Nitrogen transactions along the digestive tract of lambs concurrently infected with Trichostrongylus colubriformis and Ostertagia circumcincta

Twelve lambs, paired on the basis of live weight, were cannulated in the abomasum, in the proximal jejunum approximately 4 m distal to the pylorus and in the terminal ileum. Six were infected with 3000 Trichostrongylus colubriformis and 3000 Ostertagia circumcincta larvae each day for 18 weeks and the remainder were pair-fed to individual infected lambs. All animals were offered ryegrass (Lolium perenne)–white clover (Trifolium repens) pasture, cut daily. Dry matter (DM) intake, live weight, faecal egg concentration, plasma pepsinogen and plasma protein concentrations were measured weekly. During weeks 7 and 17 after commencement of infection, the flow of digesta along the gastrointestinal tract was measured together with enteric plasma loss and true digestion and absorption of ¹²⁵I-labelled albumin in the small intestine. DM intake was depressed by parasitism, being 1331, (se 70), 423 (se 32) and 529 (se 52) g/d during weeks 3, 7 and 17 respectively. The flow of nitrogen at the proximal jejunum and in faeces was increased by parasitism during week 7 and at the abomasum and ileum during week 17. Plasma protein-N loss (g/d) into the gastrointestinal tract was 0.68 (se 0.091) and 1.97 (se 0.139) during week 7, and 0.85 (se0.158) and 1.96 (se 0.396) during week 17, in control and infected sheep respectively. True digestion and absorption of albumin in the proximal small intestine, the site of infection, was very low (mean 0.08) and was not affected by parasitism. Between the abomasum and terminal ileum absorption of albumin was high (mean 0.87) and again was not affected by parasitism. It was calculated that of the total increase in endogenous protein passing from the ileum tract as a result of infection, plasma protein comprised only a small percentage (10–36%). The major proportion of digestion and absorption of protein occurred in the distal small intestine beyond the site of infection and was not affected by infection

Strategies to improve local beef cattle industry supply chains during the pandemic of Covid-19

Covid-19 has highlighted the importance of the local fresh-food supply chains especially with respect to food that cannot be stored or where access to overseas sources is closed. Meat is one fresh-food commodity greatly affected. Beef production is one of the most effective commodities for alleviating poverty for smallholders and if they can more directly participate in the supply chain, they can reap good financial rewards. Farmers usually formulate cattle feed rations on cheapest cost inputs, rather than on a least cost basis which still meets metabolisable energy (ME), crude protein (CP) and neutral detergent fibre (NDF) requirements. The ACIAR project, Profitable feeding strategies for smallholder cattle in Indonesia, has investigated rations that promote high live weight gain and low feed conversion (FCE, kg feed/kg gain) and determined that high ME rations are required at high intakes if low FCE and high income over food costs (IOFC) are to be achieved. The prices and availability of ration ingredients vary markedly across Indonesia and so a flexible system of ration formulation is required to take advantage of local price fluctuations. A Least Cost Ration (LCR) formulator and a least cost App (Beefupp) have been developed which can be used by entrepreneurial farmers, co-operatives and small commercial feed companies to formulate and alter rations quickly as circumstances change. The application of these principles has led to two-fold increases in IOFC for farmers. Government support for farmer led initiatives in the grinding, formulating, mixing and/or pelleting will support effective local co-operatives, farmer groups or small commercial feed companies

Weaning and supplementation increase liveweight gain of Bali (Bos javanicus) cattle of small-holder farmers in Central Lombok, Indonesia

