The current National Academies of Sciences, Engineering and Medicine (NASEM) dry matter intake (DMI) prediction models are inadequate for DMI prediction of beef cattle in the Northern Great Plains. Four studies were conducted to account for additional variation in DMI and average daily gain (ADG) caused by weather variables. Experiment 1 and 2 had 13,895 steer-weeks observations, experiment 3 had 13,739 steer-weeks observations, and experiment 4 had 2,161 cow-weeks observations, respectively. Experiment 1 examined the influence of ambient temperature and solar radiation on DMI of beef steers. In experiment 2, 3, and 4, we examined the influence of ambient temperature, range of temperature, dew point, solar radiation, wind speed and their lags (two-week lag and monthly lag) on DMI of beef steers, ADG of beef steers, and DMI of beef cows, respectively. After adjusting for week of the year, linear and quadratic relationships of predictor variables on response variables were evaluated. In experiment 1 and 2, body weight (BW) had both linear and quadratic relationship with DMI of steers. In experiment 3 and 4, BW had a linear relationship with ADG of steers and DMI of cows, respectively. Week of the year, BW, and dietary energy density (NEm) were accounted for in the base model in experiment 1, 2 and 4 while in experiment 3, DMI was also accounted for. For the models, stepwise regression procedure was utilized. In experiment 1, ambient temperature and solar radiation interacted (P = 0.0001) and accounted for additional variation in DMI of beef steers. In experiment 2, weather variables and their interactions (P = 0.0001) accounted for additional variation in DMI of beef steers. In experiment 3, weather variables (P = 0.0001) accounted for additional variation in ADG of beef steers. In experiment 4, wind speed interacted (P <0.001) with ambient temperature and range of temperature which all accounted for additional variation in DMI of beef cows. These studies show that weather variables interact and cause variation in DMI and ADG in beef cattle. This has helped in better understanding the relationship between weather variables with DMI and ADG. This will improve the accuracy of DMI and ADG prediction equations and help beef cattle producers in managing their feed resources more efficiently.

BACKGROUND: Both endo- and ectoparasites pose a great challenge to the health of pigs worldwide, placing a significant burden on low-resource countries where veterinary care is minimal. As part of a larger clinical trial assessing the use of ivermectin (IVM) mass drug administration to humans and pigs for the control of malaria vectors in the Mopeia district in Mozambique, a longitudinal study to assess the impact of IVM administration on pig health was performed. METHODS: Beginning in March 2022, IVM was administered to pigs in the intervention area once a month for three consecutive months. Seventy pigs from the treatment group and 70 pigs from the control group were randomly selected for inclusion in the study. Fecal samples were collected monthly for three months and analyzed for the presence of strongyle eggs, strongyle eggs in the larval stage (strongyles – larval) and Ascaris suum using the modified McMaster test. Fecal samples were also collected two weeks after each dose of IVM was given to pigs in the treatment group for determination of a fecal egg reduction count. Juvenile pigs were measured twice a month for the first 3 months of the study, then once monthly for another three months. Visual exam for ectoparasites was performed on all pigs for the presence of ticks, lice or scabies at the same time points. RESULTS: Overall, 55% [95% CI: 48-62%] of pigs were positive for Ascaris suum, 95.2% [95% CI: 91-98%] were positive for strongyle eggs, and 72.5% [95% CI: 65.5-79%] were positive for strongyle – larval. A significant difference in the ivermectin treatment group was only seen one month after the second dose of ivermectin was administered: pigs in the treatment group had a 23.6% lower prevalence of strongyles (p = 0.003) and 18% lower prevalence of strongyles – larval (p = 0.03). Pigs in the treatment group also had lower EPG for Ascaris suum (diff = 102 EPG; p = 0.006), strongyles (diff = 642 EPG; p < 0.001), and strongyles - larval (diff = 217 EPG; p < 0.001). Analysis of covariance regression found no significant difference(P>0.05) in average daily weight gain (ADG) between the treatment and control groups. CONCLUSION: IVM delivered once monthly for three months has a small impact on pig