Context Increasing cow reproduction rates and annual liveweight gain present the best opportunity for maximising profitability of cattle herds in the seasonally dry rangelands of northern Australia. Herd-management and feed-base strategies exist and target heifer reproduction, liveweight of steers, and herd structure to increase whole-of-herd productivity. Aims To use a desk-top model to determine the effect of supplementation in the first or second dry season after weaning on the break-even thresholds of the long-term productivity and profitability of an entire beef enterprise in response to changes in supplement costs and steer prices. Methods Whole-of-herd desktop analyses were conducted using an Excel© version of the Breedcow Dynama software on a modelled cattle breeding herd in the Victoria River District and Katherine regions of the Northern Territory, Australia. Key results Gross margins across the entire herd were increased in response to supplementation of weaners to achieve an extra 0.3 kg/day liveweight gain in the first dry season, with a break-even threshold of AU$678/t of supplement when steer prices were AU$3.50/kg liveweight. A concentrated supplementation period of heifers in the second dry season after weaning to achieve 0.8 kg/day had a break-even threshold of AU$696/t at the same price structure. Conclusions At recent steer prices and supplement costs, feeding all weaners in the first dry season after weaning, or just the heifer cohort for a short duration in the second dry season after weaning increased gross margins across the entire cattle herd and altered herd structure. The application of a sensitivity analysis demonstrated the steer price and supplement-cost thresholds, at which weaner supplementation is likely to be profitable. Implications These results have provided evidence and a framework for decision-making to assess the potential financial benefits associated with weaner and yearling heifer supplementation. The approach and results will assist producers to make tactical or strategic decisions on the adoption of weaner supplementation and the development of novel feeding systems in cattle breeding herds located in the seasonally dry rangelands of northern Australia within prevailing economic conditions. Moreover, they have provided target supplement costs by which to identify potential new supplements or feeding scenarios.

Context Formulating diets using agro-industrial by-product concentrates to increase the growth performance and cost efficiency of Ongole crossbred bulls. Aims This study was conducted to evaluate the inclusion of agro-industrial by-products of dried cassava powder (DCP), mixed copra meal (CM), palm kernel cake (PKC) and soybean hull (SBH) into rations at low and high levels of feeding on bull liveweight gain and farmer profitability. Methods Fifty Ongole crossbred bulls with an initial bodyweight (BW) of 227 ± 66.5 kg and aged between 12 and 18 months, were arranged in a randomised complete-block design of five treatments, with 10 heads per treatment. The control group (T0) was provided the current feeding system (CFS) fed ad libitum. The supplemented treatments consisted of CFS ad libitum + concentrate (50% DCP, 25% CM, 25% PKC) at 1% BW/day (T1), CFS ad libitum + concentrate (50% DCP, 25% CM, 25% SBH) at 1% BW/day (T2), CFS ad libitum + concentrate (50% DCP, 25% CM, 25% PKC) at 2% BW/day (T3), CFS ad libitum + concentrate (50% DCP, 25% CM, 25% SBH) at 2% BW/day (T4). The experiment was conducted for 12 weeks. Key results The BW gain over 12 weeks (kg) for T0, T1, T2, T3 and T4 was 39.5, 56.2, 68.9, 57.5 and 62.1 kg respectively. The income over feed cost was significantly higher in T2. Conclusions Supplementation with by-products increased bull liveweight gain compared with current feeding practices. A concentrate supplementation of DCP mixed with CM and SBH at 1% BW/day was the most effective and profitable supplementation method to increase income of farmers in this district and there was no advantage of increasing the level of supplement. Implications A combination of DCP, CM and SBH to form a concentrate supplement and fed at 1% BW/day will increase bull liveweight gain and income of farmers.

This study aimed to analyze the farmers' willingness in adopting local feed innovation and to analyze its background factors. This study involved 106 cattle farmers who lived in Arjowilangun and Kucur villages of Malang Regency, East Java. Data were collected from respondents through personal interviews with structured questionnaires. This study also used descriptive statistical analysis and Probit regression as the methods. The research results showed that most of the farmers were willing to partially adopt local feed innovation. Social and economic factors that statistically gave significant influence on the farmers' willingness in adopting the local feed innovation are age, the number of cattle, cattle agribusiness type, membership in a farmer's group, and the perception towards the cattle farming conditions. Age and the number of cattle negatively affect the farmers' willingness while membership in a farmer's group and perception towards the cattle farming conditions has a positive effect on the farmers' willingness in adopting local feed innovation. Farmers who are running the cattle fattening business have larger probabilities to reject the local feed innovation. Furthermore, optimizing coaching and assisting activities through the farmer's group can be an effective way to increase the farmers' willingness to entirely adopt the local feed innovations.

