Effect of a Garlic and Citrus Extract Supplement on the Lactation Performance and Carbon Footprint of Dairy Cows under Grazing Conditions in Chile.

Two trials were conducted to evaluate the effect of a garlic and citrus extract supplement (GCE) on the milk production performance and carbon footprint of grazing dairy cows in a Chilean commercial farm. A total of 36 early- to mid-lactation and 54 late-lactation Irish Holstein-Friesian cows were used in Trial 1 and Trial 2, respectively. In both trials, the cows were reared under grazing conditions and offered a supplementary concentrate without or with GCE (33 g/cow/d) for 12 weeks. The concentrate was fed in the afternoon when the cows visited the milking parlour. Consequently, the results of milk production performance in these trials were used to determine the effect of feeding with GCE on the carbon footprint (CFP) of milk using a life cycle assessment (LCA) model. In Trial 1 and Trial 2, feeding with GCE increased estimated dry matter intake (DMI, kg/d) by 8.15% (18.4 vs. 19.9) and 15.3% (15.0 vs. 17.3), energy-corrected milk (ECM, kg/d) by 11.4% (24.5 vs. 27.3) and 33.5% (15.5 vs. 20.7), and feed efficiency (ECM/DMI) by 3.03% (1.32 vs. 1.36) and 17.8% (1.01 vs. 1.19), respectively. The LCA revealed that feeding with GCE reduced the emission intensity of milk by 8.39% (1.55 vs. 1.42 kg CO2-eq/kg ECM). Overall, these results indicate that feeding with GCE improved the production performance and CFP of grazing cows under the conditions of the current trials.

Digestibility and nitrogen balance of goats on high and low protein rations supplemented with a commercial tannin feed-additive.

Despite the increasing importance of goat production in response to high demand for their products and their relative robustness to environmental stressors, and in contrast to other ruminant species, little data is available on how tannin extract feeding affects their feed intake, nutrient digestion and nitrogen (N) metabolism. Therefore, a trial in Oman investigated the respective variables by using a commercial tannin feed additive. In a 4 (treatments) x 3 (periods) x 2 (animals) Youden square, two weaned Batinah bucks each were fed a high or low protein diet of Rhodes grass hay and crushed barley grain, with or without the addition of a chestnut and quebracho tannin extract at 2 g/kg metabolic weight. Feed offered, feed refused and faeces and urine excreted were quantified to determine diet digestibility, total N excretion, N retention and rumen microbial protein synthesis (MPS). Due to their young age and low live weight, feed intake of goats was relatively low. Crude protein level and tannin addition had no statistically significant effect on dry matter (DM) and N intake, DM digestibility, N excretion in faeces and urine, as well as MPS. In consequence, no benefit of tannin feeding could be confirmed for the goats' N retention, irrespective of diet composition. These results indicate, on one hand, an effective neutralisation of the tested tannin extract along the gastrointestinal tract of goats, but on the other hand, that stimulation of MPS or N retention by tannins cannot be evidenced when diet components are present that simultaneously release energy and protein, as is the case with barley.

Responses of community traits and soil characteristics of Achnatherum inebrians-type degraded grassland to grazing systems in alpine meadows on the Qinghai-Tibet Plateau.

Introduction: Scientific grazing management is of great significance for the ecological health and sustainable use of alpine meadows. Methods: To explore appropriate management methods of alpine grasslands of the Qinghai-Tibet Plateau degraded by Achnatherum inebrians (Hance) Keng ex Tzvele presence, we studied the effects of different grazing systems on the A. inebrians population, grassland vegetation community traits, soil characteristics and soil microbial community structure for cold- season grazing plus supplementary feeding pasture (CSF) and four-season open public pasture (FOP) in Tianzhu County, Gansu Province. Results: Compared with FOP, the CSF site showed significantly inhibited reproduction of A. inebrians, especially the crown width, seed yield and number of reproductive branches per plant were as high as 50%, significantly increased the aboveground biomass of edible forage and soil water content by 57% and 43-55%, better soil nutrients, and significantly reduced soil bulk density by 10- 29%. Different grazing systems affected the composition and diversity of soil microbial communities, with a greater effect on fungi than on bacterial flora. The most abundant phyla of bacteria and fungi were Proteobacteria and Ascomycota for CSF (by 30-38% and 24-28%) and for FOP (by 67-70% and 68-73%), and the relative abundance and species of bacterial and fungal genera were greater for CSF than FOP. The α-diversity indexes of fungi were improved, and the ß-diversity of fungi was significant difference between CSF and FOP. However, the grazing utilization time was prolonged in FOP, which reduced the diversity and abundance of soil bacteria and increased soil spatial heterogeneity. The use of A. inebrians-type degraded grassland in the cold season, and as a winter supplementary feeding and resting ground, could effectively inhibit expansion of A. inebrians, promote edible forage growth, enhance grassland productivity and community stability, and improve soil structure. Discussion: The results guide healthy and sustainable utilization of A. inebrians-type degraded grassland in the Qinghai-Tibet Plateau.

Anchoring grassland sustainability with a nature-based small burrowing mammal control strategy.