health. To counteract the multiple health challenges pigs face in these settings, different dosing schedules along with education on husbandry issues related to nutrition and sanitation should be investigated in order to maximize impact on pig health. / Master of Science / A study was conducted in rural Mozambique in the district of Mopeia to determine the effectiveness of ivermectin against common parasites of swine when administered to pigs. The study began in March of 2022, at the beginning of rainy season, and ivermectin was given to pigs once a month for three months. Pigs were visited twice a month for the first three months, and then once a month for another three months. At various time points, fecal samples were collected, pigs were examined for evidence of ectoparasites (ticks, lice and scabies infestation), and young pigs were measured to determine their rate of growth. Fecal samples were analyzed for the presence of common internal parasites (endoparasites) affecting pigs in the area. The burden of endo and ectoparasites was estimated before any ivermectin was administered, and then compared in treated and untreated pigs over the course of the study. Similarly, the effect of ivermectin on growth rates in young animals was determined. The results of this study found that there was a high burden of common endoparasites in pigs in the Mopeia district, which was only minimally affected by the use of ivermectin delivered once a month. Among the treated pigs, a fecal egg count reduction test suggests that these parasites are potentially resistant to ivermectin, although other issues may be responsible for these results. The burden of ectoparasites was generally low (<10%), with ivermectin only significantly reducing the prevalence of ticks. Young animals that received ivermectin had a 15% increase in their growth rate, but this was not statistically significant. In conclusion, the use of ivermectin once a month for three months in pigs, as part of a malaria intervention, has some minimal positive health effects on treated pigs. Given the poor management practices, poor nutrition and lack of veterinary care in these pigs, it is likely that to have a greater impact on pig health, ivermectin will need to be delivered under a different dosing schedule and alongside owner education on pig management practices.

O objetivo do presente trabalho foi avaliar o desempenho reprodutivo de leitoas que foram selecionadas com baixos ganhos de peso diários (GPD) aos 160 dias de vida. Leitoas da linhagem Camborough® (n = 3301) foram alocadas em quatro grupos de acordo com o GPD no momento da seleção: G1 (n = 799) leitoas com GPD ≥480 a ≤ 530g/dia, G2 (n = 978) leitoas com >530 a ≤ 580g/dia, G3 (n = 916) fêmeas com >580 a ≤ 630g/dia e G4 (n = 608) leitoas com >630 a ≤ 810g/dia. Não foram encontradas diferenças na idade de início de estimulação com o macho e manifestação do primeiro estro entre as classes (P> 0,05). Na cobertura todos os grupos diferiram entre si sendo o G4 o grupo mais precoce e com maior peso (P< 0,05). O GPD da seleção até a cobertura diferiu entre as classes, sendo que o G1 teve maiores ganhos de peso quando comparado ao G3 e G4 respectivamente (P< 0,05). As médias de nascidos totais, nascidos vivos e intervalo desmame-estro não diferiram entre os grupos (P> 0,05). As remoções entre a seleção e a cobertura pós-desmame foram maiores no G1 e G2 quando comparados ao G4 (P< 0,05). Quando agrupados G1 e G2 e, a partir disso, formadas duas classes de acordo com o peso na cobertura (≤ 130 kg e > 130 kg), o grupo > 130 kg obteve 0,93 leitão a mais no primeiro parto (P< 0,05). Em conclusão, leitoas selecionadas com baixos GPDs (inferiores a 630g/dia) podem ser incorporadas no plantel sem gerar prejuízos no desempenho reprodutivo até o primeiro parto, desde que alcancem 130 kg no momento da cobertura. / The aim of this study was to evaluate the reproductive performance of gilts selected with low average daily gain (ADG) at 160 days of age. Camborough® gilts (n = 3301) were allocated into four groups according to ADG at selection: G1 (n = 799) represented the group of gilts with ADG ≥480-≤ 530g/day, G2 (n = 978) corresponded to gilts with >530- ≤ 580g/day, G3 (n = 916) represented the gilts with > 580-≤ 630g/day and G4 (n = 608) gilts with > 630-≤ 810g/day. There were no differences in the age at the onset of boar exposure and first estrus expression among groups (P> 0.05). Age and weight at insemination were different (P< 0.05) among groups. Gilts from G4 were inseminated earlier and heavier. The