Feed intake and apparent digestibility of hay-supplemented brassica diets for lambs

Do Brassica Vegetables Affect Thyroid Function?-A Comprehensive Systematic Review

Brassica vegetables are widely consumed all over the world, especially in North America, Asia, and Europe. They are a rich source of sulfur compounds, such as glucosinolates (GLSs) and isothiocyanates (ITCs), which provide health benefits but are also suspected of having a goitrogenic effect. Adhering to PRISMA guidelines, we conducted a systematic review to assess the impact of dietary interventions on thyroid function, in terms of the potential risk for people with thyroid dysfunctions. We analyzed the results of 123 articles of in vitro, animal, and human studies, describing the impact of brassica plants and extracts on thyroid mass and histology, blood levels of TSH, T3, T4, iodine uptake, and the effect on thyroid cancer cells. We also presented the mechanisms of the goitrogenic potential of GLSs and ITCs, the limitations of the studies included, as well as further research directions. The vast majority of the results cast doubt on previous assumptions claiming that brassica plants have antithyroid effects in humans. Instead, they indicate that including brassica vegetables in the daily diet, particularly when accompanied by adequate iodine intake, poses no adverse effects on thyroid function.

Effects of reseeding with perennial ryegrass, chicory or tyfon in pure stands or mixtures on lamb performance postweaning

Many producers reseed old pasture (OP) with the objective of improving lamb performance. Old pasture was reseeded with perennial ryegrass plus white clover (RGC), RGC plus chicory (CG), RGC plus tyfon (TG), chicory (C), or tyfon (T) to generate five treatments. In addition, a contiguous block of OP was included in the study for comparative purposes. Lambs (n = 286) were assigned to one of the five treatments plus the section of OP from just after weaning until slaughter. Grazing commenced 45 days after the desiccation of OP for reseeding. All lambs were managed by rotational grazing and drafted for slaughter at a specified target BW. No concentrate supplement was offered during the study. For the RGC, CG, TG, C and T treatments and the OP section, the average herbage NDF concentrations were 524, 473, 402, 352, 256 and 565 (SE 15.4) g/kg DM; total grazing days were 5 213, 4 005, 4 466, 2 262, 3 496 and 3 677 (SE 629.3); BW gain to slaughter was 211, 175, 205, 211, 199 and 203 (SE 9.5) g/day; days to slaughter were 91, 100, 84, 86, 78 and 88 (SE 4.8). Compared to RGC, the C, T, CG and TG treatments had lower herbage NDF concentrations (P < 0.05), and there was no difference (P > 0.05) for BW gain or days to slaughter. Chicory yielded significantly fewer (P < 0.05) grazing days, but tended to give a higher (P < 0.06) carcass weight than RGC. It is concluded that neither reseeding OP with RGC, including either C or T with RGC as a multispecies sward, nor growing pure stands of C or T increased (P < 0.05) lamb BW gain from weaning to slaughter or reduced days to slaughter.

Canola as a potential forage

The nutritive quality of four cultivars of canola forage (Brassica napus L.), Orient, Midas, Global, and Hybrid (Cobra × Regent), which were harvested in the early-spring period, were compared with green-winter barley (GWB) in terms of their yields, chemical composition, in vitro gas production variables, in situ crude protein (CP) degradation, and predicted dry matter intake (PDMI). Data were statistically analyzed using a completely randomized design with four replications and three samples per replication. The study was based on a randomized complete block design, and data were analyzed using SAS, general linear model procedure for normal distribution. The canola dry matter (DM) yield was highest in Orient cultivar and lowest in Midas (P &lt; 0.05). Organic matter (OM), CP, neutral detergent fiber (NDF), and lignin(sa) concentration of the four cultivars ranged from 862 to 865, 218 to 247, 295 to 340, and 35 to 53 g/kg DM, respectively. The estimated OM disappearance (OMD), effective degradability of CP, effective rumen degradable protein (ERDP), digestible undegradable protein, and metabolizable protein (MP) of the forages were from 636 to 671 g/kg, 878 to 910, 172 to 193, 1.9 to 3.4, and 112 to 126 g/kg DM, respectively. Compared to Global and Hybrid cultivars, Orient and Midas contained higher CP, OMD, ERDP, MP concentration, and PDMI, but lower NDF, acid detergent fiber (ADF), and lignin(sa) concentrations (P &lt; 0.05). The level of glucosinolates in the forages ranged from 0.38 to 1.51 µmol/g DM, which is below the detrimental level for ruminants. Compared to winter canola cultivars, GWB had higher DM yield (P &lt; 0.003), NDF, lignin(sa), PDMI (P &lt; 0.01), and digestible undegradable protein (P &lt; 0.04), but had lower OMD (P &lt; 0.03), ERDP (P = 0.01), and MP (P &lt; 0.009). Based on the obtained results, the variation in the nutritive quality among the canola cultivars is relatively small, and the Orient cultivar, which is most comparable to GWB, was judged to be nutritionally the best among the cultivars.