Over the last 40 years, a burrowing mammal eradication policy has been prevalent on the Qinghai-Tibetan Plateau (QTP). This policy is based on similar burrowing mammal eradication programs in other areas and is justified on the assumptions that burrowing mammals compete with livestock for forage and contribute to grassland degradation. However, there is no clear theoretical or experimental evidence supporting these assumptions. This paper synthesizes the ecological functioning of small burrowing mammals in natural grasslands and discusses the irrationality and consequences of burrowing mammal eradication for sustainable livestock grazing and grassland degradation. Past burrowing mammal eradication efforts have failed because increased food availability for the remaining rodents and reduced predator populations led to rapid population rebounds. Herbivores differ in diet, and there is clear evidence that burrowing mammals, especially plateau zokors Myospalax baileyi, have a different diet than livestock. In QTP meadows, burrowing mammal eradication induces a shift towards plant communities with fewer species preferred by livestock and more species preferred by burrowing mammals. Thus, eradicating burrowing mammals has the opposite effect, a reduction in livestock preferred vegetation. We suggest that the policy of poisoning burrowing mammals needs to be reconsidered and revoked as soon as possible. We argue that incorporating density-dependent factors such as predation and food availability are essential for maintaining a low burrowing mammal density. For degraded grasslands, we suggest that the optimal sustainable approach is to decrease the intensity of livestock grazing. Lower grazing induces changes in vegetation structure and plant species composition that increases predation on burrowing mammals and decreases the abundance of plants preferred by burrowing mammals. Such a nature-based grassland management system maintains the density of burrowing mammals at a low stable density while minimizing human management and interventions.

Increasing levels of calcium salts of palm fatty acids affect production responses during the immediate postpartum and carryover periods in dairy cows.

Our objective was to determine the dose-response effects of calcium salts of palm fatty acids (CSPF) on nutrient digestibility and production responses of early-lactation dairy cows grazing on tropical pastures and to evaluate carryover effects throughout mid and late lactation. Forty multiparous dairy cows (Jersey × Holstein) with (mean ± standard error of the mean) 20 ± 1.69 kg of milk/d and 20 ± 5.0 d in milk were used in a randomized complete block design. During the treatment period, all cows were kept in a grazing system. The treatments were offered for 90 d (treatment period) and consisted of 4 increasing levels of CSPF: 0 (0 kg/d), 0.2 (0.2 kg/d), 0.4 (0.4 kg/d), and 0.6 (0.6 kg/d). Each treatment had 10 animals. Increasing CSPF from 0 to 0.6 kg/d replaced an equivalent amount of a corn-based concentrate supplement offered at 10 kg/d on an as-fed basis (8.96 kg/d as a dry matter basis). All cows were housed and received a diet without fat inclusion fed as total mixed ration once a day from 91 to 258 d of the experiment (carryover period). During the treatment period, increasing CSPF linearly decreased dry matter intake (1.20 kg/d), linearly increased neutral detergent fiber digestibility (3.90 percentage units), and quadratically increased total fat digestibility (6.30 percentage units at 0.4 kg/d CSPF). Increasing CSPF linearly increased the yields of milk (4.10 kg/d), milk fat (0.11 kg/d), milk lactose (0.19 kg/d), energy-corrected milk (ECM; 3.30 kg/d), and feed efficiency (ECM/dry matter intake, 0.34 kg/kg), and linearly decreased milk protein content (0.38 g/100 g), body weight change (0.05 kg/d), and body condition score (0.37). We observed interactions between CSPF and time during the carryover period. Overall, CSPF supplementation linearly increased or tended to increase milk yield until 202 d of the experiment with a similar pattern observed for all the other yield variables. In conclusion, supplementing CSPF from 0 to 0.6 kg/d during 90 d increased neutral detergent fiber and total fat digestibility and the yields of milk, milk fat, and ECM in early-lactation dairy cows grazing on tropical pastures. Most production measurements linearly increased during the treatment period, indicating that 0.6 kg/d CSPF was the best dose. Also, supplementing CSPF from 0 to 0.6 kg/d for 90 d during early lactation had positive carryover effects across mid and late lactation.

Dung avoidance behavior in Crioula Lanada lambs naturally infected with gastrointestinal nematodes in a rotational pasture system / Comportamento de afastamento do bolo fecal em cordeiros Crioula Lanada naturalmente infectados com nematoides gastrintestinais em sistema de pastoreio rotacionado

Abstract This study aimed to evaluate foraging distance (FD) from the dung, parasitological and physiological factors in 18 Crioula Lanada lambs naturally infected by nematodes with three infection levels (IL) in a Voisin Grazing System. In the pre-experimental phase animal feces collection, deworming, observer training, animal adaptation and dung demarcation were carried out; in the experimental phase, grazing distance, feces, pasture and blood sampling. An initial exploratory analysis was carried out (Kruskal-Wallis test). Fixed predictors were selected with a cumulative logit regression model; an ordinal logistic regression mixed model identified influencing factors of ordinal responses for (i) FD, (ii) infective larvae quantity (L3). Animals approached the dung when the radiation or temperature were more intense (P < 0.05). Paddock entry/exit, IgG and L3 influenced FD over time (P < 0.05). L3, in turn, was influenced by IL, FEC and corpuscular volume (CV). In the High IL group, FD varied between 60-100 cm. Greater L3 and FEC were found in the High and Low IL from the 4th week (P < 0.05). Naturally infected Crioula Lanada lambs increased the distance from the dung, which was not related to IL but to the dynamics of solar radiation and parasitological and immunological factors.

