene IL4 and IL13, three regions of IFNg, and four regions of TNFa were sequenced in the search for SNPs. Two SNPs were found in the gene IL2 (intron 1 and intron 2), one SNP was found in IL4 (intron 3) one SNP in IL13 (intron 1) six SNPs in IFNg (two in the exon 1, one in the intron 1, one in the intron 2, one in the exon 3, and one in the exon 4) and ten SNPs were found in the gene TNFa (two in the promoter region, two in the intron 2 and six in the exon 4). Among all the SNPs found within exons only the second SNP of the IFNg exon 1 changes the amino acid. This SNP replaces an asparagine (allele A) by a threonin (allele C). The association study between the extremes and SNPs was performed using the Fisher exact test. A number of eight of the twenty described SNPs presented significant P value (P ≤0.05) indicating association with gastrointestinal endoparasite resistance and thus, the potential applicability as molecular markers for genetic improvement efforts involving this disease. To validate the associations, however, is necessary to study the effect of SNPs in a great number of animals and also in a variety of breeds.

The control of feral goats (Capra hircus) and relevant aspects of their biology were studied on Aldabra Atoll, Republic of Seychelles, from October 1993 - May 1994 and November 1994 - May 1995. A total of 832 goats were killed on Aldabra using both the Judas goat technique and traditional hunting methods; a total of 28 Judas goats were used during the entire campaign. The remnant goat populations on Ile Picard (N=13) and Ile Malabar (N=19) were eradicated during the first season. On Grande Terre, a total of 798 (374 M: 424 F) goats were killed. The overall kill rate on Grande Terre was 0.37 goats killed/hour with 1.66 shots fired/goat. A total of 1,042 goats were encountered of which 26.1% escaped. Mean group size was 3.2 with a range of 1 to 20. Judas goat hunting became increasingly important over time with 18.0% (n=85) of goats killed in the first season being in the presence of Judas goats; 42.3% (n=126) of goats killed during the second season were in the presence of Judas goats. The overall kill rate for the project was almost 2 times greater for Judas goat hunting (0.61 goats killed/hr) than traditional hunting (0.32 goats killed/hr); Judas goat hunting was approximately 70% more effective than traditional hunting when compared using multiple linear regression. There was a significant relationship between Judas goat home range size and the number of conspecifics killed. Feral goats on Aldabra may be unique among feral goat populations by apparently not responding to population reductions in a density-dependent manner. For the first season, the intrinsic rate of increase (r) was 0.45; r=0.39 for the second season. Twinning rates were 30.7% and 37.5% in the first and second seasons, respectively. I subjectively estimated approximately 60-120 goats remaining on all of Grande Terre at the end of the project; 84 goats were estimated using the Leslie-Davis removal method of population estimation. / Graduation date: 1998

Feral goat (Capra hircus) populations adversely impact native insular biota and physical habitats worldwide. The effectiveness of the Judas goat technique for eradicating remnant feral goats was studied on San Clemente Island (SCI), California from June 1989 through April 1991. By April 1991, 263 feral goats were killed on SCI; only 2 adult females and their offspring were believed to remain. The length of time required by radio-collared (Judas) goats to establish initial contact with remnant goats was 1 to 5 days, and time to subsequent encounters with new goats averaged 3.5 days. Duration of association between Judas goats and remnant herds ranged from 1-60 days. Judas goat home ranges averaged 4.4 km² and maximum distances Judas goats traveled to find conspecifics averaged 4.8 km. Observations of Judas goats that were associated with remnant feral goats allowed individual identification of most goats and prediction of their temporal and spatial activity patterns. This knowledge greatly expedited the eradication process and likely contributed to the preservation of threatened and endangered endemic species on SCI. Natality, survivorship, and condition of SCI goats were inversely related to decreases in population density when compared to goat populations from other islands. higher and mortality lower than in other feral goat populations, presumably because of the unusually low density of goats on SCI. The Judas goat technique allows removal of low density feral goat herds in a timely manner and should be used by resource managers wherever feral goats threaten native flora and fauna. / Graduation date: 1992

Thesis (Ph. D.)--Sverges lantbruksuniversitet, 2001. / Thesis statement in Swedish and English abstract inserted. Based on 4 previously prepared or published papers reprinted here. Includes bibliographical references.

