Methane emissions of 60 steers (321 ± 14 kg) fed isocaloric forage diets differing in crude protein (CP) content were measured at ambient daily temperatures averaging -17.5°C to determine if increased nitrogen status, measured by blood urea nitrogen (BUN), decrease CH4 as a percent of gross energy intake (% GEI) from backgrounding cattle. Average BUN concentrations (mmol L-1) were 0.81, 1.82, 3.05 and 3.51 (SE ± 0.108) for diets with 6.9% (low), 10.3% (adequate for rumen microbes), 11.1% (adequate for muscle growth) and 13.6% (excessive) CP respectively. Methane (% GEI) emissions decreased with increasing CP over time (P=0.04). Increasing CP content increased BUN levels and decreased methane emissions (% GEI). Although models were developed to predict CH4 emissions (% GEI) from steers and cows using a backward-elimination process, BUN accounted for only 0.7 to 5.7% of the partial R2 and therefore has limited value when modelling methane emission predictions. / February 2016

The objective of these studies was to develop near-infrared reflectance spectroscopy calibration equations from diet-fecal pair datasets to predict the diet quality and intake of donkeys. One hundred-forty diet-fecal pair samples were generated from two independent in vivo feeding trials conducted in the United States (N = 100) and Africa (N = 40). At each site, ten female donkeys were fed mixed diets blended from 25 forage and crop residues. The modified partial least square model (MPLS) was used to develop calibration equations for crude protein (CP), digestible organic matter (DOM), dry matter digestibility (DDM) and organic matter digestibility (OMD), for the US, Africa and US/Africa combined datasets, and dry matter (DM) and organic matter (OM) intake calibrations from the US datasets. Crude protein (CP) equations were developed with standard error of calibration (SEC) < 1.0 and coefficient of determination (R2) > 0.90, (SEL = 0.5). The US, US/Africa and Africa CP equations had SEC value of 0.77, 0.97 and 0.88 with corresponding R2 of 0.97, 0.95 and 0.88, respectively. Validation of the US CP equation resulted in a standard error of prediction (SEP) of 1.79 with corresponding coefficient of correlation (r2) of 0.82 and slope of 0.84 indicating high accuracy of prediction. In vivo derived DOM equations were also developed for the US, Africa and US/Africa datasets with SEC values of 2.58, 4.91 and 3.52, and R2 of 0.60, 0.81 and 0.84, respectively. In addition, the SEC and R2 values were 3.25 and 0.72 for US OMD, 3.28 and 0.79 for US DDM, and 4.2 and 0.85 for US/Africa OMD, and 4.3 and 0.87 for US/Africa DDM equation, respectively. Calibration equations for predicting DMI and OMI have resulted in SEC values of 3.45 and 3.21 (g/kgw0.75) and R2 values of 0.89 and 0.84, respectively. The present study explored the relationship between DMI and diet quality attributes. Crude protein and digestible organic matter to crude protein ration (DOM/CP) with r2 values of 0.60 and 0.39, respectively, have shown good correlations with intake. The present studies have confirmed the potential for the fecal NIRS profiling for predicting CP, DOM, DDM, OMD, DMI and OMI of donkeys. Both calibration and validation results have indicated that the present donkey equations were comparable to previously developed equations for ruminants; they have the capability for accurate prediction of diet quality and intake, and can be a useful tool for monitoring the nutritional well-being of donkeys with acceptable accuracy. Research works to further expand the present calibration equations with additional diet-fecal samples particularly from Africa that did not meet the required accuracy level is recommended.