Resumo O objetivo deste estudo foi avaliar a distância de forrageamento do bolo fecal (DF), fatores parasitológicos e fisiológicos em 18 cordeiros Crioula Lanada, naturalmente infectados por nematoides com três níveis de infecção (NI) em sistema Pastoreio Racional Voisin (PRV). Na fase pré-experimental, houve coleta de fezes dos animais, vermifugação, treinamento de observadores, adaptação dos animais e demarcação do bolo fecal; na fase experimental, distância, fezes, pastagem e sangue. Um modelo de regressão "logit" cumulativa selecionou preditores fixos; um modelo misto de regressão logística ordinal identificou fatores influenciadores das respostas ordinais para (i) DF (ii) quantidade de larva infectante (L3). Os cordeiros se aproximaram do bolo fecal quando a radiação ou temperatura foram mais intensas (P < 0,05). A entrada e a saída dos piquetes, a ingestão de L3 e IgG influenciaram DF (P < 0,05). L3 foi influenciada por NI, OPG e volume corpuscular. O grupo NI Alta variou a distância entre 60-100 cm. Maior L3 e a FEC foram encontrados nos grupos NI Alta e Baixa a partir da 4ª semana (P < 0,05). Cordeiros Crioula Lanada, naturalmente infectados, aumentaram a DF, sem relação com nível, de infecção, mas com a dinâmica da radiação solar e dos fatores parasitológicos e imunológicos.

Yield, nutrient composition, and horse condition in integrated crabgrass and cool-season grass rotational grazing pasture systems.

Integration of warm-season grasses into traditional cool-season pastures can increase summer forage for grazing cattle. The aim of this study was to determine impacts of this practice on yield and nutrient composition of equine rotational pasture systems as well as horse body condition. Two 1.5 ha rotational systems (6 to 0.25 ha sections/system) were evaluated: a control system (CON) (all sections mixed cool-season grass [CSG-CON]) and an integrated rotational grazing system (IRS) (three CSG sections [CSG-IRS] and three Quick-N-Big crabgrass [Digitaria sanguinalis (L.) Scop.; CRB-IRS]). Three horses per system grazed in three periods: EARLY (mid-May to mid-July), SLUMP (mid-July to mid-September), and LATE (mid-September to mid-November). Herbage mass (HM) was measured prior to each rotation and samples were collected (0800 to 1000 h) for nutrient analysis. Grazing days were tracked to calculate carrying capacity (CC). Horse condition measures were assessed monthly. Over the full grazing season, 9,125 kg of forage was available for grazing in IRS versus 6,335 kg in CON. The CC was 390 horse d for IRS, while only 276 horse d for CON. Total HM/section did not differ during EARLY when CRB was not available (CSG-IRS: 2,537 ± 605; CSG-CON: 3,783 ± 856 kg/ha), but CC was greater in CSG-IRS (220 ± 37 horse d/ha) than CSG-CON (92 ± 26 horse d/ha; P = 0.03). In SLUMP, both HM and CC were greater in CRB-IRS (HM: 4,758 ± 698 kg/ha; CC: 196 ± 31 horse d/ha) than CSG-IRS (HM: 1,086 ± 698 kg/ha; CC: 32 ± 31 horse d/ha) or CON (HM: 970 ± 493 kg/ha; CC: 46 ± 22 horse d/ha; P < 0.02). While HM did not differ by section type in LATE (1,284 ± 158 kg/ha), CC was greater in CSG-CON (84 ± 9 horse d/ha) versus CRB-IRS (32 ± 13 horse d/ha; P = 0.03) and CSG-IRS (40 ± 13 horse d/ha; P = 0.06). During SLUMP, water-soluble carbohydrates (WSC) were lower in CRB-IRS (4.46% ± 0.80%) than CSG-CON (7.92% ± 0.90%; P < 0.04), but not CSG-IRS (5.93% ± 1.04%); however, non-structural carbohydrates (NSC) did not differ (7.05% ± 0.62%). There were no differences in WSC (6.46% ± 0.54%) or NSC (7.65% ± 0.54%) by section type in LATE. Horses in IRS maintained a body condition score (BCS) of 5.78 ± 0.48, but BCS did not differ by system (CON: 6.11 ± 0.48). Thus, integrated grazing increased summer pasture yield and provided adequate nutrition to maintain horse condition, but further research is needed to improve late-season production. Integrated grazing may not, however, provide an advantage in limiting dietary NSC, as NSC remained low for all pasture sections.

Mixed Grazing and Dietary Supplementation Improve the Response to Gastrointestinal Nematode Parasitism and Production Performances of Goats.

Small ruminants are very affected by gastrointestinal nematode (GIN) parasitism worldwide. The improvement of the host protective response and the reduction of the probability of contact between hosts and parasites appear as very promising strategies. The objective of this study was to evaluate the effect of a combination of two components of these two strategies on natural GIN infection and production performances of Creole goat kids: dietary supplementation and a rotational mixed grazing system. One hundred and twenty weaned Creole kids and six Creole heifers were divided into four experimental batches: Splus (supplemented) vs. Szero (non-supplemented) × Mixed grazing (kids associated with heifers) vs. Control (kids alone), and grazing plots of forage grasses were balanced for live weight (LW) in both species. The feed intake, blood, and parasitological parameters and production performances between 3 and 11 months of age were monitored. The fecal egg count (FEC) was significantly lower and the packed cell volume (PCV) significantly higher in the Mixed grazing groups. No effect of supplementation was observed for FEC. In contrast, PCV, body condition score, and live weight were significantly higher in supplemented animals whatever the groups. Mixed grazing system and supplementation had significant effects on the slaughter parameters (P < 0.05), but there was no significant interaction. Our results suggested that the advantage driven either by mixed grazing or dietary supplementation on kids' performances would be equivalent, and the combination of both would improve the animal performances.

