RESUMO Objetivou-se realizar o monitoramento por vaca em lactação referente a qualidade e composição do leite de duas propriedades rurais na mesorregião Noroeste Rio-grandense, localizadas nos municípios de Palmeira das Missões e Pinhal - RS. Ambos os rebanhos eram mistos, com animais da raça Holandês (70%) e Jersey (30%). Foram avaliados os parâmetros: escore de condição corporal (ECC), sujidade de úbere, ordem de parto e composição do leite: teores de extrato seco total (EST) e desengordurado (ESD), lactose, gordura, proteína, caseína, nitrogênio ureico do leite (NUL) e contagem de células somáticas (CCS). A análise estatística realizada foi análise fatorial e de agrupamento. O primeiro fator compreende a relação negativa da produção de leite com a raça, teor de gordura e proteína. O segundo fator compreende a relação positiva entre dias em lactação com escore de condição corporal e teor de proteína do leite. O terceiro fator é representado pela relação contrária do teor de lactose com escore de CCS, ordem de parto e ECC. No quarto fator observa-se a relação positiva entre ordem de parto e sujidade do úbere. Na análise de agrupamento foram formados três grupos que refletem as relações encontradas na análise fatorial. O monitoramento por vaca, considerando raça, ordem de parto, escore de condição corporal, dias em lactação, produção de leite, teores de gordura, proteína e lactose, escore de contagem de células somáticas e sujidade do úbere possibilitam maior controle do rebanho, facilitando corrigir possíveis deficiências pontuais de forma rápida e minimizando as perdas produtivas e econômicas.

ABSTRACT The aim of the present study was to monitor cow milk quality and composition in two farms in the Noroeste Rio-grandense mesoregion, located in the municipalities of Palmeira das Missões and Pinhal - RS. Both herds were mixed, with animals of the Holstein (70%) and Jersey (30%) breeds. The following overall parameters were evaluated: body condition score (BCS), udder dirtiness, and calving order, and the following milk composition factors were measured: total dry extract (TDE), defatted dry extract (DDE), milk lactose, fat, and protein contents, casein, milk urea nitrogen (MUN), and somatic cell count (SCC). Multivariate statistical analysis was performed, and four factors were identified representing combinations of the measured variables. The first factor comprised negative relationships between milk production and cow breed, milk fat content, and milk protein content. The second factor comprised the positive relationships between lactation days and body condition score and milk protein content. The third factor represented the negative relationships between milk lactose content and SCC score, calving order, and BCS. The fourth factor was composed of the positive relationship between delivery order and udder dirtiness. Cluster analysis revealed that individual cows could be categorized into three groups. Monitoring the breed, calving order, body condition score, lactation days, milk production, fat, protein, and lactose contents, somatic cell counts, and udder dirtiness in cows allows greater control of the herd, allowing potential shortcomings to be rectified quickly and economic losses to production to be minimized.

ABSTRACT. This study was realized to evaluate the monthly production, composition and quality of milk (total and defatted dry extract, lactose, fat and protein) and their relation to somatic cell count (SCC) and total bacterial count (TBC) using multivariate statistical analyses. The data are from a dairy farm for the period of two years (from January 2015 to December 2016). The SCC and TBC variables were transformed to somatic cell score (SCS) and log10 (LogTBC). Factor analysis, discriminant analysis and cluster analysis were used. Through factor analysis, it was found two factors that together explained 69.5% of the total data variation. The first factor represented the inverse relationship between lactose versus fat and protein content, while the second factor represented the inverse relationship among monthly milk yield versus SCS and LogTBC. The discriminant analysis identified that lactose and protein contents and SCS were the variables that had the greatest participation in the separation of the groups formed by the cluster analysis. The groups differed mainly by the monthly production of milk, composition and SCS. Finally, there are important multivariate relations between the variables milk production, composition and quality.

ABSTRACT. This study analyzed the behavior of the annual ryegrass (Lolium multiflorum) BRS Ponteio and dual-purpose wheat (Triticum aestivum) BRS Tarumã with different doses of ammonium sulfate as topdressing and evaluated the exponential growth model to explain the physiological development of both species. For each species, a completely randomized design was used with four replications per treatment with 9m2 area, in which the following treatments were distributed: 0, 150, 250, 350 and 450 kg nitrogen per hectare applied as ammonium sulfate. The cumulative and adjusted productions to the exponential growth model at the end of the cycle were, respectively: BRS Ponteio 150 = 5,620; 250 = 5,920; 350 = 7,585 and 450 = 8,491 and BRS Tarumã 150 = 3,922; 250 = 5,060; 350 = 7,024 and 450 = 7,491 kg dry matter per hectare. The cultivars analyzed without nitrogen application had limited growth and showed no adjustment even to the first order linear model. The application of nitrogen decreased the interval between cuts and increased dry matter production per hectare following the exponential growth model.

O desempenho de ruminantes domésticos é influenciado por fatores intrínsecos ao animal, ao alimento e pela interação entre animal e alimento. O trabalho foi realizado na Estância do 28, pertencente à Fundação Maronna, Alegrete - RS, dentro da APA do Ibirapuitã. Para representar o fator solo, foram escolhidos os três tipos predominantes da APA do Ibirapuitã: Basalto Superficial, Basalto Profundo e Arenito. As amostras da pastagem natural foram retiradas por simulação de pastejo, através de coleta manual. Os parâmetros nutricionais avaliados foram: proteína bruta, fibra em detergente neutro e taxa de degradação da matéria seca. A forragem da pastagem natural oriunda do solo Basalto Superficial apresentou diferença significativa (P<0,05) nos teores de proteína sobre aquelas obtidas dos solos Basalto Profundo e Arenito, os quais não diferiram entre si. O maior teor de fibra em detergente neutro (84,54%) foi obtido na pastagem oriunda do solo Arenito, em relação às originadas dos solos Basalto Superficial e Profundo, com valores de 74,53 e 77,98%, respectivamente. Para a taxa de degradação, também houve uma diferença significativa (P<0,05). A forragem da pastagem natural oriunda do solo Arenito apresentou valor intermediário de degradação 3,61% h-1, não diferindo dos demais solos. As pastagens naturais apresentam taxa de degradação semelhantes durante a primavera e o verão e durante outono e inverno. A forragem da pastagem natural oriunda do solo Basalto Superficial apresentou qualidade nutricional superior, comprovada pela taxa de degradação da matéria seca.

Intrinsic animal and food factors and the interaction between them influence the performance of domestic ruminants. This study was done at Estância do 28, property of the Maronna Foundation, Alegrete - RS, inside the Ibirapuitã Area of Environmental Protection. In order to represent soil as a factor, the three main soil types were chosen: Superficial Basalt, Deep Basalt and Sandy. Hand plucking methods were used to obtain samples of natural pasture. Nutritional parameters considered were crude protein, neutral detergent fiber and dry matter degradation rate. The forage from natural pasture of the Superficial Basalt presented significant difference (P<0.05) in crude protein rates over the other two types of soil, which did not differ amongst themselves. The highest rate of neutral detergent fibre (84.54%) was obtained in pasture originated from Sandy soil, in relation to Superficial and Deep Basalt, with values of 74.53% and 77.98%, respectively. There was also a significant difference in the degradation rate of dry matter (P<0.05). Sandy soil pasture presented an intermediate degradation value (3.61% h-1), not differing from other soils. The forage from natural pastures present similar degradation rates during summer and spring and for the period of autumn and winter. The forage from natural pasture of Superficial Basalt type soil presented superior nutritional quality, as could be proved by the dry matter degradation rate.