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A suinocultura tem grande representatividade na economia brasileira, devido à sua importância social e cultural em regiões de produção intensiva. Em Santa Catarina, a relevância da suinocultura ganha destaque, devido à qualidade de seu rebanho e status sanitário, representando a principal atividade pecuária do estado. A modernização na suinocultura possibilitou que os produtores se especializassem em fases específicas do ciclo de produção, sendo a unidade produtora de leitões (UPL), que engloba os setores de reprodução, maternidade e desmame, sendo considerada a fase com maiores desafios. Assim, este trabalho teve por objetivo caracterizar as UPLs do Extremo Oeste Catarinense, identificando manejos adotados e os índices zootécnicos obtidos em municípios da região Extremo Oeste Catarinense. Foram aplicados questionários online, utilizando a ferramenta Forms do Google. O questionário foi composto por quatro seções, intituladas: informações gerais, gestação, lactação e desmame. Foram obtidas 14 respostas ao questionário, abrangendo nove municípios do Extremo Oeste Catarinense. O tamanho das UPLs foi heterogêneo, de 100 até mais de 1000 matrizes. A metade dos produtores declararam que a renda advinda da UPL é a renda total familiar. Em relação ao sistema de produção, 79% das UPLs estão nos sistemas cooperado ou integrado. Sobre os índices zootécnicos, 93% das UPLs relatou obter 2,0 a 2,5 partos/porca/ano. Em todas as UPLs, a inseminação foi indicada como método de reprodução utilizado. Em 86% das UPLs obteve-se a média de 11 a 15 leitões nascidos vivos/leitegada. Para a ocorrência de leitões mumificados em 86% das UPLs, o índice era de 2%; quanto aos leitões natimortos, 79% das UPLs apresentaram menos de 5%. Já para a mortalidade pré-desmame dos leitões, apenas 36% das UPLs apresentaram valor abaixo de 5% em 79% dos casos, o esmagamento foi apontado como a principal causa das mortes. Para o peso médio ao desmame, 79% dos produtores relataram obter valores entre 5 e 7 kg, realizando o desmame entre 22 e 28 dias. Como medidas de biossegurança destaca-se o uso de programas de vacinação, lavagem das instalações e uso de bebedouro tipo chupeta. Conclui-se que a maioria das granjas da região Extremo Oeste Catarinense possuem alto nível produtivo, no entanto existem fatores a serem melhorados para que se consiga chegar a resultados ainda melhores, em especial quanto a taxa de mortalidade de leitões pré-desmame.

Background and aims: The concepts of critical nitrogen (N) concentration and nitrogen nutrition index (NNI) provide effective tools for assessing the N nutritional status of pastoral systems. However, no conclusive data exist concerning the effects of stubble height at harvest on the N dilution curve [N concentration (N%) = a(biomass)⁻ᵇ] and mixed species cultivation on N nutritional status of forage plants with contrasting growth strategies. To evaluate these effects, three cool‐season perennial grasses (exploitative, Arrhenatherum elatius L.; moderately exploitative, Dactylis glomerata L.; conservative, Festuca arundinacea Scherb.) were grown under different cultivation methods either as pure stands or as a mixture and conducted two experiments. Methods: In experiment I, canopies of different grass species pure stands and mixtures were subjected to defoliation managements aimed to not exceed the critical LAI at harvest. Forage samples were collected from October 2015 to August 2016 to determine the N nutritional status throughout the seasons. In experiment II, half of each pure stand was mowed to 10 cm in height, and the other half to ground level. Thereafter, herbage samples were taken during regrowth to determine N dilution curves in both scenarios (from ground level and from stubble height of 10 cm). Results: We verified an NNI above 0.8 during autumn and winter for A. elatius, D. glomerata, and the mixture but only in winter for F. arundinacea. Dactylis glomerata grown in the mixture had a lower N% than its pure stand during autumn and winter, whereas A. elatius and F. arundinacea showed no differences irrespective of cultivation method throughout the year. The three forage species presented classical dilution curves when regrowth was initiated from ground level, but quadratic trends were observed when regrowth was initiated from stubble heights of 10 cm. Conclusions: Overall the N nutritional status of cool‐season perennial grasses was not affected by cultivation method when pastures were managed in conditions of non‐limiting N supply and with pre‐cut/grazing height targets derived from critical LAI measured at the full vegetative growth stage. Moreover, the N nutrition status in pastures managed under moderate/lenient defoliation should not be evaluated during periods of less intense canopy renewal and/or right after the cut/grazing events.