Context The planting and use of leucaena (Leucaena leucocephala) to fatten cattle is both practical and profitable for smallholder farmers in West Nusa Tenggara, Indonesia. Currently smallholder farmers feed leucaena as the primary component of a cattle fattening diet. However, the high protein content in leucaena could be more effectively used if combined with a fermentable energy source, such as cassava (Manihot utilissima). Aim An experiment was conducted to determine the ratio of leucaena to cassava corresponding to largest average daily gain and most efficient feed conversion for gain. Methods Thirty growing male Bali cattle (Bos javanicus) ~18 months of age with an initial live weight of 164 ± 1.8 kg (mean ± s.e.) were allocated to one of six experimental treatments in a randomised block design. Bulls were held in individual stalls and had access to experimental diets and water ad libitum. The diets were 20% rice straw + 80% leucaena hay (A), 20% rice straw + 65% leucaena hay + 15% cassava meal (B), 20% rice straw + 50% leucaena hay + 30% cassava meal (C), 20% rice straw + 35% leucaena hay + 45% cassava meal (D), 20% rice straw + 20% leucaena hay + 60% cassava meal (E) and 20% rice straw + 5% leucaena hay + 75% cassava meal (F). A mineral mix was provided at 1% DM of total diet and urea was added to the cassava meal at 2% DM. In consideration of animal welfare concerns, the trial was concluded on Day 77 due to observations indicating that bulls receiving the highest level of cassava (F) were experiencing significant weight loss. Key results The optimum level of inclusion of cassava was 29.5% (based on the quadratic response curve) but there was little difference in average daily gain up to 45% inclusion. Feeding a high level of cassava meal (more than 45% of diet) reduced feed intake, average daily gain and income over feed cost. Conclusion Cassava meal can be successfully and profitably incorporated into leucaena-based rations of Bali bulls for fattening. Implications Formulating rations with cassava meal and leucaena can be economically beneficial in cattle fattening systems.

Abstract In grazing systems in Northern Australia, crude protein (CP) and phosphorus (P) availability varies, affecting ruminant production due to voluntary reduced intake and therefore body weight (BW) gain. We were interested in understanding metabolic regulation in this model system, both in terms of a) identifying key tissues, and b) detecting any modifications in mitochondrial physiology, given the central role of this organelle in bioenergetic homeostasis. Merino wethers (n = 24) were subjected to three dietary regimens: High CP, High P, (Control), Low CP, Low P (Deficient), and High CP, High P, with restricted feed intake (Restricted). Mitochondrial DNA (mtDNA) copy numbers, indicative of mitochondrial content, were measured via qPCR. Transcriptomic analyses through RNA sequencing targeted mitochondria-associated gene expression changes and pathways, using the MitoCarta 3.0 database. There was a significant decrease of mtDNA copy numbers in the liver of sheep under either Deficient and Restricted diets (P < 0.01), with as much as a 2-fold difference between the Control and Deficient diets. This may suggest reduced mitochondrial biogenesis as an adaptation to decreased energy intake. When compared with the Control group, both the Deficient and Restricted groups upregulated pathways related to vitamin metabolism (Log2FC: 0.231 and 0.449) and folate and 1-C metabolism (Log2FC: 0.409 and 0.706). However, impacted pathways shared between these two comparisons (Control v Deficient, Control v Restricted) also include choline and betaine metabolism, amino acid metabolism, and glycine metabolism, which suggests similar mechanisms being impacted by decreased energy intake, regardless of whether it is due to satiety from nutrient deficiency or restricted feed intake. Notably, the creatine metabolism pathway was uniquely upregulated in the Restricted group compared with the Deficient group (Log2FC: 0.114), although the CKMT2 gene was upregulated in the Restricted group compared with both the Control and Deficient group (Log2FC: 1.30 and 0.879). Additionally, the SLC25A family pathway, responsible for mitochondrial metabolite transport, was found to be upregulated in the Restricted group when compared with both Control and Deficient groups (Log2FC: 0.33 and 0.865). Overall, this study demonstrated a pronounced decrease in mitochondrial content in the liver of growing Merino wethers subjected to nutritional deficiencies and feed restriction. Multiple metabolic pathways were shared between the comparisons of the Control diet group to both Deficient and Restricted nutritional treatments. However, the SLC25A transporter family pathway was uniquely upregulated in the Restricted group compared with either an optimal or deficient diet. The regulation of these metabolic pathways is a subject of further study that may represent a systemic response to maintain homeostasis while undergoing significantly lower energy intake, with implications for animal growth, tissue deposition, and energetic maintenance. Understanding distinctions in the response to feed restriction and nutrient deficiency induced reduction in intake may help improve production strategies for ruminants grazing in these conditions.

