Integrated crop-livestock systems (ICLS) can be an alternative to increase the productivity of agroecosystems by enhancing nutrient cycling via grazing animals. Despite the holistic approach that bears the designing of ICLS, fertilization practices are proceeded in a conventional crop basis, disregarding nutrient fluxes at the appropriate spatial and temporal dynamics. We argue that fertilization practices in ICLS must follow the same integrated approach. To test this, we compared a conventional crop fertilization strategy versus a system fertilization approach applied to two production systems being a conventional cropping system and ICLS. The conventional cropping system consisted of a soybean crop succeeded by a non-grazed Italian ryegrass cover crop. The ICLS model consisted of a soybean-Italian ryegrass rotation grazed by sheep. In the conventional crop fertilization strategy phosphorus and potassium were applied at soybean sowing and nitrogen at the Italian ryegrass establishment. The system fertilization consisted of the application of all nutrients during the Italian ryegrass establishment. Accordingly, treatments were fertilization strategies in a factorial framework with production systems randomly distributed in a complete block design with four replicates. Results indicated for the first time greater daily herbage accumulation rate (24%; P < 0.01) and total herbage production (18%; P < 0.05) in the system fertilization compared with conventional crop fertilization. Consequently, system fertilization allowed for greater stocking rates in the pasture phase (17%; P < 0.05). The ICLS presented greater equivalent soybean yield (P < 0.001), energy production (P < 0.01), and system productivity (P < 0.05) compared with the cropping system, regardless of fertilization strategies. Soybean yield was not affected by fertilization strategies or grazing. In conclusion, the adoption of system fertilization strategy and crop-livestock integration enhance the production without jeopardizing soybean grain yields, so that land use is optimized by a greater energy production per unit of nutrient applied.

Assessment of carcass bruises in steers and cull females, classified during unloading at the slaughterhouse according to genetic dominance in zebu and taurine cattle, and the presence of horns, including polled, horned and mixed batches. We considered horned the batches that included more than 20% of horned animals and mixed the batches that included less than 20% horned animals. The data were collected in a commercial slaughterhouse and included 93 batches, with a total of 2,520 animals, from different regions in Rio Grande do Sul. After evisceration, the bruises were identified and recorded in the different carcass regions: hip, round, ribs, forequarter and loin area per animal and batch. The weights of the removed tissue due to bruising was based on the average weights of various samples of bruises according to their degree of severity. Regarding the number of bruises per animal, no differences (P > 0.05) were observed between genetic groups, however, when comparing the total bruises per batch, differences were observed in all carcass regions, except for the forequarter, with a greater number of injuries in zebu than in taurine carcasses. The individual assessments showed 86.2% (P < .05) more bruises in the ribs region in horned than in polled animals carcasses. Horned batches had higher bruises mean (P < .05) compared to the polled, with increases of 65.1; 131.7 e 132.8 % in total bruises in the carcass, ribs and forequarter, respectively. The mixed batches did not differ from polled and horned batches. Zebu animals were responsible for higher industry loss totaling 1.21 kg, resulting in a economic loss of R $ 15.48 per carcass. The presence of horns resulted in greater carcass loss, 1.13 kg, with economic loss of R $ 16.11 per carcass. The bruises on carcasses are affected by the breed group and presence of horns, with zebu and horned groups leading to greater economic losses for the meat production chain. Key words: Animal welfare. Carcass cuts. Taurine. Zebu. ResumoFoi realizado um estudo para avaliar as contusões na carcaça de machos castrados e fêmeas de descarte, classificados ao desembarque no frigorífico segundo a predominância genética em taurinos e zebuínos, e a presença de chifres, incluindo mochos, aspados e mistos. Foram considerados aspados os lotes que incluíam mais de 20% de animais aspados, e mistos menos de 20% de animais aspados. coletados em uma empresa frigorífica do RS, por intermédio da análise de 93 lotes, totalizando 2.520 animais, provenientes de diferentes regiões do estado. Após a evisceração, na linha de abate, foram identificadas as contusões e contabilizadas de acordo com as regiões da carcaça: quadril, traseiro, costela, dianteiro e lombo, por animal e total do lote. Os pesos dos tecidos removidos devido às contusões foi baseado nos pesos médios de várias amostragens das contusões de acordo com o grau de severidade das mesmas. Não houve diferenças (P > 0,05) no número de contusões por animal entre os grupos genéticos, porém, quando comparados os totais por lote, observ...

This study was developed to evaluate productive efficiency during the lactation period of cows with predominant Nellore genetic composition based on their body size. Cows were divided into the following categories: light (≤ 316 kg), moderate (≥ 317 and ≤ 400 kg), or heavy (≥ 401 kg). Body weight change and total gain from birth to 210 days of age of calves born from heavy cows (0.155±0.03 and 111.6±5.1 kg) were higher than those of calves born from light (0.064±0.03 and 91.0±4.3 kg) and moderate (0.144±0.03 and 97.7±4.0 kg) cows. Calf production index differed (p < 0.05) with the herd of heavy cows (93.5±3.2 kg), producing 57.4 and 19.7% more kilograms of calf than light (59.4±2.7 kg) and moderate (78.1±2.4 kg) cows, respectively. Heavy Nellore cows produce heavier calves and have a better reproductive performance, which lead to a better calf production index. However, they require a larger area for the same herbage allowance. Calves born from heavier Nellore cows gain more weight from birth to 210 days of age and are heavier from 210 to 270 days of age.