In this study we tested whether the root biomass of mixtures composed by grass species is greater than their respective monocultures. The treatments were monocultures of Arrhenatherum elatius, Festuca arundinacea, Dactylis glomerata, and a mixture of them, cultivated in a rich-soil environment. Root biomass was evaluated on a single evaluation per season at three soil depths (0-5, 5-10, and 10-20 cm). Mixed swards presented the greatest root biomass, and this was explained by a greater concentration in the topsoil layer (0-5 cm). These findings reinforce the need for permanent soil conservation practices to not jeopardize the benefits of the more abundant root biomass reported in the mixed swards. RESUMO: O presente estudo testou se a biomassa radicular de misturas compostas por gramíneas é maior do que os seus respectivos monocultivos. Os tratamentos foram monocultivos de Arrhenatherum elatius, Festuca arundinacea, Dactylis glomerata e uma mistura delas, cultivadas em um solo rico em nutrientes. A biomassa da raiz foi avaliada uma vez por estação em três profundidades de solo (0-5, 5-10 e 10-20 cm). Os pastos mistos apresentaram a maior biomassa radicular e isso pode ser explicado pela maior concentração de raízes na camada superficial do solo (0-5 cm). Esses achados reforçam a necessidade de práticas permanentes de conservação do solo para não prejudicar os benefícios da biomassa radicular mais abundante encontrada nos pastos mistos.

The purpose of this study was to evaluate the effects of two isoproteic total mixed rations containing either red clover (Trifolium pratense L.; RC diet) or lucerne (Medicago sativa L.; LU diet) silage as the major forage source on milk yield, milk composition, and milk fatty acid (FA) profile in dairy ewes. Sixteen dairy ewes were housed individually to receive the drawn diet (eight ewes eating each diet) and milked twice a day (0700 and 1500). Total dry matter intake, milk yield, milk composition, and nitrogen use efficiency were unaffected by treatments. The n-6/n-3 FA ratio tended to decrease, whereas the total polyunsaturated fatty acids (PUFAs) and PUFAs/saturated fatty acids ratio increased in the milk fat of ewes fed the RC diet compared with ewes fed the LU diet. The presence of α-linolenic (C18:3n-3) and linoleic (C18:2n-6) acids in the milk fat was 22% higher in ewes fed the RC diet than in those fed the LU diet. Compared with the LU diet, the RC diet had no effect on milk yield and composition, but improved the milk FA profile in dairy ewes due to an increased proportion of PUFAs (in particular C18:3n-3 and, to a lesser extent, C18:2n-6) and a decreased n-6/n-3 FA ratio.

SUMMARYMixing species with different tillering peaks may enhance pasture stability, but intercropping may also alter the plants’ tillering patterns. This study aimed to evaluate tillering dynamics in black oat (Avena strigosa Schreb.) and annual ryegrass (Lolium multiflorum Lam.) pastures grown as monocultures or intercropped. Three following treatments are established: black oat and annual ryegrass pastures grown as monocultures and an intercrop composed of these two species. Tillering dynamics were measured for black oat and annual ryegrass populations separately. When intercropped, tiller birth rates of black oat decreased (20.0 vs. 28.9 tillers 100 tillers−1) and those of annual ryegrass increased (30.5 vs. 14.3 tillers 100 tillers−1), compared to their monocultures. Tiller death rates for annual ryegrass did not differ between monoculture and intercropping (23.9 tillers 100 tillers−1), but black oat presented higher mortality in monocultures (48.8 vs. 36.4 tillers 100 tillers−1). The black oat monoculture had the lowest population stability index (0.80), whereas annual ryegrass in monoculture and intercropped pastures exhibited greater values (on average, 0.92). Our results indicated that black oat and annual ryegrass present distinct tillering dynamics whether grown as monoculture or intercropped, and suggest that intercropping species with elevated death rates (black oat) with later species (annual ryegrass) could be an important tool for maintaining pasture stability throughout the growing season.

