Master of Science

Twenty-five multiparous cows in their second trimester of lactation were randomly assigned in a 5 x 5 latin square rotation to five silages: control (N), chopped added (CA), ground added (GA), chopped ensiled (CE), and ground ensiled (GE). Chopped (2-6 cm) or ground (< .5 cm) hay was added to corn green chop at 12.5% of the total forage dry matter before ensiling (CE and GE). Chopped or ground hay was also added to the control silage at the same rate prior to feeding (CA and GA). Silages were supplemented to contain 14% crude protein and 1.67 Mcal/kg on a dry matter basis and fed as a total mixed ration. Hay-containing rations averaged 22% ADF, compared to 20% ADF in the control ration. Each cow received the assigned ration for three weeks and milk samples were collected on days 19 and 20 of each feeding period. Means ± S.E. for N, CA, GA, CE and GE were: percent milk fat 3.07 ± .08, 3.31 ± .09, 3.37 ± .08, 3.28 ± .08; percent total solids 11.7 ± .11, 11.8 ± .12, 11.9 ± .12, 12.02 ± .13, 11.94 ± .12; and dry matter intake per kg metabolic body weight .170 ± .003, .161 ± .003, .163 ± .004, .158 ± .004, .166 ± .004, respectively. Percent milk fat was significantly higher in rations CE, CA, and GE when compared to N. Milk production and percent milk protein did not differ. The results indicate increased milk fat production when chopped hay (added or ensiled) or ground hay (ensiled) is included in corn silage based rations for dairy cattle. Whether chopped or ground, hay added at time of ensiling tended to stimulate milk fat production more than hay added just prior to feeding. The beneficial effect of increased hay fiber length on milk fat production was evident whether hay was ensiled with or added to corn silage. / M.S.

Two feeding trials were conducted to study the effects of source of concentrate and level of concentrate and roughage on milk composition; changes in certain blood and rumen constituents; and efficiency of conversion of feed protein to milk protein. Trial A (63 days) employed two groups of six cows each. The following rations were fed: 1) Control consisting of 1 lb. concentrate per 3.5 lb. milk, 40 lb. corn silage. and orchardgrass hay, ad libitum; 2) Low-roughage composed of 5 lb. orchardgrass hay, 10 lb. corn silage, and concentrates ad libitum. Trial B (70 days) employed two groups (four each) of late and three of early lactation. A control ration similar to that fed in trial A, except 48 instead of 40 lb. of corn silage, and a low-roughage ration of only 2 lb. hay and concentrates ad libitum, were fed to two groups in each stage of lactation. The remaining early lactation group received a ration comparable to the control except the corn in the concentrate was replaced by lactose. The twelve early lactation cows were subjected to a balance study at the end of the feeding trial. Intake of concentrates and milk yields on the low-roughage rations were higher in trial A than trial B. Percent milk fat and the acetate/propionate ratio of rumen fluid were decreased by low-roughage; while rumen propionate was increased. No significant differences in milk protein were observed. Milk SNF and lactose-mineral were increased on low-roughage in trial B. Feeding only 2 lb. hay daily resulted in bloat and diarrhea; while blood glucose and gamma globulin were increased. Lactose increased rumen butyrate and tended to increase milk fat percentages above the controls. Digestibilities of all dry matter components, except crude fiber, were higher on low-roughage. Cows on low-roughage digested a larger proportion of the dietary protein, but were loss efficient in the conversion of digested protein to milk protein. / M.S.