A reduction in voluntary feed intake is observed in ruminants consuming nutrient-deficient diets, such as those with a low CP or P content, and has been attributed to active metabolic regulation, rather than a physical constraint. The hypothalamus is the key integrator of feed intake regulation in mammals. The objectives of this experiment were to (1) establish a model of metabolic feed intake regulation in ruminants consuming diets of variable CP and P content, and (2) determine key biochemical pathways and influential points of regulation within the hypothalamus. Merino wethers [n = 40; 23.7 ± 1.4 kg liveweight (mean ± SD)] were fed one of five dietary treatments (n = 8/treatment) for 63 days in individual pens. The treatments included targeted combinations of high (H) and low (L) CP (110 and 55 g/kg DM) and high and low P (2.5 and 0.7 g/kg DM) with 9 MJ metabolisable energy (ME) per kg DM which were fed ad libitum (UMEI; unrestricted ME intake) resulting in four experimental diets (HCP-HP-UMEI, LCP-HP-UMEI, HCP-LP-UMEI and LCP-LP-UMEI). An additional nutritional treatment (HCP-HP-RMEI) restricted intake of the HCP-HP diet to an equivalent ME intake of wethers consuming the LCP-LP-UMEI treatment. Wethers offered the LCP-HP-UMEI, HCP-LP-UMEI and LCP-LP-UMEI treatments consumed 42, 32 and 49% less total DM (P ≤ 0.05), respectively than the HCP-HP-UMEI treatment, and this was not attributable to any physical limitation of the rumen. Plasma concentrations of urea nitrogen and inorganic phosphate indicated that these nutrient deficiencies were successfully established. To assess potential mechanisms, RNA-seq was conducted on samples from the arcuate nucleus (ARC), ventromedial hypothalamus and lateral hypothalamus of the wethers, yielding a total of 301, 8 and 148 differentially expressed genes across all pairwise comparisons, respectively. The expression of NPY, AGRP and CARTPT, known for their regulatory role in mammalian feed intake regulation, had a similar transcriptional response in the ARC of wethers consuming nutrient-deficient treatments and those consuming a ME-restricted treatment, despite these wethers expressing behaviours indicative of satiated and hungry states, respectively. In addition, genes involved with glycolysis (TPI1), the citric acid cycle (CS, OGDH, GLUD1, GOT1) and oxidative phosphorylation (COX5A, ATP5MC1, ATP5F1B, ATP5MC3) were downregulated in the ARC of wethers fed a nutrient deficient (LCP-LP-UMEI) relative to the non-deficient (HCP-HP-UMEI) treatment. In summary, a model for voluntary feed intake restriction was established to determine genome-wide molecular changes in the hypothalamus of young ruminants.

Context Energy supplementation with highly fermentable carbohydrates can be a strategy to maximise the efficiency of nitrogen use (ENU) from high-nutritional value forages. Aims The study aimed to investigate the independent or associated effects of two diurnal feeding times (0900 or 1700 hours) with two sources of energy supplementation (corn or citrus pulp) in the growing of F1 Angus × Nellore young bulls on palisade grass pastures, and their implications on the forage chemical composition, nutrient intake and digestibility, ENU, microbial protein synthesis, animal performance, and gain per area. Methods There were 36 bulls used as experimental animals, with initial bodyweight (BW) of 290 ± 5 kg, and 32 similar bulls were used in a put-and-take system to maintain sward characteristics. The experiment was conducted in a complete randomised design with four treatments and three replications (paddocks). The treatments consisted of energy supplementation at 0.3% BW with corn or citrus pulp fed at 0900 or 1700 hours for four periods of 28 days. For evaluation of ruminal and blood parameters, ENU, intake, and nutrient digestibility, eight ruminal cannulated 1/2 Aberdeen Angus × 1/2 Nellore young bulls were used, with 280 ± 7 kg of initial BW, distributed in a 4 × 4 double Latin square design, consisting of four periods and four treatments. Key results Supplementation at 0.3% of BW with corn or citrus pulp at 0900 or 1700 hours can reach up to 1.06 kg/day of young bulls reared on palisade grass pastures fertilised with 180 kg nitrogen/ha/year and managed at 25 cm of height compared with corn-based supplements. There were no effects on microbial protein synthesis or its efficiency. Conclusions Citrus pulp can be used as an alternative energy source to corn, because it has the same potential for animal performance, ENU and microbial protein synthesis in tropical pastures with a high proportion of soluble protein, and structural and non-fibrous carbohydrates with high dry matter digestibility. Implications Supplementing grazing beef cattle at 0.3% BW with corn or citrus pulp in the morning or afternoon is an efficient nutritional strategy to improve animal performance.