A scenario-based analysis of the effect of carbon pricing on organic livestock farm performance: A case study of Spanish dehesas and rangelands.

The current livestock farm production model is being questioned due to its excessive use of resources and impacts on the environment, and it has played a major role in climate change due to the excessive level of greenhouse gas (GHG) emissions. A valid tool in the reduction of such emissions is the imposition of a tax on CO2 emissions that can act as an economic and financial instrument. Additionally, livestock production based on grazing animals is proposed as a more sustainable model that involves improved environmental practices and provides society with various ecosystem services, including carbon sequestration. The main purpose of this paper is to estimate the maximum price per tonne of CO2 equivalent (eq) that could be borne by the various models of organic livestock farms in the dehesas and rangelands of southwestern Spain. With this purpose in mind, we have made a scenario-based estimation of the environmental-economic balance in three different scenarios considering farm emissions and CO2 sequestration levels. The results show that the maximum price that farms can bear is within a range of € 0.20 to € 792/tn of CO2 eq depending on the scenario analysed and the production model. In the cases in which carbon sequestration balances GHG emissions, the implementation of carbon pricing implies additional economic income for farm accounts.

Metabolic profile of female lambs on annual ryegrass pasture managed under different grazing intensities and methods / [Perfil metabólico de cordeiros fêmeas em pastagem de azevém manejada sob diferentes intensidades e métodos de pastejo]

The aim of this study was to evaluate the effect of grazing methods and intensities on the metabolic profile of lambs grazing ryegrass. This study was performed in Eldorado do Sul (RS). The treatments consisted of two grazing intensities with rotational and continuous stocking methods: moderate and low. The experimental design was a randomized block arranged in a factorial scheme with four replicates. To evaluate the metabolic and nutritional conditions of the lambs, blood samples were collected to evaluate phosphorus, albumin, glucose, magnesium, globulin, cortisol, urea and total proteins. The highest blood urea value was observed in the month of September in lambs kept in continuous method grazing. There was no statistical difference between the grazing intensities and grazing methods for albumin, glucose, magnesium, globulin, cortisol and total protein levels in profile lambs. The cortisol values suggested that the animals were not subjected to high stress levels. In conclusion, rearing female lambs on ryegrass, irrespective of grazing methods or intensities, allowed the maintenance of body homeostasis and did not cause any metabolic unbalances, nutritional unbalances or stress.(AU)

O objetivo deste estudo foi avaliar o efeito dos métodos e das intensidades de pastejo no perfil metabólico de cordeiros. Este estudo foi realizado em Eldorado do Sul (RS). Os tratamentos consistiram em duas intensidades de pastejo (moderada e baixa), com métodos lotação rotativa e lotação contínua. O delineamento experimental foi em blocos ao acaso, em esquema fatorial com quatro repetições. Para avaliar as condições metabólicas e nutricionais dos cordeiros, foram coletadas amostras de sangue para avaliar fósforo, albumina, glicose, magnésio, globulina, cortisol, ureia e proteínas totais. O maior valor de ureia no sangue foi observado no mês de setembro nos cordeiros mantidos em pastejo contínuo. Não houve diferença estatística entre as intensidades de pastejo e os métodos de pastejo para albumina, glicose, magnésio, globulina, cortisol e níveis de proteína total nos cordeiros perfilados. Os valores de cortisol sugeriram que os animais não foram submetidos a altos níveis de estresse. Concluindo, a criação de cordeiros em azevém, independentemente dos métodos ou das intensidades de pastejo, permitiu a manutenção da homeostase corporal e não causou desequilíbrios metabólicos, desequilíbrios nutricionais ou estresse.(AU)

Bovine digital dermatitis in the Brazilian Amazon biome and topical treatment with Copaifera reticulata oil / Dermatite digital bovina no bioma amazônico brasileiro e tratamento tópico com óleo de Copaifera reticulata

