Foram conduzidos 2 estudos com vacas leiteiras no Departamento de Zootecnia da ESALQ/USP com os objetivos de avaliar a utilização de fonte de uréia de liberação lenta (Optigen ®) e ID (intervalos de desfolhas) fixos ou variáveis em pastagens de capim Elefante. No Experimento 1, foram utilizadas 32 vacas no terço médio de lactação, produzindo 20,8 kg leite dia-1 e pesando 524 kg no início do período experimental. O tratamento controle (C) continha apenas farelo de algodão como suplemento protéico. No tratamento U30, 30 % da PB do farelo de algodão foi substituída por uréia. No tratamento O30, 30% da PB do farelo de algodão foi substituída pela uréia de liberação lenta e no tratamento O60, 60% da PB do farelo de algodão foi substituída pela uréia de liberação lenta. O delineamento experimental adotado foi o quadrado latino 4 x 4 com 8 repetições e as variáveis foram analisadas utilizando o PROC MIXED (SAS). A produção de leite não diferiu (P>0,05) entre os tratamentos C (20,2 kg dia-1), O30 (19,8 kg dia-1) e U30 (19,5 kg dia-1). No tratamento O60 a produção de leite foi reduzida (19,0 kg dia-1) em comparação aos tratamentos C e O30 (P<0,05) e U30 (P<0,06). Não houve diferenças (P>0,05) nos teores de gordura, proteína, lactose, sólidos totais e contagem de células somáticas entre os tratamentos. A concentração de uréia no leite (NUL) foi menor (P<0,05) no tratamento U30 (7,2 mg dL-1) em relação aos tratamentos O30 (9,3 mg dL-1), C (9,1 mg dL-1) e O60 (8,9 mg dL- 1). No Experimento 2 foram utilizadas 32 vacas no terço médio de lactação, produzindo 15 kg de leite dia-1, pesando 466 kg. A área experimental foi composta por 56 piquetes de Pennisetum purpureum cv. Cameroon, com 0,1 ha cada um. Os tratamentos corresponderam a duas estratégias de ID dos pastos de capim Elefante (ID fixos de 27 dias ou ID variáveis determinados pela altura do dossel de 1,0 m) e dois concentrados isoprotéicos com diferentes fontes de N (farelo de algodão e uréia de liberação lenta). Foi adotado o delineamento experimental em blocos aleatorizados e as variáveis foram analisadas utilizando o PROC MIXED (SAS). Não houve efeito (P>0,05) de fonte de N sobre os parâmetros avaliados. Houve diferença estatística (P<0,05) entre os tratamentos com ID fixos de 27 dias e os com ID variáveis para as alturas das pastagens no pré-pastejo (1,20 X 1,03 metros), no pós-pastejo (0,47 e 0,41 metros), nas massas de forragem pré-pastejo (6642 e 6209 kg MS ha-1), pós-pastejo (3666 e 3277 kg MS ha-1) e nas densidades volumétricas (55,04 e 60,06 kg MS ha-1 cm-1) para os tratamentos com ID fixos ou variáveis respectivamente. A produção de leite foi maior para os animais dos tratamentos com ID variáveis (12,59 e 12,06 kg leite dia -1) em relação aos tratamentos com ID fixos de 27 dias (10,94 e 10,66 kg leite dia -1). Os componentes do leite e taxas de ganho diário de peso não foram alterados com os tratamentos (P>0,05). / Two studies were conducted with lactating dairy cows at the Animal Sciences Department of the School of Agriculture \"Luiz de Queiroz\", University of São Paulo, to evaluate the use of a slow release urea source (Optigen®) and fixed or variable grazing intervals on Pennisetum purpureum pastures. The objective of Experiment 1 was to evaluate the partial replacement of cotton seed meal (CSM) by urea or by a slow release urea (Optigen®) on the performance of dairy cows fed corn silage. Thirty two mid lactating cows, averaging 20.8 kg of milk day-1 and 524 kg of BW at the beginning of the experimental period were used to compare the 3 treatments. The control treatment (C) contained cotton seed meal (CSM) as protein source, the U30 treatment had 30% of the CSM crude protein replaced by urea, the O30 treatment, had 30% of the CSM crude protein replaced by slow release urea and the O60 treatment, had 60 % of the CSM crude protein replaced by slow release urea. A 4x4 Latin Square design was used and the variables were analyzed using the PROC MIXED (SAS). Replacing 30% of CSM crude protein by urea (U30) or slow release urea (O30) had no effect (P>0.05) on milk yield (20.2, 19.5, and 19.8 kg day-1 respectively). However, replacing 60% of CSM crude protein by slow release urea (O60) (19.0 kg day-1) reduced milk yield compared to C and O30 (P<0.05) and U30 (P<0.06). Milk fat, milk protein, milk lactose, and milk total solids contents, and milk somatic cells counting were not different (P>0.05) among the treatments. The milk urea nitrogen (MUN) was lower (P<0.05) for the U30 treatment (7,2 mg dL-1) compared to the other treatments (9.3 mg dL-1 (O30); 9.1 mg dL-1 (C), and 8.9 mg dL-1 (O60)). On Experiment 2, were used 32 midlactating cows averaging 15 kg of milk day -1 and 466 kg of BW at the beginning of the trial. Experimental area contained 56 paddocks of Pennisetum purpureum cv. Cameroon, averaging 0.1ha each. Treatments were 2 grazing interval (fixed grazing intervals of 27 days or variable grazing intervals based on the dossel height of 1 m), and two protein supplement (CSM x slow release urea). A randomized block design was used and the variables were analyzed using PROC MIXED (SAS). There were no effects (P>0.05) for N source on the evaluated parameters. There were differences (P<0.05) between the fixed and variable grazing intervals (GI). Pre-grazing dossel height (1.03 x 1.2 m), post-grazing stubble height (0.41 e 0.47 meters), pre-grazing (6209 and 6642 kg DM ha-1) and post-grazing forage mass (3277 and 3666 kg DM ha-1) were lower (P<0.05) for variable GI compared to 27 days fixed GI. Volumetric density (55.04 and 60.06 kg DM ha-1 cm-1) was higher for variable GI (P<0.05). Cows grazing pastures managed with variable GI produced more milk (P<0.06) (12.32 and 10.8 kg milk day -1) than cows grazing pastures managed with fixed GI. Milk components and cow average daily gain were not affected by the treatments (P>0.05).