ADG from selection until mating was different among the groups, and G1 had greater weight gains when compared to G3 and G4 (P< 0.05). Total number of piglets born, number of piglets born alive and weaning to oestrus interval were not different among classes (P> 0.05). The removals since the selection until post-weaning insemination were higher in G1 and G2 when compared to G4 (P< 0.05). When gilts from G1 and G2 were grouped and categorized into two classes according to the weight at insemination (≤ 130 kg and > 130 kg), the heavier group (> 130 kg) had an increasing of 0.93 total born piglets at first farrowing (P< 0.05). The results of this study suggest that gilts selected with low ADG (less than 630g/day) could be incorporated into the breeding herd with no reproductive performance losses until the first farrowing if they reach 130 kg at insemination.

O entendimento das relações entre as características do pasto e as respostas do comportamento ingestivo animal é fundamental para o aprimoramento de inovações no manejo de pastagens, tornando os sistemas pastoris mais eficientes e competitivos. Neste estudo comparamos dois métodos de pastoreio (Rotativo x Contínuo) e duas intensidades de pastejo (Moderada e Baixa) a fim de compreendermos como as características de pastos de azevém anual (Lolium multiflorum Lam.) influenciam o comportamento ingestivo e o ganho médio diário de ovinos. Observamos que o método de pastoreio afeta a quantidade de folhas e inflorescências, influenciando a composição química da forragem, além da taxa de bocados e o tempo de pastejo dos ovinos. Por outro lado, as intensidades de pastejo influenciaram os bocados por estação alimentar e o número de refeições. Além disso, variáveis como: estação alimentar por minuto, duração das refeições e tempo de pastejo foram positivamente correlacionadas com o ganho médio diário dos animais, assim, podem ser utilizadas como preditoras do ganho médio diário de ovinos. Encontramos evidências de que em pastoreio rotativo, ambas as intensidades de pastejo estudadas promoveram um rebaixamento em torno de 45% da altura pré-pastejo. A estrutura do pasto e a composição química da forragem foram adequadas para o pastejo de ovinos até o início do estádio reprodutivo do azevém anual. No entanto, ao final do estádio reprodutivo da pastagem, ambas as intensidades de pastejo restringiram os padrões de comportamento ingestivo dos ovinos nas maiores escalas espaço-temporais. Essa restrição é acentuada durante o rebaixamento do pasto, em decorrência da redução no percentual de lâminas foliares, alterando o comportamento ingestivo de ovinos. Logo, a resposta comportamental de ovinos depende de: (i) taxa de lotação, (ii) nível de desfolha do dossel, (iii) período do estádio reprodutivo do azevém anual e composição estrutural da forragem durante o rebaixamento. / The understanding of the relationships between sward characteristics and the animals' ingestive behavior responses is fundamental for the improvement of sward management innovations, making pastoral systems more efficient and competitive. In this study, we compared two stocking methods (Continuous and Rotational) and two grazing intensities (Moderate and Low) to understand how the sward characteristics of annual ryegrass (Lolium multiflorum Lam.) influence the ingestive behavior and the average daily gain of sheep. We observed that the stocking method affect the quantity of leaf blades and inflorescences influenced forage chemical composition, as well as the bite rate and grazing time of sheep. On the other hand, grazing intensities had influence the bites by feeding station and meals number. Moreover, variables as feeding station per minute, meals duration and grazing time were positively correlated with the average daily gain, thus, they can be used as predictors for the average daily gain of sheep. We found evidence that both grazing intensities studied promote a grazing down around 45% of pre-grazing sward height in rotational stocking. Sward structure and forage chemical composition, were adequate for sheep grazing until the beginning of the sward reproductive stage. However, from the stage 2 of grazing down at the end of the sward reproductive stage, both grazing intensities apparently restricted the sheep‟s ingestive behavior patterns in the larger spatial and temporal scales of grazing. Therefore sheep‟s behavioral response depends on: (i) stocking rate, (ii) canopy defoliation level, (iii) period of sward reproductive stage and forage structural composition during grazing down.