Bovine Digital Dermatitis (BDD) was studied in crossbred dairy cows grazing in Rondon do Pará, in the state of Pará, as well as in Açailândia and Cidelândia, in the state of Maranhão, Brazilian Amazon biome. The digits inspection from the dairy cows during milking was performed in ten farms comprising four visits (August and November 2016; April and July 2017). The cows were kept all year in pastures, and were mechanically milked on concrete floors and the animals were protected against the rains in eight farms, maintaining a daily cleaning, however, it could not be found a concrete floor in pre- or post-milking to ensure milking parlor on three farms. Manual milking on no concrete floors was performed in two farms. No preventive measures against hoof lesions were adopted. The BDD prevalence was 1.3% (22/1664), and no statistical difference among rainy or no rainy season was obtained (p = 0.72). The BDD lesions were classified according to "M system" (M0 = no lesion, M1 = active ulceration <2cm, M2 = active ulceration >2cm, M3 = healing stage, M4 = chronic stage, M4.1 = M4 with active ulceration). Regarding the 22 BDD lesions observed, 22.7% (5/22) were M1 stage, 36.4% (8/22) M2, 22.7% (5/22) M3, 13.6% (3/22) M4 and 4.5 (1/22) M4.1. Hypertrophic hairs at the edges of the lesions caused by fly larvae of genus Cochliomyia spp. as well as alterations on the hoof were also observed. Topical treatment was performed in six BDD lesions with a raw extract from trees of the genus Copaifera reticulata (Copaiba oil) and compared with the treatment of salicylic acid paste in five BDD lesions. The lesions were protected with a bandage for seven days and followed weekly until recovery. The complete therapeutic responses were 83.4% (5/6) and 75% (3/4), respectively, with an average time of seven weeks. The BDD in the Amazon biome occurs in low prevalence, not seasonal, and presents macro and microscopic features similar to BDD lesions from dairy cattle kept in free-stall housing. The treatment with copaiba oil showed similar results to the treatment of salicylic acid paste and can be used in control measures to BDD in the Amazon biome.(AU)

A dermatite digital bovina (DDB) foi estudada em vacas mestiças leiteiras nos municípios de Rondon do Pará no Pará, Açailândia e Cidelândia no Maranhão, bioma amazônico brasileiro. Para tanto, foram realizadas quatro visitas a 10 propriedades, nos meses de agosto e novembro em 2016 e abril e julho em 2017, e realizada a inspeção dos dígitos de 1.664 vacas em lactação durante a ordenha. Nestas propriedades as vacas eram criadas a pasto durante todo o ano e ordenhadas mecanicamente em oito propriedades. As quais, as salas de ordenha tinham piso concretado, com proteção contra as chuvas e era realizada a limpeza diariamente. No entanto, em três dessas propriedades, as salas de pré ou pós ordenha tinham piso não concretado e em duas, a ordenha era manual em piso de chão batido. Em todas elas não havia medidas profiláticas para afecções podais. A prevalência de DDB foi de 1,3% (22/1.664) e não se obteve diferença estatística entre os períodos chuvoso e não chuvoso (P = 0,72). As lesões observadas foram classificadas de acordo com o sistema M (M0-sem lesão; M1-lesão ulcerada <2cm; M2-lesão ulcerada >2cm; M3-lesão em cicatrização; M4-lesão crônica; M4.1- M4 com área ulcerada). De 22 lesões observadas, 22,7% (5/22) apresentavam-se em estágio M1, 36,4% (8/22) em M2, 22,7% (5/22) em M3, 13,6% (3/22) em M4 e 4,5% (1/22) em M4.1. Pelos hipertrofiados nos bordos das lesões, larvas de moscas do gênero Cochliomyia spp. e alterações no tecido córneo também foram observados. Nas lesões de 11 bovinos, em seis, foi realizado o tratamento tópico com extrato bruto de Copaifera reticulata (óleo de copaíba) e em cinco, com a pasta de ácido salicílico a 660mg/g e ambos os tratamentos foram protegidos com bandagem por sete dias. Após, as lesões foram acompanhadas semanalmente até a cura e obteve-se um índice de 83,4% (5/6) e 75% (3/4) de cura com esses tratamentos, respectivamente, com uma média de 7 semanas. Conclui-se que no bioma amazônico a DDB ocorre em baixa prevalência, não sazonal e com características macroscópicas semelhantes às lesões de vacas leiteiras criadas em sistema free stall. O tratamento com o óleo da copaíba apresentou resultados semelhante ao ácido salicílico e pode ser uma alternativa como medida de controle da DDB no bioma amazônico.(AU)

Effect of Mineral Supplementation on the Macromineral Concentration in Blood in Pre- and Postpartum Blackbelly Sheep.

The objective of this study was to determine the effect of mineral supplementation on the serum concentration of calcium, phosphorus, and magnesium in pre- and postpartum Blackbelly sheep throughout three successive lambing periods under free grazing conditions in the Ecuadorian Amazon Region. The field work was carried out between January 2015 and February 2018 using 20 Blackbelly sheep belonging to the Centre for Research, Postgraduate Studies and Conservation of Amazon Biodiversity, Ecuador. The flock was randomly divided into two groups: Group 1 (G1) was fed with forage plus a supplementation (Pecutrin® Mineral supplement plus vitamins A, D3, and E. Bayer HealthCare) and Group 2 (G2) was fed only with forage without mineral supplementation. Three blood samples from the coccygeal vein were taken from each sheep 30 days before lambing, 30 days after, and 60 days after lambing. Concerning the average of calcium, significant differences were found at different times inside each group and also between them (p < 0.0001 in both cases). As for the phosphorus, significant differences were found between the means of the groups for all times from 30 days after the second lambing season (p < 0.05). It was observed that the groups differed significantly in terms on the average of magnesium (considering a significance level of 0.05) 30 days before the first lambing and at all times measured from the 30 days after the second lambing (p < 0.005). In this study, we showed that Blackbelly sheep raised under free grazing conditions in the Ecuadorian Amazon Region had very low serum calcium values, and supplementation was unable to improve them. Meanwhile, phosphorus and magnesium levels were below the required values, but after supplementation, they exceeded the minimum threshold. Mineral supplementation in the rearing of sheep in grazing systems is necessary during the entire production cycle, but it must be done taking into account the soil-plant-animal relationship specifically for the Amazonian Region systems.

