Animal Production Science最新文献

Improved knowledge of the quality of the diet ingested by grazing cattle requires measurement of the diets selected, including in native pasture rangeland.

The goal of the present study was to develop empirical equations to predict the intake, digestibility and protein concentration of the diet selected from faecal crude protein concentration of cattle grazing heterogeneous native grasslands through seasonal cycles in the Pampa biome of southern South America.

In Experiment 1, cattle held in metabolism pens were fed native pasture at 15 and 22.5 g DM/kg bodyweight, or ad libitum. In Experiment 2, cattle also housed in metabolism pens were offered mixtures of the native pasture and Italian ryegrass at a proportion of 0.33 and 0.66 of the mixture, or pure ryegrass. Organic-matter intake (OMI), faecal crude protein excretion (fCP), faecal crude protein concentration (fCPc), OM digestibility (OMD) and diet crude protein concentration (dCPc) were measured in Experiments 1 and 2 and relationships were developed between the diet attributes and faecal crude protein (CP). In the Experiment 3, steers grazed native grasslands (NatG), or native grasslands overseeded with Italian ryegrass (NatG + RyeG). Intake and digestibility equations generated in Experiments 1 and 2 were then evaluated in Experiment 3 to estimate diet attributes from faecal protein measures.

Three non-linear models (exponential, hyperbolic and mixed, i.e. exponential + hyperbolic) were examined to evaluate the OMD. The mixed model had the highest R² value (0.74) and the lowest relative prediction error. OMI and dCPc were both linearly related to fCP. The OMD, OMI and dCPc equations were able to detect differences among diets in Experiment 3.

It was verified that the faecal CP can be used to estimate key nutritional characteristics in cattle grazing heterogeneous grasslands in the Pampa biome in South America.

Relationships between faecal CP and key diet attributes can be used to support further research and models for nutritional assessment of the diet and productivity of grazing cattle in the rangeland system examined.

Global food insecurity is mostly the result of human-animal competition for food, as well as recent population growth, erratic weather patterns and environmental shocks. Therefore, maximising the production of animal proteins can reduce the competition between demand and consumption. Hence, the current review aimed at outlining the use of hemp on the production, health and reproductive performances of farm animals. The data used in this review were accessed using Google Scholar, Science Direct, ResearchGate and the directory of open-access journals. It was found that industrial hemp, particularly its derivatives such as hemp-seed meal and oil, has gained attention for its potential benefits in animal nutrition and health. The impact of hemp on farm animals, their productivity, health and reproductive performance, is an area of ongoing research. Our findings on the assessment of the nutritional benefits of hemp to livestock have shown hemp to be a great nutritional source to livestock because, hemp-seed cake, a byproduct of hemp oil extraction, is rich in essential and non-essential amino acids, fibre, and healthy fats, including omega-3 and omega-6 fatty acids. When incorporated into animal feed, it can contribute to a balanced diet, potentially improving overall health and productivity. Furthermore, the health benefits may be due to the fatty acid profile in hemp that is known to have positive effects on animal reproduction (optimal fertility and gestation) and health, including anti-inflammatory properties, which could benefit conditions related to inflammation. Additionally, hemp contains compounds such as cannabinoids and terpenes that might offer therapeutic effects, although the effects of these compounds in animals are still being studied. In conclusion, there is limited direct research on hemp’s effect on reproductive performance in farm animals. Hence, more research is necessitated.

Commercial Pekin Ducks housed in conventional open-sided sheds often experience heat stress in summer. Electrolyte or osmolyte supplements can help birds cope under heat stress.

To assess the effects of water electrolyte/betaine supplementation or betaine in feed on the growth performance of Pekin ducks exposed to high ambient temperature.