This study was conducted to determine the effect of forage CP level on intake and digestion of Coastal bermudagrass hay by horses. Four cecally fistulated geldings were used in a 4 x 4 Latin square design with four treatments and four periods. Horses were fed one of four Coastal bermudagrass hays consisting of 7, 10, 13, or 16% CP during each of the 4 15-d periods. Intake and apparent digestibility were determined for each horse at the end of each period by total fecal collection. In addition, cecal fluid and blood samples were collected from each horse on the last day of each period for determination of cecal ammonia, cecal pH, plasma urea nitrogen, and plasma glucose concentrations. Crude protein concentration of Coastal bermudagrass hay influenced equine intake and digestion. Increasing CP concentration linearly increased digestible OM intake (DOMI) from 3.79 to 5.98 kg/d for 7 and 16% CP hay, respectively (P = 0.04). Furthermore, as forage CP level increased, CP intake increased linearly (P < 0.01). Forage CP level had no effect on forage DM intake. Quadratic effects (P less than or equal to 0.05) were observed for forage OM, NDF, ADF, and digestible energy. Overall digestibility was lowest for the 7% CP hay and highest for the 10% CP hay. Cecal pH remained above 6.62 irrespective of treatment and time, indicating that cecal pH was suitable for microbial growth. As forage CP level increased, cecal ammonia concentration increased linearly from 0.03 mM for the 7% to 1.74 mM for the 15% CP hay (P < 0.01). Concentration of plasma glucose also linearly increased (P = 0.04) from 68.77 to 73.68 mg/dL as CP concentration increased from 7% to 16% CP. Plasma urea nitrogen exhibited a quadratic effect as concentration increased (P < 0.01) from 4.34 to 5.61 mM for the 7 and 16% CP hays, respectively.

The objective of these studies was to develop near-infrared reflectance spectroscopy calibration equations from diet-fecal pair datasets to predict the diet quality and intake of donkeys. One hundred-forty diet-fecal pair samples were generated from two independent in vivo feeding trials conducted in the United States (N = 100) and Africa (N = 40). At each site, ten female donkeys were fed mixed diets blended from 25 forage and crop residues. The modified partial least square model (MPLS) was used to develop calibration equations for crude protein (CP), digestible organic matter (DOM), dry matter digestibility (DDM) and organic matter digestibility (OMD), for the US, Africa and US/Africa combined datasets, and dry matter (DM) and organic matter (OM) intake calibrations from the US datasets. Crude protein (CP) equations were developed with standard error of calibration (SEC) < 1.0 and coefficient of determination (R2) > 0.90, (SEL = 0.5). The US, US/Africa and Africa CP equations had SEC value of 0.77, 0.97 and 0.88 with corresponding R2 of 0.97, 0.95 and 0.88, respectively. Validation of the US CP equation resulted in a standard error of prediction (SEP) of 1.79 with corresponding coefficient of correlation (r2) of 0.82 and slope of 0.84 indicating high accuracy of prediction. In vivo derived DOM equations were also developed for the US, Africa and US/Africa datasets with SEC values of 2.58, 4.91 and 3.52, and R2 of 0.60, 0.81 and 0.84, respectively. In addition, the SEC and R2 values were 3.25 and 0.72 for US OMD, 3.28 and 0.79 for US DDM, and 4.2 and 0.85 for US/Africa OMD, and 4.3 and 0.87 for US/Africa DDM equation, respectively. Calibration equations for predicting DMI and OMI have resulted in SEC values of 3.45 and 3.21 (g/kgw0.75) and R2 values of 0.89 and 0.84, respectively. The present study explored the relationship between DMI and diet quality attributes. Crude protein and digestible organic matter to crude protein ration (DOM/CP) with r2 values of 0.60 and 0.39, respectively, have shown good correlations with intake. The present studies have confirmed the potential for the fecal NIRS profiling for predicting CP, DOM, DDM, OMD, DMI and OMI of donkeys. Both calibration and validation results have indicated that the present donkey equations were comparable to previously developed equations for ruminants; they have the capability for accurate prediction of diet quality and intake, and can be a useful tool for monitoring the nutritional well-being of donkeys with acceptable accuracy. Research works to further expand the present calibration equations with additional diet-fecal samples particularly from Africa that did not meet the required accuracy level is recommended.