Methane emissions in grazing systems in grassland regions of China: A synthesis.

The effects of grazing on methane (CH4) budgets are important for understanding the balance of greenhouse gas emissions and removals in grassland ecosystems. However, the CH4 budgets of grazing systems, that is simultaneously considering CH4 uptake by grassland soils and emissions from ruminant enteric fermentation, livestock folds and animal feces, are poorly investigated, particularly for Chinese grasslands, and thus, remained unclear currently. Here, a synthesis of 43 individual studies was carried out to assess the grazing season/annual CH4 budgets and their responses to grazing in grassland ecosystems of China. The results showed that heavy grazing (HG) significantly decreased, while light grazing (LG) and moderate grazing (MG) had no significant effects soil CH4 uptake, as compared to un-grazing sites. Grazing has shifted Chinese grasslands from a sink to source for atmospheric CH4, and the grazing season/annual CH4 budgets increased with increasing grazing intensity, while the offset of CH4 uptake by grassland soils to total CH4 emissions from sheep, sheepfolds and feces were exponentially decreased with increasing grazing intensity. Moreover, the herbage biomass (HBM), organic matter intake (OMI) and live weight gain (LWG) were decreased while CH4 emission intensities (i.e., CH4 emission per HBM, OMI, and LWG) were linearly increased with increasing grazing intensity. Our results demonstrate that mediating grazing intensity, e.g., from HG to LG, could yield the optimal balance between maintaining productive grasslands and meanwhile mitigating CH4 emissions. This study could help for building strategies with implications for grassland management in China with similar CH4 emission problems.

Contextualized re-calculation of enteric methane emission factors for small ruminants in sub-humid Western Africa is far lower than previous estimates.

Given the projected growth of methane emission by ruminants in developing countries, there is a clear need for reliable estimates of their contribution to greenhouse gas emissions. Existing studies have rarely considered sheep and goats. The objective of this study was to predict enteric fermentation methane emission factors (EFs) for Djallonké sheep and West African Dwarf goats, following the 2006 IPCC Tier 2 methodology. Estimated enteric methane emission factors, expressed per head of animal per year, were 2.3 kg CH4 and 2.0 kg CH4 for sheep and goats species, respectively. Compared with the generic Tier 1 emission factor of 5 kg CH4 head proposed by the IPCC for small ruminants in the sub-Saharan Africa region, our suggested values are 56% and 60% lower for sheep and goat, respectively. These lower values took account of the particular flock structure of both sheep and goats. These estimates also accounted for differences in live weight according to age and corresponding estimated feed intake. This work is a step forward in the revision of small ruminant emission factors and can further support assessment of mitigation strategies in Senegalese livestock farming systems.

Effects of parity on productive, reproductive, metabolic and hormonal responses of Holstein cows.

The objective of this study was to determine the effects that parity may have on production, reproduction and the metabolic status of Holstein cows managed in a production system based on total mixed ration and pasture. Primiparous (n = 22) and multiparous (n = 24) cows from a dairy farm research station in Uruguay were used in a completely randomized design. Body weight (BW), body condition score (BCS) and backfat thickness (BFT) were recorded weekly from -30 to 70 days postpartum. Milk production was measured daily, and milk composition was determined weekly. Resumption of postpartum ovarian activity and progesterone profiles were measured three times a week based on milk progesterone. Blood was collected to determine the levels of glucose, insulin-like growth factor I (IGF-1), insulin, non-esterified fatty acids (NEFA), ß-hydroxybutyrate (BHB), albumin, total protein and cholesterol. Milk production and components were lower for primiparous cows (p < 0.01) than multiparous cows. Body weights were also lower in primiparous cows than in multiparous cows (p < 0.05); however, BCS and BFT were greater (p < 0.01) in primiparous cows than in multiparous cows. Primiparous cows had greater levels of glucose, insulin and IGF-1 and lower concentrations of NEFA and BHB (p < 0.01) than multiparous cows. The intervals from calving to first ovulation were not affected by parity; however, primiparous cows showed less abnormal cycles (27.2%) than multiparous cows (50.0%) (p < 0.01). The present study found that a feeding system based on TMR and pasture was sufficient to produce over 25 L of milk per day without extending their calving to first ovulation interval in primiparous and multiparous cows. However, multiparous cows showed a greater imbalance in metabolic and hormonal profiles than primiparous cows, causing abnormal ovarian activity.

Sero-prevalence of Bovine Brucellosis and associated risk factors in mbeya region, Southern highlands of Tanzania.