Supplementing growing cattle grazing native subtropical Campos grasslands during winter improves the low, even negative, average daily weight gain (ADG) typical of extensive animal production systems in Uruguay. Nonetheless, to render the practice profitable, it is crucial to control supplement feed efficiency (SFE), that is, the difference in ADG between supplemented and control animals (ADGchng) per unit of supplement dry matter (DM) intake. Little has been studied specifically on how SFE varies in these systems. The objective of this study was to quantify the magnitude and variation in SFE of growing beef cattle grazing stockpiled native Campos grasslands during winter and assess putative associations with herbage, animals, supplements, and climatic variables. We compiled data from supplementation trials carried out in Uruguay between 1993 and 2018, each evaluating between one and six supplementation treatments. The average ADG of unsupplemented and supplemented animals were 0.13 +/- 0.174 and 0.49 +/- 0.220 kg/animal/day, respectively. In both cases, ADG decreased linearly as the proportion of green herbage in the grazed grassland was lower, but the ADG of unsupplemented animals was further reduced when winter frosts were numerous. Estimated SFE were moderately high, with an average of 0.21 +/- 0.076 ADGchng/kg DM, resulting from average ADGchng of 0.38 +/- 0.180 kg/animal/day in response to an average supplementation rate of 1.84 +/- 0.68 kg supplement DM intake/animal/day (0.86% +/- 0.27% body weight). No association was found between SFE and supplementation rate or type (protein vs. energy-based; P > 0.05), but forage allowance negatively affected it, and herbage mass positively affected it, yet in a smaller magnitude, suggesting that a balance is needed between the two to maximize SFE. Weather conditions during trials affected SFE (P < 0.05), with greater SFE in winters with lower temperatures and more frosts. Daytime grazing time was consistently lower in supplemented animals compared to their unsupplemented counterparts, whereas ruminating time during the day was similar, increasing as the proportion of green herbage decreased. Herbage intake estimated from energy balance suggested the existence of some substitution effect. This agrees with the moderately high SFE and with the total digestible nutrients-to-protein ratio of these subtropical humid grasslands being higher than in semi-arid rangelands and dry-season tropical pastures but lower than in sown pastures. LAY SUMMARY Beef cattle are reared on native grasslands worldwide. In the native Campos-the subtropical humid grasslands part of the Pampa biome in southern South America-animals often lose weight during winter due to insufficient quantity or quality of available forage. Therefore, supplementation with concentrates is advocated. Notwithstanding its productive impact, this practice is unprofitable when supplement feed efficiency (SFE) is low. We collated data from 25 trials carried out from 1993 to 2018 in Uruguay to better understand how and why SFE varies in growing cattle grazing stockpiled Campos. On average, animals gained 0.21 kg of body weight per kg of consumed supplement, but variation was large. Winters with more frosts resulted in greater responses, rendering the practice more efficient. The amount of forage per animal negatively affected efficiency, while overall forage availability positively affected it (yet in a smaller magnitude), suggesting that in order to be more efficient, a balance between them is needed. Protein concentration of supplements was associated with SFE. Nonetheless, the proportion of green biomass in offered herbage did correlate with weight gain and grazing behavior of the cattle. The total digestible nutrients-to-protein ratio of Campos winter herbage-halfway between that of rangelands and sown pastures-would explain the observed relatively high SFE.

Context Supplementing a leucaena-based diet with locally available energy sources is an important strategy to extend the use of leucaena, increase liveweight (LW) gain of Bali cattle and increase profit for the smallholder. Aims This study was conducted to evaluate the effect of various local energy supplements in leucaena-based diets on the LW gain of Bali cattle and income-over-feed costs (IOFC). Methods Forty male Bali cattle were divided into five treatment groups (n = 8) and each was fed one of the following diets: (A) control diet, including leucaena ad libitum, with corn stover at 0.5% DM LW and mineral mix, (B) control + cassava meal at 1.0% DM LW, (C) control + cassava peel at 1.0% DM LW, (D) control + cassava peel and corn grain mix at 1.0% DM LW or (E) control + commercial feed at 1.0% DM LW. The experiment was run for 140 days, which included a 20-day adaptation period. Parameters measured included intake, digestibility, imbibed-water intake, LW gain, rumen and faecal parameters, feed conversion and IOFC. Key results Supplementation of local energy sources in combination with leucaena and corn stover diets increased LW gain of male Bali cattle above that of the control diet (P < 0.05). The bulls receiving the cassava peel and corn mix supplement had the highest LW gain (0.57 ± 0.09 kg/day), which was associated with an increase in digestible organic-matter intake (DOMI). There were no treatment differences (P > 0.05) in the rumen parameters (rumen fluid pH, rumen ammonia-N concentration and volatile fatty acids) and all parameters were optimum for rumen digestion. Conclusions The addition of local energy supplements supplied at 1% of LW improved growth rate and extended the use of a limited amount of leucaena and provided a higher IOFC. Implications Replacing approximately 40% of leucaena with energy sources can have three benefits, including an increase in LW gain, an increased capacity of farmers to feed more cattle per hectare and an increased income per cattle being fattened. This can increase the production scale and subsequent farmer income, provided that the energy sources are available at affordable prices and obtainable.