Commercial Cherry Valley Pekin ducks were fed diets with a dietary electrolyte balance (DEB) of 160 (L-DEB) or 209 (H-DEB) over Days 15–41 (D15–41) of age. Over D36–41, ducks were provided with water alone or supplemented with betaine in the feed (BF), or betaine and an ‘in-house’ electrolyte (E) formulation at 50%, 100% or 150% (D36–41) or at 100% for only 36 h on D40–41. There were 12 treatments with four replicate pens for each treatment. On D36–41 of age, temperature was increased to 28–32°C for 9 h (from 08:30 hours to 17:30 hours) and then returned to 22–24°C for the remainder of the day. Individual liveweights were taken on D28, D35, D41. During these times, feed intake and water consumption were determined. On D41, one male and one female from each pen were weighed, euthanised and breast muscle was removed and weighed. Birds were collected for commercial processing at 04:00 hours on D42.

Over D15–35, the DEB had no effect on bird performance. Over D36–41, for liveweight gain (LWG) there were significant interactions between treatment × week (P < 0.001) and treatment × diet (P = 0.017). Supplements E150 and E100 + 36 h supported LWG more than did other treatments, while treatments BF, E50 and E100 supported higher LWG than in controls. On the L-DEB diet, the control birds had a LWG lower than in other treatments (P < 0.05). On the H-DEB diet, the E50 supplement had highest LWG, but comparable to that in E100 + 36 h. The supplements had no effects on breast muscle yield, weight losses during transport and lairage or processed carcass weights.

The electrolyte supplements supported higher LWG during exposure to moderately adverse high temperature. Supply for 36 h supported LWG equivalent or better than did other treatments given over 6 days. The benefits could be related to increased water intake and not just electrolyte supply.

Water electrolyte plus betaine supplementation supports improved Pekin duck performance during a moderately high temperature challenge.

The attitudes of stockpeople towards their animals directly affects the human–animal relationship, in turn affecting stockperson behaviour and animal welfare and productivity. Little is known about the attitudes of Australian stockpeople towards dairy youngstock under their care.

We aimed to explore Australian stockperson attitudes and management practices associated with calf management and reported replacement heifer outcomes.

A convenience sample surveying 91 Australian dairy stockpeople was used to explore common calf-rearing practices, as well as attitudes of stockpeople towards youngstock and current issues in youngstock welfare and management on Australian dairy farms.

Management of both replacement and non-replacement calves varied considerably by farm, and reported practices did not correlate with herd management or demographic data. Factor analysis identified nine principal components related to attitudes towards primiparous heifer and calf welfare and management practices. Variables calculated from these components rarely correlated with demographic factors; however, female respondents were more likely to have positive attitudes towards current issues in calf management (P = 0.013). Several correlations were found between the component variables. Participants who believed it was difficult to use higher-welfare practices to manage the herd were less likely to believe their trusted advisors valued these practices (P < 0.001), or believe these practices were important themselves (P < 0.001). These participants were more likely to believe that early lactation heifers were difficult to handle (P < 0.001), and less likely to believe that it was important to separate cows and calves for calf health (P = 0.006). Respondents who believed that heifers were difficult to handle in early lactation were more likely to believe heifers on their farm were underperforming (P < 0.001).

Factors external to farm demographics appear to shape the attitudes of Australian stockpeople and on-farm dairy youngstock management decisions. Attitudes towards youngstock appear to be linked to on-farm cultures, particularly the perceived difficulty of performing tasks linked to good welfare outcomes, and the perceived value placed on these practices by trusted advisors.

The results indicate that further research using a more representative sample is needed to better understand those responsible for Australian dairy youngstock management and the key drivers behind their management choices, to best tailor approaches to encouraging implementation of best practice on-farm.