Jordbruket är en sektor som står för en stor del av vår klimatpåverkan där animalieproduktionen bidrar med ungefär 15 %, främst från idisslare. För att minska klimatpåverkan kan klimatberäkningar utföras för att hitta möjligheter till förbättring. Dessa beräkningar är komplexa med stora osäkerheter. Studien syftar till att utvärdera två verktyg, Cool Farm Tool (CFT) och Vera, för beräkning av klimatpåverkan från gårdar med idisslare. Utvärdering skedde utifrån precision och hur väl resultatet redovisas utifrån gårdarnas möjlighet att använda resultatet för att identifiera förbättringsmöjligheter. Verktygen diskuterades också utifrån användarvänlighet. För utvärdering utfördes beräkningar i verktygen för tre system, en mjölk- och två nötköttssystem. För jämförelse utfördes egna beräkningar utifrån ett livscykelperspektiv. Resultatredovisningen analyserades utifrån egna och klimatrådgivares upplevelser. Även ett eget förslag till resultatredovisning redogörs. Resultaten från beräkningarna blev 1,1–1,2 kg koldioxidekvivalenter per liter fett och proteinkorrigerad mjölk och 8,6–8,7 kg koldioxidekvivalenter per kg levandevikt för djur till slakt för mjölkkor, 11–12 kg koldioxidekvivalenter för djur till slakt från nötsystemet med uppfödning av mjölkraskalvar som inte används för rekrytering och 14–17 kg koldioxidekvivalenter för köttsystemet med dikor. Skillnaderna mellan de två verktygen beror främst på skillnader i ”global warming potentials” och beräkningar av emissioner från fodersmältning, gödselhantering och foderproduktion. Vera har en stor fördel i att det använder svenska beräkningsmetoder och därmed är mer anpassat för svenska gårdar. Den är också flexibel då det finns schabloner som ofta går att ändra. CFT går snabbare att använda och det går att hantera bristfällig data till viss del. Vera redovisar resultatet på flera sätt med möjlighet att upptäcka områden för förbättring. CFT redovisar inte lika detaljerat. Vera skulle behöva minska tiden som går åt till att leta och lägga till produkter medan CFT skulle kunna öka sin flexibilitet och resultatredovisning. / The agricultural sector stands for a large part of our contribution to climate change where the livestock stands for about 15 %, mostly from ruminants. To reduce the climate impact climate calculations can be executed to find possibilities for improvements. These calculations are complex with great uncertainties. The purpose of the study was to evaluate two tools, Cool Farm Tool (CFT) and Vera, for climate calculations from farms with ruminants. The precision and how well the results are presented to identify improvement opportunities were evaluated. The tools ease of use where also discussed. For evaluation, calculations were performed with the tools for three systems, one milk system and two beef systems. For comparison, own calculations were performed with a life cycle perspective. The presentations of the results were analysed from own and advisor experiences. A suggestion for presentation of the results is also presented. The results from the calculations became 1.1–1.2 kg carbondioxide equlivents per litre fat and protein corrected milk, 8.6–8.7 kg carbondioxide equlivents per kg live-weight for slaughter from meat from milking cows, 11-12 kg carbondioxide equlivents from meet from the beef system with breeding of milk breed calves that don’t get used for replacement, and 14-17 kg carbondioxide equlivents for the beef system with suckler cows. The differences between the tools are mostly depending on different global warming potentials, calculations of emissions from enteric fermentation, manure management and feed production. Vera has a great advantage in using Swedish calculation methodes and therefore more suitable for Swedish farms. It is also flexible since there are standard values that mostly can be changed. CFT is faster to use and it can manage limitations in data at some level. Vera presents the results in several ways with the possibility to discover areas for improvement. CFT does not present the results in the same detail. Vera needs to limit the time needed to look for and ad products while CFT needs to improve the flexibility and presentation of results.

Le produzioni zootecniche italiane giocano un ruolo importante nel settore agroalimentare, spaziando dagli aspetti sociali a quelli economici ed ambientali. L'Italia è leader nella produzione di latte vaccino di qualità per il consumo diretto ed è il principale paese europeo produttore di formaggi DOP. Tuttavia, la produzione di latte ha impatti sull'ambiente in quanto l'allevamento contribuisce ai gas serra presenti, principalmente dal processo digestivo degli animali, gestione degli effluenti e acquisto di alimenti, oltre alla potenziale immissione di sostanze inquinanti in acqua e suolo. L’analisi del ciclo di vita (Life Cycle Assessment, LCA) applicata in un’ottica di obiettivo di sviluppo agricolo ed agroalimentare sostenibile, permette di individuare le principali criticità legate al settore lattiero-caseario, e di predisporre azioni di mitigazione ambientale. A tal proposito, la Commissione Europea (CE) ha sviluppato la metodologia Product Environmental Footprint (PEF) e specifiche Category Rules (PEFCR) per armonizzare le scelte metodologiche di LCA e fornire criteri oggettivi di confronto dell'eco-compatibilità di prodotti. Il progetto LIFE TTGG (The Tough Get Going) applica la relativa PEFCR per il calcolo delle prestazioni ambientali nelle filiere Grana Padano e Comté DOP, ponendo le basi per trasformare le problematiche ambientali che scaturiscono dalle attività dei singoli produttori, in opportunità di miglioramento, nell’ottica della transizione ecologica del Paese. / The livestock breeding in Italy plays an important role in the agri-food sector, spanning from social to economic and to environmental aspects. Italy is a leader in the production of quality milk for direct consumption and is the main European country producing PDO cheeses. However, milk production carries impacts on the environment, as livestock farming contributes to greenhouse gas emissions, mainly resulting from animals’ digestion system, manure management and feed purchase, as well as pollutants. With the aim of a sustainable agricultural and agri-food development, it is important to identify, through Life Cycle Assessment (LCA), main criticalities related to the dairy sector, in order to adopt environmental mitigation actions. In this regard, the EC has developed the Product Environmental Footprint (PEF) methodology and specific Category Rules (PEFCR), harmonizing the methodological choices of LCA and providing objective criteria to compare the eco-compatibility of products. The LIFE TTGG (The Tough Get Going) project applies the PEFCR, calculating the environmental performance of the Grana Padano and Comté PDO supply chains and laying the bases for transforming the environmental problems arising from the activities of individual producers into opportunities for improvement, with a view to the Country's ecological transition.

