Animal Production Science最新文献

Traditional smallholder pig farming plays an important role in farmers’ income and national food security in the low- and middle-income countries in Southeast Asia including Laos; however, its productivity is low and it is often environmentally unsustainable.

The objectives of this study were to evaluate the effects of using fermented bed-floor housing compared with the conventional concrete-floor housing on growth, carcass treats and economic return on raising Laos native pigs.

The study was conducted at the Faculty of Agriculture, National University of Laos. Twenty four castrated native pigs, aged ±3 months with initial liveweight of 17 ± 2 kg/head, were randomly assigned to the following housing types as treatments: (1) conventional concrete-floor system (CS) as control, and (2) fermented bed-flooring system (FB). The pigs were fed with similar diet with 16.01% crude protein and 11,796 kJ/kg gross energy for a period of 84 days after a 14-day adaptation to the feed. Each treatment was replicated four times (pens), with three pigs/pen. Data on feed intake, liveweight change, carcass trait and costs and returns of production in the two treatments were analysed using Student’s paired-sample t-test.

Pigs kept in FB flooring had higher DM and nutrient (crude protein, crude fibre, ether extract and organic matter) intakes than did their counterparts raised in the CS, but the differences were not significant when adjusted to bodyweight basis. There were also no significant differences in growth performance (average daily gain (ADG) and feed conversion ratio (FCR)), and carcass traits, except that pigs from FB had higher hot carcass weight, dressing percentage and rib and bone weights. Native pigs kept in the FB system had significantly higher total production costs because of the cost of the bedding material, but also had four-fold higher net income return generated from the sale of the fermented floor compost.

Fermented bed-flooring system has no significant impact on growth and key carcass traits, but significantly enhanced profit.

Fermented bed-flooring system should be promoted for rearing local pigs under smallholder farms to increase profit and protect the environment in the low- and middle-income countries.

Poultry diets consist of several ingredients contributing specific amounts of nutrients and it is assumed that the supply from each ingredient is additive when diets are formulated. However, the additivity of apparent metabolisable energy (AME) and ileal amino acid digestibility in broiler diets combining sorghum with different protein sources has not been examined.

To determine the additivity of AME along with ileal digestibility values for protein and amino acids in diets combining sorghum with different protein sources.

The digestibility assays, based on semi-purified diets containing sorghum, sunflower meal (SFM), meat and bone meal (MBM), soybean meal (SBM), canola meal (CM), and cottonseed meal (CSM), were fed individually, or sorghum was combined with the different protein sources. Each diet was fed to three cages of 12 17-day-old broilers for 7 days. Excreta was collected for the final 3 days and at the end of the assay, digesta was collected from the terminal ileum for digestibility determination.

When sorghum was mixed with the different protein sources, all predicted values for protein digestibility were additive, but for AME only the value for sorghum + SFM was additive. All other predicted AME values for sorghum combinations were different (P < 0.05) from the determined value. There were significant (P < 0.05) differences between predicted and determined amino acid digestibility coefficients, but amino acids showing associative effects varied among the different sorghum protein source combinations.

Overall, the present results indicated that caution should be exercised when predicting the AME and apparent ileal amino acid digestibility values for sorghum-based diets from values determined with individual feed ingredients.

The study indicated that positive and negative interactions are likely to occur among dietary ingredients in mixed diets, which has implications for both energy and protein utilisation.

Successful freezing of ram semen has not yet reached the desired levels. The main reason for this situation could be due to the fact that the spermatozoa of this species have a lipid composition different from that of other species.

The objective of the study was to evaluate the effect of different concentrations of L-carnosine added to the extender on ram semen after being frozen and thawed.

Semen was collected from six Akkaraman rams twice a week for a period of 3 weeks. Pooling was performed at each time. The semen were reconstituted with a pre-prepared tris + egg yolk solution and different amounts of L-carnosine to form experimental groups (Group 1: 1 mM, Group 2: 5 mM, Group 3: 10 mM, Group 4: 20 mM, Group 5: control) and were drawn into 0.25 mL mini straws. Subsequently, the samples were subjected to freezing by using an automated freezing device. Following the freezing process, the straws were placed in containers containing liquid nitrogen and thawed after 24 h.

After thawing, it was found that the samples containing 5 mM L-carnosine had superior results in all analyses. This concentration exhibited significantly higher percentages of progressive, total, and rapid sperm motility, live spermatozoa, high mitochondrial membrane potential rate, and higher GSH-Px concentrations. In addition, it was determined that 5 mM L-carnosine group protected the membrane integrity and significantly decreased the rate of abnormal spermatozoa, acrosomal damage rate, low mitochondrial membrane potential and apoptotic cell rate.

As a result, It was determined that adding 5 mM of L-carnosine to the semen extender during the freezing of ram samples would be beneficial for successful freezing.