Objetivou-se avaliar diferentes maneiras de manejar o campo nativo durante o período hibernal para alimentar ovelhas no inicio de gestação e determinar a melhor metodologia para tal fim, por meio das características produtivas e comportamentais dos animais assim como modificação na estrutura e qualidade da pastagem. Para tal, foram testados, com delineamento em blocos casualizados com quatro tratamentos e três repetições, dois métodos de pastoreio (contínuo (LC) e rotativo (LR)) e dois níveis de oferta de forragem (12 e 18% OF). As variáveis utilizadas para descrever as características produtivas dos animais foram: ganho médio diário das ovelhas e cordeiros, escore de condição corporal das ovelhas e o ganho de peso, em unidade de área, das ovelhas, cordeiros e o ganho total por área. Além destes, foram avaliados parâmetros de comportamento ingestivo, que são o tempo diurno de pastejo, ruminação e outras atividades, número, tamanho e intervalo de refeições, número, tempo e número de passos entre estações alimentares e taxa de bocados. As variáveis medidas no pasto foram: massa de forragem, taxa de acumulo, altura, massa de folhas verdes, colmos, leguminosas e “outras espécies”, e as características bromatológicas (proteína bruta, FDN, etc.) do pasto ao longo do tempo de duração do experimento. Os resultados apontaram que as OF, apesar de provocar modificações significativas na massa de forragem e altura do pasto, teve pouca influencia nos parâmetros de comportamento animal em pastejo e pouca influencia no desempenho produtivo dos animais, provavelmente devido ao baixo contraste que as ofertas de forragem intermediárias proporcionaram durante o inverno. Os métodos de utilização da pastagem também não apresentaram influência marcante sobre o desempenho produtivo das ovelhas, mas modificou drasticamente o comportamento ingestivo dos animais. Os animais manejados em LR apresentaram menores tempos de pastejo do que os animais mantidos em LC, e esse tempo variou também entre os dias de avaliação. A interação dos dois fatores não teve influência no peso dos cordeiros ao nascer, porém, influenciaram as características estruturais e bromatológicas do pasto. Onde no manejo no inverno foi constituído pelo método contínuo e 12% de OF, a pastagem apresentou uma menor quantidade de outras espécies e presença predominante de espécies de melhor qualidade, ficando mais “limpa” e melhor qualidade nutricional na primavera. Essa melhor qualidade nutricional, por sua vez, apesar de não modificar significativamente os ganhos individuais de ovelhas e cordeiros, modificou a quantidade de peso vivo produzido em unidade de área. / The main objective was to evaluate strategies to manage the grassland during the winter season to feed ewes at the early pregnancy and determine the best method for this purpose, through the animal production characteristics, their ingestive behavior as well as modification of the structure and quality of the pasture. The experiment was set up in a randomized block design with four treatments and three replicates, two grazing methods (continuous (CS) and rotational (RS)) and two levels of herbage allowance (HA; 12 - and 18% LW). The variables used to describe the animals performance were: average daily gain of sheep and lambs, ewes body condition score and weight gain in unit area of the sheep, lambs and total gain per area. It was also assessed parameters of ingestive behavior as the diurnal grazing time, ruminating and other activities, number , size and range of meals, number, time and step number between feeding stations and biting rate. The variables measured in the pasture was: herbage mass, accumulation rate, height, mass of green leaves, stems, legumes and 'other species' and nutritive characteristics values (crude protein, NDF, etc.) of the pasture over all time of duration of the experiment. The results showed that the HA, although cause some significant changes in herbage mass and sward height, had little influence on animal behavior parameters and little influence on the productive performance of animals, probably due to the low contrast that intermediate herbage allowance provided. The grazing methods also had no significant influence on the performance of the sheep, but dramatically changed the ewes grazing behavior. The smaller area in the RS promoted a shorter grazing time than the time observed on a CS, and the grazing time on RS also varied during the days. The interaction of the two factors did not influence the weight of lambs at birth, however, influence the structural and chemical characteristics of the pasture. Where the management in winter was constituted by CS and 12% HA, the pasture had a lower amount of other species, being “cleaner” and, also presents a better nutritional quality in the subsequent spring. This improved nutritional quality, in turn, while not significantly modify the ewes and lambs individual gains, changed the amount of weight produced on unit of area, been more productive than other combinations.

