Archives of Animal Nutrition最新文献

Despite the increasing importance of goat production in response to high demand for their products and their relative robustness to environmental stressors, and in contrast to other ruminant species, little data is available on how tannin extract feeding affects their feed intake, nutrient digestion and nitrogen (N) metabolism. Therefore, a trial in Oman investigated the respective variables by using a commercial tannin feed additive. In a 4 (treatments) x 3 (periods) x 2 (animals) Youden square, two weaned Batinah bucks each were fed a high or low protein diet of Rhodes grass hay and crushed barley grain, with or without the addition of a chestnut and quebracho tannin extract at 2 g/kg metabolic weight. Feed offered, feed refused and faeces and urine excreted were quantified to determine diet digestibility, total N excretion, N retention and rumen microbial protein synthesis (MPS). Due to their young age and low live weight, feed intake of goats was relatively low. Crude protein level and tannin addition had no statistically significant effect on dry matter (DM) and N intake, DM digestibility, N excretion in faeces and urine, as well as MPS. In consequence, no benefit of tannin feeding could be confirmed for the goats' N retention, irrespective of diet composition. These results indicate, on one hand, an effective neutralisation of the tested tannin extract along the gastrointestinal tract of goats, but on the other hand, that stimulation of MPS or N retention by tannins cannot be evidenced when diet components are present that simultaneously release energy and protein, as is the case with barley.

The increasing spread of ragworts is observed with concern. Ragworts like tansy ragwort (Jacobaea vulgaris Gaertn.) or marsh ragwort (J. aquatica) contain pyrrolizidine alkaloids (PA) which may induce hepatotoxic effects. Grazing animals usually avoid ragworts if their pasture management is appropriate. Preserved feed prepared from ragworts contaminated meadows may, however, lead to a significant exposure to PA. Previous studies on toxicity of PA for dairy cows revealed inconsistent results due to feeding ragwort plant material which was associated with heterogeneous PA exposure and thus failed to conclusively deduce critical PA doses. Therefore, the aim of the present study was to expose dairy cows (n = 4 per group) in a short-term scenario for 28 days with increasing PA doses (PA1: 0.47 mg PA/kg body weight (BW)/day (d); PA2: 0.95 mg PA/kg BW/d; PA3: 1.91 mg PA/kg BW/d) via oral administration by gavage of a defined PA-extract. While group PA3 was dosed with the PA-extract alone, groups PA2 and PA1 received PA-extracts blended in similar volumes with molasses to provide comparable amounts of sugar. Additionally, two control groups were treated either with water (CON_Water) or with molasses (CON_Molasses) to assess the effects of sugar without PA interference. While clinical traits including dry matter intake, milking performance, rectal body temperature, ruminal activity and body condition score (BCS) were not influenced by PA exposure, activities of enzymes indicative for liver damages, such as gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH), increased significantly over time at an exposure of 1.91 mg total PA/kg BW/d.

Silage fermentation is a complicated biochemical process involving interactions between microbes and metabolites. However, the overall metabolome feature of ensiled forage and its response to lactic acid bacteria inoculation is poorly understood. Hence, in this study metabolome profiles of whole-plant corn silage inoculated with or without Lactiplantibacillus plantarum were characterised via solid-phase microextraction/gas chromatography/mass spectrometry (SPME-GC-MS), gas chromatography/time-of-flight mass spectrometry (GC-TOF-MS), and Liquid chromatography/Q Exactive HFX mass spectrometry (LC-QE-MS/MS) analysis. There were 2087 identified metabolites including 1143 reliably identified metabolites in fresh and ensiled whole-plant corn. After ensiling, the increased metabolites in whole-plant corn were mainly composed of organic acids, volatile organic compounds (VOC), benzene and substituted derivatives, carboxylic acids and derivatives, fatty acyls, flavonoids, indoles and derivatives, organooxygen compounds (including amines and amides), phenols, pyridines and derivatives, and steroids and steroid derivatives, which includes neurotransmitters and metabolites with aromatic, antioxidant, anti-inflammatory, and antimicrobial activities. Phenylacetaldehyde was the most abundant aromatic metabolite after ensiling. L-isoleucine and oxoproline were the major free amino acids in silage. Ensiling markedly increased the relative abundances of 3-phenyllactic acid, chrysoeriol, 6-O-acetylaustroinulin, acetylcholine, γ-aminobutyric acid, pyridoxine, and alpha-linoleic acid. Inoculation with L. plantarum remarkably changed silage VOC composition, and essential amino acids, 3-phenyllactic acid, and cinnamaldehyde compared with untreated silage. The present study does not only provide a deeper insight into metabolites of the ensiled whole-plant corn but also reveals metabolites with specific biological functions that could be much helpful in screening novel lactic acid bacteria to well ensile forages. Inoculation with L. plantarum significantly affects the metabolome in ensiled whole-plant corn.