The addition of 5 mM L-carnosine to ram-semen extenders ensures the freezability of the semen of this species; thus, this protocol could be used to perform artificial insemination with frozen ram semen.

Livestock production in the Greater Mekong Subregion (GMS) reflects the inefficient smallholder ‘keeper’ system that has been slow to adapt to the rapidly expanding demand for animal protein-sourced foods in the region as urban economies have flourished and food preferences altered. The prolonged surge in demand, with only modest increases in local production, has increased the movement of animals and products into and from the GMS, accompanied by surging risks of transboundary animal disease (TAD) incursions, including the one health (OH) threats of zoonoses and antimicrobial resistance. As a consequence, the region has been subjected to epidemics of highly pathogenic avian influenza (HPAI), new strains of foot-and-mouth disease (FMD) virus, with recent incursions of African swine fever (ASF), lumpy skin disease (LSD), porcine reproductive and respiratory syndrome (PRRS) and risks of peste petits ruminants (OPR) occurring in Southeast Asia (SEA) and beyond. These incidents reflect inadequate biosecurity, a sustainability issue that was clearly of relevance in the covid-19 pandemic, reflecting ecosystem health (EH) deficits, including land-use issues and unregulated trading in wildlife-sourced and poorly processed foods through the predominant ‘wet markets’. These challenges are increasingly confounded by slow adaption to the impacts of the climate crisis, including flooding, drought, crop failures and hypothermia episodes. The increase in animal and product movements enhances disease transmission risk, yet coincides with emerging concerns of greenhouse-gas emissions (GHGe) from livestock production, especially from large ruminants, as the world attempts to find pathways in managing the climate crisis. Despite the prolonged collaborative efforts of the SEA China FMD program from 1997 to 2023, a recent review confirmed persistent deficits in biosecurity, vaccine resourcing, disease surveillance, engagement of farmers, and national emergency disease-response capacities. A major project is about to fund major improvements in livestock value chains in Cambodia, including more effective biosecurity, surveillance and emergency disease-response capacities for TADs, antimicrobial resistance (AMR) and zoonoses. Similarly, a private-sector investment in Laos has developed a more climate-resilient livestock-feeding system that decreases GHGe impacts from ruminant production. These developments are likely to extend beyond both countries and be potentially transformational for the livelihoods of many of the poorest citizens in the region.

Muscle fibre characteristics are important internal factors that can directly affect pork quality. Especially muscle-fibre types can interconvert with the influence of certain factors.

The purpose of this experiment was to study the differences in meat quality among Songliao black pigs, Jilin Hua pigs and Dongliao black pigs, and the molecular mechanism of the differences.

First, the conventional meat-quality traits of each breed were determined. Second, the muscle-fibre characteristics of different muscles were analysed by the haematoxylin–eosin staining and immunohistochemistry. Next, the activity of several key oxidative/glycolytic enzymes was detected with kits. Finally, quantitative polymerase chain reaction was used to analyse the expression abundance of myosin heavy-chain (MyHC) genes and key genes related to muscle fibre-type transformation.

The results of meat-quality measurement showed that Songliao black pigs were superior to Jilin Hua pigs and Dongliao black pigs in water-holding capacity, tenderness and intra-muscular fat; and Jilin Hua pigs were superior to Dongliao black pigs in water-holding capacity. The diameter and area of muscle fibres were the smallest, the density was the largest, the proportion of oxidative muscle fibres, oxidative enzyme activity and expression abundance of oxidative genes were the highest in Songliao black pigs, followed by Jilin Hua pigs and Dongliao black pigs. The proportions of oxidative muscle fibres ranged from 10.37% to 33.6% in Songliao black pigs, from 6.96% to 26.42% in Jilin Hua pigs, and from 5.86% to 17.42% in Dongliao black pigs. The psoas major exhibited the smallest muscle-fibre diameter, the highest density, followed by triceps brachii, biceps femoris and longissimus thoracis. The oxidative muscle fibre proportions of the psoas major and triceps brachii were significantly greater than those of the biceps femoris and longissimus thoracis. The expression abundances of AMP-activated protein kinase (AMPK), silencing information regulator 1 (SIRT1) and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) (Sirt1/AMPK/PGC-1α) pathway and mitochondrial function-related genes were the highest in Songliao black pigs, followed by Jilin Hua pigs and Dongliao black pigs.

The results showed that Songliao black pigs had the best meat quality, followed by Jilin Hua pigs and Dongliao black pigs. The meat quality of psoas major and triceps brachii was significantly greater than that of biceps femoris and longissimus thoracis. This experiment suggests that transformation of oxidative muscle fibres can be promoted through the Sirt1/AMPK/PGC-1α pathway.