Annual temperate grasses go through abrupt changes in morphological composition during the growing season, which can affect ingestive behavior of grazing cattle. However, few studies have examined the effects of gradual structural changes in annual temperate pastures on the herbage intake rate during the growing season. We hypothesized that lenient grazing (removal of 40% of the initial pre-grazing height) maintains short-term intake rate (STIR) of grazing cattle over the entire growing season, even with decreased leaf/stem ratios. The studied pastures contained Avena strigosa, Lolium multiflorum and a mixture of the two species. Short-term intake rate was measured using the double weighing technique, evaluating both bite rate and bite mass. The percentage of stem + pseudostem and leaf lamina lengths in the herbage mass were measured. Relationships between sward structure and animal ingestive behavior were also examined. As the pasture growing season progressed, the STIR of heifers grazing annual temperate grass swards was affected more by the time required to take a bite than by bite mass. Moreover, the sward structure also changed after each grazing cycle, reducing the pre-grazing leaf/stem ratio. However, reductions in the pre-grazing leaf lamina mass (up to 37% of the sward herbage mass) and/or in the leaf lamina length (up to 52% of the extended tiller height) did not affect the STIR of grazing heifers, since the animals maintained their bite mass and time per bite. In summary, with a grazing down target of 40% of the pre-grazing height, reductions in STIR of heifers grazing annual temperate grasses occurred when the pre-grazing leaf lamina percentage was

International audience; The objective was to quantify the flow of intestinal nutrients and nitrogen excretion and retention in sheep receiving isoproteic diets. Eight Texel x Lacaune wethers (average body weight = 25±2.5 kg) were fitted with duodenal cannula and housed in metabolic cages. Wethers were assigned to the treatments in a crossover design with two periods of 20 days each, and all feces and urine produced by the wethers were collected. The treatments consisted of two isoproteic (160 g kg−1 of crude protein on dry matter basis) diets composed of red clover (RC) or lucerne (LU; Medicago sativa) silages plus corn silage and concentrate feed. The digestible organic matter and metabolizable energy intake did not differ between treatments. The intestinal non-ammonia N (NAN) flow was 5.9 g day−1 (37%) higher in RC wethers than in those of the LU treatment. This result was a consequence of both an increase in the efficiency of microbial protein synthesis (12.7% higher) and a decrease in ruminal degradable protein (RDP) content (20% lower) of the diet. However, the increase in the intestinal NAN flow was accompanied by a reduction in intestinal digestibility of N, resulting in similar daily N retention between treatments. The reduction of RDP content was probably the main reason for reductions in N urinary excretion in RC wethers compared with those in the LU treatment, showing that RC silage may be a tool for mitigating the impact of N excretion in ovine production systems, without changes in N retention.