Two in vivo experiments studied the effects of different alfalfa hay (AH) to alfalfa silage (AS) ratios including 100:0 (AH100), 50:50 (AH50:AS50) and 0:100 (AS100) in total mixed rations (TMR) of dromedary camels. In experiment (Exp.) 1, a total of 18 multiparous Baluchi dairy camel [100 ± 5 days in milk (DIM); 3.65 ± 0.539 kg milk yield] were randomly allocated to one of the three groups (n = 6) for 42 d of experimental period. Dry matter intake (DMI) and milk yield were recorded daily, and blood samples were collected on days 0, 21 and 42. In Exp. 2, 18 male Baluchi camel calves [275 ± 14 days of old; 105 ± 8 kg BW] were housed in individual shaded pens for 150 days. DMI was recorded daily and individual weights of camels were recorded monthly. Blood samples were collected on days 0, 75 and 150. In Exp.1, feeding different dietary AH:AS ratios altered neither DMI (p = 0.351) nor milk yield (p = 0.667). Of all milk components, only the milk urea nitrogen (MUN) was increased (p = 0.015) by AS feeding (both AH50:AS50 and/or AS100). AS feeding tended to increase AST (p = 0.099) and ALT (p = 0.092) levels in lactating camels. In Exp. 2, DMI (p = 0.845), average daily gain (ADG; p = 0.092) and return per kg BW gain (p = 0.710) of silage-fed camels were similar to those of hay-fed group. The plasma concentration of BUN (p = 0.014) and AST (p = 0.014) were increased in camels fed AS100. Overall, the results suggest that both AS and/or AH could be used in dromedary camel diets based on the climatic condition, season and available facilities; however, the long-term use of AS (as sole forage) should done with caution due to the potential risk of impaired liver function. Further studies needed to explore the impact of hay versus silage feeding on digestibility, rumen function and nitrogen pollution in camel feeding.

This study was conducted to evaluate the effect of substitution of soybean meal (SBM) for formaldehyde-treated sesame meal (FTSM) on nutrient intake and digestibility, ruminal and blood parameters and milk production and composition in lactating Murciano-Granadina goats. Forty lactating goats were randomly assigned to one of the following four treatments: (1) diet with 16.5% CP, containing SBM (CON); (2) diet with 16.5% CP, containing untreated SM (USM); (3) diet with 16.5% CP, containing FTSM (FT); and (4) diet with 14.5% CP containing FTSM (LPFT). The results showed that nutrient intake was highest in the FT group (p < 0.001), while it was similar between the CON and LPFT groups, except for the intake of CP, which was higher in the CON group. The FT and LPFT had lower ruminal pH compared to CON and USM groups (p < 0.001), with goats in group FT having the highest volatile fatty acids (VFA) production (p < 0.001). The highest propionate concentration was observed in the LPFT treatment (p < 0.001), followed by the FT, CON, and USM treatments. Goats offered USM and LPFT treatments presented the highest and lowest acetate: propionate values, respectively, among the experimental groups (p < 0.001). The results also showed that LPFT goats had the lowest blood urea nitrogen (BUN) level (p = 0.004), while FT goats presented a lower non-esterified FA (NEFA) level compared with CON and LPFT goats (p = 0.01). Goats offered the FT diet had the highest milk yield (p = 0.002) and energy-corrected milk yield (p < 0.001) among all dietary groups. The highest milk fat (p < 0.001), protein (p = 0.001), lactose (p = 0.007), total solids (p = 0.003), and solids-not-fat (SNF) (p = 0.003) contents were observed in FT goats, which didn't differ from USM goats. The inclusion of formaldehyde-treated SM increased the percentage of C18:3 (p < 0.001) and C20:1 (p = 0.04) FAs compared with USM and CON treatments. Milk from USM, FT, and LPFT goats had lower levels of saturated (p < 0.001) and medium-chain FAs (p = 0.014) compared with CON goats, whereas milk from CON goats had lower levels of unsaturated, monounsaturated, and long-chain FAs compared to other groups (p < 0.001). The lowest and the highest concentrations of polyunsaturated FAs were observed in CON and LPFT goats, respectively (p = 0.001). It can be concluded that SBM can be advantageously replaced by formaldehyde-treated SM in the diet as a feasible alternative to improve feed intake and production performance of dairy goats.