By analysing the meat-quality traits and the molecular mechanism of m

The increasing intensification of pasture-based systems has subjected the cows to different productive environments, which could affect physiological responses and, consequently, their productive performance.

The aim was to determine the effect of contrasting housing facilities (outdoor soil-bedded vs compost-bedded pack barn) used in partial confinement in pasture-based systems, on the metabolic adaptation during early lactation and its impact on productive and reproductive performance of autumn- and spring-calving dairy cows, having as a positive control a zero-grazing confined system in compost barn.

Multiparous Holstein dairy cows that calved in autumn (n = 36) and spring (n = 48) were distributed in the following three treatments from calving to 90 days in milk (DIM): outdoor soil-bedded–grazing (OD-GRZ), compost barn–grazing (CB-GRZ), compost barn–total mixed ration (CB-TMR). Milk production, total milksolids (TMS), body condition score, non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), cholesterol, insulin, insulin-like growth factor-1 (IGF-1), and the proportion of cows with corpus luteum were determined in repeated measurements.

In both calving seasons, milk production and TMS yields did not differ between OD-GRZ and CB-GRZ, but were greater in CB-TMR (P < 0.0001). In autumn, NEFA and BHB were not affected by treatments, but cholesterol increased faster in CB-TMR (P = 0.0500). In spring, NEFA and cholesterol concentrations were not affected by treatment, but BHB remained greater in OD-GRZ until 90 DIM than in the other treatments. IGF-1 and insulin did not differ between treatments in autumn, but in spring, IGF-1 was greater in CB-TMR (P < 0.0001). The proportion of cows with corpus luteum was not different between pasture-based treatments, but both were greater than CB-TMR up to 40 DIM in autumn (P = 0.0489) and during the entire study in spring CB-TMR (P = 0.0285).

Although no differences were found among housing facilities in partial confinement, except that in spring OD-GRZ cows had greater BHB concentrations, confined cows prioritised milk production instead of reproductive function, despite presenting better energy indicators than did pasture-based cows.

Outdoor housing combined with grazing can increase the risk of greater BHB concentrations, indicative of subclinical ketosis, under heat-stress conditions, when compared with indoor housing. Confined cows increased milk production but had a delay in the resumption of ovarian cyclicity, even having a better energy status than pasture-based cows.

There is some evidence that physiological stages such as breeding, pregnancy, parturition and lactation may trigger oxidative stress. It has also been observed in several species, including sheep, that age affects their vulnerability to oxidative stress.

This study investigated the effects of supplemental β-carotene and age on the oxidative status of grazing ewes around breeding, pregnancy, parturition and early lactation as well as on their production and reproduction performance.

Hundred and four ewes were divided into two broad age groups (young = 1–3 years, and old = 4–6 years). Within age groups, ewes of similar age were randomly assigned to four treatment groups (A1, A2, A3, C) by using a completely randomised block design. The young (n = 13) and old (n = 13) sheep in Groups A1, A2 and A3 were daily drenched with 100 mg, 75 mg and 50 mg β-carotene respectively. Group C was unsupplemented (Control). Supplementation lasted 28 days before oestrus synchronisation; 14 days during oestrus synchronisation (CIDR) and hand-mating; 18 days post-hand-mating; 30 days before lambing; and 15 days after lambing. All animals were grazed on Kikuyu grass (Pennisetum clandestinum). Six ewes from each group (total = 24) were sampled for blood to measure oxidative and hormonal status during the experiment.

Supplemental β-carotene at ≥75 mg/day may act as a pro-oxidant in ruminants under oxidatively stressed conditions such as parturition. Age did not affect the ewes’ oxidative status. The supplemental β-carotene did not affect bodyweight, oestrus parameters, corpus luteum size, conception rate and litter size. Except for a tendency of lambs from supplemented ewes to have heavier weight at 15 days old (P = 0.080), age group and supplemental β-carotene did not affect the lamb mortality rate or weight at birth or 15 days old. Older ewes showed earlier and longer duration of oestrus than did younger ewes.

Supplementation of grazing ewes with β-carotene should not be ≥75 mg/day, especially at parturition period, because it may work as a pro-oxidant. The older ewes seem to have earlier oestrus with a longer duration than do the younger ones.

Caution is urged when administering high doses of β-carotene to ewes during the peri-parturient period.

Selection for growth rate has received considerable attention in beef cattle but the evidence for an improvement in the efficiency of feed conversion is equivocal.

To examine whether feed efficiency by beef cattle finished in a feedlot had been changed in response to divergence selection for growth rate.