L’objectif de cette étude était de déterminer l’impact d’une infection intra-mammaire (IIM) subclinique causée par staphylocoque coagulase-négative (SCN) ou Staphylococcus aureus diagnostiquée durant le premier mois de lactation chez les taures sur le comptage de cellules somatiques (CCS), la production laitière et le risque de réforme durant la lactation en cours. Des données bactériologiques provenant d’échantillons de lait composites de 2 273 taures Holstein parmi 50 troupeaux ont été interprétées selon les recommandations du National Mastitis Council. Parmi 1 691 taures rencontrant les critères de sélection, 90 (5%) étaient positives à S. aureus, 168 (10%) étaient positives à SCN et 153 (9%) étaient négatives (aucun agent pathogène isolé). Le CCS transformé en logarithme népérien (lnCCS) a été modélisé via une régression linéaire avec le troupeau comme effet aléatoire. Le lnCCS chez les groupes S. aureus et SCN était significativement plus élevé que dans le groupe témoin de 40 à 300 jours en lait (JEL) (P < 0.0001 pour tous les contrastes). La valeur journalière du lnSCC chez les groupes S. aureus et SCN était en moyenne 1.2 et 0.6 plus élevé que le groupe témoin respectivement. Un modèle similaire a été réalisé pour la production laitière avec l’âge au vêlage, le trait génétique lié aux parents pour la production laitière et le logarithme népérien du JEL de la pesée inclus. La production laitière n’était pas statistiquement différente entre les 3 groupes de culture de 40 à 300 JEL (P ≥ 0.12). Les modèles de survie de Cox ont révélé que le risque de réforme n’était pas statistiquement différent entre le groupe S. aureus ou SCN et le groupe témoin (P ≥ 0.16). La prévention des IIM causées par SCN et S. aureus en début de lactation demeure importante étant donné leur association avec le CCS durant la lactation en cours. / The objective of this study was to determine the effect of a subclinical intramammary infection (IMI) caused by coagulase-negative staphylococci (CNS) or Staphylococcus aureus diagnosed during the first month of lactation in heifers on somatic cell count (SCC), milk production and culling risk during the entire first lactation. Bacteriological analysis data of composite milk samples taken from 2,273 Hostein heifers among 50 dairy herds were interpreted according to the National Mastitis Council guidelines. Among the 1,691 heifers meeting the selection criteria, 90 (5%) were diagnosed with S. aureus, 168 (10%) with CNS, and 153 (9%) were negative (no pathogen isolated). Test-day SCC transformed in natural logarithm (lnCCS) was fit in a linear regression model with herd as random effect. The lnSCC in S. aureus and CNS groups were significantly higher than in negative group from 40 to 300 days in milk (DIM) (P < 0.0001 for all contrasts). At test-day level, lnSCC in S. aureus and CNS groups was on average 1.2 and 0.6 higher than the negative group respectively. A similar model was used for milk yield with age at calving, parent average genetic value for milk yield and natural logarithm of tested DIM included. Milk yield was not statistically different between culture groups from 40 to 300 DIM (P ≥ 0.12). Compared with negative heifers, the culling hazard ratio estimated using Cox survival analysis in S. aureus and CNS infected heifers was not significant (P ≥ 0.16). Prevention of CNS or S. aureus IMI in early lactation remains important for its association with SCC during the ensuing lactation.

Das Ziel der Arbeit bestand darin zu untersuchen, inwieweit durch Kombination von einfach zu erhebenden Daten des Melkprozesses mittels Fuzzy Logic die Bewertung der Eutergesundheit in Automatischen Melksystemen (AMS) verbessert werden kann. Eigene Forschungen richteten sich auf die Evaluierung unterschiedlicher Milch- bzw. Melkparameter hinsichtlich ihrer Eignung als Inputvariable verfeinerter Erkennungsmodelle für Euterkrankheiten am Melkroboter sowie auf die Entwicklung und Optimierung von Fuzzy Logic Modellen. Im Rahmen eines Vorversuches ist geprüft worden, welche Variablen Eingang in das Erkennungsmodell finden sollten. Zu diesem Zweck wurden neben der Erhebung von Prozessdaten eines AMS Astronaut(r) am 26. und 27. Juli 2001 mit Geräten des Typs LactoCorder(r) low flow insgesamt 754 Einzelmessungen an Eutervierteln durchgeführt und verarbeitet. Die Auswertung dieses Datenmaterials ergab, dass zwischen "unauffälligen", d.h. mehr oder weniger gesunden, und "auffälligen", d.h. mehr oder minder kranken Eutervierteln gewisse Unterschiede hinsichtlich der viertelbezogenen Parameter normierte Milchbildungsrate und normierter Milchfluss sowie der normierten Zwischenmelkzeit bestehen, welche für eine Modellierung nutzbar sind. Auch die elektrische Leitfähigkeit sollte in das weitere Vorgehen einbezogen werden. Die Funktionalität einfacher Fuzzy Logic Modelle ist anhand von 74 erstellten Datensätzen erfolgreich getestet worden. Vom 4. bis 9. März 2002 fand in einem Betrieb mit zwei parallel arbeitenden AMS Astronaut(r) in einer Herde von 103 melkenden Kühen die Hauptuntersuchung statt. 