A cross-sectional study was conducted to establish the seroprevalence of brucellosis and associated risk factors in indigenous and exotic breeds of cattle from 178 farms in Mbeya region. A total of 1211 cattle (929exotic cattle from 108 commercial farms and 282 indigenous cattle from 70 traditional farms) were tested for Brucella antibodies using the Rose Bengal Plate Test (RBPT) and competitive Enzyme Linked Immunosorbent Assay (c-ELISA) as screening and confirmatory tests, respectively. The overall animal-level seroprevalence was 9.3%; 11.3% (95% CI: 9.4-13.5) in indigenous cattle and 2.8% (95% CI:1.4-5.6) in exotic cattle. Further, the overall herd level seroprevalence was 32.0%; 50.5% (95% CI: 40.9-59.9) in indigenous cattle and 4.2% (95% CI: 1.3-12.4) in exotic cattle. Infections were higher in cattle aged 6-10 years old, (39.8%; 95% CI: 31.2-49.1) followed by those aged 1-5 years (5.8%; 95% CI: 4.8-6.6) and 11-15years old (2.7%; 95% CI: 0.8-8). When compared to cattle sampled from herds size of 1-50, those sampled from the herd sizes of 51-100 and 101-150 had higher odds of brucellosis seropositivity [(OR=3.6, CI: 1.76-7.16, p<0.001) and (OR=3.0, CI: 1.09-8.04, p=0.033). The odds of seropositivity in animals which calved on pasture was 3.0 (CI: 1.1-7.8, p=0.028) compared to those that calved at home. Brucella seroprevalence was also observed to vary according to districts, with Mbarari district recording the highest (45.4%). It is evident from the study that Brucellosis is present in Mbarari, Mbeya and Momba districts of Mbeya Region. The findings of this study provide some baseline data that could contribute to the design and implementation of brucellosis control measures in the study areas.

The use of targeted selective treatments on controlling gastrointestinal nematodes in different sheep categories under grazing system / O uso de tratamentos seletivos no controle de nematóides gastrointestinais em diferentes categorias de ovinos sob sistema de pastejo

Infections with gastrointestinal nematodes can impair both the animal health and performance. Thereby, the aim of this study was to evaluate the use of targeted selective treatments as the FAMACHA© system and faecal egg count on controlling gastrointestinal nematodes in different sheep categories under grazing system. Thirty Santa Inês sheep, six in each category (six weaning, six weaned lambs, six non-pregnant ewes, six pregnant ewes and six lactating ewes were used. Sheep were weighed, and blood and faecal samples were collected on day 0, 15, 30, 45, 60 and 75 for determination of faecal egg count (FEC), packed cell volume (PCV), total plasma protein (PPT) and the mucosa colour by FAMACHA© system in the morning (1) and afternoon (2). The faecal egg count was higher (p=0.0039) in weaning and weaned lambs compared to the non-pregnant, pregnant and lactating ewes. Also, FEC differed between ewes with higher counts in lactating ewes. The observation of eye mucosae showed a frequency of 100% of FAMACHA© scores ranged of 2.45 to 2.91 in the morning, differing (p=0.0494) among the categories, where weaned lambs showed better score. The animal categories and period interaction had a significant (p=0.0148) effect on FAMACHA© score 1 with better score in weaned lambs compared to the pregnant ewes at day 0, 15 and 75. In addition, weaned lambs were presented better FAMACHA© score compared with weaning lambs and lactating ewes at day 45 than weaning lambs at day 60 and 75. Packed cell volume in the morning and in the afternoon was influenced by days of collection with lower percentage at 30 days of experiment. The FAMACHA© system seems to be a suitable method to detect parasite infections. However, use of all available methods increases the accuracy of the diagnosis and promotes better control of gastrointestinal nematodes in grazing sheep.(AU)

Infecções por nematóides gastrointestinais podem prejudicar tanto a saúde como o desempenho animal. Diante disso, objetivou avaliar o uso de tratamentos seletivos como o sistema FAMACHA© e a contagem de ovos por grama de fezes no controle de nematóides gastrointestinais em diferentes categorias de ovinos sob sistema de pastejo. Trinta ovelhas Santa Inês, seis em cada categoria (seis cordeiros lactentes, seis cordeiros desmamados, seis ovelhas não-prenhes, seis ovelhas prenhes e seis ovelhas lactantes) foram utilizadas. Os ovinos foram pesados, amostras de sangue e fezes foram coletadas nos dias 0, 15, 30, 45, 60, 75 para determinação de ovos por grama de fezes (OPG), volume globular (VG), proteínas plasmáticas totais (PPT) e avaliação da mucosa ocular pelo sistema FAMACHA© pela manhã (1) e pela tarde (2). A contagem de ovos por grama de fezes foi maior (p=0,0039) nos cordeiros lactentes e desmamados comparado às ovelhas não prenhes, prenhes e lactantes. Também o OPG diferiu entre ovelhas com maior contagem em ovelhas lactantes. A observação da mucosa ocular mostrou que a frequência do escore FAMACHA© variou de 2,45 a 2,91 pela manhã, diferindo (p=0,0494) entre categorias, aonde cordeiros desmamados mostraram melhor escore. A interação categoria animal e período teve um efeito significante no escore FAMACHA© 1 com melhor escore em cordeiros desmamados comparado às ovelhas prenhes nos dias 0, 15 e 75. Além disso, cordeiros desmamados apresentaram melhor escore FAMACHA© comparado com os cordeiros lactentes e ovelhas lactantes aos 45 dias e com cordeiros lactentes nos dias 60 e 75. O volume globular pela manhã e pela tarde foi influenciado pelos dias de coleta com menor porcentagem aos 30 dias de experimento. O Sistema FAMACHA© mostrou ser um método eficaz para detectar infecções parasitárias. Contudo, o uso de todos os métodos disponíveis aumenta a acurácia do diagnóstico e promove melhor controle de nematóides gastrointestinais em sistemas de pastejo.(AU)