Two trials were conducted to evaluate the effects of gender on optimal CP concentrations (TRIAL 1) and gender and anabolic implants on the somatotropic axis in feedlot cattle (TRIAL 2). More specifically, the objective of TRIAL 1 was to examine the effects of 3 dietary CP concentrations on performance, carcass characteristics, and serum urea nitrogen (SUN) in finishing steers and heifers and the objective of TRIAL 2 was to evaluate the effects of ovariectomy (OVX) and implantantation (200 mg of trenbolone acetate and 28 mg of estradiol benzoate; Synovex-Plus) on performance, serum urea nitrogen (SUN), serum IGF-1, and mRNA expression of hepatic IGF-1, GH receptor, and E receptor-α as well as pituitary GH, E receptor-α and GHRH receptor in feedlot heifers. TRIAL 1 results indicated that ADG was optimized when both steers and heifers were fed 12.5% CP and G:F was optimized for steers fed 12.5% CP but heifer G:F was optimal at 14.0% CP. Feeding diets containing 11.0% CP appears to cause a protein deficiency in both steers and heifers. TRIAL 2 data indicated that gender had no influence on performance or SUN in feedlot heifers. Serum IGF-1 is increased more in OVX heifers than intact heifers due to a greater response to implantation from the OVX heifers. However, the reason for the extra increase in serum IGF-1 is not clear, although trends in gene expression analysis suggest the possibility that the increased serum IGF-1 may be controlled outside of the somatotropic axis. Further research is warranted to examine the effects of OVX and anabolic implants on the somatotropic axis.

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / This study evaluated the nutritional quality of the forage plants in Namaqualand Granite Renosterveld vegetation in the Kamiesberg uplands of the Leliefontein communal area, South Africa. Determining the quality of forages is one of the most important factors necessary for the effective management of rangelands as it impacts on the nutrient needs of animals and consequently, the grazing capacity in rangelands. The edible portions of various forage plants were collected in the wet and dry seasons in 2012 and 2013 after which the nutritional quality (mineral nutrient content; crude protein (CP); fibre, neutral detergent fibre (NDF) and acid detergent fibre (ADF); dry matter digestibility (DMD); dry matter intake (DMI); metabolizeable energy (ME); and relative forage value (RFV)) as well as the anti-nutritional quality (total phenolics (TP); condensed tannins (CT); and silicon (Si) concentrations) of the plants were determined. Plants were thereafter grouped into their respective growth forms: grasses (15 species), herbs (15 species), leaf succulents (17 species), non-succulents (134 species), reeds (7 species), trees (8 species) and stem succulents (2 species) for statistical analyses. There were generally only a few significant differences for each forage growth form, when comparing the nutritional and anti-nutritional qualities between the two seasons. Certain forage types such as leaf succulents were found to have a high nutritional value in terms of their mineral nutrient content, CP, DMD and ME , but were also found to contain high concentrations of one or more anti-nutritional factors. However, within each season, results showed that for both the nutritional quality and anti-nutritional quality, there was a significant difference between the different growth forms within each season. This suggests that both of these quality parameters are essential in order to draw meaningful conclusions regarding forage quality of these semi-arid rangeland plants. Further research is needed at the species level to determine what plant species are the most nutritious in terms of both nutritional and anti-nutritional quality in order to inform the potential production of these species on a commercial scale.