One of the constraints for improving productivity of Bali cattle in west Nusa Tenggara Province is the low growth rate of weaned calves. Results of on-station experiments showed that Sesbania grandiflora (sesbania) supplementation can significantly increase live weight gain of weaned calves. The objective of this experiment was to investigate whether sesbania supplementation can increase live weight gain of weaned calves and improve farmer income. This experiment was carried out in Tandek, Labulia Village (treatment village) and in Kelebuh and Sukaraja villages (control villages) central Lombok District from April to October 2008. A total of 21 calves (9 males and 12 females) aged 237±7 days with initial live weight of 122.3±4.5 kg were monitored in Kelebuh and Sukaraja villages (control villages). During the same period, 25 calves (13 males and 12 females) aged 237±6 days with initial weight of 108.8±4.1 kg were monitored in Tandek Village (treatment village) and fed fresh sesbania at 1% dry matter of live weight. To ensure that sesbania was fed at the recommended level, regular weighing of sesbania offered by each farmer was conducted 2-3 times per week. All calves were weighed every month to determine live weight gain. Farmers from the control villages and other villages were invited to a field day conducted in the treatment village at the end of the experiment. The results showed that sesbania supplementation significantly increased live weight gain (0.36±0.01 kg/day for calves in the treatment village compared to 0.22±0.01 kg/day for those in the control villages), increased body condition and health of the calves and improved farmer income. Weaning management and supplementation with sesbania was very easy to implement so most of the farmers participated in this study stated that they were willing to continue this feeding management

Ingestive behaviour and forage intake responses of young and mature steers to the vertical differentiation of sugarcane in pen and grazing studies

SUMMARY Sugarcane is an important forage resource in sub-tropical and tropical areas as it is used during the winter or dry season when the growth rate of pastures is significantly reduced. The current research study assessed the effect of four vertical sections of sugarcane in a pen trial and the level of sugarcane utilization in a grazing trial on the ingestive behaviour and forage intake of two age groups of steers (1 and 2 years old). The pen trial was comprised of two simultaneous 4 × 4 balanced Latin square designs (one for each age group of animals) of four periods, four animals and four feeding treatments, which consisted of four equal vertical sections of sugarcane. Dry matter (DM) and digestible DM (DDM) intake per kilogram of metabolic weight declined gradually from top to bottom of the sugarcane, with no significant differences between the age groups of steers. This difference in intake was associated with a decline in intake of neutral detergent fibre (NDF) as a proportion of the liveweight of the animal and an increase of total chewing time per kilogram of DM or NDF from top to bottom of the sugarcane. It was concluded that the toughness of plant material played a significant role regulating intake, which was higher for the top sections of sugarcane. In the grazing trial, steers of both age groups grazed down sugarcane in three plots over 9 days. Steers grazed up to four distinctive grazing strata. Digestible DM intake (DDM intake) was high at low levels of horizontal utilization of the top grazing stratum but DDM intake started to decline sharply when this stratum was removed in 0·92 of paddock area (i.e. equivalent to 0·08 of the pasture area remaining un-grazed). It was concluded that the proportion of un-grazed area of the pasture can be used as a grazing management strategy to control forage intake for sugarcane

A Multi-Physic Modelling Insight into the Differences between Microwave and Conventional Heating for the Synthesis of TiO2 Nanoparticles

Microwave-assisted synthesis of nanoparticles usually leads to a smaller and more uni-formly distributed particle size compared to conventional heating (e.g., oil bath). Numerical simulation can help to obtain a better insight into the process in terms of temperature distribution or to evidence existing different temperature profiles and heating rates between the two techniques. In this paper multi-physics numerical simulation is used to investigate the continuous flow synthesis of titanium oxide nanoparticles starting from alkoxide precursors. Temperature-dependent permit-tivity of reactants has been measured, including the effects of permanence at the maximum synthesis temperature. A temperature homogeneity index has been defined to compare microwave and conventional heating. Results show that when using microwave heating at 2450 MHz, in the inves-tigated conditions, a much higher temperature homogeneity of the reactants is reached. Moreover, reactants experience different heating rates, depending on their position inside the microwave ap-plicator, while this is almost negligible in the case of conventional heating

Small differences in biohydrogenation resulted from the similar retention times of fluid in the rumen of cattle grazing wet season C3 and C4 forage species