The Angus cattle used came from three lines of cattle selected for over five generations for fast growth rate to yearling age (High-line), slow growth (Low-line), or from an unselected Control-line. Over sequential years, a cohort of steers, then of heifers and then of steers, representative of the lines, were measured for feedlot performance, and carcase- and meat-quality traits. The animals were fed a high-energy feedlot ration and after an adjustment period they underwent a performance test of at least 70 days of duration. After slaughter, muscle samples were taken for subsequent measurement of the components of the endogenous calpain proteolytic enzyme system. Their carcasses underwent a standard chiller assessment and meat samples were taken after 1 day and 14 days (steers) or 17 days (heifers) for objective measurement of tenderness.

Cattle from the High-line grew 48% faster (P < 0.05), and ate 48% more feed (P < 0.05) than did those from the Low-line, but had similar (P > 0.05) feed conversion ratio and residual feed intake. There were no differences between the High-line and Low-line in the visual meat-quality attributes of meat colour, fat colour and marbling, and no differences in the objective measurements of tenderness and connective-tissue toughness. There was no evidence of a selection response in the circulating concentrations of the metabolites and hormones measured, nor in the endogenous calpain proteolytic enzyme system in muscle.

The superior growth demonstrated by the High-line cattle over the feedlot test was accompanied by a higher feed intake, with no evidence for an improvement in feed efficiency.

Selection for growth rate is a powerful tool to alter animal performance but the beef industry needs to be cognisant of the proportional increase in feed requirement from breeding bigger animals.

The ensiling process presents losses that are associated with the fermentative profile, resulting in lower nutritional value, and lower aerobic stability of silages.

This study aimed to evaluate the effects of chitosan and microbial inoculants addition in Mombasa grass (Megathyrsus maximus) silage (MGS) fermentation profile and losses, chemical composition, in situ degradation, and aerobic stability.

Forty experimental silos (PVC tubing with 28-cm inner diameter and 25-cm height) were used in a randomised block (n = 5) design to evaluate the following treatments: (1) MGS without additives (control, CON); (2) MGS treated with 5.0 × 10⁴ colony-forming units (CFU) of Lactobacillus buchneri (NCIM 40788) per gram of fresh matter (LBB); (3) MGS treated with 1.6 × 10⁵ CFU of L. plantarum and 1.6 × 10⁵ CFU of Pediococcus acidilactici per gram of fresh matter (LPP); and (4) MGS treated with 6 g/kg DM of chitosan (CHI).

The treatments did not alter the pH, ammonia-N, butyric, and lactic acid concentrations in the silage. The use of LPP reduced the ethanol content, while CHI increased propionic and branched-chain fatty acids compared with other treatments. Fermentation losses and dry-matter recovery were not affected by treatments. Chitosan reduced the organic matter of the MGS in relation to the other treatments, without having an impact on the other variables of chemical composition. The treatments did not influence the in vitro degradation, nor the pH and temperature after aerobic exposure of the silage.

Chitosan increases ethanol compared with homofermentative lactic acid bacteria inoculation and does not affect ammonia-N of Mombasa grass silage. In addition, chitosan and microbial inoculants have limited effects on Mombasa grass silage fermentation losses, nutritional value, and aerobic stability.

Chitosan does not reduce fermentation losses or improve the nutritional value of grass silage.

For an ensiling to succeed, the knowledge about the factors that might influence the fermentation dynamics and nutrient loss is mandatory. One of the strategies is the use of additives such as tannins, as they can decrease proteolysis and increase the total organic acids.

The aim was to investigate the effects of tannins on fermentation patterns and nutritional value of sorghum silage.

Silages containing 0.0, 7.5, 15.0, 22.5, and 30.0 g/kg of tannin on fresh matter were studied. To produce the silage, the tannin was added to the forage and manually homogenised before ensiling. The study was conducted in three experiments. In the first experiment, five replications of each level of inclusion were produced and assigned in a completely randomised design. The chemical composition and fermentation patterns of all experimental units were evaluated. The second experiment consisted of analysing the aerobic deterioration by using a PET bottles system. This experiment was conducted in a completely randomised split plot, with five replications and five treatments with the inclusion of different levels of tannin (main plots) and the hours of exposure of silage to air (subplot). In the third experiment, five levels of tannin (main plots) and incubation times (subplots) were evaluated as for in situ digestibility (ruminal degradability) in a randomised blocks design with three replications (animals).

The inclusion of tannins in sorghum silage caused quadratic effects on pH, acetic acid, lactic acid, total organic acids, ammonia nitrogen, dry matter content, crude protein content and in situ digestibility, when the level varied from 10.5 to 22.7 g tannin/kg fresh matter. There was a decreasing linear effect for aerobic deterioration as increasing levels of tannin in sorghum silage.

The inclusion of tannin as an additive in sorghum silage is recommended for the production of good quality silage. The use of condensed tannins optimise fermentation patterns (especially increasing lactic acid and decreasing ammoniacal nitrogen), chemical composition, providing less aerobic deterioration and improve digestibility.

This study revealed that condensed tannins can improve fermentation patterns and the nutritive value of sorghum silage.