It is unclear to what extent and on which variables does supplementing beef cattle on native grasslands affect sward structure, specifically on the dynamics of its grazing horizons. Three hypotheses were tested: (i) during a grazing down process under similar forage allowance, supplemented animals take longer to finish each grazing stratum, than their unsupplemented counterparts, (ii) in both cases, the upper stratum will be heavily depleted before the subsequent strata are grazed, (iii) some species and/or forage fractions are consumed faster than others, regardless of the animals being supplemented (corn dried distillers grains with solubles, DDGS, at 0.7% of their body weight, BW, on a dry matter, DM, basis) or not. Three blocks of stockpiled native grasslands were used and split into two treatments plots (n = 6), on which either supplemented (S) or control (C) heifers of 10.6 +/- 0.6 months of age and an initial BW of 143 +/- 9 kg, were used. A 2.5 x 0.5 m observation grid was installed on the sward, generating 384 observation points on each plot. On these observation plots, sward height (SH) and visually assessed green forage mass percentage (%G) were registered every other day for 12 consecutive days. No differences were found between the horizontal grazing dynamics between supplemented and control animals in terms of how they switched from the upper grazing horizon to the successive ones. In both cases, when the upper grazing horizon was heavily depleted, the subsequent horizon was being depleted by its half. Differences of preference for C3 species over C4 was observed for both treatments, but this effect was more meaningful for control animals. Grazing time never fully compensated for the decline in intake rate during depletion throughout the grazing horizons. Pasture intake declined when the animals transition from grazing the top grazing horizons to the lower horizons, irrespective of the level of supplementation. Managing the sward structure in terms of sward height will be beneficial to maximizing individual animal performance, for both C and S animals. Native grasslands paddocks with a greater C3 gasses predominance will always be preferred to C4 dominated paddocks, regardless of an eventual supplementation practice.

Previous studies on winter supplementation of growing cattle grazing stockpiled native Campos grasslands suggest that forage allowance (FA), herbage mass, and weather conditions before and during the supplementation period could all affect supplement feed efficiency (SFE)—that is, the difference or change in average daily gain (ADG) between supplemented (S) and control (C) animals (ADGchng, kg) per unit (kg) of supplement dry matter (DM) intake. In this study, we analyse data from fifteen collated winter supplementation trials carried out in Uruguay between 2004 and 2018. The working hypotheses of this research paper were: (i) that average substitution rates are positive, and (ii) that ADGchng is not constant throughout the supplementation period and that its variation may be attributed to sward, animal or weather variables. There were two main objectives: (i) to estimate the average supplement substitution rate (sSbR, kg forage, f, dry matter, DM intake reduction: kg supplement DM intake) and potential herbage intake substitution rate (hSbR, kg fDM intake reduction: kg fDM intake of control animals), and its association with SFE, and, (ii) to assess the existence of different phases and supplementation response patterns and its association with other relevant variables. Estimated substitution rates were always positive (sSbR = 0.3–1.1 kg/kg; hSbR = 0.1–0.3 kg/kg) and were negatively and moderately associated with SFE. Supplementation proved to be a dynamic process where three possible supplementation responses over the supplementation period were identified (linear, quadratic and Weibull). While linear patterns did not appear distinctly associated with any particular set of variables, quadratic models were mostly associated with herbage biomass and substitution rates, whereas Weibull models were the clearest in their association with frosts. Regardless of the response pattern, at the beginning of the trials it was the animals’ body weight and supplement quality that most influenced supplement response, whereas towards the end, supplementation intake, supplemented animals’ ADG and forage quality played a more relevant role. The estimated parameters and response patterns are expected to be used as inputs in decision support systems for livestock farmers in the future.

The present study investigated the effects of different combinations of cassava powder and palm kernel cake on intake and digestibility of Ongole Crossbred bulls fed a fixed amount of rice straw. Ongole bulls (n=24) were assigned to five dietary treatments (n=5 bulls/treatment for all treatments, except for T3 that had n=4 bulls) and allocated to individual pens in a completely randomized block design. The ration consisted of 5 g rice straw dry matter (DM)/kg liveweight.day with the different concentrate combinations offered ad libitum . Concentrates were prepared with different ratios of cassava powder and palm kernel cake respectively: 88:12 (T1), 75:25 (T2), 62:38 (T3), 50:50 (T4), and 38:62 (T5). Bulls were fed twice a day with drinking water available at all times. The experiment consisted of a 14-day adaptation period and a 7-day measurement period. Dry matter and organic matter (OM) intake were not different between treatments, although DM digestibility and OM digestibility were higher in T2 compared to T4 and T5 treatment diets (P<0.05). Bulls fed the T2 and T3 nutritional treatments had a higher digestible OM intake than bulls fed the other nutritional treatments (P<0.05). It is concluded that including cassava powder at 63 to 75% and PKC at 25 to 38% in a concentrate is the best ratio in a total mixed ration for fattening bulls when fed a small fixed amount of rice straw.

