Animal Production Science最新文献

Australia is renowned for its climate variation, featuring years with drought and years with floods, which result in significant production and profit variability. Accordingly, to maximise profitability, dryland farming systems need to be dynamically managed in response to unfolding weather conditions.

The aim of this study is to identify and quantify optimal tactical livestock management for different weather-years.

This study employed a whole-farm optimisation model to analyse a representative mixed enterprise farm located in the Great Southern region of Western Australia. Using this model, we investigated the economic significance of five key livestock management tactics. These included timing of sheep sales, pasture-area adjustments, rotational grazing, crop grazing and sheep nutrition adjustments.

The results showed that, on the modelled dryland mixed-enterprise farm in the Great Southern region of Western Australia, short-term adjustments to the overall farm strategy in response to unfolding weather conditions increased expected profit by approximately 16%. Each tactic boosted profit by between A$7704 and A$53,171. However, we outline several complexities that farmers must consider when implementing tactics.

The financial gains from short-term tactical management highlighted their importance and farmers’ need to develop and apply those skills. The tactical skills promote business resilience and adaptability in the face of climate uncertainties.

The study highlighted the economic value of dynamic livestock management in response to climate variations, offering farmers in the Great Southern region the means to underpin profitable and sustainable farm practices.

Brazilian red propolis stands out for its diverse composition, which includes phenolic compounds whose effects may be similar to those of synthetic feed additives.

The objective of this study was to evaluate the effects of red propolis extract on the carcass and meat characteristics of lambs finished under confinement conditions.

The meat quality characteristics of the longissimus lumborum muscle were evaluated in 35 Santa Inês lambs, with an average age of 5 months and an initial average body weight of 17.08 ± 2.36 kg (mean ± s.d.), submitted to five distinct treatments (0, 7, 14, 21, 28 mL of red propolis extract/animal.day) over 68 days.

The use of propolis did not affect (P > 0.05) the characteristics of the carcass, as well as the chemical composition and cholesterol content. Among the physico-chemical parameters of meat, only the shear force had a quadratic effect (P < 0.05). There was also an exponential effect for lipid oxidation (P < 0.05), where the treatment with propolis had greater antioxidant effect. Meat with a lower content (P < 0.05) of saturated fatty acids was observed in sheep that received extract. There was also an increase (P < 0.05) in the content of monounsaturated acids and consequently an improvement in nutritional quality, atherogenicity and thrombogenicity indexes of desirable fatty acids.

The red propolis extract improved the lipid profile of the lamb meat. We recommend the inclusion of 7 mL red propolis extract/animal.day (or 59.50 mg total flavoloids/animal.day) in the diet of lambs finished under confinement conditions.

The red propolis extract proved to be a viable alternative as a natural feed additive.

Dietary supplementation with trace mineral chromium (Cr) has been shown to enhance the physiological responses of broilers subjected to heat stress (HS), modulate gene expression, and improve performance.

This study aimed to evaluate the impact of chromium–methionine (CrMet) supplementation on growth performance, body temperatures, lymphoid organ weights, hormones, blood parameters, and the expression of heat-shock protein-70 (HSP-70) and insulin-like growth factor-1 (IGF-1) genes in broilers under HS conditions (33°C for 12 h/day).

In the first experiment, 336 22-day-old male broilers were randomly distributed into four blocks with six treatments (0, 0.10, 0.20, 0.40, 0.80, and 1.20 mg/kg CrMet) and eight replicates with seven birds per cage. These broilers were subjected to HS from 22 to 43 days of age. In the second experiment, 24 male broilers, in total, at 43 days of age, previously exposed to HS, were randomly distributed to the same six treatments from the first experiment, with four replicates. Breast samples were collected for the analysis of HSP-70 and IGF-1 expression.

A quadratic effect (P < 0.05) was observed on bodyweight gain (BWG) and feed conversion ratio (FCR). The supplementation of 0.71 and 0.68 mg/kg improved BWG and FCR, respectively. At 28 days of age, cloacal and mean body temperatures, corticosterone, and thyroid hormones were quadratically affected (P < 0.05), while at 43 days of age, a linear effect (P < 0.05) was observed on haemoglobin concentration. There was a reduction (P < 0.05) in the expression of HSP-70 and an increase in IGF-1 (P < 0.05) in the breast tissue of broilers supplemented with CrMet.

The supplementation with 0.71 mg/kg and 0.68 mg/kg of CrMet improved BWG and FCR, respectively. Additionally, the supplementation with 0.80 mg/kg improved hormones, reduced HSP-70 and increased the expression of IGF-1 in broilers during HS.

These findings suggest that CrMet can be included in the diet of broiler chickens subjected to HS to enhance physiological responses and performance.

Timely pregnancy diagnosis is critical for reducing non-production days and improving the reproductive efficiency of sheep flocks.