Twenty-four cows in a production trial and 8 cows fitted with ruminal and duodenal cannulas were used in 4 x 4 Latin squares to investigate the effects of dietary protein degradability and supplemental fat on rumen, blood, and milk components. Diet dry matter contained 16% CP with two levels of rumen undegradable protein (RUP) obtained by substituting blood meal for soybean meal. Treatments were 29% RUP, 0% added fat; 29% RUP, 2.7% added fat (Calcium soaps of fatty acids); 41% RUP, 0% added fat; and 41% RUP, 2.7% added fat. Dry matter intake was depressed 6.2% by added fat. Plasma urea N (PUN) increased with added fat and 41% RUP, however greater changes were observed due to time of feeding. Milk production increased 7.1% in both breeds and 4% fat corrected milk increased by 8.4% in Jerseys fed added fat. Milk protein yield decreased in Holsteins fed 41% RUP. Milk protein content was reduced 7.1% by added fat and 3.9% by 41% RUP, and milk urea N (g/100g N) was increased by added fat and 41% RUP. Milk urea N followed PUN pattern throughout the day. Added fat reduced content, but not yield, of milk components. Blood meal substitution decreased content and yield of milk protein and casein N. / Master of Science

Thesis (MScAgric (Animal Sciences)--University of Stellenbosch, 2007. / The objective of this investigation was to determine the effect of supplemented conjugated linoleic acid (CLA) on milk production and milk composition of lactating dairy cows in production systems commonly used in South Africa. In the first of three trials, samples of 24 bulk tanks were collected to get an impression of the CLA status of milk in the Western Cape Province, South Africa. Six samples were each collected from Jersey and Holstein herds in total mixed ration (TMR)-based systems. Another six samples were each collected from Jersey and Holstein herds on pasture-based systems. An additional three samples were also collected from co-op silos. One of these came from a mixed herd on TMR, one from a Jersey herd on TMR and the third sample from a mixed herd on pasture. The CLA levels of the milk were within the range reported in literature, albeit on the low side. The mean CLA level in milk fat of cows from pasture and TMR-based systems were 10.5 and 5.45 mg/g of fatty acids, respectively. This is in agreement with trends reported in the literature with cows on pasture having higher levels of CLA in their milk than cows on TMR’s. In this study, breed had no effect on the CLA level in milk fat.

Au cours de leur lactation, les vaches laitières font face à d’importants besoins en calcium du fait de la production laitière. L'augmentation très rapide de ces besoins en début de lactation fait que l’organisme des vaches peut difficilement s’adapter par une hausse de l’ingestion et de l’absorption digestive de calcium. L’organisme doit puiser dans les réserves osseuses, qui seront reconstituées plus tard en fin de lactation. Ces cycles de mobilisation et reconstitution osseuses restent cependant impossibles à quantifier chez la vache laitière sur de larges effectifs et les conséquences d’une mauvaise reconstitution osseuse sur les lactations suivantes restent inconnues. Cette thèse avait pour objectif de développer un indicateur des phénomènes de mobilisation et reconstitution osseuse au cours de la lactation.Plusieurs facteurs de mobilisation osseuse ont pu être identifiés, comme la race, la parité ou l’alimentation. Cependant, les cycles de mobilisation et de reconstitution osseuse n’ont pas pu être reliés à des variations de la composition du lait en Ca et P. Il a cependant pu être montré, que contrairement à ce qui est décrit dans la littérature, un apport insuffisant en Ca en début de lactation n’est pas toujours accompagné d’une augmentation de la mobilisation osseuse, mais peut être compensé par une augmentation des capacités d’absorption digestive. Cette thèse montre aussi la nécessité de quantifier les conséquences d’un apport insuffisant de calcium alimentaire sur les performances de production et la santé des vaches laitières sur l’ensemble de la lactation. / During lactations, dairy cows faces huge calcium requirements due to milk production. Because of the fast increase in those requirements at the beginning of the lactation, the organism of dairy cows can hardly adapt by increasing intake and digestive calcium absorption. The organism must mobilize calcium from its storage pool, bones, which will replenish later in lactation. Those cycles of bone mobilization and reconstitution remain impossible to quantify for important number of dairy cows and the consequences of an incomplete bone reconstitution on following lactation remain unknown. The aim of this PhD was to develop an indicator of the phenomenon of bone mobilization and reconstitution during lactation.Several factors increasing bone mobilization have been identified, such as breed, parity or diet. However, the cycles of bone mobilization and reconstitution could not be related to variation in milk Ca and P content. However, it has been showed that, an insufficient Ca supply in early lactation does not always induce a higher bone mobilization, as it has been described in the literature, but can be compensated by an increase in digestive absorption capacity. The thesis also showed the need to quantify the consequences on insufficient dietary calcium supply on dairy cows’ milk production and health throughout lactation.