4 282 Messungen mit LactoCorder(r) low flow-Geräten an 359 Eutervierteln sind einzeln analysiert worden. Nach Entfernung eventuell fehlerhafter oder nicht eindeutig zuzuordnender Datensätze verblieb eine nutzbare Datenbasis von 2 826 Datensätzen, welche an 195 "unauffälligen" und an 41 "auffälligen" Eutervierteln gemessen worden waren. Die statistische Aufbereitung der absoluten Parameterwerte ergab hoch signifikante Differenzen zwischen "unauffälligen" und "auffälligen" Vierteln für die untersuchten Eingangsvariablen Milchbildungsrate, Milchfluss, Zwischenmelkzeit und Leitfähigkeit. Zur weiteren Modellierung wurden 527 aus den Rohdaten berechnete, normierte Datensätze verwendet, weil diese weitgehend unbeeinflusst von störenden individuellen und Umwelteinflüssen sind. Es sind drei verschiedene Ansätze zur Modellierung der normierten Parameter verfolgt, eingehend analysiert und untereinander sowie mit den Alarmmeldungen der AMS verglichen worden. Während Ein-Parameter-Modelle die höchsten Spezifitätswerte aufzeigten, konnten für die Verknüpfung der vier Eingangsvariablen durch Indexmodelle die besten Sensitivitätswerte ermittelt werden. Das optimale Ergebnis erzielte jedoch die Modellierung mit Hilfe von Fuzzy Logic. Sie ergab mit 5,9 Prozent die niedrigste statistische Wahrscheinlichkeit von Fehlklassifizierungen (falschen Diagnosen). Die Alarmliste der AMS wies zwar eine ähnlich geringe Fehlerquote auf, war jedoch zugleich durch eine schlechte Sensitivität charakterisiert. In einer abschließenden vergleichenden Diskussion mit aktuellen Forschungsergebnissen bestätigte sich die Richtigkeit beider Grundannahmen der vorgelegten Dissertation: 1. Aus Daten des Melkprozesses zu ermittelnde, viertelbezogene Parameter eignen sich zur Ergänzung von Leitfähigkeitsmessungen für die Erkennung von Euterkrankheiten. 2. Fuzzy Logic ist eine handliche und wirkungsvolle Methodik zur Modellierung der Zusammenhänge zwischen Melk- und Milchparametern einerseits und der Eutergesundheit andererseits. / The goal of the work was to examine to what extent the evaluation of the udder health in Automatic Milking Systems (AMS) can be improved by the combination of simply measurable data of the milking process by means of Fuzzy Logic. Own investigations were centred on the evaluation of different milking and milk parameters regarding their suitability as input variable of recognition models for udder diseases as well as on the development and optimisation of Fuzzy Logic models. In the context of a preliminary study, it was examined which variables should form the input of the recognition model. For this purpose, besides the collection of the process data of an AMS Astronaut(r), 754 measurements of single udder quarters were accomplished with measuring devices LactoCorder(r) low flow and were individually processed. The evaluation of this data resulted in certain differences between "inconspicuous" (healthy) and "conspicuous" (more ore less ill) udder quarters regarding the quarter-related parameters milk production rate, milk flow and milking interval which are usable for model building. Also the electrical conductivity should be included into further procedures. The functionality of simple Fuzzy logic models was tested successfully on the basis of 74 generated data sets. The main investigation took place in a dairy farm with two parallel working AMS Astronaut(r) in a herd of 103 milking cows. 4,282 measurements at 359 udder quarters with devices LactoCorder(r) low flow were individually analysed. After removal of possibly incorrect data records or those which could not clearly be assigned remained a usable database of 2,826 records measured at 195 "inconspicuous" and at 41 "conspicuous" udder quarters. The statistic analysis of the absolute parameter values resulted in highly significant differences between "inconspicuous" and "conspicuous" quarters for the examined input variables milk production rate, milk flow, milking interval and electrical conductivity. For the further modelling, 527 standardised data sets computed from the raw data were used because these are largely uninfluenced by disturbing individual and environmental determinants. Three different approaches of model building for the standardised parameters were pursued, analysed and compared among themselves as well as with the alerts of the AMS. While the One-parameter-models pointed out the highest specificity values, the best sensitivity values were determined for the linkage of the four input variables by index-models. However, the optimal result of modelling was obtained by Fuzzy logic. It resulted in the lowest probability of false classifications (wrong diagnoses) with 5,9 per cent. The alarm list of the AMS featured a margin of error which was similar low, however, at the same time it was characterised by bad sensitivity. A concluding discussion with current investigation results confirmed the correctness of both basic assumptions of the dissertation: 1. Quarter-related parameters which can be calculated from data of the milking process are suitable as a complement to conductivity measurements for the detection of udder diseases. 2. Fuzzy Logic represents a manageable and effective methodology for modelling the interrelations between milking and milk parameters on the one hand and the udder health on the other hand.

