Denise Adelaide Gomes Elejalde

Efeito de níveis de suplementação sobre o comportamento ingestivo de bezerras em pastagem de aveia (Avena strigosa Schreb.) e azevém (Lolium multiflorum Lam.)

Foi avaliado o comportamento ingestivo de bezerras de corte submetidas a diferentes niveis de suplementacao energetica. Os niveis testados foram (0; 0,5; 1,0; 1,5% do peso vivo), em pastagem de aveia preta (Avena strigosa Schreb.) e azevem (Lolium multiflorum Lam.). O suplemento foi farelo de trigo, fornecido diariamente as 14h. Para registro das atividades de pastejo, ruminacao, ocio e permanencia no cocho, adotou-se a observacao visual, feita a cada dez minutos, durante 24 horas, em quatro datas. Para cada nivel de suplementacao, foram observados seis animais dos grupos geneticos Charoles, 3/4 Charoles/Nelore e 5/8 Nelore/Charoles, com aproximadamente oito meses de idade e peso inicial de 158 kg. Os animais que receberam suplementacao diminuiram o tempo de pastejo em relacao aos nao-suplementados, sem alteracao no consumo estimado de forragem. Os animais que receberam suplementacao a 1,5% do PV permaneceram mais tempo no cocho, aumentando a frequencia de retorno ao cocho nos maiores niveis de suplementacao. Os niveis de suplementacao nao interferiram nos tempos de ruminacao e ocio.

Fertilization and oversowing on natural grassland : effects on pasture characteristics and yearling steers performance

The objective of this study was to evaluate the vegetal and animal production of a natural pasture on a Mollisol soil in the region of Campanha, in RS. The experimental design consisted of complete randomized blocks with three replicates, which enables the comparison between natural unfertilized pastures with fertilized pastures and pastures fertilized and overseeded with Lolium multiflorum, Lotus corniculatus cv. Sao Gabriel and Trifolium repens cv. Lucero (NPO). Data were submitted to the analyses of variance considering seasons of the year as time repeated measurements. Aberddeen Angus calves of about nine months of age were used in continuous stocking with variable stocking rate in order to maintain forage offer at 13% of live weight. Data were collected between July 7th (2007) and May 3rd (2008), totaling 302 days. Fertilized and oversown pastures showed higher green forage mass mainly in the spring, as result of higher dry matter (DM) accumulation rate. Average daily live-weight gain for fertilized pasture (0.581 kg/day) was higher than for natural pasture (0.473 kg/day). Higher live-weight gains were obtained in the fall (0.869 kg/day). Stocking rate showed interaction with the seasons of the year, with higher stocking rates obtained in oversown pasture (701 kg of LW/ha) and fertilized pasture (667 kg of LW/ha) during the spring. Live-weight gain per hectare from natural pasture (224 kg LW/ha) was lower than on fertilized (310 kg LW/ha) and over-sown pasture (287 kg LW/ha). Forage mass, dry matter content, forage allowance and pasture height explained 61% of the average live weight gain. Despite the good performance of native grasslands in this region in its natural condition, the utilization of different inputs as fertilization and oversowing of winter cultivated species promoted positive differences in forage production and its distribution along the year and in animal yield.

Quality of the forage apparently consumed by beef calves in natural grassland under fertilization and oversown with cool season forage species

The objective of this study was to evaluate the chemical composition of the forage apparently consumed by steers in a natural grassland on region of Campanha, in Rio Grande do Sul, Brazil, subjected or not to different inputs: NP - natural pasture without inputs; FNP - fertilized natural pasture and INP - improved natural grassland with fertilization and over-seeded with cultivated winter species. Three Angus steers testers and a variable number of regulator animals per experimental unit were utilized in order to maintain 13 kg of DM/100 kg of live weight (LW) as forage allowance. One time at each season, hand plucking samples were performed along the daily grazing time simulating forage harvested by the animals. The collected samples after drying and grind were submitted to chemical analysis to determine the forage quality. Except in winter and spring, the values of neutral detergent fiber were higher than the critical value of 550 g/kg of DM, which could limit forage intake, demonstrating that the values of forage on offer provided (15.6; 13.7; 13.5; 15.8 kg of DM/100 kg of LW/day in summer, autumn, winter and spring, respectively) were not restrictive to intake. The oversowing of winter cultivated species or fertilization positively alter the degradable fiber content. The seasons had marked influence on the chemical composition of forage apparently consumed; positively increasing some fractions of forage chemical composition in the seasons in which native or cultivated winter species increased their participation. The forage chemical composition is the determining factor in animal performance in natural pasture.