Com o objetivo de estudar os efeitos do uso da Somatotropina Recombinante Bovina (rBST) no lipidograma e constituição do leite de bubalinos foram utilizadas 28 búfalas divididas em dois grupos: Grupo 1 constituído de 14 búfalas nas quais foi realizada uma aplicação de 500 mg de rBST e Grupo 2 - constituído de 14 búfalas que não receberam qualquer tratamento hormonal (grupo controle). Durante o experimento, os animais tiveram amostras de plasma e soro sanguíneo, bem como de leite colhidas periodicamente nos seguintes momentos: dia da aplicação da rBST, 1º, 3º, 5º, 7º, 10º e 14º dia após a aplicação da rBST. A fim de minimizar possíveis influências da fase da lactação, todas as búfalas utilizadas no experimento estarvam entre 100 e 200 dias de lactação e com produção de leite variando entre 5 e 10 litros por dia. O lipidograma foi avaliado por meio da determinação dos teores séricos de colesterol, triglicérides, ácidos graxos não esterificados e &beta;-HBO e teores plasmáticos de glicose, enquanto a constituição do leite de búfalas foi avaliada por meio de determinação dos teores lácteos de gordura, proteína, lactose, sólidos totais e do número de células somáticas. Durante a avaliação dos resultados obtidos podemos notar que a aplicação da somatotropina recombinante bovina não influenciou os teores séricos de NEFA, colesterol e triglicérides bem como os plasmáticos de glicose. No entanto os teores séricos de &beta;-HBO foram afetados pelo tratamento instituído, pois verificou-se que, a partir do 1º dia após o início do tratamento hormonal, os teores séricos de -HBO no grupo tratado com rBST eram entre 0,21 e 0,55 mg/dL maiores do que os encontrados no grupo controle. Quando avaliamos a composição do leite temos que os resultados nos permitem afirmar que o tratamento instituído não interfere nas concentrações de gordura, lactose, sólidos totais e no número de células somáticas. Nos primeiros dias após a aplicação da rBST ocorria uma diminuição dos teores lácteos de proteína, sendo verificado que no 3º dia após o início do tratamento hormonal os valores lácteos de proteína encontrados no grupo tratado com rBST (3,59 &plusmn; 0,22 g/dL) eram significativamente menores do que os observados no grupo controle (3,89 &plusmn; 0,22 g/dL). A partir do 5º dia após o início do tratamento hormonal, os valores de proteína passam a oscilar sem que qualquer diferença estatística entre o grupo tratado e controle possam ser observados. / With the aim to evaluate the influence of recombinant bovine somatotropin (rBST) in the lipid profile and milk composition of lactating Murrah water buffaloes, we collected and analyzed samples of blood serum and plasma and milk of clinically healthy animals. We determined the concentrations of cholesterol, triglycerides, nonesterified fatty acids (NEFA), -hydroxibutyrate (-HBO) and glucose from the blood samples. Milk samples were collected after milking and the following parameters were evaluated: fat, protein, lactose, total solids and somatic cell count. The influence of rBST was studied through 28 animals divided in 2 experimental groups: Experimental Group 14 animals that received a single application of 500mg rBST; Control Group - 14 animals that didn´t receive any hormonal treatment. Blood and milk samples were collected in the following moments: day of rBST application, 1st, 3rd, 5th, 7th, 10th and 14th day after the rBST application. To minimize the influence of lactation, the samples were collected between 100-200 days of lactation and the milk yields per cow range from 5 10 Liters. According to the results of this research, we concluded that one single application of rBST didn´t affect the NEFA, cholesterol, triglycerides and glucose blood levels. The serum &beta;-HBO concentration was influenced by the hormonal treatment. In the experimental group, after 24 hours from the treatment, the &beta;-HBO level ranged 0.21 - 0.55 mg/dL and it was greater than that of control group. The fat, lactose, total solids and somatic cell count were not influenced by the rBST treatment. In the first days after the application of rBST, the milk protein decreased gradually reaching its low level in the 3rd day after the application (3.59 ± 0.22 g/dL) and was significant lower than that of control group (3.89 ± 0.22 g/dL). After the 5th day, the milk protein values oscillated without any statistical difference between both groups.