Performance and feed intake of beef heifers on rotational grazing of natural grassland receiving protein and energy supplement in cool season / Desempenho de bezerras de corte em pastoreio rotativo em pastagem natural recebendo suplemento proteico-energético

ABSTRACT: The aim of this study was to evaluate the performance and feed intake of grazing beef heifers on two grazing intervals determined by thermal sum related to leaf elongation duration during cool season on natural grasslands. A complete randomized block design experiment with two treatments and three replications was conducted from May to September 2011 in the central part of the state of Rio Grande do Sul, Brazil. The treatments were two thermal sums calculated at 375 and 750 degrees-days (DD) to determine the intervals between grazing periods in a rotational grazing system. Thirty six beef heifers with average age of 18 months old and (initial body weight = 220±14kg) were used, all heifers received ground corn supplement at a rate of 5g kg-1 of body weight per day, at 2p.m., throughout the experiment and had free access to mineral and protein supplementation (450g kg-1 of CP). Similar average daily gain (ADG), beef production gain (BPG) and feed intake (FI), were obtained in both treatments. Leaf elongation duration is an alternative grazing management tool for improved animal production and to increase animal stocking rate.

RESUMO: Objetivou-se avaliar o desempenho e consumo de matéria seca de bezerras manejadas em pastoreio rotativo, com intervalos de pastoreio definidos por duas somas térmicas relacionadas à duração de elongação foliar de dois grupos funcionais de gramíneas durante a estação fria em pastagem natural. O delineamento experimental foi o de blocos completamente casualizados, com dois tratamentos e três repetições de área na região central do Rio Grande do Sul, Brasil. Os tratamentos foram duas somas térmicas: 375 e 750 graus-dias (GD), que determinaram os intervalos entre os pastoreios. Foram utilizadas trinta e seis bezerras de corte com idade média de 18 meses e peso corporal médio de 220±14kg. Durante todo o experimento, as bezerras receberam como suplemento grão de milho moído a uma taxa de 0,5% do peso corporal por dia, às 14:00 horas e tiveram livre acesso à suplementação proteínada (45% PB). Não houve diferença para o ganho médio diário, ganho de peso por área e consumo de matéria seca entre os tratamentos. A soma térmica como intervalo de descanso entre os pastoreios mostrou-se uma alternativa de manejo para aumentar a taxa de lotação.

Grazing system and floor type effects on blood biochemistry, growth and carcass characteristics of Nguni goats.

OBJECTIVE: Purpose was to determine the effects of grazing system and floor type on concentrations of blood metabolites, activity of creatine kinase, body weight and carcass characteristics of castrated Nguni goats. METHODS: Forty eight, 7 month old goats were randomly allocated to herding and tethering treatments from 0800 to 1300 hours and accommodated on slatted and earth floors daily. Blood samples were collected by jugular venipuncture every fifteenth day for metabolite analysis. Slaughter was done at a commercial abattoir following 5 months of monitoring. RESULTS: Tethered goats had significantly higher concentrations of urea (5.19 mmol/L) (p< 0.001), creatinine (55.87 µmol/L) (p<0.05), total protein (64.60 g/L) (p<0.01), and globulin (49.79 g/L) (p<0.001), whereas herded goats had higher glucose (3.38 mmol/L) (p<0.001), albumin (15.33 g/L) (p<0.05), albumin/globulin ratio (0.34) (p<0.01), and body weight (24.87 kg) (p< 0.001). Slatted floors caused higher (p<0.01) albumin at 15.37 g/L. The interaction of grazing system and floor type affected creatinine, total protein, globulin at (p<0.01) and albumen/globulin ratio at (p<0.01). The least creatinine concentration and albumin/globulin ratio was in herded and tethered goats that were accommodated on earth floors, respectively. The highest total protein and globulin concentrations were in serum of tethered goats that were accommodated on earth floors. The highest (p<0.05) dressing percentage (45.26%) was in herded goats accommodated on slatted floors. CONCLUSION: Herding of goats lowered globulin concentration, improved estimated feed intake, blood glucose and albumin concentrations, albumin globulin ratio, increased body weights and weight related carcass characteristics. Floor type had very little effects on metabolites where earth floors only reduced albumin concentration. Tethering and housing goats on earth floors resulted in double stress that increased chronic infections.

Effect of increased feeding of dietary α-linolenic acid by grazing on formation of the cis9,trans11-18:2 isoform of conjugated linoleic acid in bovine milk.

Feeding systems such as grazing affect the fatty acid profile of bovine milk fat. In addition, milk fat is formed as the product of fatty acid metabolism in cow bodies before being secreted into milk. However, how grazing influences milk fatty acid profile through the metabolism has not been completely characterized. When fatty acid concentrations in Holstein milk were compared between grazing and non-grazing periods, α-linolenic acid was significantly higher in the grazing period than in the non-grazing period. This could be explained with an increase in α-linolenic acid feeding with grazing. α-linolenic acid had a linear positive correlation with conjugated linoleic acid (9c,11t-18:2) (CLA) and vaccenic acid (VA) during the grazing period, whereas CLA had higher correlation with linoleic acid rather than with α-linolenic acid during the non-grazing period. These data indicate that the high content of dietary α-linolenic acid affects CLA and VA formation in milk of grazing periods via α-linolenic acid metabolism into VA.