Auf den Grünlandstandorten ist die Mutterkuh- und Schafhaltung sowie die Futterproduktion von Anwelksilage und Heu verbreitet. Weitere Grünlandflächen sind aber vorhanden, eine alternative Nutzungsform stellt die Jungrinder- und Färsenaufzucht dar. Im Rahmen dieser Arbeit wurde untersucht, inwieweit sich die Stall- bzw. Weidehaltung vom 15. bis zum 21.Lebensmonat von weiblichen Jungrindern auf das spätere Wachstum bis zum 100.Laktationstag der 1.Laktation, die Fruchtbarkeit, die Erkrankungen und Abgänge während der Aufzuchtphase, der 1.und 2.Laktation sowie die Milchleistung in den ersten beiden Laktationen auswirkt. Bis zum 14. und ab dem 22.Lebensmonat wurden beide Versuchsgruppen unter einheitlichen Stallbedingungen gehalten. In dem von Mai 2000 bis Dezember 2002 dauernden Versuch wurden zu Beginn nach zufäll-iger Auswahl jeweils 74 Jungrinder der Rasse Deutsche Holstein in die Stall- und Weide-gruppe eingeteilt. Die Untersuchungsergebnisse zeigen, dass im Vergleich zur Stallhaltung eine begrenzte Weidehaltung von Jungrindern zu einer deutlich geringeren Lebendmasseentwicklung a.p. Fruchtbarkeitsproblemen und größeren gesundheitlichen Risiken in der 1.Laktation führen. Mit der 2.Laktation konnten sich die Milchkühe aus der Weidegruppe stabilisieren und erreichten eine höhere Milchleistung, bessere Fruchtbarkeitsparameter und ein geringeres Abgangsgeschehen im Vergleich zu den Kühen aus der Stallgruppe. Die Weidenutzung kann das tierische Leistungspotential gut ausschöpfen, wenn eine ord-nungsgemäße Vorbereitung der Tiere an die Weidebedingungen erfolgt und ein zu hohes kompensatorisches Wachstum der Färsen nach der Weideperiode vermieden wird, um Probleme bei der Abkalbung und Spätfolgen in der Laktation zu verhindern. Folgende Optimierungsmaßnahmen der produktionstechnischen Bedingungen der Weidehalt-ung sind erforderlich: * Kontinuierliche Kontrolle der Lebendmasse und des Exterieurs der Weidetiere und gegebenenfalls Rückführung in die Stallhaltung * Verbesserung der Pflanzenstruktur des Grünlandes * Durchführung von regelmäßigen Pflegemaßnahmen auf dem Grünland / In the meadow land sites mother cow and sheep keeping as well as food production of wilted silage and hay is spread. Further pasture land areas are existing, an alternative form of use is the raising of young cattle and heifers. In the context of this dissertation is was examined to what extent there are effects of the cowshed and meadow keeping from the 15th up to the 21st month of life of female young cattle on the later growth up to the 100th day of the first lactation, the fertility, the illnesses and deaths during the period of raising, the first and second lactation as well as the milk results within the first two lactations. Up to the 14th and from the 22nd month of life both test groups were kept under the same cowshed conditions. At the beginning of the test from May 2000 up to December 2002 74 young cattle of the breed "Deutsche Holstein" were divided up into the cowshed as well as the pasture keeping by an accidental choice. The test results show that, in comparison to cowshed keeping, a limited pasture keeping of young cattle leads to a clearly lower liveweight development a.p., fertility problems and bigger health risks in the first lactation. With the second lactation the dairy cows could stabilize and reached a higher milk result, better fertility parameter and a lower death rate in comparison to the cows of the cowshed group. The use of the meadows can exhaust the animal potential well, if there is a proper preparation of the animals for the meadow conditions and if a compensatory growth of the heifers, that is too high, is avoided after the meadow period to prevent problems with the calving in the lactation. The following optimization measures of the production methods of the meadow keeping are necessary: * continuous checks of the liveweight and the appearance of the animals and if necessary return to the cowshed keeping * improvement of the plant structure of the pasture land * implementation of regular care measures on the pasture land

O objetivo principal do estudo é ofercer uma contribuição metodológica testando os métodos mais usados na análise da eficiência relativa, vis a vis comparando um produtor com um grupo de produtores assemelhados, ou então, um produtor com toda a amostra, como é o caso da fronteira estocástica. Os métodos testados foram o DEA (análise envoltória de dados), a fronteira estocástica e o procedimento de Varian, tendo como objetivo da investigação produtores de leite. Para se testar a hipótese que os produtores de leite são eficientes, quanto à escolha da isoquanta e do ponto que minimiza custo, dada a pressuposição de que os agricultores realizam escolhas corretas, utilizam-se dois grupos de métodos. Os métodos não paramétricos aproximam-se mais do ideal de comparar um produtor com o grupo em que se insere. A base de tecnologia é a do grupo, sem apelo à função de produção. Os paramétricos são mais exigentes, pois pressupõem uma função de produção que tem que ser estimada; porém, são mais ricos e consistentes, no que tange ao teste de hipótese. O DEA é classificado de não paramétrico, porque não propõe uma função com os parâmetros que são estimados. Mas, implicitamente, gera uma função de produção, via programação linear. São menos estruturados que a fronteira estocástica, e mais exigentes que o procedimento de Varian, no sentido de que este não pressupõe qualquer fronteira explícita, como o método da fronteira estocástica, ou fronteira implícita, como o DEA. O DEA e o procedimento de Varian são deterministas, visto não associar aos modelos qualquer estrutura de probabilidade. A fronteira estocástica explicitamente associa ao modelo uma estrutura de probabilidade, pela forma que se define o termo do erro da regressão; desta forma é mais rica em testes de hipótese. Duas amostras foram utilizadas para se testar as hipóteses propostas. A primeira refere-se a um grupo de 143 produtores comerciais de leite, com as propriedades distribuídas nos seis maiores estados produtores do Brasil. A segunda amostra de produtores de leite é composta de 114 observações localizadas no estado de Minas Gerais. O método de Varian foi o que produziu menos distúrios em relação aos insumos ou produto. Estabelece maiores incrementos à renda líquida que a fronteira estocástica e menos do que DEA. Sua solução fica mais próxima daquilo que é factível para cada produtor fazer. O método prescinde do conceito de uma fronteira, reordenando os custos em relação aos produtores que produziram mais e gastaram menos, embora o procedimento de reordenamento requeira programação quadrática. Portanto, é um método aderente à gestão. A fronteira estocástica não objetiva nem aumentar a renda líquida e nem reduzir custos. Seu efeito sobre a renda líquida foi até negativo e produziu um maior distúrbio nos insumos e muito pequeno no produto, o que sempre ocorrerá, quando a função de produção se ajustar adequadamente aos dados. O método Varian foi mais apropriado para testar a hipótese de que os produtores, por tentativa e erro, acabam se localizando na fronteira