Breech flystrike is a painful, debilitating and potentially lethal disease caused by the larvae of the blowfly, Lucilia cuprina, and, despite many years of research, it remains a serious financial and animal-welfare issue for the Merino sheep industry in Australia. The common methods of prevention, namely insecticides, crutching and ‘mulesing’, are problematical, so alternative approaches are needed. Breeding for resistance to breech strike is a fundamentally attractive proposition, but the trait itself is difficult and expensive to quantify in large numbers of sheep in extensive production systems. Several indirect traits are correlated with susceptibility to flystrike, but a large proportion of the variation in susceptibility remains unexplained. The common thread through those indirect traits is odour, so we turned to the biology of insect olfaction and its role in fly–sheep interactions. L. cuprina uses odours to detect and locate potential hosts over long distances, to guide orientation and landing behaviour, and to select egg-laying sites. Preliminary studies demonstrated the importance of confining our work to gravid female L. cuprina, and also validated the use of flies reared in the laboratory for experimentation. Using laboratory-reared flies and a combination of gas chromatography–mass spectrometry with electroantennographic detection, we identified odouriferous compounds from sheep that the antenna of L. cuprina can detect. To determine whether the identified compounds were attractive or repulsive, we needed to use a behaviour test. In preliminary studies, we compared four behaviour bioassays (Y-tube, landing time, visiting frequency, and trap) and found the trap to be the most effective. We observed that L. cuprina was attracted by several compounds in Merino wool, including octanal, nonanal and dimethyl trisulfide. We also found that the wool levels of octanal and nonanal are heritable in Merino sheep, suggesting that these compounds might be useful as traits in selection for flystrike resistance. Another possibility is that these olfactory-active compounds might guide efforts to modify the genome of sheep, or perhaps even L. cuprina. Success in these endeavours could save as much as A$200 m per year for the Australian Merino-based industries, while also improving the image of wool in world markets.

Few experiments have demonstrated how alternative fibre sources such as micronised citrus pulp in the diet of sows during pregnancy and lactation can influence the productive and biochemical parameters of the sows.

The aim of the study was to compare different fibre sources fed to sows during gestation for effects on serum biochemical and reproductive parameters, and to determine how these effects may relate to sow and piglet performances.

In total, 220 sows of average initial liveweight 240.72 ± 29.42 kg were allotted to a completely randomised design with four treatments and 55 sows per treatment. The treatments comprised different fibre sources (micronised citrus pulp, soybean hulls and coffee husks) included in the feed, with a maize–soybean-meal-based diet as the control. Productive and biochemical parameters were assessed.

Productive and reproductive performance during gestation and lactation, and litter birth weight, were not influenced (P > 0.05) by treatment. Placental efficiency (g fetus produced/g placenta) was lower (P < 0.05) in sows receiving soybean hulls than coffee husks (4.9 vs 5.4). Control sows presented lower (P < 0.05) stillborn rate than those supplemented with soybean hulls (1.08% vs 2.72%). Blood glucose, creatinine, lactate, triglycerides, total protein, cholesterol and urea were not influenced (P > 0.05) by treatment. Postprandial blood glucose and triglycerides levels were higher (P < 0.05) than preprandial levels, whereas preprandial cholesterol was higher (P < 0.05) than postprandial (67.74 vs 62.51 mg/dL).

Diverse fibre sources minimally impacted sow performance; coffee husks emerged as a potentially advantageous choice.

Nutritional strategies to enhance reproductive and productive performance can be developed by incorporating coffee husks, micronised citrus pulp or soybean hulls in sows’ feed. Use of these fibre sources did not alter reproductive and productive parameters or blood metabolites of the sows.

Porcine gametes require energy for the physiological processes that allow fertilisation. Succinate dehydrogenase (SDH) plays a pivotal role in both, the tricarboxylic acid (TCA) cycle and the respiratory chain.

The aim of this work was to study the participation of SDH in the in vitro oocyte maturation, sperm capacitation and acrosome reaction in porcine species.

Cumulus–oocyte complexes (COCs) from abattoir-derived porcine ovaries were collected by aspiration and were incubated in maturation media, with the addition of increasing concentrations (0, 1, 5 and 10 mM) of malonate (a specific inhibitor of SDH). Nuclear maturation and cytoplasmatic maturation were analysed. Semen samples were incubated for 2 h in capacitating medium with 40 mM sodium bicarbonate, as sperm capacitation inducer, and the addition of increasing concentrations of malonate (0, 1, 5 and 10 mM). Sperm capacitation state and true acrosomal reaction were evaluated. SDH activity was determined in sperm and oocyte extracts by the spectrophotometric method.