The aim of this study was to investigate the serum proteomic profile of ewes in different gestational stages and explore the potential of differentially expressed proteins as biomarkers for early gestation.

Serum samples were collected from two groups: pregnant sheep (n = 4) and non-pregnant sheep (n = 4) on Day 14 after mating. The differentially expressed proteins were detected using tandem mass-tag (TMT) labelling with liquid chromatography tandem-mass spectrometry. The differentially expressed proteins were confirmed using enzyme-linked immunosorbent assay (ELISA). Furthermore, six selected proteins were evaluated in ewes (n = 35) on Day 14 from mating by using ELISA to assess their potential as biomarkers for early pregnancy. Receiver-operating characteristic (ROC) curves were used to analyse the diagnostic accuracy of these proteins.

Twenty proteins, of a total of 555 proteins detected, showed differential expression between pregnant and non-pregnant sheep. From the ROC-curve data, CHI3L1 (AUC = 0.992), PSMB4 (AUC = 0.976) and LGALS3BP (AUC = 0.844) had high predictive value in the diagnosis of early pregnancy.

In this study, CHI3L1, PSMB4 and LGALS3BP were found to be differentially expressed proteins in the serum of pregnant sheep. Therefore, these three proteins carry a high probability as candidate biomarkers for early gestational embryo attachment in ewes.

Early pregnancy diagnosis enables timely identification of non-pregnant ewes, resulting in optimised resource allocation and enhanced economic benefits for farmers by reducing production costs.

Rising demand from Vietnam for Lao goat meat has triggered a rapid increase in goat numbers in Lao Peoples Democratic Republic (Lao PDR). Despite the increased market opportunity for smallholder farmers in Laos, goat production remains low input within free-grazing management systems.

Qualitative research was conducted to explore the role that goat production plays in farmers’ livelihood strategies and farming systems, including the benefits and associated trade-offs, so as to inform development approaches to improve goat husbandry and productivity.

Semi-structured interviews were conducted with 30 smallholder goat farmers across five villages in southern-central Laos. Interview transcripts were analysed using grounded theory methodology with the assistance of the Nvivo 12 software program.

The interviews showed that goats were a profitable and liquid asset for farmers. Income from goats was used for small expenses that occurred frequently or at short notice, such as household loans or debts, utility and medical costs and buying food and clothing for family members. Goats had socio-cultural purposes, with some farmers preferring to consume goats during celebratory occasions over other livestock species. Managing goats was easy and benefited the wider farming system by providing goat manure to fertilise crop plantations.

Goat productivity and goats’ unique subsistence and socio-cultural roles can be enhanced by improving goat kid management, goat-house design and cleaning, and by implementing disease management. These activities can be low input.

The government policy and future development projects in Laos should focus on increasing goat productivity rather than increasing the scale of farmers’ goat enterprises. The majority of farmers may not benefit from significantly increasing the scale of their goat enterprises because of trade-offs associated with free-grazing management, including goats damaging crops or becoming lost or involved in accidents such as dog attacks and car accidents.

Delaying sowing date of maize allows producers to achieve stabilised yield. Delays in the sowing date generate changes in the grain structure, which may affect the ruminal degradability of the maize starch.

The objective of this study was to evaluate the effects of maize sowing date on ruminal starch degradability, and how it is related with grain physical characteristics and source:sink ratio during the grain-filling period.

To study the effects of maize sowing date on grain physical characteristics and on starch in situ effective degradability (ED; 6%/h passage rate from the rumen), eight treatments were defined on the basis of eight different sowing dates in Argentina of a commercial semi-dentate maize hybrid (Dekalb 7210 VT3P), as follows: Treatment 1 (13 October), Treatments 2, 3, and 4 (4, 17 and 26 November respectively), Treatments 5, 6 and 7 (3, 15 and 28 December, respectively) and Treatment 8 (5 January). For each sowing date, three plots of maize were sown in a complete randomised-block design and harvested at grain physiological maturity.

Starch ED of ground (2.0-mm) grains ranged from 631 to 801 g/kg and showed a ‘J’-shape response, being lower for the sowing dates from 17 November to 3 December and highest on the sowing date of 5 January. Grain density increased until the sowing date of 17 November, and then decreased. Grain vitreousness and hardness were initially not affected, but started to decline after the sowing date of 17 November. Grain test weight was not affected until the sowing date of 15 December, when it started to decline. The source:sink ratio during the grain-filling period decreased as the sowing date was delayed. Effective starch degradability was negatively correlated with the physical characteristics evaluated and the source:sink ratio.

Delaying sowing date affected the maize source:sink ratio during the grain-filling period; this was associated with changes in grain physical characteristics and with an increase in ruminal starch degradability.

Delaying sowing date increases dry matter (DM) and starch effective degradability, and therefore could affect cattle weight gain and feed conversion efficiency.