Vivian Fischer

Comportamento ingestivo diurno de novilhos em pastejo submetidos a níveis crescentes de suplementação energética

The trial aimed to observe the ingestive behavior of grazing beef steers submitted to different energetic supplementation levels and kept under an improved natural pasture. Thirty eight beef steers without definite breed, aging 12 to 15 months and weighing 159,97 kg were used. Animals were kept under set stocking in a natural pasture improved with Lotus Subbiflorus and invaded with Eragrostis plana Ness. Two levels of ground sorghum grain were offered as an energetic supplement, and treatments consisted of control or without supplement (T0); 0,75% of mean live weight (T0.75), 1,5% of mean live weight (T0.75). Animals were randomly assigned to treatments according to a complete randomized design. Considering the overall mean, diurnal grazing time (P=0.0059), total rumination time (P=0.0013) and walking time (P=0.0076) followed by a quadratic trend in relation to the supplement levels, and showed larger values for control, T0.75 and T1.5, respectively. Diurnal idling followed a positive linear trend with increasing supplementation levels (P=0.0001). Biting rate and total bites number followed linear (P=0.0001) and quadratic trends (P=0.0002), respectively, with increasing supplementation levels. There were no differences for feeding stations visited per minute and for time spent at the trough between treatments.

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.

Comportamento ingestivo de vacas Jersey alimentadas com dietas contendo diferentes fontes de gordura nos primeiros 100 dias de lactação

This trial aimed to describe and compare the feeding behavior of Jersey cows at the beginning of lactation and fed diets with different fat sources. Fat sources tested were tallow, calcium salts of palm oil and ground soybean, representing sources of mainly saturated, unsaturated-protected and unsaturated fats, respectively. Eight cows weighing 389±27 kg, with body condition score from 3 to 3.5 and yielding 21.8±3.5 L/day were used. Animals were randomly allocated to treatments according to a replicated Latin square design, with eight animals, four treatments and four experimental periods. Feeding behavior consisted of the daily times of eating, ruminating and idling, number and duration of mean periods of those activities. Feeding behavior was recorded on three days per experimental period, for 24 hours a day at intervals of five minutes, individually for each animal. There were no significant differences concerning feeding behavior attributes among treatments. Probably the absence of treatment effects was due to similar dry matter and NDF intakes.

Relação entre o genótipo e o temperamento de novilhos em pastejo e seu efeito na qualidade da carne

The effect of two genetic groups, Aberdeen angus (AA) and 50% Nellore x 50% Aberdeen angus (NA), on temperament and meat quality of 40 steers averaging 2 years of age and 336.4 ± 29.39 kg of body weight was evaluated in this trial. Animals were assigned to treatments according to a completely randomized design. Temperament was evaluated through measurements of composite behavior score (BS) and flight time (FT). NA steers had higher BS than AA steers in this trial. Conversely, AA steers had greater FT values than NA steers on evaluations 1 and 4: 2.1 vs. 1.3 e 4.7 vs. 2.3 seconds, respectively. Mean daily weight gain was negatively related with overall BS (r = -0.47, P=0.0075, n=30) while the opposite was observed with overall FT (r = 0.39, P=0.0336, n=30). Within the NA group, more reactive animals gained less weight. Steers with higher BS showed lower pH1 values: 6.47, 6.28 and 6.09, respectively, for BS of 1, 2 and 3. Steers with smaller FT showed lower pH1: 6.1, 6.43, and 6.43, respectively, for TF of 1, 2 and 3. Meat of NA steers showed pH1 lower than that of AA steers: 6.17 vs. 6.57. It was observed 23% more color a* (P=0.0394) and 9% more color b* (P=0.0808) on meat from NA steers with larger FT values. Color L* was negatively related with BS3 and pH24 (r= -0.54 and -0.39, respectively) whereas color b* was negatively related with pH3 and pH7 (r= -0.39 and r= -0.45, respectively). Crossbred and more nervous steers had lower weight gain and poorer meat quality.The effect of two genetic groups, Aberdeen angus (AA) and 50% Nellore x 50% Aberdeen angus (NA), on temperament and meat quality of 40 steers averaging 2 years of age and 336.4 ± 29.39 kg of body weight was evaluated in this trial. Animals were assigned to treatments according to a completely randomized design. Temperament was evaluated through measurements of composite behavior score (BS) and flight time (FT). NA steers had higher BS than AA steers in this trial. Conversely, AA steers had greater FT values than NA steers on evaluations 1 and 4: 2.1 vs. 1.3 e 4.7 vs. 2.3 seconds, respectively. Mean daily weight gain was negatively related with overall BS (r = -0.47, P=0.0075, n=30) while the opposite was observed with overall FT (r = 0.39, P=0.0336, n=30). Within the NA group, more reactive animals gained less weight. Steers with higher BS showed lower pH1 values: 6.47, 6.28 and 6.09, respectively, for BS of 1, 2 and 3. Steers with smaller FT showed lower pH1: 6.1, 6.43, and 6.43, respectively, for TF of 1, 2 and 3. Meat of NA steers showed pH1 lower than that of AA steers: 6.17 vs. 6.57. It was observed 23% more color a* (P=0.0394) and 9% more color b* (P=0.0808) on meat from NA steers with larger FT values. Color L* was negatively related with BS3 and pH24 (r= -0.54 and -0.39, respectively) whereas color b* was negatively related with pH3 and pH7 (r= -0.39 and r= -0.45, respectively). Crossbred and more nervous steers had lower weight gain and poorer meat quality.