Spring-sown winter-type canola (Brassica napus) as summer–autumn forage for sheep production in southern Australia

Context Filling the summer–autumn feed gap is a key priority for sheep producers in southern Australia’s high-rainfall zone. Aim Our research aimed to determine whether spring-sown winter-type canola (Brassica napus L.) could increase herbage mass and nutritive characteristics during summer and autumn relative to other forage options in southern Australia’s HRZ. Methods A field experiment was conducted at Hamilton, Victoria, Australia, in 2014 and 2016 testing seven forage treatments replicated four times in the complete block design. The treatments were: canola (two treatments of different cultivars), forage brassica (B. napus), lucerne (Medicago sativa L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.) and perennial ryegrass (Lolium perenne L.). Key results Herbage mass and nutritive characteristics of the canola varieties did not differ (P &gt; 0.05) from forage brassica. Herbage mass in March 2014 was 3.35–3.64 t dry matter (DM)/ha for brassicas; 1.05–1.37 t DM/ha for perennial ryegrass, plantain and chicory; and 2.94 t DM/ha for lucerne (P &lt; 0.001, l.s.d. = 1.20). In March 2016, herbage mass was 1.86–2.05 t DM/ha for brassicas and 2.14–2.49 for the other forage treatments (P &lt; 0.05; l.s.d. = 0.47). Brassicas had higher (P &lt; 0.05) metabolisable energy (ME) concentrations and lower (P &lt; 0.05) neutral detergent fibre (NDF) concentrations on most sampling dates than chicory, plantain, lucerne and perennial ryegrass. The crude protein (CP) concentration of the brassica treatments was not different (P &gt; 0.05) from that of the other forage treatments. Concentrations of ME, CP and NDF were very similar between years for the brassicas, with March ME, CP and NDF concentrations of 12.0–13.2 MJ/kg DM, 14.0–20.1% DM and 16.7–23.6% DM. Conclusion Canola provided increased or equivalent levels of herbage mass and nutritive characteristics compared with other forage options in south-western Victoria on most, but not all, sampling dates. However, the annual spring-sowing requirement is a challenge under variable spring-rainfall conditions and may limit productivity if there is poor establishment. Implications Spring-sown canola is a viable alternative forage for livestock producers and offers a potential second income stream in high-rainfall-zone livestock farming systems.

Inclusion of ripe mango as a source of energy in diets for Creole lambs in the dry tropics

The aim of this investigation was to evaluate the use of ripe mango as a source of energy in an integral diet consisting of regional products for fattening lambs. Twenty-seven Creole lambs were used and given a 10-day period to adapt to the diet. Three treatments were evaluated: T1 = 40% mango; T2 = 50% mango; and T3 = control diet. In the in vitro analysis, partial and accumulated production of biogas and methane, degradation of dry matter, and neutral detergent fiber were determined. In the in vivo analysis, dry matter intake (DMI), daily weight gain (DWG), apparent digestibility of nutrients, and ruminal characteristics were estimated. The experimental design was completely random. The in vitro results helped hypothesize that the diets with low fiber content would not affect potential dry matter intake. With the exception of the protozoa count, ruminal characteristics were not different among diets (p > 0.05). In productive response, T3 was 13.73% higher DMI than T1, which was 32.24% higher than T2. T3 promoted 61.22% more DWG than T1 and T2. T2 displayed better digestibility of dry matter, organic matter, neutral detergent fiber, and crude protein than T3 (p < 0.05). Fattening lambs fed rations that contain 40% and 50% mango reduces the dry matter intake and daily weight gain relative to the control, although apparent digestibility is higher than for the control diet.