Currently accepted optimum protein levels for growth in the horse may be reduced with amino acid supplementation. This study investigated the effects on growth and protein status of Thoroughbred foals offered a supplement with a typical CP level to a supplement that had a lower CP level fortified with limiting amino acids. The control supplement (CS) contained 14% CP, 3.0 Mcal/kg DM, 10% corn oil, 22% soybean meal, 1.4% calcium, and three sources of fiber. The experimental supplement (LTS) contained 9% CP, 3.0 Mcal/kg DM, 10% corn oil, 3% soybean meal, 1.4% calcium, three sources of fiber, and was fortified with .6% lysine and .4% threonine. Lysine and threonine are the first two limiting amino acids in common diets of the horse. Mares and foals were fed twice daily (0700 and 1400) and kept on 30-acre pastures (mixed grass/white clover) until weaning (7 months). Weanlings continued on specified supplements and pastures for seven additional months. Physical measurements and blood samples were taken monthly. Measurements included weight, average daily gain (ADG), body condition (BC), wither height, hip height, length, girth, forearm length, front and hind cannon length, physis and fetlock circumference. Blood analysis included total protein (TP), albumin (ALB), creatinine (CREA), and plasma urea nitrogen (PUN). Effect of diet and time were evaluated by analysis of variance with repeated measures. No differences were found in physical measurements between the CS and LTS groups (ADG 0.8(0.4 kg/day, BC 4.9(0.05) for the observational period. Blood data also showed no difference for the period (ALB 2.9 ( 0.03 g/dl, TP 5.7 ( 0.10 g/dl, CREA 1.1 ( 0.02 mg/dl). These results suggest that the foals offered the LTS faired as well or better than foals on the CS. Lower levels of crude protein (CP) in the diet will result in less nitrogen pollution of pasture lands due to better utilization in the horse. By fortifying a low protein diet with the first two limiting amino acids, the protein is used more efficiently for growth and development, thereby benefiting both the horse and the land. / Master of Science

Master of Science / Department of Animal Sciences and Industry / Micheal J. Brouk / The study objective was to evaluate the application of supplemental rumen-protected lysine (RP Lys) to maintain milk production when reducing the crude protein levels in a lactating dairy cow diet. Twelve lactating multiparous Holstein cows, averaging 129 DIM, 50.2 kg milk yield, 3.6% fat and 2.9% true protein were randomly assigned to one of four 3x3 Latin squares. Each 14-d period had 11 d for adaptation followed by 3 d of data collection. Cows were offered one of three experimental treatment rations formulated with CPM Dairy (v3.0); Positive control (PC) — formulated to meet all nutrient requirements; Test diet (Test) — negative control diet formulated to meet nutrient requirements, except deficient in metabolizable protein (MP) (approximately 200 g/d) and first limiting in metabolizable Lys (approximately 10 g/d); and Test+RPL — same basal diet as negative control + RP-Lys to provide 14.5 g/d of MP-Lys. For Test+RPL, 45g of RP-Lys (AminoShure-L®; Balchem Corp., New Hampton, NY, containing 23.4g Lys) was top-dressed on the TMR once daily. The PC diet resulted in lower dry matter intake (P = 0.03) as compared to either the Test or Test+RPL diet. PC, Test, and Test+RPL cows averaged 42.6, 42.9, 43.6 kg/d of milk and 27.3, 28.4, 28.8 kg/d of DMI, respectively. Crude protein intake for the PC, Test, and Test+RPL diets was 4.83, 4.67, and 4.74 kg/d respectively. MUN decreased (P < 0.01) for cows on Test and Test+RPL diets as compared to PC diet (12.5, 12.5 and 14.9 mg/dL, respectively). Milk yield, milk components, milk component yields, FCM, ECM, SCM and production efficiencies (milk, ECM, SCM and FCM) did not differ (P > 0.05) among treatments. A post-study CPM Dairy evaluation using final chemical composition analyses of the feedstuffs and average production data from the animals predicted that diets supported more than 47 kg of milk and Lys was not limiting. Cows on the study produced slightly less milk, however DMI was 5-8% more than predicted by initial formulations. Formulation accuracy of the MP and Lys deficient diet may have been improved if data had been available from an initial adjustment period measuring DMI, body weight, milk yield and milk composition. It is also possible that the bioavailability of the RP Lys was not as great as thought during the diet formulation process. However, given the fact that the post-trial CPM analysis did not indicate a deficiency of Lys, it is not very likely that this impacted the results of this trial.

Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2018-09-28T18:11:26Z No. of bitstreams: 1 Edgard Gonçalves Malaguez.pdf: 624903 bytes, checksum: 6111134e8079c358a6202f314465611a (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2018-09-28T18:11:37Z (GMT) No. of bitstreams: 1 Edgard Gonçalves Malaguez.pdf: 624903 bytes, checksum: 6111134e8079c358a6202f314465611a (MD5) / Made available in DSpace on 2018-09-28T18:11:37Z (GMT). No. of bitstreams: 1 Edgard Gonçalves Malaguez.pdf: 624903 bytes, checksum: 6111134e8079c358a6202f314465611a (MD5) Previous issue date: 2018 / O objetivo deste estudo foi identificar os parâmetros que impactam na interface planta-animal e nutrição de bovinos em função dos diferentes níveis de intensificação da pastagem nativa do Bioma Pampa. O experimento teve início em agosto de 2015 e finalizado em maio de 2017. Porém, o processo das intensificações dos tratamentos começou em março de 2015. A área destinada para o experimento foi de aproximadamente 34 ha de pastagem natural. Foram avaliados os tratamentos: Campo nativo (CN); CN com calagem e adubação com fósforo e potássio (CNA); CNA com introdução de azevém anual (Lolium multiflorium) (40 kg ha-1 de sementes) e adubação nitrogenada correspondendo a 80 kg/ha/ano (CNAN); CNA com introdução de azevém anual e semeadura de leguminosas (CNAL). O grupo de animais foi constituído de novilhas em recria da raça Braford com peso aproximado no início do experimento de 136 kg de peso corporal. O delineamento experimental foi em blocos completamente casualizados com duas repetições de área e quatro tratamentos totalizando oito unidades experimentais (UEs). No capítulo I, os períodos utilizados para as avaliações foram realizados em dois momentos distintos; março e outubro de 2016. Foram avaliadas as estruturas do dossel, qualidade da pastagem e os aspectos nutricionais. Foi evidenciado crescentes consumo e digestibilidade em outubro, nos tratamentos CNAN e CNAL, assim como a relação do consumo de proteína degradável no rúmen com consumo da matéria orgânica digestível (CPDR: CMOD) foram mais altas para este mesmo período, que consequentemente influenciou o ganho médio diário (GMD), com maiores ganhos nos tratamentos CNAN 0,627 kg/dia e CNAL com 0,574 kg/dia. No capítulo II, as coletas foram mensalmente durante todo o experimento. A digestibilidade da matéria orgânica (DMO) consumida pelas novilhas, foi maior nos tratamentos CNAN e CNAL 0,635 e 0,641 g/kg DMO, respectivamente. Porém, durante a primavera foi obtido a melhor DMO com média 0,653 g/kg de DMO. A concentração proteína bruta na dieta (CPB), apresentou comportamento semelhante ao DMO. Foi criado dois modelos com uso de regressões múltiplas considerado a análise de stepwise. O primeiro modelo utilizando a estrutura da pastagem e a digestibilidade permitiu explicar 42 % da variabilidade para GMD. No segundo modelo com as variáveis; CPDR:CMOD, CMOD e CMS determinaram o coeficiente de 87 %. Conclui-se que, há medida que se intensifica a pastagem nativa há um impacto da qualidade do alimento e nos parâmetros nutricionais dos ruminantes, que são determinantes para estimativa do desempenho. / The objective of this study to identify the parameters that affect the plant-animal interface and the nutrition of cattle due to the different strategies of intensification of the native pasture from Pampa Biome. The experiment started in August 2015 and ended in May 2017. However, the process of intensifying treatments began in March 2015. The area destined for the experiment is approximately 34 ha of natural pasture, average. The following treatments were evaluated: native pasture (NP); NP with liming and fertilization with phosphorus and potassium (NPF); NPF with introduction of annual ryegrass (Lolium multiflorium) (40 kg ha-1 of seeds) and nitrogen fertilization corresponding to 80 kg / ha / year (NPFRN); NPF with introduction of annual ryegrass and legume sowing (NPFRL). The animals were composed of Braford breed with approximate weight at the beginning of the experiment of 136 kg of body weight. The experimental design was completely randomized blocks with two replicates and four treatments totaling eight experimental units (EUs). In Chapter I, the periods used for the evaluations were carried out at two different times; March and October 2016. Were evaluated canopy structures, pasture quality and nutritional aspects. Increasing intake and digestibility were evidenced in October, in the NPFRN and NPFRL treatments, as well as the relation of the intake of degradable protein in the rumen with intake of the digestible organic matter (RDP:DOMI) were higher for this same period, that consequently influenced the average daily gain (ADG), with higher gains in the treatments NPFRN 0.627 kg/day and NPFRL with 0,574 kg/day. In Chapter II, the collections were monthly throughout the experiment. The digestibility of organic matter (DOM) consumed by heifers was higher in treatments NPFRN and NPFRL 0.635 and 0.641 g/kg DMO, respectively. However, during the spring the higher DOM was obtained with a mean of 0.653 g/kg. The crude protein concentration in the diet (CPC) presented similar behavior to DOM. Two models were created using multiple regressions considered stepwise analysis. The first model using the pasture structure and the digestibility allowed explaining 42% of the variability for ADG. In the second model with the variables: RDP:DOMI, DOMI and DMI determined the coefficient of 87%. It was conclude that, as native pasture intensifies, there is an impact on the quality of the food and on the nutritional parameters of ruminants, which are determinant for estimating performance.

