Effect of recovery period of mixture pasture on cattle behaviour, pasture biomass production and pasture nutritional value.

Pasture management that considers pasture growth dynamics remains an open question. Conceptually, such management must allow for grazing only after the recuperation of the pasture between two separate timely grazing periods when pasture reaches optimum recovery, as per the first law of Voisin's rational grazing system. The optimum recovery period not only implies a pasture with better nutritional value and higher biomass yield but one that also reduces the production of enteric methane (CH4) to improve the grazing efficiency of cattle. Therefore, this study aimed to evaluate three different recovery periods (RP) of mixed grasses on the grazing behaviour of heifers, as well as herbage selectivity, herbage yield and nutritional value, in vitro degradability and CH4 production. Based on these criteria, three pasture RPs of 24 (RP24), 35 (RP3) and 46 (RP46) days were evaluated in six blocks using a randomized block design. At each predetermined RP, samples of the pasture were taken before the animals were allowed to graze. Right after collecting the pasture samples, heifers accessed the pasture during 4 h consecutively for grazing simulation and behavioural observations. We also measured the bite rate of each animal. The pasture growing for 24 days had the highest biomass production, best nutritional value, best efficiency of in vitro CH4 relative emission (ml) per DM degraded (g) and bite rate of the three RPs. Heifers all selected their herbage, irrespective of RP, but with different nutritional value and higher in vitro degradability. However, this did not change the production of in vitro CH4. Considering the growth conditions of the area where the study was performed, we recommend the shorter RP24 as the most suitable during the summer season. The study's findings support the idea of management intervention to increase the quality of grazing systems.

Dairy heifers benefit from the presence of an experienced companion when learning how to graze.

Pasture remains important on many dairy farms, but the age of first contact with pasture varies depending on the month of birth, weaning age, and farm management. Regardless of age, naïve dairy heifers must learn to graze when first introduced to pasture. This study investigated whether being grouped with experienced dairy cows would affect the development of grazing behaviors. Sixty-three Holstein heifers (mean ± SD 14.2 ± 1.3 mo; 546 ± 60.7 kg) and 21 dry Holstein cows (2.6 ± 0.8 lactations; 751 ± 53.9 kg) were assigned into 7 groups of 12 animals (3 dry cows and 9 naïve heifers), and each was divided and assigned to an experienced (3 cows and 3 heifers) and nonexperienced (6 heifers) sub-group. Sub-groups were introduced to pasture in different paddocks without visual contact with any other cattle. No difference was found in the time after introduction to the paddock for heifers to first attempt to nibble grass [experienced: 0:23 (0:17-0:43) vs. nonexperienced 0:40 (0:35-0:46); median (quartile 1 - quartile 3), h:mm]. However, heifers grouped with experienced cows showed a shorter latency to begin grazing [experienced: 0:47 (0:28-00:52) vs. nonexperienced 2:13 (1:25-2:30)]. During the first hour after introduction to pasture, heifers in the experienced treatment showed fewer stomping events [experienced: 2.5 (1.25-4) vs. nonexperienced: 6.5 (4-8)] and vocalized less often [experienced: 3.5 (1.25-5.75) vs. nonexperienced: 7 (5-8.75)]. After this initial period, animals in both subgroups began to graze normally; treatments did not differ in grazing behaviors over the 3-d observation period. These results indicate that grouping heifers with pasture-experienced cows improves grazing behavior of dairy heifers in the first hours following introduction to pasture.

Strategies used by dairy family farmers in the south of Brazil to comply with organic regulations.

The aims of this study were to investigate the environmental, feeding, and health management of organic (ORG) family dairy farms in the south of Brazil in comparison with conventional (CONV) farms, and to assess their degree of compliance with Brazilian organic legislation and the strategies they adopt to accomplish this (n=17 per group). During 2 visits to each farm in March and September, 2010, observations were made on the environment, feed, and health management, followed by bulk milk testing, clinical evaluation, and breed assessment of each individual cow, and an evaluation of diseases and treatments reported within the period. Additional data were collected directly from the farmers through direct interviews. The number of lactating cows was, on average, 11 (range 5 to 19) in the ORG and 16 (range 7 to 42) in the CONV herds. The ORG herds presented a lower percentage of the Holstein breed; whereas CONV herds were predominantly Holstein, in the ORG herds, only 2 herds were 100% Holstein and the remaining herds were crosses of Holstein, Jersey, and Gir (Bos indicus) cattle. Milk production per cow was lower (10.2 vs. 15.1 ± 1.22 L/cow, respectively) in ORG than in the CONV farms. The ORG farms offered less concentrate feed than CONV farms and had better pasture management. Organic farmers reported using phytotherapic and homeopathic products, and pasture management as a strategy to keep infection levels of endo- and ectoparasites low, whereas CONV farmers regularly used anthelmintics and acaricides. Milk production was lower in ORG than in CONV farms, but cow health and condition scores were broadly similar, indicating that the with these strategies ORG farms were able to secure levels of animal welfare comparable with CONV farms while complying with organic regulation, although at the cost of lower cow productivity.

Short-term behavioural effects of weaning age in outdoor-reared piglets.