Context Nutritive values, particularly energy content of tropical forages, need to be accurately assessed so that rations can be more precisely formulated. Aims The research aimed to collate and compare equations used to predict metabolisable energy content in forage sorghum (Sorghum bicolor (L.) Moench) to ascertain the effect of vertical strata on metabolisable energy content to assist in producing silage of defined quality. Methods Twenty-four predictive metabolisable energy equations derived from international feeding standards were compared using forage sorghum samples grown under fertiliser and growth stage treatments. Samples were separated into leaf, stem and seed heads (where present) over four vertical strata. Key results Equations based on digestibility with crude protein were robust in the prediction of metabolisable energy and had application to routine laboratory use. Conclusions The current study suggests that predictions based on digestibility and crude protein content are best placed for metabolisable energy application. Such equations should be originally based on measured metabolisable energy content to establish a regression so as to be used for predictive purposes, and satisfy the biological requirement of in vivo and the laboratory measurement relationship with acceptable statistical error. Chemical composition relationships predicted different metabolisable energy contents. Implications Improved accuracy of the prediction of metabolisable energy content in tropical forages will provide better application of production models and more accurate decisions in ration formulation.

Context High international demand for goat meat and high prices for goat in Australia have resulted in a transition from opportunistic harvesting to more managed production systems for Rangeland goats. There is limited information available to establish feeding strategies to maximise growth rates of Rangeland goats within these developing managed production systems. Aims The aim of these experiments was to determine the response to supplements and the metabolisable energy requirements for maintenance and liveweight gain of young entire male Rangeland goats. Methods Dose–response relationships to various supplements were established in two experiments with young entire male Rangeland goats. In Experiment 1, 54 goats were allocated to rolled-wheat grain, rolled-sorghum grain, or lucerne pellet supplements offered from 0 (control) to 24 g dry matter/kg liveweight.day. In Experiment 2, 24 goats were allocated to a commercial starch-based pellet offered from 0 (control) to ad libitum. In both experiments, goats were held in individual pens and offered their daily supplement allowances with ad libitum access to Mitchell grass hay and drinking water for 70 days. Key results Total intake (30 to 32 g dry matter/kg liveweight.day) increased in a linear fashion with an increasing intake of all supplements. Maximum intake of rolled-wheat, rolled-sorghum, lucerne pellets and the commercial starch-based pellet supplements ranged from 18 to 22 g dry matter/kg liveweight.day. Unsupplemented goats lost liveweight (−20 to −32 g/day), while supplemented goats gained liveweight (0 to 126 g/day) in a linear fashion with an increasing supplement and metabolisable energy intake for all supplements, with the highest response in goats supplemented with the commercial starch-based pellets. Estimated metabolisable energy requirements to maintain liveweight (372 kJ/kg liveweight0.75.day) and for liveweight gain (35 kJ/g) of the goats were the same in both experiments. Conclusion Liveweight gain increased in a linear fashion with metabolisable energy intake, with the maximum rates of liveweight gain occurring when starch-based supplement intake was approximately 20 g dry matter/kg liveweight.day. Implications Supplementation with starch-based rations will increase liveweight gain and decrease age at turn-off of young entire male Rangeland goats; however, the local availability and cost of these supplements need to be considered.

This study investigated the effect of five post-weaning supplementation strategies and two weaning weight groups on long-term growth, puberty and pregnancy percentage of Brahman crossbred heifers. Early-weaned (118 ± 6 kg liveweight) and normally-weaned (183 ± 6 kg liveweight) heifers were allocated to group pens (n = 4 and n = 5/pen for early- and normally-weaned respectively) and offered one of five levels of post-weaning protein supplementation: 0, 1, 2.5, 5 and 10 g of supplement/kg liveweight.day with ad libitum access to a low quality sabi grass (Urochloa mosambicensis) hay during the first dry season (169 days) after weaning. After the post-weaning supplementation period, all heifers grazed the same pastures as a single mob until the end of the experiment and were exposed to fertile bulls from January to May 2016. During the first dry season, supplement intake had a positive linear effect on liveweight gain and hip width gain with no difference in the response between weaning groups. Overall, heifers with higher supplement intakes (i.e. 5 and 10 g/kg) had higher hip height gain (P < 0.005), hip width gain (P < 0.001), body condition score (P < 0.001), and concentration of insulin-like growth factor-1 (P = 0.001), triiodothyronine (P = 0.04) and insulin (P = 0.05) in plasma compared to unsupplemented heifers. These changes resulted in thicker proliferative and hypertrophic zones (both P = 0.03) of the tuber coxae growth plate, larger diameter of terminal hypertrophic chondrocytes (both P = 0.004) at the end of the post-weaning supplementation period when comparing the highest level of supplementation with unsupplemented group. Unsupplemented heifers from both weaning weight groups demonstrated compensatory liveweight gain over the first wet season while evidence of catch-up growth in skeletal dimensions was observed in the second wet season. The main determining factor for pregnancy status of two-year-old Brahman crossbred heifers was pre-mating liveweight (P < 0.001), the pre-mating liveweight was in turn affected by post-weaning supplementation (P = 0.02) or weaning weight group (P < 0.001). This study further demonstrated the positive relationship between premating weight and the occurrence of pregnancy, with an approximate 300 kg pre-mating liveweight required to achieve approximately 80% (67.1–90.3% for a 95% confidence interval) probability of pregnancy in two-year-old Brahman crossbred heifers mated for 4 months.