Enteric methane production and ruminal fermentation of forage brassica diets fed in continuous culture

The aim of the current study was to determine nutrient digestibility, VFA production, N metabolism, and CH4 production of canola (Brassica napus L.), rapeseed (B. napus L.), turnip (Brassica rapa L.), and annual ryegrass (Lolium multiflorum Lam.) fed with orchardgrass (Dactylis glomerata L.) in continuous culture. Diets were randomly assigned to fermentors in a 4 × 4 Latin square design using 7 d for adaptation and 3 d for collection. Diets were: 1) 50% orchardgrass + 50% annual ryegrass (ARG); 2) 50% orchardgrass + 50% canola (CAN); 3) 50% orchardgrass + 50% rapeseed (RAP); and 4) 50% orchardgrass + 50% turnip (TUR). Feedings (82 g DM/d) occurred four times daily throughout 4, 10-d periods at 730, 1030, 1400, and 1900 h. Methane samples were collected every 10 min using a photoacoustic gas analyzer (LumaSense Technologies, Inc.; Santa Clara, CA) during the last 3 d of the experiment. Effluent samples were collected on d 8, 9, and 10, composited by fermentor, and analyzed for VFA and pH as well as DM, OM, CP, and fiber fractions for determination of nutrient digestibility. Forage samples were analyzed for CP, NDF, ADF, minerals, and glucosinolate (GLS) concentrations. Data were analyzed using the GLIMMIX procedure of SAS. Apparent DM, OM, and NDF digestibilities and true DM and OM digestibilities were similar (P > 0.28) among diets (45.1, 63.2, 44.1, 67.1, and 87.2%, respectively). Total VFA (87.2 mol/100 mol), pH (6.47), and acetate (A: 44.6 mol/100 mol) were also not different (P > 0.20) among diets. The A:P (P = propionate) ratio was greater (P < 0.01) in ARG and CAN than RAP and TUR. Daily CH4 production was greater (P < 0.01) in ARG than all other diets (68.9 vs. 11.2 mg/d). Methane, whether expressed as g per g of OM, NDF, digestible OM, or digestible NDF fed was greatest (P < 0.01) in ARG but similar (P > 0.18) among brassica diets. A significant negative correlation was observed between total GLS and CH4 production. However, when multiple regression analysis on CH4 production was completed, neither total GLS nor individual GLS were a significant component of the model. Addition of brassicas provided similar nutrient digestibility to ARG while reducing daily CH4 production, potentially making brassicas an alternative for ARG in pasture-based ruminant diets.

Forages and pastures symposium: cover crops in livestock production: whole-system approach. Can cover crops pull double duty: conservation and profitable forage production in the Midwestern United States?