Orientador: Heraldo César Gonçalves / Banca: Edson Ramos de Siqueira / Banca: Mário de Beni Arrigoni / Banca: Claudete Regina Alcalde / Banca: Mauro Sartoi Bueno / Resumo: Foram utilizadas 50 cabras (30 da raça Alpina e 20 ½ Boer + ½ Alpina), primíparas e multíparas, com peso corporal médio de 52,7±1,07 kg, avaliadas em média até 203,9±8,04 dias de lactação. Foram testados dois sistemas de produção em pasto: SP1 -suplementação concentrada e SP2 - suplementação mineral. Os animais foram mantidos em pastagem estabelecida com Panicum maximum cv. Tanzânia. O controle leiteiro foi realizado a cada 14 dias, por meio da pesagem do leite e, em determinados os teores de gordura, proteína, lactose, sólidos totais (ST), extrato seco desengordurado (ESD), nitrogênio uréico e contagem de células somáticas (CCS). Calculou-se as variáveis: tempo para atingir o pico, produção no pico (PP), produção de leite no tempo t e persistência (PS), além dos custos de alimentação em função do sistema de produção. O grupo racial e o sistema de produção em pasto influenciaram a curva de lactação. A suplementação concentrada de cabras da raça Alpina resultou em maior tempo para atingir o pico de lactação, maiores PP e PS. O teor médio de ST, proteína e ESD do leite foram influenciados pelo grupo racial, sendo que as cabras ½ BA apresentaram valores superiores em relação às cabras da raça Alpina. Os teores de lactose e ESD foram maiores no leite proveniente do SP1 em relação ao SP2. O log da CCS foi influenciado pelo sistema de produção em pasto e as cabras do SP1 apresentaram menor CCS. Observou-se influência significativa da interação entre grupo racial e sistema de produção em pasto para as porcentagens de gordura e nitrogênio uréico. No sistema de produção em pasto, cabras da raça Alpina devem ser suplementadas com ração concentrada. A suplementação com ração concentrada apresentou uma maior renda líquida total por cabra, proporcionando maior lucro ao produtor. / Abstract: Fifty goats were used (30 Alpine and 20 ½ Boer + ½ Alpine), primiparous and multiparous, with average body weight of 52.7 ± 1.07 kg, evaluated averaging to 203.9 ± 8.04 days of lactation. Were tested two pasture on systems: SP - concentrate supplementation and SP - mineral supplementation. Animals were kept in pasture established with Panicum maximum cv. Tanzania. Milk control was performed every 14 days, by weighing milk and were determined levels of fat, protein, lactose, total solids (TS), solids non fat (SNF), milk urea nitrogen and somatic cell count (SCC) in milk samples. It was calculated some variables: time to reach peak, production at peak (PP), milk production on t time and persistence (PS), in addition, cost of food according to the production system. Breed group and pasture production system influenced the lactation curve. Concentrate supplementation of Alpine goats resulted in longer time to reach peak of lactation, higher PP and PS. Average content of TS, SNF and protein were influenced by breed group, and ½ BA goats showed higher values in relation to Alpine goats. Content of lactose and SNF observed was greater in milk of animals from PS1 compared to PS2. Log of SCC was influenced by pasture production system and goats from SP1 had lower values. It was observed influence of interaction between breed group and pasture production system for percentages of fat and milk urea nitrogen. Alpine goats, on pasture production system should be supplemented with concentrate. Concentrate supplementation showed a higher total net income per goat, and consequently, a higher profit to producer. / Doutor