RESUMOPastos consorciados de aveia e azevém anual têm sido recomendados para uso no inverno/primavera em ambientes subtropicais. No entanto, o impacto do pastejo leniente sobre parâmetros qualitativos e produtivos destes, comparativamente aos seus monocultivos, é pouco conhecido. Objetivou-se avaliar possíveis variações nas composições morfológica e bromatológica, além da produção de biomassa em pastos de aveia-preta (Avena strigosa cv. IAPAR 61) e azevém anual (Lolium multiflorum Lam. cv. comum) quando cultivados puros ou em consórcio ao longo de toda estação de crescimento e submetidos a pastejo leniente. Os três tratamentos (aveia pura, azevém puro e aveia + azevém em consórcio) foram distribuídos em um delineamento em blocos completos ao acaso, com quatro repetições. Novilhas da raça Holandesa foram utilizadas como agentes de desfolhação, e os pastos foram rebaixados em 40% da altura inicial quando as alturas atingiam 17, 20 e 23cm para o azevém, o consórcio e a aveia, respectivamente. A relação lâmina:colmo diminuiu com o avanço da estação de crescimento em todos os tratamentos, mas a proporção de colmos no estrato pastejável se manteve abaixo de 20% da matéria seca até o início do estádio de desenvolvimento reprodutivo, independentemente do tipo de pasto. Os teores de proteína bruta e fibra em detergente neutro no estrato pastejável foram, respectivamente, superiores a 16% e inferiores a 50% nos quatro primeiros ciclos de pastejo. O consórcio e o azevém puro apresentaram as maiores taxas de acúmulo médio de forragem (32,6kg MS ha-1 dia-1), porém o maior período de utilização do consórcio resultou em maior produção total de matéria seca (4809kg MS ha-1). O pastejo leniente não prejudica a qualidade da forragem no estrato pastejável durante todo o estádio de desenvolvimento vegetativo de pastos anuais de inverno. A associação entre aveia-preta e azevém anual aumenta a produção de matéria seca total de forragem em comparação aos mesmos pastos cultivados puros. ABSTRACTMixed pastures of oats + annual ryegrass have been considered a good alternative for animal feeding during the winter/spring period in subtropical regions. However, the impacts of lenient grazing under their qualitative and productive aspects, when compared to their monoculture, remain unclear. Thus, the aim of this study was to evaluate the morphological and chemical composition and biomass production of black oat (Avena strigosa cv. IAPAR 61) and annual ryegrass (Lolium multiflorum Lam cv. common) swards cultivated pure or intercropped, throughout the growing season and submitted to lenient grazing. Treatments (oats, annual ryegrass and intercropping oats + annual ryegrass) were arranged in a complete randomized block design with four replications. The pastures were defoliated in 40% of pre-grazing height by Holstein heifers, when the heights reached 17, 20 and 23cm for the ryegrass, intercrop and oat, respectively. The leaf blade:stem ratio decreased with the advance of the growing season for all treatments, but the proportion of stems in the grazed stratum remained lower than 20% of dry matter until the pastures begun reproductive development. Similarly, the crude protein (CP) and neutral detergent fiber (NDF) levels in grazed stratum were, respectively, above 16% and below 50% from the first to fourth grazing cycles. Mixed pastures of black oat + ryegrass and ryegrass alone had higher forage accumulation rate (average = 32.6kg DM ha-1 day-1), but mixed pastures were used for a longer period, resulting in a greatest total DM production (4809kg DM ha-1). Lenient grazing does not reduce the forage quality in potential grazing layer throughout the growing vegetative stage. Intercropping black oat and ryegrass increases total DM production when compared to their monocultures.

Cyclocephala flavipennis Arrow, 1914 (Coleoptera: Melolonthidae), popularly known as white grub, is an insect widely disseminated in the South Region of Brazil. Despite the frequent occurrence of this white grub in areas cultivated with winter cereals, it is generally not considered a pest, since it feeds on straw and dead plant material. However, in 2015 and 2016, this insect has been identified as the damage-causing agent in the perennial winter pastures in Lages, Santa Catarina, Brazil. Damage was observed in patches and caused reduction in root depth and mass, resulting in loss of vigor, accelerated senescence in aerial parts, and death of tillers in Festuca arundinacea Schreb. and Dactylis glomerata L. plants. RESUMO: Cyclocephala flavipennis Arrow, 1914 (Coleoptera: Melolonthidae), conhecido popularmente como coró-pequeno, é um inseto amplamente disseminado na região sul do Brasil. Embora seja encontrado com frequência em áreas cultivadas com cereais de inverno não é considerado inseto praga, por alimentar-se preferencialmente de palha e restos de plantas. Entretanto, nos anos de 2015 e 2016 foi identificado como causador de danos em pastagens perenes de inverno em Lages, Santa Catarina, Brasil. Os danos foram observados em reboleiras e promoveram redução na massa e profundidade de raízes, resultando em perda de vigor, senescência acelerada da parte aérea e morte de perfilhos de plantas de Festuca arundinacea Schreb. e Dacytilis glomerata L.