O entendimento das relações entre as características do pasto e as respostas do comportamento ingestivo animal é fundamental para o aprimoramento de inovações no manejo de pastagens, tornando os sistemas pastoris mais eficientes e competitivos. Neste estudo comparamos dois métodos de pastoreio (Rotativo x Contínuo) e duas intensidades de pastejo (Moderada e Baixa) a fim de compreendermos como as características de pastos de azevém anual (Lolium multiflorum Lam.) influenciam o comportamento ingestivo e o ganho médio diário de ovinos. Observamos que o método de pastoreio afeta a quantidade de folhas e inflorescências, influenciando a composição química da forragem, além da taxa de bocados e o tempo de pastejo dos ovinos. Por outro lado, as intensidades de pastejo influenciaram os bocados por estação alimentar e o número de refeições. Além disso, variáveis como: estação alimentar por minuto, duração das refeições e tempo de pastejo foram positivamente correlacionadas com o ganho médio diário dos animais, assim, podem ser utilizadas como preditoras do ganho médio diário de ovinos. Encontramos evidências de que em pastoreio rotativo, ambas as intensidades de pastejo estudadas promoveram um rebaixamento em torno de 45% da altura pré-pastejo. A estrutura do pasto e a composição química da forragem foram adequadas para o pastejo de ovinos até o início do estádio reprodutivo do azevém anual. No entanto, ao final do estádio reprodutivo da pastagem, ambas as intensidades de pastejo restringiram os padrões de comportamento ingestivo dos ovinos nas maiores escalas espaço-temporais. Essa restrição é acentuada durante o rebaixamento do pasto, em decorrência da redução no percentual de lâminas foliares, alterando o comportamento ingestivo de ovinos. Logo, a resposta comportamental de ovinos depende de: (i) taxa de lotação, (ii) nível de desfolha do dossel, (iii) período do estádio reprodutivo do azevém anual e composição estrutural da forragem durante o rebaixamento. / The understanding of the relationships between sward characteristics and the animals' ingestive behavior responses is fundamental for the improvement of sward management innovations, making pastoral systems more efficient and competitive. In this study, we compared two stocking methods (Continuous and Rotational) and two grazing intensities (Moderate and Low) to understand how the sward characteristics of annual ryegrass (Lolium multiflorum Lam.) influence the ingestive behavior and the average daily gain of sheep. We observed that the stocking method affect the quantity of leaf blades and inflorescences influenced forage chemical composition, as well as the bite rate and grazing time of sheep. On the other hand, grazing intensities had influence the bites by feeding station and meals number. Moreover, variables as feeding station per minute, meals duration and grazing time were positively correlated with the average daily gain, thus, they can be used as predictors for the average daily gain of sheep. We found evidence that both grazing intensities studied promote a grazing down around 45% of pre-grazing sward height in rotational stocking. Sward structure and forage chemical composition, were adequate for sheep grazing until the beginning of the sward reproductive stage. However, from the stage 2 of grazing down at the end of the sward reproductive stage, both grazing intensities apparently restricted the sheep‟s ingestive behavior patterns in the larger spatial and temporal scales of grazing. Therefore sheep‟s behavioral response depends on: (i) stocking rate, (ii) canopy defoliation level, (iii) period of sward reproductive stage and forage structural composition during grazing down.

