ABSTRACT
The behavior and performance of steers on pasture regarding water availability in troughs or in ponds were compared. Eight paddocks were randomly allocated to one treatment: POND (~30 m of diameter) or TROUGH (water trough, 120 cm diameter and 60 cm high and 500 L capacity). Eight groups of six beef steers were randomly assigned to one of the paddocks. The first 10 days were considered for animal habituation. Animals were individually weighed (days 0, 30, 60, and 90). Beginning in the day after each weighing on days 30 (Month 1), 60 (Month 2), and 90 (Month 3), behavior and animal distribution in the paddock were recorded by direct visual observation in three periods of 4 consecutive days. Water temperature and fecal and herbage DM were also recorded in these periods. Water intake was measured during 16 random days in the troughs. Data were analyzed using Generalized Linear Mixed Models, with treatment and period as fixed effects. TROUGH steers gained more weight (0.44 vs. 0.34 kg/day/animal; P ≤ 0.007) during the experiment and were heavier than the others at the end of the study (P ≤ 0.05). POND steers spent more time drinking water, but TROUGH steers increased the number of drinking events throughout the study (P ≤ 0.05), suggesting an adaptation for the new type of water source. Both treatments increased grazing time throughout the study, but not ruminating time (P ≤ 0.05). Walking time differed between treatments in all periods of behavior observation (P ≤ 0.05). Events of animal licking and ingesting salt of POND steers reduced throughout the study (P ≤ 0.05). The number of drinking events of TROUGH steers increased throughout the study, and drinking events were longer for POND steers than TROUGH steers (P ≤ 0.05). TROUGH steers spent more time on pasture on Month 2 (P ≤ 0.05). Period collection did not affect the water intake of TROUGH treatment (P > 0.05). This study demonstrates that water available in troughs rather than ponds for steers on pasture has positive effects on their weight gain and affects cattle behavior.
ABSTRACT
Social hierarchy affects the access of animals to feed resources. On daily rotational pasture systems, supplementation time may influence feeding behavior. This trial was designed to test the effect of grain delivery time on the feeding behavior of heifers. Heifers divided into two groups according to breed (n = 15 Braford and n = 19 Jersey) were tested in a crossover design with two treatments: INITIAL-supplement at 8 am (entry time to a fresh paddock), and MIDDLE-supplement at 4 pm (middle time of paddock use). Animals entered a new paddock every morning, and grain supplement at 2 kg/animal/day was offered at the fence line (1 m/animal). Then, ingestive and other behaviors were registered by direct visual observation through scan sampling at 2-min intervals for 1 h after grain supply. Agonistic interactions were recorded continuously (instigator-victim) to build a social matrix whereby each heifer was defined as dominant, intermediate, or subordinate. Weekly pasture samples were collected according to the order that animals left the feeding area, using the hand-plucking technique, to determine crude protein and fiber content. Heifers spent more time grazing on the INITIAL treatment (p < 0.0001) but exhibited more behaviors on the MIDDLE treatment (p < 0.0001). Dominant heifers spent more time eating grain (p = 0.0008), whereas subordinate heifers spent more time grazing along the paddock (p = 0.0067), but not along the fence (p = 0.0008). The crude protein content of pasture samples was higher for the INITIAL treatment (p < 0.0001). Behavioral interaction occurred with respect to the order of leaving the feeding area, social rank, and crude protein consumed (p = 0.04). Subordinate heifers consistently grazed more and ate less grain supplement than dominant and intermediate heifers. However, when grain supplement was offered at the time animals entered the paddock, more grazing activity took place during supplement feeding, and subordinate heifers could select a high-protein diet. In the INITIAL treatment, this means that subordinate animals could benefit from the better pasture available, keeping a distance from dominant heifers, reducing agonistic interactions and likely improving their welfare.
ABSTRACT
Este trabalho foi realizado com o intuito de se obter um levantamento das pastagens naturais da regiäo de Santa Maria, a qual foi subdividida, para este objetivo, em quatro localidades: Dilermando de Aguiar, Pains, Santa Flora e Säo Martinho. O levantamento utilizou estimativas visuais da freqüência de espécies através do método BOTANAL e permitiu a identificaçäo de 61 espécies, dentre as quais 45 apresentaram contribuiçäo significativa para a biomassa aérea da vegetaçäo. No distrito de Pains, encontrou-se maior freqüência das espécies Axonopus affinis, Eragrostis plana, Desmodium barbatum e Aristida spp.. Em Dilermando de Aguiar, houve maior contribuiçäo de Calamagrostis viridiflavescens, Schizachyrium microstachyum e Paspalum notatum a qual foi, também, uma espécie abundante em Santa Flora, assim como Desmodium incanum. As espécies mais freqüentes em Säo Martinho foram: Baccharis trimera, Paspalum plicatulum e Erianthus angustifolius. O teste de aleatorizaçäo mostrou que, em todas as localidades, ocorreu diferença significativa na sua composiçäo florística (P= 0,0058), evidenciando a inexistência de associaçäo entre os tipos fisionômico-florísticos e os tipos de solo. A partir disto, este levantamento permite que se estabeleçam prioridades quanto à pesquisa e manejo das pastagens naturais dos diferentes grupos fisionômico-florísticos da regiäo