The aim of this study was to evaluate the effects of the association between red clover (RC;Trifolium pratense) and a tropical grass (kikuyu grass) on the proteolysis of ensiled material andthe in vitro degradation of protein and organic matter. Red clover and kikuyu grass were ensiledin the following proportions: 0:1000, 250:750, 500:500, 750:250, and 1000:0 g/kg of dry matter(DM). The fraction of rapidly degradable protein, the ammonia nitrogen (NH3-N) content of thesilo, the in vitro protein degradation, and the degradation rate decreased linearly (P < 0.001) asthe RC content in the ensiled material increased. Cumulative gas production after 24 h incubationshowed a positive quadratic effect when RC was increased to 500 g/kg (P < 0.001). The silageswith the highest RC content reduced proteolysis more effectively during ensiling and ruminalfermentation. Inter-species synergistic effects positively affected in vitro gas production, whichwas optimal when RC and kikuyu grass were ensiled in the same proportions as that of total DM.

Oat and ryegrass intercropping in pastures is widely used in regions with subtropical climates. The aim of this study was to evaluate the tiller size/density compensation mechanisms in monoculture and intercropping swards of black oats (Avena strigosa Schreb cv. IAPAR 61) and annual ryegrass (Lolium multiflorum Lam. cv common) under intermittent grazing. Treatments (black oat, annual ryegrass and their mixture) were assigned according to a complete randomized block design with four replicates. Ryegrass, oat and intercropped pastures were grazed when the swards reached a height of 17, 25 and 23 cm, respectively, and with a level of defoliation of 40%. The aerial biomass was determined with a rising plate meter, and the tiller population density (TPD) was estimated by counting tillers in three 10 cm diameter PVC rings per paddock. The mass per tiller was estimated based on the aerial biomass and the TPD of each paddock. Total herbage production did not differ among treatments, with values around 7400 kg DM ha−1. TPD decreased and mass per tiller increased linearly in the monoculture treatments. Tiller size/density compensation was observed in the three plant communities (treatments) according to the self-thinning rule. In addition, no relationships were found when each species was analysed individually in the intercrop treatment. The results suggest that species in grass mixed swards adjust their population to keep a relatively constant leaf area index (LAI) over the grazing seasons, and that would help pastures to stabilize herbage production.

Multi-species pastures have been viewed as a means to increase forage production relative to monocultures through enhanced three-dimensional occupation of the canopy, which will intercept and use the incident radiation more efficiently. For this to occur, increased production of photosynthetically active tissues such as leaves is required. We tested the hypothesis that intercropping of black oats (Avena strigosa Schum.) and annual ryegrass (Lolium multiflorum Lam.) can increase total and leaf forage production compared with their monocultures. Monocultures and mixed pastures of black oat and annual ryegrass were established, and their tiller morphogenetic and structural traits, as well as components of herbage production, were measured throughout the usage period of the pastures. There was no difference between treatments for total growth rate (77.1 kg dry matter (DM) ha–1 day–1), but annual ryegrass pastures presented the greatest stem growth rate (38.1 kg DM ha–1 day–1). Taking into account only the vegetative phase, the intercropped pasture produced 20% more leaf than the monocultures. There were no differences between species, either in monoculture or intercropped, for phyllochron, final leaf length, leaf elongation duration and leaf elongation rate. The most important modification in morphogenetic variables due to the inter-specific competition was an increase in senescence rate of annual ryegrass leaves. The average specific green leaf weight in the intercropping pastures corresponded to 84.6% and 137.5% of those values observed for black oat and annual ryegrass pastures, respectively. On the other hand, the intercropping pastures presented 43.5% more tillers than the black oat pastures and 17.8% fewer tillers than the annual ryegrass pastures. It is suggested that intercropping black oat and annual ryegrass does not change tiller ontogenetic processes and that the association of their different size and shape in intercropped pastures could increase pasture leaf production over their monocultures.