Jorge Fainé Gomes

Avaliação da qualidade do leite na bacia leiteira de Pelotas, RS. Efeito dos meses do ano

RESUMO - Os efeitos dos meses do ano sobre a composicao e producao do leite foram avaliados atraves do acompanhamento de 10 unidades produtoras de leite, divididas em tres sistemas de producao classificados como especializado (ES), semi-especializado (SE) e nao-especializ ado (NE), durante 11 meses do ano. Foram coletadas amostras de leite diretamente dos tanques refrigeradores para determinacao das caracteristicas fisico-quimicas e contagem de celulas somaticas (CCS). Quantificaram-se a incidencia de mastite e a producao media de leite (litros/vaca/dia) e coletaram-se amostras de agua utilizada para consumo e limpeza, de pastagem, concentrado e silagem. O delineamento adotado foi o completamente casualizado, em arranjo fatorial desbalanceado, considerando como fatores os meses do ano, os sistemas de producao e a sua interacao. Nao foi encontrada variacao significativa entre os meses estudados para producao de leite, valores de crioscopia, porcentagens de gordura, extrato seco, nitrogenio nao-proteico, CCS, composicao quimica, contagem de coliformes da agua e composicao bromatologica do concentrado. Os maiores valores de proteina verdadeira do leite foram observados em outubro e novembro, enquanto os maiores de caseina, em outubro, novembro, marco e abril. O extrato seco desengordurado foi superior em dezembro e a acidez variou juntamente com a incidencia de mastite, sendo superior nos meses de novembro e maio. Em relacao a proteina bruta, ocorreu interacao entre meses e sistemas. Foram observadas correlacoes negativas entre producao de leite e gordura, mastite e CCS, e correlacao positiva entre producao de leite e lactose. O leite produzido nos diversos meses do ano diferiu, principalmente, quanto a incidencia de mastite, fracao proteica, extrato seco desengordurado e acidez. A qualidade da agua nao se modificou expressivamente nos meses em que foi amostrada e se apresentou dentro dos limites considerados aceitaveis.

Produção de forrageiras anuais de estação fria no litoral sul do Rio Grande do Sul

Annual cold season forage species, Avena strigosa Schreb cv. IAPAR-61 Ibipora, Lolium multiflorum Lam cv. Comum, Lotus subbiflorus Lag cv. El Rincon, Avena sativa L. cv. UPF-16, Trifolium subterraneum L. cv. Woogenellup, Trifolium resupinatum L. var. resupinatum cv. Kyambro, Secale cereale L. cv. BR-1, Trifolium vesiculosum Savi cv. EMBRAPA-28 Santa Tecla and Vicia angustifolia L. were evaluated using a randomized block design with three replicates, from 1994 to 1996, at Terras Baixas Experimental Station, EMBRAPA - Temperate Climate Research Center, Pelotas, RS, Brazil, in Planosol, Pelotas chart unity. The area was conventionally prepared, and the fertilization was in accordance with the soil analysis results. The first cutting was made 60 days after the emergence, and the following cuts were at 28 days intervals. The annual forage DM yield (DM, kg/ha•year) and the average CP and NDF contents were determined. There was effect of the interaction between years and species. Avena strigosa IAPAR-61, L. multiflorum Comum and L. subbiflorus El Rincon were outstanding by the high forage production potential, as well as by their growth over autumn/winter, winter/spring and spring, respectively. All the evaluated species produced forage of high nutritional value, in terms of CP and NDF contents. Vicia angustifolia had always the highest CP content and the greatest relative production over the winter. Trifolium subterraneum Woogenellup was an only species that produced sufficient reliable seeds to assure an adequate natural regeneration of the plant in the beginning of the second year.

Ocorrência do leite instável não ácido no noroeste do Rio Grande do Sul

ABSTRACT The unstable non-acid milk (UNAM) is characterized by loss of casein stability, which results in its precipitation at the alcohol test even though titratable acidity be lower than 18oD. This trial aimed to estimate the occurrence of UNAM in the Northwest of Rio Grande do Sul, state and to verify seasonal variation and its effects on milk composition. From September 2002 to August 2003, approximately 200 dairy farms were monthly monitored. Milk samples from bulk tank were collected and analyzed for titratable acidity; precipitation at alcohol 76% test; percentages of fat, crude protein, lactose, total solids; and somatic cells count, totalizing 2,396 milk samples. UNAM occurrence was 55.2%, being highest in February and March 2002. UNAM occurrence was reduced as milk production of farms increased. Fat percentage did not vary between normal milk and UNAM. However, crude protein, lactose, total solids, and solids non-fat contents were lower in UNAM than in normal milk. Keywords: milk composition, milk quality, stability, alcohol test

Produção e qualidade do leite em sistemas de produção da região leiteira de Pelotas, RS, Brasil

This research was aimed at characterizing milk yield and quality of three production systems at Pelotas dairy region. From September 2001 up to August 2002, nine dairy production units were visited for 11 months. Production units were classified as specialized (S), partially specialized (PS) and non-specialized (NS). Bulk tank milk was sampled to analyze physical and chemical attributes and somatic cells count (SCC). Mastitis percentage and 4% fat-corrected milk yield were evaluated. A completely randomized split-plot design was adopted. Cryoscopic index differed between specialized and non-specialized systems (P<0.10), but all values were within the normal range. Specialized system showed lower mastitis occurrence than partially specialized and non-specialized systems (P<0.10). Production systems did not differ for 4% fat-corrected milk yield, contents of protein, casein, fat, lactose, solids non-fat, total solids, non-protein nitrogen, as well as titrable acidity and somatic cells count. Higher technology level application reduced mastitis occurrence, contributing to a better milk quality.

Suplementação energético-protéica no desenvolvimento corporal de novilhas Jersey em pastejo

The trial was conducted to evaluate the effects of three levels of energy-protein supplementation with corn ground and soybean meal on grazing dairy heifers body development. Fifteen Jersey heifers, aged of 6 to 18 months and weighing 142,2 ± 7,8 kg, were used. Animals were kept under rotational grazing system and fixed stocking rate on a ryegrass and black oats pasture. Animals were classified by their initial body weight and randomly assigned to treatments according to a complete randomized block in a split plot design: 100% corn ground, 70% corn ground + 30% soybean meal, 40% corn ground + 60% soybean meal. Evaluation was performed over six periods of 28 days. No effects for treatments were detected on animals body development attributes as increases in daily live weight gain, total live weight gain, increments of height at withers and heart girt, probably due to high values for pasture quality herbage mass.