Orientador: Heraldo Cesar Gonçalves / Banca: Paulo Roberto de Lima Meirelles / Banca: Claudete Regina Alcalde / Banca: Reinaldo de Paula Ferreira / Banca: Marco Aurélio Factori / Resumo: Foram utilizadas cabras da raça Saanen, não gestantes e não lactantes, canuladas no rúmen, mantidas em confinamento. Foi avaliada a substituição do milho e do farelo de soja, pela raspa de mandioca e pela alfafa, respectivamente. O experimento foi conduzido no delineamento em quadrado latino, com as dietas: MISO: milho triturado e farelo de soja; MASO: raspa de mandioca e farelo de soja; MIAL: milho triturado e alfafa; MAAL: raspa de mandioca e alfafa. Foram avaliados: consumo, parâmetros ruminais (pH e amônia), produção de ácidos graxos de cadeia curta (AGCC) e cinética da degradação das dietas, em cabras adultas em mantença. A inclusão da raspa de mandioca e da alfafa não influenciou o consumo de massa seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN) e nutrientes digestíveis totais (NDT), o peso corporal das cabras, nem a produção de amônia. O pH ruminal e as produções de AGCC foram influenciados pelos tempos de colheita, sendo que as produções de ácido acético, butírico e AGCC totais apresentaram efeito cúbico, com máxima produção ocorrendo, aproximadamente, às 4 horas e mínima às 10 horas, após o fornecimento da dieta. O pH, a produção de ácido propiônico e a proporção acetato:propionato apresentaram efeito quadrático, com menor valor, aproximadamente, às 8 horas, maior produção às 7 horas e a maior proporção às 9 horas, após o arraçoamento, respectivamente. A produção de ácido acético e AGCC totais foram influenciadas pelas dietas, sendo que a com inclusão de mandioca e alfafa apresentaram os maiores valores. A degradabilidade da MS, PB e FDN foram influenciadas pelas dietas, sendo que as com mandioca e mandioca + alfafa apresentaram as maiores degradabilidades efetivas, dessa forma, demonstrou-se que a mandioca e a alfafa podem substituir o milho e o farelo de soja dos concentrados, sem alterar o consumo de MS e ... / Abstract: Were used four Saanen goats, non-pregnant and non-lactating, rumen cannulated, kept in feedlot. It was evaluated the replacement of corn and soybean meal by cassava meal and alfalfa, respectively. The experiment was conducted in Latin square design, with diets: MISO: ground corn and soybean meal; MASO: cassava and soybean meal; MIAL: ground corn and alfalfa grazing; MAAL: cassava and alfalfa grazing. Intake, ruminal parameters (pH and ammonia), production of short chain fatty acids (SCFAs) and degradation kinetics of roughage and concentrate were evaluated in adult goats in maintenance. The inclusion of cassava meal and alfalfa didn't affect the intake of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and total digestible nutrients (TDN), neither the body weight of goats and the ammonia nitrogen production. The ruminal pH and the production of short chain fatty acids were influenced by the harvest time, and the total SCFA, acetic and butyric acids production showed cubic effect, with maximum production occurring about 4 hours, and minimum 10 hours after the supply of diet. The pH, the production of propionic acid and acetate: propionate ratio showed a quadratic effect, the lower values about 8 hours, the highest production to 7 hours, and the highest ratio of 9 hours after feeding, respectively. The acetic acid production and total SCFA were influenced by the diets, but the diets that contained cassava and alfalfa showed the highest values. The degradability of DM, CP and NDF were affected by the diets, the diets with cassava and cassava + alfalfa had the highest effective degradability. Thus, showing that the cassava and alfalfa can replace the corn and soybean meal concentrates, without changing the dry matter intake and the rumen environment of goats, improving the production of acetic acid and the degradability of the diet. / Doutor