The present study investigated the effect of varying the proportion of dried cassava and palm kernel cake on in situ rumen degradation kinetics in Ongole Crossbreed. Ongoles were fed two different concentrate rations of cassava and palm kernel cake (PKC) varying in percentage with one concentrate mixture comprising 80% cassava with 20% PKC and the other concentrate mixture was 50% cassava mixed with 50% PKC. Each concentrate mixture was fed with rice straw to make a total mixed ration of approximately 80% rice straw and 20% concentrate. Each ration was fed to one of two rumen fistulated cattle in a cross-over design. Each period was of two weeks with an adaptation period. In situ degradation was measured in the second week. A sample of the mixed concentrate was measured into each nylon bag such that the proportion of cassava or PKC was the same as the ration concentrate being fed ie 80:20 or 50:50 cassava:PKC respectively. Each mixed concentrate treatment (5 g) was weighed in quadruplicate into nylon bags and then incubated in the rumen for 4, 8, 16, 24, 48, 72, and 96 h, removed at these times, dried and analysed for DM and organic matter. The degradation kinetics of dry matter and organic matter were higher (P<0.05) in the 80:20 concentrate treatment than the 50:50 concentrate treatment. The immediately degradable fraction, the potentially degradable fraction, fractional degradation rate, and theoretical degradability were higher (P<0.05) in the 80:20 concentrate treatment thanthe 50:50 dietary treatment even though this had a higher crude protein content. In conclusion, degradation rate of the 80:20 cassava concentrate was higher and reflected the higher starch content of this mixed ration. It would be the better concentrate mixture as a supplement but if fed at high levels the 50:50 concentrate mixture would be a safer option to avoid acidosis.

Formulating rations using locally produced protein and energy sources is an important strategy to increase beef production in developing countries. Gliricidia sepium leaf meal (GLM), dry cassava powder (DCP), soybean hulls (SBH), peanut husks (PH) and palm kernel cake (PKC) in various combinations, were processed either as a mash or a pellet, to produce a concentrate supplement diet (CSD) for Ongole crossbred bulls in an Indonesian village fattening system. Bulls were given the current feeding system (CFS) ad libitum (T0, control) and CFS ad libitum + 1 % live weight (on approximate DM basis) of five different CSD (T1, T2, T3, T4 and T5). Treatments were: T1 (CFS + CSD mash: 25 % GLM + 25 % SBH + 50 % DCP), T2 (CFS + CSD pellet: 25 % GLM + 25 % SBH + 50 % DCP), T3 (CFS + CSD pellet: 50 % GLM + 25 % SBH + 25 % DCP), T4 (CFS + CSD pellet: 50 % GLM + 5 % SBH + 20 % DCP + 10 % PH + 15 % PKC) and T5 (CFS + CSD mash: 50 % GLM + 5 % SBH + 20 % DCP + 10 % PH + 15 % PKC). The experiment was carried out for 12 weeks and arranged in a randomized complete block design with 10 head per treatment. Animals were ranked and blocked based on pre-experiment live weight. The measured experimental variables consisted of growth performance and blood profile. Results showed that CSD supplementation significantly (P < 0.05) increased dry matter intake and average daily gain of Ongole crossbred bulls without affecting the feed to gain ratio. There were no differences in the average daily gain (ADG) between CSD treatments despite a difference in crude protein (CP) content (9 vs 13 % CP) between high and low DCP inclusion levels (25 % vs 50 %) and inverse GLM inclusion, or mash vs pelleted processing method. This suggested that the response was due primarily to increased metabolisable energy supply rather than CP supply. Daily income over feed cost (IOFC) was highest in T5 treatment (38 % higher than the control) which was formulated to provide the lowest cost of CSD ration. In conclusion, pelleting did not affect the performance of bulls, GLM and DCP could be used effectively at high levels, and a least cost ration approach was most effective in increasing the daily IOFC for smallholder farmers.