eficiente, no ponto que minimiza o custo. Uma ves que exige somente que os agricultores racionalizem os custos, obedecendo à regra de racionalização, e passando ao largo da dinâmica de mercado, pela qual os produtores convergem para o custo mínimo, o que pode demandar muito tempo, em função de restrições, inclusive de emprego em outros setores da economia. Com os dados de um ano ou de poucos anos, quando não se pode captar o movimento de convergência, o DEA e a maximização da renda líquida são procedimentos inadequados para testar a hipótese de Schultz. / The objective of the study is test the most applied methods in the analysis of the relative efficiency, purposing the comparation between a producer and a group of resembled producers, or a producer with the entire sample, as the stochastic frontier’s (random border) case. The tested methods were the DEA (Data Envelopment Analysis), the stochastic frontier and the Varian procedure, analyzing mainly milk producers. Looking for testing the hypothesis that the milk producers are efficient, relating choice of isoquant and the cost minimization point, giving the assumption of the producers achieve correct choices, and it was selected two group methods. The non parametric methods (distribution free) is the best approach to compare a producer with its group. The technology basis is supported by the group, without going through the production function. The parametric procedures are more exigent because they assume a production function that has been estimated, however is more consistent to the hypothesis test. The DEA is classified of non parametric approach, because it does not consider a function with estimated parameters, but, implicitly, it generates a production function, using linear programming. Its less structuralized than the stochastic frontier, more exigent than the Varian procedure, considering the sense that this method does not estimate any frontier, explicitly, as the stochastic frontier method (implicit border), or the DEA. The DEA and the Varian procedure are deterministic, not associated with models that hold back some structure of probability. The stochastic frontier is an associate to the probability structure model, since it defines the term of the regression error making richer the hypothesis tests. Two samples had been used to test the hypotheses. The first one takes a group of 143 commercial milk producers, whose farm enterprises were distributed in the six biggest producer states of Brazil. The second is established by a group of 114 milk producers located in the state of Minas Gerais. The Varian method produced little disturb related to the inputs or outputs. The net income obtained was bigger than the stochastic frontier and smaller than the DEA. This solution is near to the decision of producer based on feasible to make. The method requires the concept of a frontier, rearranging the costs in related to the producers that had produced more and spent less, even so, the reordering procedure requires quadratic programming. Therefore, it is a very convenient method of management. The stochastic frontier doesn’t pursue increase in the net income reduce the costs. In this study the effect on the net income was negative and produced larger disturbs in the inputs and smaller in the products. Facts that will always occur when the production function is adjust to the data. The Varian method was more appropriate in testing hypothesis of the producers, using the experiment and error test, locating them in the efficient frontier, where the point minimizes the costs is located. Therefore it demands that the producer rationalize the costs following the rationalization rule, where the producers drive themselves minimum cost. This procedure can demand much time, in function of constraints of the other sectors of the economy. Considering data of one or more years the DEA and the maximization of the net income have been inadequate procedures to test the hypothesis of Schultz, when it cannot collect convergence movement.

Dans un contexte de fluctuation des prix des intrants et d’une demande croissante en produits à base de lait de chèvre issus de pratiques respectueuses de l’environnement et des animaux, le pâturage peut retrouver une place plus importante dans l’alimentation des chèvres laitières. D’après la synthèse bibliographique, les facteurs de variation de l’ingestion et des performances au pâturage ont été très peu étudiés chez les chèvres laitières en conditions tempérées. L’objectif de la thèse a été de comprendre quelle est l’influence des pratiques de gestion du pâturage (disponibilité en herbe et en temps pour pâturer) sur la régulation de l’ingestion et les performances des chèvres laitières, dans le but d’affiner les recommandations aux éleveurs et d’élaborer les bases d’un modèle de prévision de l’ingestion. D’après les 6 essais réalisés : (1) les chèvres recevant entre 0,6 et 1,0 kg/j de compléments s’adaptent à des restrictions de temps d’accès de 11 à 6 h/j, en augmentant leur vitesse d’ingestion et surtout le pourcentage du temps passé à pâturer jusqu’à 95 % du temps d’accès, (2) les chèvres recevant 0,6 kg de concentrés et un temps d’accès d’au moins 11 h/j peuvent s’adapter à une restriction de quantité d’herbe offerte jusqu’à 2,3-2,6 kg MS/chèvre/j, (3), le poids vif et la production laitière sont des paramètres déterminant de la quantité d’herbe ingérée alors que la parité et le stade de lactation n’ont pas montré d’effet significatif. Ce travail a permis d’établir les premières lois de réponse d’ingestion, de production laitière et d’adaptation comportementale des chèvres laitières à des variations de temps d’accès et de quantité d’herbe offerte au pâturage. / In the context of prices volatility and growing demand for goat's milk products from respectful practices of the environment and animals, grazing can become more important in the diet of dairy goats. According to the literature review, the factors of variation of intake and performance of grazing dairy goats have been poorly studied under temperate conditions. The aim of this thesis was to understand the influence of grazing management practices (availability of pasture and access time to grazing) on the regulation of intake and performance of dairy goats, with the aim of refining recommendations for farmers and to elaborate a model of intake prediction. Based on the six trials conducted: (1) goats receiving between 0.6 and 1.0 kg/day of supplements adapt themselves to access time restrictions from 11 to 6 h/d, by increasing their intake rate and especially the percentage of time spent grazing up to 95% of access time, (2) goats receiving 0.6 kg of concentrates and an access time of at least 11 h/day can adapt to a restriction of pasture allowance up to 2.3-2.6 kg DM/goat/day, (3) live weight and milk production are the main variables affecting intake while parity and stage of lactation had no significant effect. This work provides the first response laws of intake, milk production and behavioural adaptation of grazing dairy goats to variations of access time to pasture and to pasture allowance.