Goats are found in almost every country and are an important source of protein and produce lactose-free milk. In South Africa, survival rates of goat kids are low, mainly due to malnutrition. Intensive goat production systems based on cultivated pastures were evaluated, at various stocking rates to evaluate the effects of improved nutrition on goat production. The pastures chosen to be evaluated for goat production were Pennisetum clandestinum (Kikuyu) and Secale cereale (Stooling rye). Kikuyu is one of the more important dryland summer pasture species in KwaZulu-Natal. Three stocking rates of goats on kikuyu were evaluated using ewes with kids. When analysing the period to weaning, the ewes lost weight in all stocking rate treatments and for both years. The years had a significant effect on weight loss (P<0.001; R²=95.7%) with a mean ADG of -0.0267 kg.animalˉ¹.dayˉ¹. There was a significant difference between ADGs between stocking rates, with ADGs of -0.0157, -0.026 and -0.0384 kg.animalˉ¹.dayˉ¹ at stocking rates of 30, 45 and 60 goats.haˉ¹ respectively (P<0.001; R²=95.7%). The analyses of the entire grazing period showed no significant difference in ewe ADGs between treatments, but a significant difference between the two years (P=0.03), with a mean ADG of -0.0205 kg.animalֿ¹.dayֿ¹. There was no significant difference between kid masses between treatments. There was a significant difference between kid performance between years (P<0.001; R²=21.8%). However, factors such as ewe start mass (P<0.001) and whether the kid was a singleton or a multiple (P=0.015) had an influence on kid ADG, while gender had no significant effect (P=0.446). Interpretation of the combined ewe plus kid weight revealed that the high stocking rate produced the highest total mass per hectare (P<0.001) with an overall mean of 2377 kg.haˉ¹. Kid ADG was positively correlated to ewe ADG (P=0.013; R²=5.8%) although this was not a strong relationship. Protein was negatively correlated to pasture height (P=0.036; R²=30.8%) and had a quadratic relationship with ADG (P<0.001; R²=48.4%) with maximum ADG occurring at protein levels of 26.17%. Rainfall was different between the two seasons, which affected pasture growth, with the stocking rates in the second year being too low, so the maximum stocking rate per hectare was not reached. Stooling rye is a pasture used predominantly in South Africa and is a good source of high quality winter feed. Four stocking rates were evaluated over winter, using pregnant ewes. Rainfall was not an important variable since supplementary irrigation was given and the difference in temperatures between the years was negligible. The rate of weight gain showed a similar response for both years with the level of weight gain varying significantly between years (P=0.001; R²=90.2%). The regressions for ADG on stocking rate were determined and were y=0.2340-0.00293x for 2001 (P=0.151; R²=58.0%) and y=0.1292-0.002198x for 2002 (P=0.137; R²=61.6%). Gain per hectare was determined, as were the stocking rates at which maximum gain per hectare were achieved and this was determined to be 40 goats.haֿ¹ during 2001 and 29 goats.haֿ¹ for 2002. The respective ADGs at these stocking rates were 0.1168 and 0.0633 kg.dayֿ¹ and daily gains.haֿ¹ were 4.672 and 1.898 kg.haֿ¹.dayֿ¹ respectively. Herbage analyses revealed that there were extremely high levels of protein in the pasture (33.87%) even though the pasture was not excessively fertilised. Average daily gain was negatively related to NDF levels (P=0.006; R²=38.4%). ADF levels (P<0.001; R²=48.4%) and NDF levels (P<0.001; R²=60.4%) showed a quadratic relationship with pasture age. Blood serum revealed that selenium levels in all treatments were lower than the normal range, while all other minerals were within the normal range. To maximise animal performance, the highest quality pasture should be offered to producing animals, namely growing animals. The seasonal variation between years has a large effect on the performance of goats on pastures. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

This study was conducted on the grazing of West African Dwarf (WAD) goats managed by 41 farmers in Nigeria. The study focused on the use of "fodder banks" by small-scale farmers. The objective of the research was to determine the effect of seeding Stylosanthes hamata on herbage productivity and goat performance under three grazing management systems: tethering (conventional), free grazing natural pasture or free grazing legume-seeded pasture (fodder bank). / Irrespective of the system of management, goats grazing the various pastures had a weaning weight of 6.0 $ pm$ 0.3 kg. At 6, 9 and 12 months the body weights were 9.3 $ pm$ 0.41, 11.7 $ pm$ 1.36 and 12.6 $ pm$ 0.73 kg, resulting from an average daily gain (ADG) of 49.0 $ pm$ 4.0, 33.4 $ pm$ 4.0, 31.0 $ pm$ 0.1 and 25.0 $ pm$ 0.03 g day$ sp{-1}$ for the growth periods of birth to 3 months (pre-weaning) 3-6, 3-9, and 3-12 month (post-weaning) growth periods, respectively. There were no significant differences among the grazing systems with regard to birth weights and 3-month body weight (weaning weight). However, during the 3 to 6-month growth period, the ADG of goats tethered on natural pasture was higher than that observed for goats grazing S. hamata seeded pasture or fenced natural pasture, but this difference disappeared with time. At the 12-month period goats grazing fodder banks were heavier than goats tethered on natural pasture during the late wet season period, but the effect was not significant. Although animals lost weight during the late rainy season, animals grazing fodder banks seemed to have lost less weight than those grazing natural pasture. (Abstract shortened by UMI.)