Saccharina latissima is a brown seaweed that could be used in ruminant feeding, but its fast deteriorating and seasonal growth nature limit their utilisation in the practice. Ensiling could be used as a preservation method, but information of its effects on the nutritional value of the seaweed is limited. This study evaluated the in vitro ruminal fermentation of different S. latissima silages using ruminal inoculum either from goats fed a mixed diet (60:40 oat hay:concentrate) or from sheep fed a high-forage diet (90:10 alfalfa hay:concentrate) to simulate different small ruminant production systems. S. latissima was ensiled in vacuum bags without additives (Control), with formic acid (4 g/kg seaweed; FA), with lactic acid bacteria (LAB) or with LAB after a pre-wilting treatment to reach a seaweed dry matter (DM) content of 30% (30LAB). Ensiling S. latissima decreased (p < 0.05) the content in DM, neutral detergent fibre and total extractable polyphenols, but nitrogen and fat content were unaffected. For both ruminal inoculums, ensiling decreased (p < 0.05) the asymptotic gas production after 120 h of fermentation (excepting for FA silage with goats' inoculum), but the total volatile fatty acid (VFA) production was unaffected. The VFA profile shifted towards greater (p < 0.05) acetate and lower (p < 0.05) propionate proportions in all silages compared with the pre-ensiling S. latissima. When goats inoculum was used, greater (p < 0.05) CH₄ production compared with pre-ensiling S. latissima was observed in all silages, except Control one, which led to greater (p < 0.05) CH₄/total VFA ratio. In contrast, no differences among samples (p > 0.05) in either CH₄ production or CH₄/total VFA ratio were observed when sheep' inoculum was used. Fermentation of all samples started earlier with goats' inoculum than with sheep' inoculum, which was attributed to the different diet fed to the animals. These results suggest that ensiling S. latissima with either formic acid or lactic acid bacteria could be a viable conservation method to preserve the nutritive value.

The chemical composition and amino acids (AA) digestibility were determined in insect meals from mealworms, crickets, black soldier fly (BSF) larvae and BSF prepupae, and soybean meal. Six caecectomised laying hens were individually housed in metabolism cages and fed either a basal diet or one of five assay diets. Diets and hens were arranged in a 6 × 6 Latin square design with 6 subsequent periods. In each period, the laying hens were fed their respective diet for 9 d, and excreta samples were quantitatively collected twice daily from day 5 to 8. On day 9, a sterile plastic bag was attached to the cloaca of each hen to collect excreta for microbiota analysis. The AA digestibility of the insect meals and soybean meal were calculated using a linear regression approach. Crude protein (CP) concentrations in crickets and mealworms were higher than the value in soybean meal, BSF prepupae and BSF larvae. Ether extract concentrations were high in the insect meals and low in the soybean meal. The digestibility of most essential AA in soybean meal was higher (p < 0.05) than in crickets and BSF prepupae and not different from AA digestibility in mealworms and BSF larvae (except for arginine and histidine). The gene copy number of Escherichia coli in excreta from hens fed with BSF prepupae was lower (p < 0.05) than those fed with BSF larvae, whereas the gene copy number of Bacillus spp. and Clostridium spp. in excreta from hens fed with crickets was lower (p < 0.05) than those fed with BSF larvae. In conclusion, the chemical composition and AA digestibility varied among insect meals based on insect species and life stage. The high level of AA digestibility of insect meals supports the assessment that insect meals are a suitable feed component for laying hens, but differences in AA digestibility should be considered in diet formulation.

Particle size and storage time are factors that can affect the fermentation quality and digestibility of rehydrated corn grain silage (RCS). The objective of this study was to evaluate the effect of particle size and storage time on chemical and microbiological characteristics, aerobic stability, and ruminal degradability of RCS. Corn grains were ground to pass through either a 3 mm (fine) or 9 mm (coarse) screen, rehydrated to 44.3% moisture and ensiled in 200 L polyethylene buckets. Samples were taken before and after ensiling at 10, 30, 90 and 200 days of storage to assess microbial counts, fermentation end products, and DM ruminal degradability. DM degradation was evaluated with incubation times of 0 (bag wash), 3, 6 and 48 h in 3 rumen-cannulated cows. The effective ruminal degradation (ERD) was calculated based on soluble fraction (A), degradable fraction (B) and passage rate (kp) defined as 7.0%/h: A + B [kd/(kd + kp)]. Aerobic stability was evaluated in silages after 200 days of storage, and pH and temperature were analysed up to 240 h of aerobic exposure. At 90 and 200 d of storage, fine RCS resulted in lower crude protein and greater NH₃-N concentrations than coarse RCS. Coarsely ground RCS had a lower temperature at the beginning of storage than finely ground corn. Finely ground RCS had greater yeast counts and ethanol concentrations than coarsely ground RCS during storage time. Fine RCS was more susceptible to aerobic deterioration, reaching maximum temperature and pH values faster than coarse RCS. DM ruminal degradability increased over the storage time. The particle size of the rehydrated corn grain silage did not affect the kd values after 90 d of storage, while for the ERD, a long fermentation time was necessary (200 d). Considering the fermentation characteristics and the kinetics of ruminal DM degradation, fine grinding is recommended for short storage periods and coarse grinding may be a strategy to increase the rate of grinding when the storage period is greater than 200 d.