The effects of forage type and season on retention time (RT) and the fatty acid (FA) profile of the rumen fluid (RF) of steers grazing a range of grasses and a legume/grass mix were evaluated. Four rumen cannulated steers (790 +/- 17 kg body weight (BW) grazed individual wet season pastures (herbage mass 2600-6200 kg DM/ha of C3 ryegrass Lolium perenne and C4 grasses pangola Digitaria eriantha, signal grass Brachiaria decumbens, star grass Cynodon dactylon, kikuyu Penniseturn clandestinum, and speargrass Heteropogon contortus in both seasons, and a mixture of leucaena Leucaena leucocephala and green panic Panicum maximum in the dry season. Each grazing period consisted of at least 21 d, followed by a 3 d collection period. On d 22 CrEDTA was used to estimate RT (182 mg Cr/100 kg BW via the cannula) and RF samples were collected at 0, 4, 8, 12, 16, 24, 28, 32 and 48 h after dosing for Cr analysis. Diet crude protein (CP) and dry matter digestibility (DMD) were estimated by faecal NIBS. Concentration of NH3N and volatile fatty acids (VFA) in RF was determined at 0, 8 and 16 h after dosing. Dry season speargrass had the lowest CP (18 and 39 g/kg DM in plucked sample (PS) and estimated by faecal NIRS, respectively) and DMD (49%), which was associated with a low NH3N (9 mg NH3N/L) and VFA concentration (70 mM) in RF, and much longer RT of Cr (20 h) than the other grasses. The RT of Cr of the other wet season grasses was similar across all forage species (8- to 11 hours). Total VFA in RF was lowest for steers grazing dry season grass, intermediate for grasses in the wet season and highest for steers grazing the legume/grass mix. Speargrass had the highest non-glucogenic:glucogenic VFA. Ryegrass had higher CP (190 g/kg DM) and DMD (68%), but steers grazing this pasture had similar NH3N concentration in RF to steers grazing kikuyu and leaucaena/grass mix (above 100 mg NH3N/L). Palmitic and stearic acid in RF were much higher than in plucked samples, but all grasses had similar total saturated FA in RF with a greater degree of saturation for ryegrass. A higher CLA c9,t11 in RF of steers grazing ryegrass most likely resulted from the linoleic content in the forage and the higher intake of ryegrass resulting in accumulation in RF. Total unsaturated FA (TUFA) content of RF was reduced markedly compared to forage samples with some small differences between species indicating an extensive biohydrogenation despite the grass type and season. It was concluded that RT of Cr in the rumen of cattle grazing wet season grasses was similar across all forage species (8 to 11 hours) and would not result in different times for biohydrogenation within the rumen

Responses to various protein and energy supplements by steers fed low-quality tropical hay. 2. Effect of stage of maturity of steers

Dose response curves to various supplements were established in two pen-feeding experiments (Exp1 and Exp2) with Bos indicus crossbred steers of two age groups (Young, 10–12 months; Old, 33–36 months) fed low-quality tropical grass hays ad libitum. Diets included supplements based on (Exp1) cottonseed meal (CSM; intake (as fed) 0–10 g/kg liveweight (W).day) and a barley mix (Bar; 0–20 g/kg W.day) and (Exp2) a molasses mix (MUP) and a Bar mix, both fed at 0–20 g/kg W.day. Urea was provided with the Bar mixes and urea/copra meal with the MUP mix. Growth rates of Young steers increased linearly with Bar and MUP supplements but asymptotically with CSM whereas those of Old steers increased asymptotically with all supplement types. With supplement intake expressed on a liveweight basis (g/kg W.day), responses were greater for both steer age groups with CSM compared with Bar (Young, P < 0.001; Old, P < 0.01) and Bar compared with MUP treatments (Young, P < 0.01; Old, P < 0.05). Furthermore, Old steers outperformed their Young counterparts with both CSM (P < 0.05) and Bar (P < 0.001) supplements fed in Exp1 and with Bar and MUP supplements (P < 0.01) fed in Exp2. When supplement intake was expressed in absolute terms (kg/day), growth responses were not different between age groups for different supplements except that Old steers had a higher daily W gain on Bar than their Young counterparts (P < 0.05). Intake of hay (W-corrected) was higher for Young compared with Old steers without supplement but was variably reduced for both steer groups with increasing supplement intake. The results of these experiments have implications for supplement formulation for steers at different stages of maturity grazing low-quality forages