Orientador: Mauro Dal Secco de Oliveira / Banca: Flávia Fernanda Simili / Banca: Luiz Carlos Roma Júnior / Banca: Atushi Sugohara / Banca: Paulo de Figueiredo Vieira / Resumo: Este trabalho teve como objetivo estudar as diferentes proporções de cana-de-açúcar hidrolisada e silagem de milho na alimentação de vacas leiteiras através da composição bromatológica, consumo de nutrientes, digestibilidade in vitro, parâmetros sanguíneos, produção de leite, composição do leite e avaliação econômica parcial das dietas. Foram utilizadas oito vacas da raça Holandesa, distribuídas em dois quadrados latinos 4 x 4, com quatro períodos de 19 dias cada, sendo 14 dias de adaptação e cinco dias de coleta. As vacas foram alimentadas com dietas contendo 100% de cana-de-açúcar hidrolisada (CH); 70% de CH + 30% de silagem de milho (SM); 50% CH + 50% SM; e 100% SM. O concentrado foi fornecido na proporção de 1 kg para cada 2,5 kg de leite produzido. A cana-de-açúcar utilizada foi a IAC 862480 com 12 meses de crescimento, picada no tamanho de partícula de 8 mm, hidrolisada com 0,5% de cal hidratada (95% de hidróxido de cálcio) + 2,0 litros de água + 100kg de cana-de-açúcar picada, com base na matéria natural. As dietas com cana-de-açúcar hidrolisada como único volumoso e as dietas com 70% CH + 30% SM causaram menor consumo de matéria seca, proteína bruta e de nutrientes digestíveis. A menor digestibilidade in vitro da fibra em detergente neutro foi de 34,92% para a dieta com 100% cana-de-açúcar hidrolisada. As produções de leite e as produções de leite para 3,5% de gordura (PL3,5%G) diminuíram linearmente (P<0,05) com associação das proporções de cana-de-açúcar hidrolisada à silagem de milho nas dietas. A composição do leite, os níveis de glicose, proteína total, colesterol total e gama-glutamiltransferase não foram influenciados pelas diferentes proporções de cana-de-açúcar hidrolisada nas dietas (P>0,05). As dietas com cana-de-açúcar hidrolisada apresentaram melhor custo/beneficio. Embora todas as proporções possam ser utilizadas, recomenda-se a associação de ... / Abstract: This study aimed to evaluate chemical composition, nutrient intake, in vitro digestibility, blood parameters, milk production, milk composition and partial economic evaluation of dairy cows fed diets with different proportions of sugarcane hydrolyzed with hydrated lime and corn silage. Eight Holstein cows, designed into two 4 x 4 Latin Squares with four periods of 19 days each, 14 days of adaptation and five days of data collection. The cows were fed with diets containing 100% hydrolyzed sugarcane (HS); 70% HS + 30% corn silage (CS); 50% HS + 50% CS; and 100% CS. The concentrate was supplied at the rate of 1 kg for every 2.5 kg of milk. The sugarcane used was IAC 862480 with 12 months of growth, particle size of 8 mm, hydrolyzed with 0.5% hydrated lime (≥ 95% calcium hydroxide) + 2,0 liters water + 100 kg chopped sugarcane, based on natural matter. Diets with hydrolyzed sugarcane as the only forage and diets with 70% HS + 30% CS decreased dry matter, crude protein and digestible nutrients intake. The lower in vitro neutral detergent fiber digestibility was 34.92% for the diet with 100% hydrolyzed sugarcane. Milk yield and 3.5% fat-corrected milk yield decreased linearly (P<0.05) as corn silage was being replaced hydrolyzed sugarcane in diets. The milk composition, the levels of glucose, total protein, total cholesterol and gamma-glutamyltransferase were not influenced by different proportions of hydrolyzed sugarcane in the diets (P>0.05). Diets with hydrolyzed sugarcane showed better cost-benefit. Although all proportios can be used, it's recommended the combination of 50% of the corn silage and hydrolyzed sugarcane due to reach results closer to corn silage and reduce the cost of the kilogram of milk / Doutor