The addition of 10 mM of malonate decreased both nuclear and cytoplasmic maturation rates (P < 0.05) without affecting COC viability (assessed using fluorescein diacetate). A lower level of capacitation (induced by bicarbonate) and acrosome reaction (induced by follicular fluid) was observed with the addition of 5 mM of malonate (P < 0.05) without affecting motility and viability of sperm at this concentration. The activity of SDH was 0.35 ± 0.1 × 10⁻⁵ and 2.37 ± 0.9 × 10⁻⁵ U/COC for immature and in vitro matured COC extracts (P < 0.05) respectively, and 0.44 ± 0.16 U/10¹⁰ sperm for boar sperm extracts.

In conclusion, because it has been proposed that aerobic and anaerobic metabolic pathways of cells are changed depending on the oxygen availability and the composition of metabolic substrates in their environment, our results suggest that energy obtained through the mitochondrial respiration (TCA cycle and oxidative phosphorylation) is necessary to support oocyte maturation, sperm capacitation and acrosome reaction in the porcine species.

The study of enzymatic activity in gametes is essential for understanding the mechanisms that control the energy production required to achieve successful fertilisation. This knowledge has significant implications for the development of assisted reproductive technologies.

Although beef consumption has been linked to increased blood cholesterol, it has positive impacts on human health and provides essential nutrients of high biological value.

This study investigated the effects of aging time on beef quality, the chemical composition of the Longissimus thoracis (LT) muscle, and the metabolite and fatty acid profile of the subcutaneous fat from young bulls finished in feedlot with a high-lipid diet.

Fifty young bulls were divided into groups following their breed composition, Nellore (n = 25) and Angus × Nellore crossbred (n = 25), and randomly assigned into four pens. The feedlot phase consisted of 105 days of feed, and the diet (80% concentrate) was formulated to meet or safely exceed the requirements of beef cattle to achieve an average daily gain of 1.6 kg/day. After slaughter, meat samples were collected between the 11th and 13th ribs 24 h postmortem. Steaks were aged for 1, 14, 28, and 42 days.

No differences were observed for total weight loss, drip loss, and cooking loss between the genetic groups (P > 0.05). An increase in lipid oxidation was observed for TBARS in the LT beef and subcutaneous fat (P < 0.01). Shear force was influenced by breed and aging time (P < 0.01). There was a significant interaction between aging time and the parameters L* a*, b* c*, and h* (P < 0.01). The crossbred animals had greater (P < 0.01) concentrations of collagen, and Nellore had greater (P < 0.01) concentration of moisture in their LT beef. In total, 33 metabolites were identified in beef extract, and differences were observed in beef from both groups. Nellore animals had higher concentrations of polyunsaturated fatty acids and conjugated linoleic acid.

The shear force, collagen concentration, and moisture were affected by breeds, while the aging time affected lipid oxidation, shear force, and colour parameters. Different breeds and a high-lipid diet modified the metabolite profile of meat and the profile of subcutaneous fat.

These findings suggest that genetic manipulation could potentially be used to improve beef quality.

The use of insects as a sustainable source of animal-based food and in the human diet is increasing. Special attention has been given to black soldier fly larvae (BSFL) because this insect can consume organic waste and convert organic matter into high-quality nutrients that can be used for animal feed. In addition, BSFL rapidly reproduce, can convert large volumes of biomass, can be fed with a variety of organic material, and present a high feed conversion rate. Recent studies have also indicated that BSFL have a lower environmental impact than has livestock production, because they use less water and land mass, although life-cycle assessment analysis is required confirm this. Moreover, this insect is a rich source of protein, lipids, and minerals, and may have beneficial medicinal effects due to the presence of bioactive compounds. However, BSFL as well as any other insect species, present some challenges regarding their low consumer acceptance and limited information related to their food safety. Therefore, this review aims to collect information from the current literature regarding aspects related to rearing conditions and characteristics of BSFL as a sustainable source of nutrients. In addition, it will summarise the nutritional profile, the main bioactive compounds, and the challenges with human consumption of BSFL.