Data from a recent survey suggest that the major reasons Nebraska farmers plant cover crops are to improve soil organic matter, reduce erosion, improve soil water holding capacity, produce forage, and increase soil microbial biomass. Many of these benefits appear to be positively correlated with production of above-ground biomass. Thus, selecting species that will produce the greatest biomass should be beneficial for both soil conservation and forage production. Furthermore, the limited data available suggest that grazing of cover crops does not have large negative crop production, soil, or environmental impact. In the Midwestern United States, the production window following wheat harvest, male row destruction in seed corn, and to a lesser extent following corn silage harvest is long enough to produce 2,500 to 4,500 kg DM per hectare of high-nutritive value, fall forage. In the past 4 yr, we have conducted eight trials using predominantly oats and brassicas planted in mid- to late-August. Forage nutritive value of oats and brassicas is extremely high in early November (70% to 80% IVDMD; 14% to 23% CP) and remains high through December with only a 4% to 7% unit decrease in IVDMD and no change in CP concentration. Thus, it appears that delayed grazing could be an option to maximize potential forage yield. Fall-weaned calves (200 to 290 kg BW) grazing oats with or without brassicas in November and December (48 to 64 d) at stocking rates of 2.5 to 4.0 calves per hectare have ADG between 0.60 and 1.10 kg. The cost of gain has ranged from $0.53 to $2.08/kg when accounting for seed costs plus establishment ($60 to 117/ha), N plus application ($0 to 58/ha), fencing ($11/ha) and yardage ($0.10 calf-1 d-1). Although soybeans and corn harvested for grain do not provide a large enough growing window to accomplish fall grazing, similar dual purpose cover crop practices are often accomplished by planting winter-hardy small grain cereal grasses, such as cereal rye or winter triticale in the fall and grazing in the spring. However, traditional planting dates for corn and soybean result in a 30 to 45 d grazing period prior to corn and a 45 to 60 d period prior to soybean planting. Planting cover crops to provide late fall or early spring grazing has potential. However, incorporating forage production from cover crops into current cropping systems greatly increases the need for timeliness of management since the window of opportunity for forage production is quite narrow.

Consumo, digestibilidade e pH ruminal de novilhos submetidos a dietas com tortas oriundas da produção do biodiesel em substituição ao farelo de soja

O experimento foi realizado com quatro novilhos Holandês x Zebu, fistulados no rúmen, mantidos em baias individuais e dispostos em um quadrado latino 4x4 repetido no tempo. Teve duração de 88 dias e os animais foram alimentados com feno de tifton-85 e mistura concentrada com farelo de soja, tortas de dendê, amendoim e girassol, que constituíram os quatro tratamentos. Avaliaram-se o consumo, a digestibilidade aparente total e o pH ruminal. O consumo de matéria seca (MS), proteína bruta (PB), carboidratos não fibrosos (CNF) e nutrientes digestíveis totais (NDT) foi menor (P<0,05) na dieta com torta de dendê em relação às demais. Os consumos de extrato etéreo (EE) e fibra em detergente neutro (FDN) não diferiram entre dietas (P>0,05). As digestibilidades totais dos nutrientes não foram influenciadas pelas dietas (P>0,05). A concentração do pH ruminal não foi influenciada pelas dietas, entretanto houve efeito do tempo de coleta. As tortas de amendoim e girassol oriundas da produção do biodiesel podem substituir o farelo de soja na dieta de novilhos. A substituição total do farelo de soja pela torta de dendê diminuiu o consumo de MS.

Utilisation of forage rape (Brassica napus) and Persian clover (Trifolium resupinatum) diets by sheep: effects on whole tract digestibility and rumen parameters

This study investigated the effect of increasing the proportion of forage rape or Persian clover in the diet on dry matter intake (DMI), whole tract digestibility and rumen function. Two experiments were conducted simultaneously; each in a 3 by 3 Latin square design with rumen-fistulated sheep fed either increasing amounts (10, 25 or 40% DM of the diet) of forage rape (experiment 1) or Persian clover (experiment 2). The remaining diet comprised short-rotation ryegrass, cereal-based pellets and maize silage, formulated to give similar metabolisable energy (MJ/kg DM), neutral detergent fibre and protein values between treatments. Purine derivatives excreted in the urine were used to estimate microbial protein synthesis. The study found similar DMI within forage rape and Persian clover treatments, although total DMI was 16% higher for the latter (29 v. 25 g/kg liveweight.day, respectively). The in vivo DM (mean = 0.75) and neutral detergent fibre (mean = 0.65) digestibility coefficients were similar (P > 0.05) within and between experiments. The mean (±s.e.) rumen pH in sheep fed forage rape-based diets (6.17 ± 0.10) was higher than for Persian clover-based diets (5.70 ± 0.09). The efficiency of microbial N supply expressed as microbial N (g/day) per kg of digestible organic matter fermented in the rumen was also similar (P > 0.05) within and between forage rape and Persian clover treatments (mean = 23.4 g microbial N/kg digestible organic matter fermented). The results indicate that increasing the proportion of high nutritive value forage rape or Persian clover within the diet of sheep did not affect the efficiency of feed utilisation.