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The objective was to evaluate the production and efficiency of 24-month-old Red Angus primiparous cows of different weights at weaning and repetition of pregnancy. Before calving, the females were managed in natural prairies and fed sweet clover (Lotus corniculatus) and ryegrass (Lolium multiflorum Lam.), with loads of 315 and 501 kg ha-1, respectively. Females were divided into groups according to the average birth weight into light 346.15 ± 3.39 kg; moderate 381.95 ± 2.99 kg; and heavy 412.63 ± 3.33 kg weights. The indicators evaluated were: primiparous weights and body conditions at calving and weaning, daily average and total gains, fixed-time artificial insemination (FTAI), and accumulation. Calves at birth and weaning had their daily average and total weights evaluated. In terms of production, the daily average and total gains per pair and effective herd production (EHP) of the weight groups were measured. At weaning, morphometric measures, viz. croup height and thoracic perimeter had a linear relationship increasing with the weight at calving. In FTAI and cumulative pregnancy, the groups of light and moderate cows were more efficient than the heavy group cows, with values of 81.25%, 75.00%, and 55.56%, respectively. The EHP differed between the groups with values of 37.07 ± 1.71, 28.13 ± 1.50, and 19.99 ± 1.68 kg, for light, moderate, and heavy, respectively. Light cows were 31.8% and 85.4% higher in effective production than moderate and heavy cows, respectively. Knowledge of the production system is important for enhancing breeding efficiency. The improvement in productive performance is related to the adequacy of metrices used in the production system.

Comportamento ingestivo de ovinos em gramíneas tropicaisMadruga Moreira, S.; Tavares Costa, P.; Albandes Fernandes, T.; Duarte Farias, G.; Oteiro Faria, P.; Farias Silveira, R.; Peter Gonçalves, B.; Denardin Costa, O.; Barbosa Silveira, I. e Pedroso, C.E. Universidade Federal de Pelotas. Brasil. REVISÃO BIBLIOGRAFICA Palavras chave adicionais Comportamento animal. Ovinocultura. Pastejo. Brasil. RESUMOO objetivo desta revisão foi discutir os principais fatores que afetam o comportamento ingestivo de ovinos manejados em pastagens de gramíneas tropicais. Conhecer os hábitos destes animais é importante para se realizar o manejo adequado às suas necessidades, respeitando seu bem-estar e aumentando os índices produtivos. Ovinos pastejam basicamente no período diurno, consumindo cerca de 2-5% de seu peso corporal por dia, com tempo variando de acordo com a disponibilidade e o tipo de alimento, dificilmente ultrapassando 12 horas, pois tempos maiores interferem em outras atividades. A ruminação, atividade que demanda mais tempo depois do pastejo, divide-se em 15-20 vezes ao longo do dia, variando de poucos minutos a mais de uma hora, sendo maior à noite. A espécie forrageira, devido às suas características físico-químicas e de manejo, influencia a resposta animal. Com baixa disponibilidade de massa de forragem, os ovinos realizam até 65 bocados/minuto, mas em oferta satisfatória, essa frequência pode cair 50%. A área de bocado é afetada pela estrutura da pastagem. Com maior proporção de folhas há aumento na taxa e peso de bocados. Uma baixa proporção de folhas reduz o peso de bocados, aumenta o intervalo entre estes e o tempo total de pastejo. Os dados sobre o comportamento ingestivo de ovinos em gramíneas tropicais ainda são deficientes, havendo grande divergência entre autores.information Cronología del artículo. Recibido/ Ingestive behavior of sheep in tropical grass sUmmarYThe aim of this review was to discuss the most important factors that affect the feeding behavior of sheep grazing tropical grasses. Know the habits of these animals is important to perform the appropriate management to their needs, respecting their welfare and increasing the productive indexes. Sheep graze basically during the day, intake approximately 2-5% of their body weight per day, with time varying according to the feed availability and type, rarely exceeding 12 hours, because higher times affect in others activities. Rumination, an activity that requires more time after the graze, is divided into 15-20 times in the day, varying from few minutes to more of one hour, being higher at night. The forage species, due to their physical-chemical and management characteristics, influence the animal response. With low forage mass availability, sheep perform 65 bite/minute, but in a satisfactory offer, this frequency can reduce 50%. The bite area is affected by the pasture structure. With a higher proportion of leaves occurs the increase in the bite rate and weight. A low proportion of leaves reduces the bite weight, increase the bite interval and the...

The system fertilization approach emerged to improve nutrient use efficiency in croplands. This new fertilization concept aims at taking advantage of nutrient cycling within an agroecosystem to obtain maximum production from each nutrient unit. To monitor this effect, methodologies such as the Normalized Difference Vegetation Index (NDVI) are promising to evaluate plant biomass and nutrient content. We evaluated the use of NDVI as a predictor of shoot biomass, P and K uptake, and yield in soybean. Treatments consisted of two production systems [integrated crop-livestock system (ICLS) and cropping system (CS)] and two periods of phosphorus (P) and potassium (K) fertilization (crop fertilization—P and K applied at soybean sowing—and system fertilization—P and K applied in the pasture establishment). NDVI was evaluated weekly from the growth stage V2 up to growth stage R8, using the Greenseeker® canopy sensor. At the growth stages V4, V6, R2, and R4, plants were sampled after NDVI evaluation for chemical analysis. Soybean yield and K uptake were similar between production systems and fertilization strategies (P &gt; 0.05). Soybean shoot biomass and P uptake were, respectively, 25.3% and 29.7% higher in ICLS compared to CS (P &lt; 0.05). For NDVI, an interaction between the production system and days after sowing (P &lt; 0.05) was observed. NDVI increased to 0.95 at 96 days after sowing in CS and to 0.92 at 92 days after sowing in ICLS. A significant relationship between NDVI and shoot biomass, and P and K uptake was observed (P &lt; 0.05). Our results show that the vegetation index NDVI can be used for estimating shoot biomass and P and K uptake in the early growth stages of soybean crops, providing farmers with a new tool for evaluating the spatial variability of soybean growth and nutrition.