Characteristics of forage and feeding behavior of Nellore heifers fed hydrolyzed sugarcane

The objective of this study was to evaluate the chemical characteristics of the forage and ingestive behavior of Nellore heifers fed hydrolyzed sugarcane in different periods of storage. Twenty-four heifers with initial body weight of 119.6±8.1 kg were utilized. The experimental design was completely randomized, in which the treatments were diets with fresh sugarcane and hydrolyzed sugarcane (5 g of lime kg-1 of chopped sugarcane) stored for 24, 48 or 72 hours as the only roughage. The addition of lime to sugarcane associated with its storage up to 72 hours provided an increase of 20% of the potentially degradable cell wall of carbohydrates, from 382.4 to 458.8 g kg-1 of total carbohydrates. The in vitro digestibility of dry matter was altered by the storage of hydrolyzed sugarcane, increasing 7.08% when the storage time was increased from 24 to 72 hours. Heifers fed fresh sugarcane remained more time consuming compared with heifers fed other diets. The time used for water intake was not influenced by the diet. The rumination time presented a quadratic variation in relation to storage time of the hydrolyzed sugarcane, with higher values for the of hydrolyzed sugarcane diets stored for 48 hours. Heifers fed hydrolyzed sugarcane spent more time on other activities than those fed fresh sugarcane. The supply of hydrolyzed sugarcane stored up to 72 hours in the proportion of 600 g kg-1 of dry matter in the diet, alters the intake patterns, reducing the feed intake in Nellore heifers.

Consumo de matéria seca e desempenho de novilhas Nelore alimentadas com dietas contendo cana-de-açúcar hidrolisada

The study aimed to evaluate the nutrients intake and performance of Nellore heifers fed with chopped sugarcane, fresh (FS) or treated (HS) with 0.5% of Ca(OH)2 and stored during 24, 48 or 72 hours. It was used twenty-four heifers with nine months age and 119.6±8.1kg of initial body weight. The experimental design was completely randomized with four treatments and six replications. The dry matter intake showed an average reduction of 29% by adding Ca(OH)2, and didnt change with the storage period. Calcium intake was increased by the use of HS in the diet, while maintaining acceptable levels of intake. Heifers fed with HS stored during 24, 48 and 72 hours had, respectively, average daily weight gain of 41, 30 and 35% lower than those fed with FS. The treatment of sugarcane with Ca(OH)2 is not recommended for feeding Nellore heifers, due to limited intake and lower weight gain.

Terminação de novilhos de corte Angus e mestiços em pastagem natural na região da Campanha do RS

The viability for slaughtering steers of distinct breeds with four teeth at most, on different types of pasture (natural, fertilized and fertilized with overseeding) with winter species was evaluated. The experimental design was randomized blocks with three replicates (padlocks). Data were analyzed according to the seasons (winter and spring) and submitted to analyses of variance. Angus calves and crossbred calves were used, both 20 months of age on average. Total forage mass and the pasture height showed differences between pasture type and seasons. Carrying capacity rate and green forage mass showed interaction between pasture type and season. Yield per unit area during the experimental period was higher in fertilized (259 kg/ha) and oversown pasture (263 kg/ha) than natural pasture (126 kg/ha). Average live-weight gain was higher for the Angus steers (1.087 kg/day) and during the winter (1.251 kg/day). Rib eye area did not show statistical difference between the pasture type and breeds at slaughtering time. Fat thickness showed interaction according to pasture and breeds, where crossbred steers were fatter on fertilized pasture and Angus steers were fatter on oversow pasture. Crossbred animals got lower slaughtering weight (505 kg), yet higher carcass yields (51.6%). Only steers kept on natural pasture did not reach enough fatness for commercialization. The use of fertilizer and seed on the natural pasture allows for slaughtering young steers regardless of the breed. Pasture condition allows different productive performances according to the animal genetics used. Crossbreeding is an alternative to increase important attributes on carcass and to reduce the finishing phase duration.

Padrões de comportamento ingestivo de cordeiras recebendo ou não suplemento em pastagem de milheto

The ingestive behavior and displacement and forage searching patterns of female lambs in Pearl millet (Pennisetum glaucum (L.)) were evaluated when lambs were kept exclusively on Pearl millet pasture and on pearl millet pasture receiving supplement. The supplement used was a commercial ration given daily at 17h. The experimental design was completely randomized, with two area replicates. The animals that received supplement reduced the grazing time and increased the idling time. The intake, displacement and forage searching patterns were influenced by changing on pasture structure along the Pearl millet stage of development and were not modified by supplement supply.