There is a growing demand for beef products across developing countries. Formulating rations to include locally available waste products has the potential to increase the live weight gain (LWG) of cattle and improve the livelihoods of smallholder farmers; however, upper limit inclusion levels of cassava peel products require investigation. An experiment evaluated the effect of using cassava peel silage (CPS) at the DM inclusion levels of 30, 40, 50, 60 and 70% (with the remainder protein meals and maize stover in the diet) on the LWG of crossbred Limousin x Ongole bulls (269 +/- 48.8 kg). Thirty bulls, approximately two years of age, were allocated in a completely randomised block design with six blocks based on initial live weight (LW) and five treatments based on level of CPS. The combination of CPS (with 2% urea of the CPS) and protein meals significantly affected LWG with the highest values obtained at levels of 30 and 50% inclusion of CPS (1.16-1.35 kg/day) (P < 0.05). Polynomial analysis of LWG data revealed the optimal LWG is theoretically achieved at 37% CPS with a LWG of 1.31 kg/day; however, LWG was similar from 30 to 50% inclusion levels and then declined. There was little significant difference at CPS inclusion levels of 30-60%, for DM intake (DMI) which ranged from 2.3 to 2.6% LW, organic matter (OM) digestibility (77.8- 81.6%), feed conversion ratio (FCR) (6.56-7.56 kg DM/kg LWG) and feed cost of gain (Indonesia rupiah (IDR)/kg LW 18 612 - 21 398). At a high (70%) level of CPS inclusion, these values were markedly changed when compared to the 30% inclusion level of CPS. Feed treatments did not affect rumen pH, NH3-N, con-centration or molar percentage of volatile fatty acids or protozoal population (P < 0.05). Rumen pH mea-sured three hours after morning feed ranged from 6.7 to 6.8 and NH3-N ranged from 14.1 to 19.3 mg NH3- N/dl. It was concluded that inclusion of CPS up to 60% mixed with protein meals and urea and 20% maize stover maximised LWG and profitability of the production system. (c) 2022 The Author(s). Published by Elsevier B.V. on behalf of The Animal Consortium. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Context Formulating supplements with Gliricidia sepium leaf meal (GLM) and cassava powder to promote liveweight gain of Ongole bulls. Aims This study was conducted to evaluate the effect of using GLM as a substitute for copra meal (CM) or soybean hulls (SBH) in a concentrate containing dry cassava powder (DCP) on the average daily gain of Ongole bulls and income over feed cost. Methods Forty Ongole bulls were allocated in a randomised block design with 10 head per treatment. The control group (R0) was provided the current feeding system (CFS) fed ad libitum, with supplemented treatments consisting of the current feeding system fed ad libitum + 1% liveweight (on approximate DM basis)/day of three different concentrate supplement diets (R1, R2 and R3). R1 concentrate contained 50% DCP, 25% CM and 25% SBH; R2 was 50% DCP, 25% GLM and 25% SBH; and R3 was 50% DCP, 25% CM and 25% GLM. The bulls belonged to cooperative smallholder farmers in the Banaran and Bleberan villages, Playen Subdistrict, Gunungkidul Regency, Yogyakarta, Indonesia. The experiment was performed for 12 weeks from 22 December 2018 to 16 March 2019. Key results The average weight gain of bulls (kg/head) in the treatments R0, R1, R2 and R3 were 0.31, 0.75, 0.61 and 0.62, respectively. The income over feed cost of supplement treatments R1, R2 and R3 was double that of the control (R0). Conclusions It was concluded that GLM can replace the use of SBH and CM in a cassava-based supplement and increase the income of farmers in this district. Implications Cassava powder can be combined with GLM to form a concentrate that increases the average weight gain of Ongole bulls and income of farmers.

Penelitian ini bertujuan untuk menentukan kombinasi optimal pemberian lamtoro dan jerami jagung fermentasi pada tingkat pemberian kulit ubi kayu yang tetap dalam ransum sapi Bali jantan. Sebanyak 20 ekor sapi Bali jantan berusia 1,5-1,8 tahun (190 ± 12,34 kg) dibagi menjadi empat kelompok perlakuan. Pada setiap kelompok perlakuan, sapi jantan diberi pakan empat tingkat jerami jagung fermentasi (10%, 30%, 40% dan 60%) dengan tingkat penurunan lamtoro yang sesuai (70%, 50%, 40% dan 20%) dan tingkat kulit singkong yang tetap (20%). Pemberian jerami jagung fermentasi sebanyak 10% dengan 70% lamtoro memberikan pertambahan bobot hidup tertinggi (Pertambahan bobot badan; 0,41 kg/hari). Terdapat hubungan linier dan kuadrat antara pertambahan bobot badan terhadap pemberian jerami jagung fermentasi. Pertambahan bobot badan kemungkinan besar terkait dengan tingkat konsumsi bahan kering (20 – 21 g/kg BB) dan ketersediaan protein dalam ransum. Hubungan antara konsumsi jerami jagung fermantasi dan pertambahan bobot badan dapat digunakan untuk menentukan kombinasi optimal antara pemberian lamtoro dengan jerami jagung fermentasi dan kulit singkong dalam ransum. Peningkatan penambahan pemberian jerami jagung fermentasi hingga 35% dan penurunan pemberian lamtoro sampai 45% dalam ransum hanya menghasilkan sedikit perubahan pertambahan bobot badan, hal ini memberikan ruang yang lebih besar terhadap penggunaan jerami jagung fermentasi pada sistem penggemukan dengan ketersediaan lamtoro yang terbatas.