O objetivo do presente trabalho foi avaliar o desempenho reprodutivo de leitoas que foram selecionadas com baixos ganhos de peso diários (GPD) aos 160 dias de vida. Leitoas da linhagem Camborough® (n = 3301) foram alocadas em quatro grupos de acordo com o GPD no momento da seleção: G1 (n = 799) leitoas com GPD ≥480 a ≤ 530g/dia, G2 (n = 978) leitoas com >530 a ≤ 580g/dia, G3 (n = 916) fêmeas com >580 a ≤ 630g/dia e G4 (n = 608) leitoas com >630 a ≤ 810g/dia. Não foram encontradas diferenças na idade de início de estimulação com o macho e manifestação do primeiro estro entre as classes (P> 0,05). Na cobertura todos os grupos diferiram entre si sendo o G4 o grupo mais precoce e com maior peso (P< 0,05). O GPD da seleção até a cobertura diferiu entre as classes, sendo que o G1 teve maiores ganhos de peso quando comparado ao G3 e G4 respectivamente (P< 0,05). As médias de nascidos totais, nascidos vivos e intervalo desmame-estro não diferiram entre os grupos (P> 0,05). As remoções entre a seleção e a cobertura pós-desmame foram maiores no G1 e G2 quando comparados ao G4 (P< 0,05). Quando agrupados G1 e G2 e, a partir disso, formadas duas classes de acordo com o peso na cobertura (≤ 130 kg e > 130 kg), o grupo > 130 kg obteve 0,93 leitão a mais no primeiro parto (P< 0,05). Em conclusão, leitoas selecionadas com baixos GPDs (inferiores a 630g/dia) podem ser incorporadas no plantel sem gerar prejuízos no desempenho reprodutivo até o primeiro parto, desde que alcancem 130 kg no momento da cobertura. / The aim of this study was to evaluate the reproductive performance of gilts selected with low average daily gain (ADG) at 160 days of age. Camborough® gilts (n = 3301) were allocated into four groups according to ADG at selection: G1 (n = 799) represented the group of gilts with ADG ≥480-≤ 530g/day, G2 (n = 978) corresponded to gilts with >530- ≤ 580g/day, G3 (n = 916) represented the gilts with > 580-≤ 630g/day and G4 (n = 608) gilts with > 630-≤ 810g/day. There were no differences in the age at the onset of boar exposure and first estrus expression among groups (P> 0.05). Age and weight at insemination were different (P< 0.05) among groups. Gilts from G4 were inseminated earlier and heavier. The ADG from selection until mating was different among the groups, and G1 had greater weight gains when compared to G3 and G4 (P< 0.05). Total number of piglets born, number of piglets born alive and weaning to oestrus interval were not different among classes (P> 0.05). The removals since the selection until post-weaning insemination were higher in G1 and G2 when compared to G4 (P< 0.05). When gilts from G1 and G2 were grouped and categorized into two classes according to the weight at insemination (≤ 130 kg and > 130 kg), the heavier group (> 130 kg) had an increasing of 0.93 total born piglets at first farrowing (P< 0.05). The results of this study suggest that gilts selected with low ADG (less than 630g/day) could be incorporated into the breeding herd with no reproductive performance losses until the first farrowing if they reach 130 kg at insemination.

