Flânia Mônego Argenta

Behavior patterns of cows with Charolais or Nellore breed predominance fed diets with plant extract or monensin sodium

The objective of this research was to study the ingestive behavior of feedlot cows fed additives based on plant extracts or monensin sodium. Twenty-four Charolais and Nellore crossbred cows with age and average initial weight of 7 years and 423 kg, respectively, were used. The experimental diets were plant extracts: basal diet + 5 g/animal/day of a natural additive composed of 750 mg of essential oil of thyme (Thymus vulgaris), 150 mg of garlic (Allium sativum), 250 mg of rosemary extract (Rosmarimus officinalis), 250 mg of canola oil (Brassica napus), 250 mg extract of quillaja (Quillaja saponaria), and 3350 mg of corn starch; sodium monensin: basal diet + 300 mg/monensin/animal/day; and control: basal diet without additive. The basal diet contained sorghum silage and concentrate in a 62:38 ratio. The experimental design was completely randomized with a 3 × 2 (3 diets and 2 breed predominances) factorial arrangement, and means were compared using DMS test at 5% of significance. The type of additive consumed did not alter animal feeding behavior. Cows with Charolais predominance consumed more dry matter (13.78 vs. 12.38 kg/day) and neutral detergent fiber (7.81 vs. 6.89 kg/day), ruminated for longer (8.47 vs. 7.82 h), spent more time chewing (13.05 vs 12.01 h), had a greater number of chews per minute (58.88 vs 53.21) and a greater number of ruminal bolus (541.43 vs. 464.09 boluses/day); however, cows with Nellore predominance had greater idling time (11.82 vs. 10.74 h).

Productivity and production efficiency of cows of different genetic groups submitted to cultivated pastures during pre or postpartum.

Avaliou-se atraves do desenvolvimento de vacas e bezerros ate o desmame aos 90 dias e tambem do desempenho reprodutivo desde a prenhez ate a desmama, a produtividade e a eficiencia de 94 vacas de corte dos grupos geneticos Charoles (CH), Nelore (NE), ½CH ½NE e ½NE ½CH submetidas aos seguintes sistemas de alimentacao: vacas mantidas exclusivamente em pastagem nativa (PN); vacas mantidas em pastagem cultivada (PC), composta por aveia (Avena sativa), azevem (Lollium multiflorum) e trevo vesiculoso (Trifolium vesiculosum) durante o periodo de 15 de julho a 15 de setembro e o restante do periodo experimental em pastagem natural (PCN); e vacas mantidas em pastagem cultivada durante o periodo de 15 de setembro a 15 de novembro, e o restante do periodo em pastagem nativa (PNC). As vacas mantida em PC produziram 22,6% a mais de bezerros do que as vacas mantidas exclusivamente em PN, bem como foram mais eficientes no indice de producao de bezerros (eficiencia dos rebanhos), com 57,0 vs 37,0 kg de bezerros/vaca mantida no rebanho. Na producao de kg de bezerros por vaca, as femeas mantidas em PC no pos-parto (69 kg) foram superiores (P 0,05), sendo estas superiores as puras na produtividade e eficiencia produtiva.

Development and reproductive performance of beef heifers supplemented with brown rice meal and/or protected fat on temperate grasslands

The response of energy supplementation was evaluated on the development and reproductive performance of beef heifers on temperate grasslands. Twenty-eight Charolais × Nellore heifers, with initial average age of 18 months and initial live weight of 274.9 kg were utilized. The animals were maintained on oat + ryegrass pasture and distributed in the following treatments: no supplementation (NS): heifers kept exclusively on pasture; MEG: supplementation with protected fat Megalac®; BRM: supplementation with brown rice meal; BRM+MEG: supplementation with BRM + protected fat. The average final weight of the heifers was of 403.4 kg and corresponded to 89.5% of the adult weight. The body condition of heifers increased linearly with daily increase of 0.012 points, correlating positively with the final weight. There was interaction between treatment and period for average daily weight gain. The highest daily weight gain, 1.395 kg, occurred in the first period when the animals were supplemented with BRM+MEG. In the last period, the NS animals presented the lowest daily weight gain, 0.888 kg. Supplementation with brown rice meal and/or protected fat does not interfere in the intake of pasture by heifers or increase the total intake of dry matter, not changing, therefore, the average daily weight gain at the end of the period of grazing. The daily weight gain does not change during supplementation. The use of temperate pasture with and without supplementation promotes the proper development of the structure and reproductive tract of heifers, benefiting the animal performance indexes in the first mating at 25-27 months of age.