Vitamin D₃ has an integral part in calcium and phosphorus homoeostasis, which in turn plays a key role in egg production of hens. The present study aimed to investigate whether an additional vitamin D₃ supplementation improves the laying performance and egg quality of hens according to their genetic potential. For this purpose, four layer lines (low performing: R11 and L68; high performing: WLA and BLA) supplemented either with 300 or 3000 IU vitamin D₃ per kg feed were compared concerning serum 25-hydroxyvitamin D₃ (25-OHD₃), calcium, phosphorus and alkaline phosphatase (ALP), laying performance and egg quality. The higher supplementation of vitamin D₃ increased 25-OHD₃ serum concentrations in all genotypes, except for R11 and WLA hens in week 49, and also elevated vitamin D₃ and 25-OHD₃ content in the egg yolk (p < 0.05). In week 29, 3000 IU vitamin D₃ decreased pooled least squares means (LSMeans) of serum calcium concentrations considering all genotypes and increased the ALP concentrations in BLA hens (p < 0.05). Considering the whole experimental period daily egg mass of R11 hens was increased by an additional vitamin D₃ supplementation (p < 0.001). Regarding all genotypes and the whole experimental period the pooled LSMeans of breaking strength of eggs from hens fed 3000 IU vitamin D₃ were higher than those of hens fed 300 IU (p = 0.044). In conclusion, present results give evidence that the higher vitamin D₃ supplementation might have genotype-dependently beneficial effects on calcium and phosphorus homoeostasis of hens, which might improve feed efficiency in the early laying period and promote the persistence of the laying period irrespectively of genotype. The increase of serum 25-OHD₃ by the higher vitamin D supplementation supported the higher transfer of vitamin D in the egg yolk and improved genotype-dependently the breaking strength of the eggshell.

Concentrate-rich starter diets are commonly fed to dairy calves to stimulate growth performance. However, feeding high amounts of starter feed with low inclusion of forage fibre may jeopardise the development of the gastrointestinal tract (GIT). Moreover, studies investigating the effects of feeding on carcass and meat quality of young calves at rearing are rare. The objective of this research was to investigate the effect of hay quality and concentrate inclusion on the traits of GIT development, slaughter performance and veal quality of young dairy calves. The feeding trial covered the first 14 weeks of life. Seventeen male and three female Holstein calves (n = 20) were randomly allocated to four experimental groups, which received besides acidified whole milk different solid feeds: (1) 100% medium-quality hay (MQH), (2) 100% high-quality hay (HQH), (3) 30% medium-quality hay and 70% concentrate (MQH+C) and (4) 30% high-quality hay and 70% concentrate (HQH+C). The acidified whole milk was fed in the first 12 weeks of life, and calves had ad libitum access to solid feed and water from birth till slaughter. Calves were kept in individual boxes equipped with straw and slaughtered at the end of week 14. After slaughter, gut development traits, rumen histology, slaughter performance and meat quality were assessed. Overall, both concentrate inclusion and hay quality showed major effects on rumen histology and development of the GIT in dairy calves with minimal effects on most carcass cuts and meat quality traits. Concentrate-fed calves had significantly higher average daily gains, final body weights, blood amounts and proportions of organs from the circulatory and respiratory systems. Proportions of liver and kidneys were lowest in MQH-fed calves. The proportion of GIT was significantly lower in groups fed concentrates, but the weight of the reticulorumen was unaffected by solid feed. Concentrate feeding led to thicker keratin layer and epithelium as well as wider papillae in the rumen. Hay quality particularly affected the width of the papilla and epithelium thickness, while feeding hay without concentrate enhanced the thickness of submucosa and muscularis, as well as the size of parotid glands. In conclusion, the type of solid feed affects the development of the GIT with concentrate feeding holding the risk to induce keratinisation of rumen epithelium while enhancing performance and carcass traits.