The aim of this diploma work was to analyse the results of the Aberdeen Angus meet oxherd breeding in an ecological farming with the welfare relationship to the animals and at the same time to compare the efficiency after the system change of the farming at the farm Angus, Rančice, owned by Šebelka. The research was done in the period of years 2006 ? 2011. The survey range includes 65 heads of thorough-bred cows as well as 204 heads of Aberdeen Angus calves born in the tracked period. The number of births, the birth process, and the age before lay out and related reasons were recorded by the cows. By the calves we noted the live mass and average daily gain in the growth process. The range of the calves was then sorted our by year of the birth, gender, rank of the birth, by genitors and by the way of farming. The data entries were elaborated in the MICROSOFT EXCEL and evaluated in STATISTICA 7 CZ. The number of spontaneous birth without cowman assist equals 94,12%, only 4,41% of births required the necessary support. By the monitored number of calves no matter of the gender was noted the lowest and the highest live mass by the birth in the year 2007 (36,81 kg resp. 38,77 kg). The group of calves born in 2010 reached the highest average weight in 120 days as well as in 210 days (192,27 kg resp. 309,04 kg). The lowest average weight in 120 days was noticed in year 2009 (168,96 kg), in 210 day in 2008 (262,31 kg). The best growth ability from the birth to 120 days was by the group of calves born in 2010 (1,409 kg) compared to the lowest result in 2009 (1,099 kg). The average daily gain from 120 till 210 days reached its minimum in 2009 (1,171 kg), the maximum numbers were noted in 2010 (1,412 kg). The growth intensity from the birth till 210 days circulated in the range of 1,071 kg (2008) and 1,377 kg (2010). In the ecological agriculture system were noted statistical better efficiency results (live mass, growth intensity) compared to conventional agriculture system.

The purpose of this thesis was to evaluate the level of performance of Aberdeen Angus beef cattle breed bred in Less-favoured areas in southern Bohemia. This evaluation was carried out on Mr. Lepša?s farm in the years 2010 and 2011. 74 basic herd cows and 108 purebred calves born during this period were selected for this purpose. The date of birth, number of births, age at first calving and the average time interval between calving were checked on cows and the date of birth, the weight at birth and the weight in the age of 120 and 210 days were checked on calves. Average daily increments in the interval from birth to 120 days of age, from 120 to 210 days of age and from the day of birth to 210 days were calculated. The group of calves was sorted out by following parameters. Year of birth; sex and year of birth; month of birth; order of calving of the mother. Microsoft Excel was used for processing the statistic data. Basic statistical characteristics for the monitored parameters were calculated and differences between groups were verified by single-factor analysis of variance (F-test) and paired t-tests for the corresponding levels of significance. Breeding cows were evaluated by age and number of births. Cows with 1 (23%) or 2 (17.6%) births are represented in the largest number in the herd including even the cows with 15 births. Cows at first calving reached an average age of 813 days and average length of the interval between calving was 393 days. Calves regardless of sex reached the average birth weight of 33.72 kg in the year 2010, 33.31 kg in 2011, in 120 days of age the average live weight reached 207.95 kg in 2010, 202.94 kg in 2011 and calves in 210 days of age reached an average weight of 309.61 kg in 2010 and in 2011 306.09 kg. Average daily gain of calves from birth to 120 days reached 1451 g in 2010, 1.413 g in 2011, between 120 and 210 days of age the average daily gain was 1413 g in 2010, 1169 in 2011 and in the period from birth to 210 days of age it was 1314 g in 2010 and 1299 g in 2011. Analysis of breeding from economic perspective by comparing revenues (including subventions) and expenditures in each year resulted in findings that the breeding is moderately profitable and it follows that without subventions which constitute an important part of the revenue would be difficult to realize this breeding.