Foi conduzido um estudo com vacas leiteiras no Centro de Análise e Pesquisa Tecnológica do Agronegócio - Bovinos de Leite, do Instituto de Zootecnia, em Nova Odessa, SP, com o objetivo de avaliar os efeitos da substituição parcial do farelo de soja da dieta por uma fonte de proteína microbiana derivada de levedura (PML), e a sua combinação com uma ureia de liberação lenta (ULL), sobre o consumo de MS, produção e composição do leite, bem como alguns parâmetros sanguíneos e o balanço nitrogenado. Foram utilizadas oito vacas primíparas da raça Holandês, distribuídas aleatoriamente em dois quadrados latinos 4x4 em tratamentos arranjados em esquema fatorial 2x2, sendo que cada período experimental foi composto por 28 dias com 21 dias de adaptação e 7 dias de coleta. Foram comparadas quatro dietas, compostas por 49% de volumoso (47% de silagem de milho e 2% de feno de Tifton) e 51% de concentrado, com teor médio de 16,8% de proteína bruta e 2,5Mcal/kg EM. Na dieta controle (CTL = sem PML e sem ULL) o farelo de soja foi a principal fonte proteica e nas outras três dietas o farelo de soja foi parcialmente substituído por 15 g/kg MS de PML (com PML e sem ULL) ou por 7,5 g/kg MS de ULL (sem PML e com ULL) ou ambos, 15 g/kg MS PML+ 7,5 g/kg MS de ULL (com PML e com ULL). Houve interação entre PML e ULL para o consumo de MS (P=0,0003) e produção de leite (P=0,0013). As vacas que receberam o tratamento ULL tiveram menor consumo de MS, sem afetar a produção de leite comparado às vacas que receberam o tratamento PML+ULL (P&le;0,05). Não houve interação para os componentes do leite obtido, exceto para o extrato seco desengordurado (P=0,0086), as vacas que receberam o tratamento CTL tiveram os maiores teores de ESD no leite comparada as vacas que receberam o tratamento ULL (P=0,0002) e esses teores mais elevados foram iguais aos das vacas que receberam o tratamento PML (P=0,066). Apesar de não ter havido interação, as vacas que receberam os tratamentos sem ULL tiveram maiores teores de proteína, caseína e sólidos totais no leite comparado às vacas que receberam os tratamentos com ULL (P&le;0,05). Não houve interação entre PML e ULL para eficiência na produção de leite (P=0,0694), porém a eficiência na produção de leite corrigida para energia foi maior para as vacas que receberam tratamentos com ULL do que as vacas que receberam os tratamentos sem ULL (P&le;0,05). Não houve interação entre PML e ULL para os parâmetros sanguíneos analisados (P&gt;0,05) exceto para o teor de K (P=0,0098). Os teores de hematócrito e hemoglobina foram maiores nas vacas que receberam tratamento com ULL comparado aos valores encontrados nas vacas que receberam tratamento sem ULL (P&le;0,05), não afetando a homeostasia. O teor de N retido (balanço de N) foi maior para os animais que receberam o tratamento CTL devido a diferença encontradas no teor de N ingerido e excretado nas fezes (P&le;0,05). A eficiência do uso de N aumentou com a substituição do farelo de soja por PML, ULL ou ambos (P&le;0,05). A substituição do farelo de soja pela PML, ULL ou por ambos em dietas de vacas leiteiras, teve efeitos sobre o consumo de MS, a produção e composição do leite, bem como na ingestão de N, secreção de N no leite, excreção fecal de N e no balanço nitrogenado. De maneira geral, é possível fazer a substituição do farelo de soja pela PML, ULL ou ambos, sem afetar negativamente os parâmetros de produtividade. Os resultados obtidos foram similares ao tratamento CTL em relação ao consumo, produção de leite e balanço nitrogenado permitindo espaço para a inclusão de alimentos mais baratos e garantindo melhor fornecimento de energia. / This study was conducted to evaluate the effects of partial replacement in the diet of dairy cows of soybean meal by a yeast-derived microbial protein source (YMP) or a combination of YMP with a slow release urea (SRU), on dry matter intake, milk production and composition, blood parameters and nitrogen balance. Eight first lactation cows were distributed randomly into two 4x4 Latin squares, in a 2x2 factorial arrangement of treatments, with four periods with 28 days each one (21 days of adaptation and 7 days of collection). The base diet had 49% roughage (47% corn silage and 2% Tifton hay) and 51% concentrate, with an average of 16.8% crude protein and 2.5 Mcal/kg dry matter (DM). In the control diet (CTL = without YMP and without SRU) soybean meal was the main protein source and in the three other diets the soybean meal was partially replaced by 15 g/kg DM of YMP or 7.5 g/kg DM SRU, or both, 15 g/kg DM YMP plus 7.5 g/kg DM SRU. There was an interaction between YMP and SRU for DM intake (P=0.0003) and milk production (P=0.0013). The cows that received SRU treatment had lower DM intake not affecting milk production compared to cows that received the YMP+SRU treatment and differences among treatments for DM intake and milk production (P&le;0,05). There was no interaction of the milk components, except for nonfat dry milk (P=0.0086), the cows that received CTL treatment had the highest nonfat dry milk compared to cows received the SRU treatment (P=0.0002) and these higher levels were equal to those of cows received the YMP treatment (P=0.066). Although there was no interaction, the cows that received the treatments without SRU had higher protein, casein and total solids in milk compared to cows received treatments SRU (P&le;0.05). There was no interaction between YMP and SRU for milk production efficiency (P=0.0694), but efficiency in the milk production corrected for energy was greater for cows received SRU treatments than cows received treatments without SRU (P&le;0.05). There was no interaction between YMP and SRU for the analyzed blood parameters (P&gt;0.05) except for the K content (P=0.0098). The levels of hematocrit and hemoglobin were higher in cows that received treatment with SRU compared to cows that received treatment without SRU (P&le;0.05), not affecting homeostasis. The nitrogen retained (N balance) was higher for animals that received CTL treatment due to differences in N content ingested and excreted in the feces (P&le;0.05). The efficiency of use of N increased with the substitution of soybean meal for PML, ULL or both (P&le;0.05). The substitution of soybean meal by YMP, SRU or both in dairy cow diets, had effects on DM intake, milk yield and composition, as well as N intake, milk secretion of N, fecal excretion of N and nitrogen balance. In general, it is possible to replace soybean meal for PML, ULL or both, without impacting negatively the production performance parameters. The results obtained in the CTL treatment in the consumption of dry matter, production of milk and nitrogen balance allowing the inclusion of cheaper feeds allowing for better energy supply.