Age at weaning affects the behaviour of piglets weaned in conventional confined environments. The adaptation of piglets to this event, which exposes piglets to important stressors, has not been examined in detail in outdoor systems. The aim of this study was to compare the behaviour of piglets weaned at 3 or 4 weeks of age in an outdoor production system. Six replicates of four piglets born and raised outdoors, originated from different litters but previously acquainted, were weaned at the age of approximately 20 (D20) or 30 (D30) days in 36 m2 outdoor pens and offered high-quality diets. Their behaviour was recorded by direct visual observation during four consecutive days after weaning (days 1 to 4). Data were analysed by repeated measures ANOVA. An effect of weaning age was observed on feeding and rooting ( P < 0.01), and a day-by-weaning age interaction for escape attempts, vocalizing, walking and fighting ( P < 0.01), and playing ( P < 0.03). Compared to D30 piglets, D20 piglets showed a higher frequency of escape attempts on day 1, vocalized more during days 1 and 2, and walked more during days 1 to 3 ( P < 0.05). Feeding behaviour, on the other hand, was higher in D30 piglets on days 1 to 3 ( P < 0.05). On days 3 and 4, D30 piglets spent more time interacting with peers (playing and fighting; P < 0.05) and on day 4 were more active than D20 piglets ( P < 0.05). As previously reported in confined environments, age at weaning affected the behaviour of piglets raised on the outdoors system. Weaning appeared to be more stressful for the piglets at 3 than at 4 weeks of age. The impact of weaning age on welfare cannot be ignored, especially when outdoor breeding of pigs is proposed to address welfare concerns of the public.

Effect of water trough type on the drinking behaviour of pasture-based beef heifers.

The objective of this study was to investigate the effects of different trough types on the water consumption and drinking behaviour of pasture-based beef heifers. Two trials were implemented with 32 beef heifers to test two different types of water troughs, namely a rectangular concrete trough (RC) and a round polyvinyl chloride water tank (PVC). In Trial 1, both troughs were simultaneously available to groups of four animals within eight paddocks. In Trial 2, the animals were distributed in pairs throughout 16 paddocks and, in a crossover design, were exposed to one type of trough at a time. In both trials, estimated water intake was per four animals. Number of drinking bouts, time spent drinking and amount of water intake from the RC and PVC trough were recorded in both trials. Data were statistically analysed by analysis of variance. In Trial 1, group and trough effect were in the model. In Trial 2, stage, pair and trough were tested. In Trial 1, where both types of troughs were available, animals had a higher number of drinking bouts (3.32 v. 0.57 ± 0.09; P < 0.01), longer drinking periods (144.21 v. 22.81 ± 7.3 s; P < 0.01) and greater intake (160.21 v. 23.76 ± 13.06 l; P < 0.01) from the PVC water tank, compared to the RC trough. In Trial 2, all groups drank more often (5.10 v. 3.28 ± 0.32; P < 0.001), for longer periods (167.23 v. 115.23 ± 15.61 s; P < 0.02) and with higher intake (141.36 v. 118.47 ± 5.01 l; P < 0.02) from the PVC than from the RC trough. Thus, heifers not only prefer, but also drink more from a PVC water tank in comparison to a RC trough.

Produção e qualidade do pasto de coastcross consorciado ou não com amendoim forrageiro com ou sem aplicação de nitrogênio / Production and quality of coastcross pasture associated or not with forage peanut with or without nitrogen

Avaliaram-se a taxa de acúmulo foliar (TAF), a produção total de forragem (PTF), a composição química da forragem e os valores de digestibilidade in vitro da matéria seca (DIVMS) do coastcross (Cynodon dactylon) e do amendoim forrageiro (Arachis pintoi) em pastagem consorciada. Foram avaliados os tratamentos (parcelas): coastcross + A. pintoi sem nitrogênio (CA0); coastcross + A. pintoi com 100kg de nitrogênio (CA100); coastcross com 200kg de nitrogênio (C200) e coastcross + A. pintoi com 200kg de nitrogênio (CA200), e as estações (subparcelas) do ano inverno, primavera, verão e outono. Utilizou-se um delineamento experimental em blocos ao acaso, em esquema de parcelas subdivididas no tempo, com duas repetições. Os tratamentos com os maiores níveis de adubação de nitrogênio apresentaram TAF mais alto que os demais (P<0,05). No verão ocorreu a maior PTF, seguida da primavera, outono e inverno, mas estes não diferiram entre si. Não houve diferença (P>0,05) entre os tratamentos para as variáveis proteína bruta, fibra em detergente neutro e digestibilidade in vitro de matéria seca, tanto para as frações de folhas do coastcross, como para a planta inteira do A. pintoi. A adubação nitrogenada, quando aplicada à pastagem de coastcross singular ou associada ao amendoim forrageiro, proporcionou aumento da TAF e da PTF, com maior produtividade e qualidade no verão.

Forage accumulation rate (FAR), total forage production (TFP), chemical composition and in vitro dry matter digestibility (IVDMD) of coastcross pasture mixed with Arachis pintoi (AP) were evaluated. Treatments plots were: coastcross + A. pintoi without N (CA0); coastcross + A. pintoi with 100kg of N (CA100); coastcross with 200kg of N (C200); and coastcross + A. pintoi with 200kg of N (CA200); and seasons of the year (split-plots): winter, spring, summer, and autumn were analyzed. A randomized block design was used subdivided into time plots, with two replications. Treatments with the highest fertilizer levels presented higher FAR than others (P<0.05), with higher TFP during the summer, followed by spring, autumn, and winter, with no differences among then. There were no differences (P>0.05) among treatments for CP, NDF, and IVDMD on coastcross leaf fractions and Arachis pintoi whole plant. Nitrogen fertilization, when applied to single coastcross pasture or mixed with forage peanut, increased accumulation rate and forage accumulation, with higher productivity and quality in summer.