O presente trabalho teve como objetivo estudar os efeitos da suplementação de ácido linoléico conjugado (CLA), associada à redução do nível de proteína bruta (PB) da dieta de frangos de corte. No primeiro ensaio, o período experimental transcorreu dos 21 aos 41 dias, quando 1440 machos da linhagem Ross, com mesmo peso inicial, foram distribuídos em delineamento inteiramente casualizado, em esquema fatorial 3x3, sendo três níveis de CLA (0%, 0,5% e 1,0%) e três níveis de PB (19%, 17%, 15%). Houve redução do ganho de peso e aumento da conversão alimentar apenas em função do decréscimo de PB e ambos os fatores elevaram o índice econômico mensurado. Os rendimentos de carcaça inteira e peito diminuíram proporcionalmente a PB da dieta. Houve interação entre CLA e PB para o tamanho do fígado, ambos os fatores elevaram a gordura abdominal. Em relação aos parâmetros analisados em amostras de peito, o pH elevou-se proporcionalmente, em relação a PB, as intensidades de vermelho e amarelo foram modificadas ou pela PB, ou pelo CLA e para a luminosidade houve interação. Quanto ao perfil de ácidos graxos, a PB elevou somente o ácido esteárico e o CLA aumentou os ácidos graxos saturados e reduziu os monoinsaturados. Houve incorporação crescente dos isômeros de CLA, em função da maior inclusão do produto nas dietas com 19% ou 17% de PB. Nas dietas com 15% de PB, ocorreu um limite máximo para a incorporação do CLA. No segundo experimento, utilizando 144 aves Ross e mesmo delineamento e modelo experimental, houve efeito quadrático da PB para o balanço de nitrogênio e interação entre CLA e PB para a digestibilidade da PB dietária. / The objective of this research was to study the effects of the conjugated linoleic acid, known as CLA, associated with reduction of crude protein (CP) level in broiler diets. At first assay, the period of experiment was conducted from 21 to 41 days, when 1440 male broilers from Ross line, with the same weight initial, were allocated in accordance to a completely randomized design, with factorial model 3x3, corresponding in 3 CLA inclusions levels (0%, 0,5% and 1,0%) and 3 CPs levels (19%,17%,15%). Weight gain reduction and increased feed conversion were only related to decrease of CP inclusion and both of factors, CP and CLA inclusion levels, elevated the economic index parameters. Carcass and breast meat yields decreased due to the reduction of CP addition in diets. The interaction between CLA and CP factors modified in liver size, and both elevated the abdominal fat percents. In relation to parameters analyzed in breast samples, the pH elevated proportionally to CP inclusion, the redness and yellowness were modified by CP or CLA addition and interaction of both were detected to luminosity parameter. About fatty acid composition, the addition of CP only elevated the stearic acid and CLA inclusion improved the saturated fatty acid levels and reduced the monounsaturated fatty acid levels. An improvement on incorporation of CLA isomers was verified due to more inclusion of this product in 19% or 17% CPs diets. In the case of 15% CPs diets, the incorporation of CLA isomers had a maxim limit. In the second assay, using 144 Ross line broilers with the same design and model, a quadratic effect for nitrogen balance was verified due to CP diets and an effect of interaction between CLA and CP inclusion was found to digestibility of dietary CP.