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The experiment was conducted in the Sheep Division of the Universidade Federal de Santa Maria (UFSM) to determine nutrient intake, and yield and composition of milk from ewes, as well as its relationship with performance and carcass characteristics of either single or twin lambs. Sixteen multiparous ewes from an alternate crossing between Texel and Ile de France breeds were used. Eight ewes supported single lambs, and the others supported twin lambs. Animals (ewe + lambs) were allocated in individual stalls immediately after parturition, and the milk production was then estimated weekly. Protein, fat, lactose, total solids, and milk density were determined in the milk samples. At 56 days of age all animals were weaned and 16 lambs (8 single and 8 twin lambs) were randomly selected and maintained in individual stalls until reaching a pre established slaughter weight, which was approximately 28 kg of body weight. Qualitative and quantitative measures were then done on the carcasses and on every other body component. There was no effect (P<0.05) of the number of suckling lambs on nutrient intake, milk yield and composition of the ewe s milk. However, nutrient intake linearly increased (P<0.05) as a function of the time in the experiment. Single lambs presented higher body weights at both birth and weaning (P<0.05), as well as they had greater average daily gain from the birth to the weaning (P<0.05). The better performance of these animals, however, was not maintained after the weaning. Twin lambs presented greater nutrient intake when it was calculated as a percentage of the BW and in g/kg BW0.75, resulting in a highest proportion (P<0.05) of rumen in relation to the body weight of the animals. On the other hand, single lambs had more elevated values of carcass dressing percentage (P<0.05). Results showed that due the similarity between milk yields of ewes supporting either single or twin lambs, before the weaning single lambs present a potential of growth higher than that of twin lambs, once the individual milk intake is also more elevated for these animals. Thus, the slaughter weight is reached early and the carcasses have better quality. / O experimento foi conduzido no Laboratório de Ovinocultura da Universidade Federal de Santa Maria (UFSM) com o objetivo de determinar o consumo de nutrientes, a produção e composição do leite de ovelhas e sua relação com o desempenho e características da carcaça de cordeiros oriundos de parto simples ou duplo. Foram utilizadas 16 ovelhas multíparas provenientes do cruzamento alternado entre as raças Texel e Ile de France, sendo oito paridas de cordeiros gêmeos e oito de cordeiros simples. Os animais (ovelha + cordeiro(s) foram alojados em baias individuais imediatamente após o parto, procedendo-se a estimativa da produção de leite semanalmente. Foram determinados os teores de proteína, gordura, lactose e sólidos totais e a densidade do leite. Aos 56 dias os animais foram desmamados e 16 cordeiros foram mantidos em confinamento, em baias individuais, sendo oito nascidos de parto simples e oito de parto gemelar. Os cordeiros permaneceram confinados até atingirem o peso de abate pré-estabelecido de aproximadamente 28 kg de peso corporal. Foram feitas, então, mensurações qualitativas e quantitativas da carcaça e dos componentes do peso corporal. Não foi observado efeito (P>0,05) do tipo de parto sobre o consumo de nutrientes, a produção e a composição do leite das ovelhas. O consumo de nutrientes, contudo, aumentou linearmente (P<0,05) em função do tempo em que as ovelhas permaneceram no confinamento. Cordeiros nascidos de parto simples apresentaram peso superior ao nascimento e ao desmame (P<0,05), bem como maior ganho de peso médio diário no período pré desmame (P<0,05). O melhor desempenho destes animais, entretanto, não foi sustentado no período pós desmame. Cordeiros nascidos de parto gemelar apresentaram maior consumo de nutrientes (P<0,05) quando expressos em % do PV e em g/kg PV0,75, o que resultou em maior proporção (P<0,05) de rúmen em relação ao peso corporal destes animais. Por outro lado, cordeiros oriundos de parto simples apresentaram superioridade nos rendimentos da carcaça (P<0,05). Os resultados demonstraram que, devido à similaridade na produção de leite de ovelhas amamentando um ou dois cordeiros, cordeiros oriundos de parto simples apresentam potencial de crescimento superior aos nascidos de parto gemelar no período pré-desmame, em função de um maior consumo individual de leite, vindo a atingir o peso de abate mais precocemente e com carcaças de melhor qualidade.