Ganho de peso de novilhos mantidos em pastagem natural na encosta do sudeste do Rio Grande do Sul, recebendo níveis crescentes de suplementação energética

The trial was conducted to evaluate the effects of energy supplementation with ground sorghum grain on grazing beef steers weight gain. Sixty five steers without definite breed, aging 12 to 15 months and weighing an average 140 kg of live weight were kept under set stocking on a natural pasture improved with Lotus subbiflorus. Treatments consisted of control or without supplement (T0); 0.75% of mean live weight (T0.75) and 1.5% of mean live weight (T1.75) of ground sorghum grain. Animals were randomly assigned to treatments according to a complete randomized design. Considering the overall mean of the trial, supplement levels showed a linear positive effect on daily weight gain, of 0.36, 0.52 and 0.76 kg/animal for T0, T0.75 and T1.5, respectively. Energy supplementation resulted in greater weight gains for supplemented animals compared to not supplemented animals, during all the experiment.

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.

AVALIAÇÃO DAS ATIVIDADES DO COMPORTAMENTO INGESTIVO DE VACAS EM LACTAÇÃO EM PASTAGEM NATIVA E TIFTON 85 NA REGIÃO DA CAMPANHA DO RIO GRANDE DO SUL

Este trabalho foi conduzido com o objetivo de comparar as atividades que definem o comportamento ingestivo, producao e qualidade do leite de vacas holandesas, na fase final de lactacao, alimentadas exclusivamente em tipos de pastagem e ofertas de forragem. Os animais foram alocados em pastagem nativa (10 e 16% de oferta de massa verde seca) e pastagem cultivada de Tifton 85 ( Cynodon spp )( 10% de oferta de massa verde seca). Foram utilizadas nove vacas com peso medio de 356 kg e produzindo diariamente 9,6 litros de leite. Os animais foram bloqueados por numero de partos e producao de leite, distribuidos aleatoriamente aos tratamentos segundo o delineamento quadrado latino, repetido no tempo, com nove animais, tres tratamentos e seis periodos experimentais. As atividades ingestivas consistiram nos tempos diarios de pastejo , ruminacao, descanso e taxa de bocados. O registro do comportamento foi realizado durante 24 horas consecutivas por periodo experimental, sendo avaliadas as atividades com intervalo de dez minutos, individualmente para cada animal. A qualidade do leite nao mostrou diferenca quanto ao teor de proteina e lactose. Nao foram verificadas diferencas significativas entre os tratamentos quanto ao tempo de pastejo , enquanto que as atividades de ruminacao foram superiores na pastagem nativa e o ocio no Tifton 85. As caracteristicas forrageiras das pastagens interferiram no tempo de pastejo dos animais. A disponibilidade de material verde nas diferentes pastagens nao alterou massa de bocado e a producao de leite.xa0 Palavras-chave: descanso entre pastejos , qualidade do leite, ruminacao, tempo de pastejo , oferta de forragem. ABSTRACT This research aimed at comparing the activities that define ingestive behavior in Holstein cows fed exclusively on pasture, upon different periods and levels of forage on offer, in the final period of lactation . The cows grazed native pastures (10 and 16% of dried green mass on offer) and Tifton 85 ( Cynodon spp ) pastures (10% of dry green mass on offer). Nine cows, with mean LW of 356 kg and yielding 9, 6 L/day milk were used as experimental animals.xa0 The animals were blocked based on the number of calving s and milk production. They were randomly allocated to treatments according to a replicated Latin Square Design, with nine animals, three treatments and six experimental periods. Feeding behavior was measures as daily periods of grazing, ruminating, idling and biting rates, recorded over a full 24-h experimental period. C ow activity was recorded every 10 minutes. Milk quality did not show any difference s in terms of protein and lactose. Grazing time did not show extreme differences among treatments. However, ruminating time was significantly higher on native pasture and idling time on Tifton 85. The characteristics of each pastures affected the time cows spent grazing. The amount of green forage mass on offer had no effects on traits such as bite mass and milk production. Key words : milk quality, rumination, grazing time, forage on offer.