O objetivo deste trabalho foi estimar as exigências e a eficiência energética de vacas de corte lactantes e não gestantes, bem como do par vaca/bezerro. Posteriormente foi correlacionada a eficiência do par vaca/bezerro durante a lactação com a eficiência das mesmas vacas durante a terminação. Na fase de lactação os pares vaca/bezerro foram avaliados desde após o nascimento (17±5, d DP) até a desmama (210 d). Após a desmama foi conduzido o ensaio de terminação (67 d) e abate somente das matrizes. Foram avaliadas 10 vacas adultas ½ Caracu x Nelore (CN) e 10 ½ Angus x Nelore (AN), acasaladas com touros Red Angus (RA) e Canchim (CC), respectivamente. Na lactação o oferecimento da dieta (2,30 Mcal EM/kg e 12,4% PB) variou individualmente ao longo do período com objetivo de manter constante o peso das matrizes ao longo da lactação. A mesma dieta foi oferecida a vontade para a progênie. Durante o ensaio de terminação em confinamento a dieta (2,37 Mcal EM/kg e 10,5% PB) foi fornecida à vontade. A ingestão de matéria seca das matrizes foi de 92,4 g MS/kg PM0,75 (CV=3,2%; P=0,458). Vacas AN apresentaram produção de leite corrigida para gordura 12% superior (P<0,05). A concentração energética do leite (Mcal/kg) das vacas CN foi 9,4% superior (P<0,05). A eficiência (Mcal leite/Mcal EM ingerida) não foi diferente. A exigência de energia metabolizável de lactação (EMl) foi maior (P<0,05) para vacas AN em relação as CN, 90,1 e 74,2 (EMl, kcal EMl/kg PM0,75), respectivamente. Bezerros ½CC¼AN¼NE apresentaram ingestão de energia metabolizável (IEM) proveniente do leite 11,3% (P<0,05) superior. Bezerros ½RA¼CR¼NE foram 10,7% mais eficientes (g GP210d/Mcal IEM leite+dieta sólida). Não houve diferença para eficiência dos pares vaca/bezerro, contudo houve considerável variação individual, onde a eficiência média foi 35,3 g GP210d/Mcal IEM par (CV=11,5%). A eficiência do par foi positivamente relacionada ao ganho do bezerro (r=0,79; P<0,01) e negativamente relacionada à IEM do par (r=-0,58; P<0,05). Vacas CN ao abate apresentaram EGS 29% menor, AOL 13% maior e maior proteína no corpo vazio (P<0,05). Vacas AN apresentaram 14,7% maior proporção de órgãos internos relativo ao peso vazio e maior peso dos intestinos (P<0,01). As correlações fenotípicas demonstraram associação entre as eficiência de secreção do leite das vacas nas fase de lactação e de ganho de peso na fase de terminação (r=0,43; P=0,09). A eficiência de secreção de leite das vacas na lactação apresentou correlação com a eficiência do par (r=0,68; P<0,01). O consumo alimentar residual (CAR) das vacas na terminação foi correlacionado com o CAR das vacas em lactação (r=0,53; P<0,05) e com o CAR dos pares (r=0.62; P<0.01). Isso indica que vacas de corte mais eficientes durante a terminação são também mais eficientes no período de cria. / This study estimated the requirements and feed efficiency of non-pregnant lactating beef cows, as well as cow calf pairs. It also correlated the efficiency of the cows and their progeny during lactation to efficiency determined for the same cows in a finishing trial after weaning. In the lactating phase cow calf pairs were evaluated from just after birth (17±5, d) to weaning at 210 d. The finishing trial for the mature cows started after weaning and lasted 67 d after wich cows were slaughtered. Twenty adult cows were evaluated, 10 ½ Caracu x Nelore (CN) and 10 Angus x Nelore, bred to Red Angus (RA) and Canchim (CC) bulls, respectively. During lactation the diet (2.30 Mcal ME/kg and 12.4% CP) was offered in variable amounts to maintain individual live weight and condition score constant. The same diet was offered ad libitum to the calves. During the finishing phase cows were fed ad libitum (2.37 Mcal ME/kg e 10.5% CP). The dry matter feed intake of cows was 92,4 and SD 2,9 g DM/kg BW0,75. AN cows had fat corrected milk 12% higher compared to CN cows (P<0.05). However, milk energy content (Mcal/kg) was 9.4% higher (P<0.05) for CN cows. Efficiency of milk production (Mcal milk/Mcal ME intake) was not different. Metabolizable energy for lactation (MEl) was higher (P<0.05) for AN cows in comparison to CN, respectively 90.1 and 74.2 (MEl, kcal MEl/kg BW0,75). ME milk intake was 11.3% (P<0.05) higher for ½CC¼AN¼NE calves. Rates of gain were not different between calves, but ½RA¼CR¼NE were 10.7% more efficient (g LWG210d/Mcal MEI milk+solid diet). There was no difference in cow calf pairs efficiency, but there was a great individual variability with a mean of 35,31 g and SD of 4,08 g LWG210d/Mcal EM for the pair. Cow/calf pair efficiency was positively related to calf weight gain (r=0.79; P<0.01) and negatively to the pair metabolizable energy intake (r=-0.58; P<0.05). At slaughter CN cows presented backfat thickness 29% lower, longissimus muscle area 13% higher and higher empty body weight protein (P<0,05). AN cows had 14.7% higher relative internal organ weight and higher total intestine weight (P<0.01). The phenotypical correlations between efficiency indexes indicate moderate association between cow efficiency measured during lactation and in a short finishing period after weaning (r=0.43; P=0.09). Exist correlations between cow efficiency lactation and efficiency of the pair (r=0.68; P<0.01). Residual Feed Intake (RFI) during the finishing phase was moderately correlated to the RFI calculated during the lactation period for the cow calf pairs RFI (r=0.62; P<0.01) and the cows (r=0.53; P<0.05) indicated that beef cows more efficient in feed conversion during the finishing phase are more efficient during the lactation period.