Archives of Animal Nutrition最新文献

The cis-9 trans-11 and trans-10 cis-12 isomers of conjugated linoleic acid (CLA) are associated with anticancer and lipolytic effects in tissues, respectively, but in lactating cows, the latter isomer reduces the milk fat concentration, a detrimental aspect for the dairy industry, as it reduces the yield of milk derivatives. Therefore, the objective of this study was to evaluate the effect of providing protected palmitic acid (PA_P) to grazing lactating Holstein cows supplemented with soybean oil as a source of conjugated linoleic acid, on milk production, fat concentration and mitigation of milk fat depression. Nine multiparous Holstein cows were used, distributed in three groups of three cows each, with initial means of days in milk, live weight, milk production, and number of calvings: 124 ± 16 days, 494 ± 53 kg, 20.9 ± 1.3 kg, and 3.2 ± 2.2, respectively. A crossover design with three treatments was used: control (base diet, BD, = grazing +4 kg concentrate without soybean oil + 2.5 kg corn silage), soybean oil (BD with inclusion of 300 g dry basis soybean oil cow^-1 day^-1), and soybean oil + PA_P (BD with inclusion of 300 g dry basis soybean oil and 412 g PA_P cow^-1 day^-1). The groups of cows were on rotational grazing in a mixed pasture of Alfalfa (Medicago sativa) and Orchard grass (Dactylis glomerata). The variables evaluated were as follows: dry matter intake (DM), milk production, concentration of protein, fat and lactose in milk, and milk fat profile. Statistical analysis was through PROC MIXED and comparison of means with Tukey's test (p < 0.05). There were no differences (p > 0.05) between treatments in dry matter intake, milk production or milk protein and lactose content. But the addition of PA_P in the cow diet increased fat-corrected milk production (p = 0.010), yield (p = 0.030) and fat concentration (p = 0.040), and improved the milk fatty acid profile, by increasing (p = 0.010) the concentration of cis-9, trans-11 CLA in milk fat. Soybean oil supplementation in the diet of grazing lactating cows showed no differences in productive variables, and did not cause the expected milk fat depression. However, combining soybean oil with PA_P improved the fatty acid profile, increasing the cis-9, trans-11 isomer CLA and palmitic acid in milk fat, with higher yield and fat concentration.

An experiment was conducted to determine the digestible energy (DE) of insect fat (IF) from black soldier fly larvae (BSLF) for growing pigs. Saturated fatty acids (SFA) were the dominant group of fatty acids in the IF, with lauric acid (C12:0) and palmitic acid (C16:0) comprising the greatest concentrations in this group. Linoleic acids (C18:2) and oleic acids (C18:1) were the main unsaturated fatty acids. The IF contained 37.63 MJ/kg gross energy and 2.55 g/kg nitrogen. During the experiment, a DE bioassay was performed wherein growing pigs were fed one of the two experimental diets (either a maize-wheat-barley-soy basal diet or a diet containing 50 g/kg IF plus 950 g/kg of the basal diet). The DE of the IF was calculated based on the differences between the DE values of basal and test diet (substitution method). The DE of the IF was determined to be 36.86 MJ/kg. The IF contains a DE level comparable to vegetable oils, including soybean, rapeseed, corn and palm oils. The results showed that the examined fat from BSLF is a good source of available energy and can be incorporated in pig diets as an alternative energy source.

The objective was to investigate the effect of rainfall on sodium (Na) dissolution and total losses by runoff of loose mineral mixtures (MM) available in uncovered feeders to grazing cattle, as well as the possible impacts on their growth performance and fulfilment of Na nutritional needs. Experiments (n = 7) were conducted to quantify the amount of Na lost due to rainfall and to evaluate the effects of different Na levels in the MM (35, 70, 105, and 140 g Na/kg) on MM assumed intake and growth performance. Cattle grazed Brachiaria sp. pastures and received free-choice MM in uncovered feeders throughout four to nine evaluation periods lasting 14 to 21 d each. MM assumed intake from the feeder was measured in each period as the difference between the supplied MM mass and the unconsumed MM mass. A new methodology was proposed to measure MM losses by runoff (exclusion feeder). The mass of runoff MM and the volume of runoff rainwater were both determined and analysed for their mineral content. The dietary Na requirement was estimated using different feeding systems. The minimum MM Na content to meet dietary Na requirements was estimated in different scenarios. Sodium chloride composed 28% of the runoff MM mass, in average. The action of rain may reduce MM Na content by 28% in a single rainfall event. Na content strongly affected MM assumed intake and, possibly, growth rate. MM losses by runoff were estimated at 25.5%, according to the exclusion feeder methodology. The minimum required MM Na content for meeting dietary Na needs may reach up to 87.3 g Na/kg. About 27% of evaluated periods may have failed to fully meet cattle Na requirements. The action of rain in unsheltered loos MM may result in unbalanced mineral consumption and unmet Na needs, leading to impaired mineral nutrition of grazing cattle, especially in tropical conditions.

This study aimed to evaluate the intake, digestibility, ingestive behaviour, productive performance, rumen fermentation and carcass yield of lambs fed diets with Parkia platycephala pods (PP) replacing ground corn. For this, twenty-eight castrated male lambs (18.34 ± 4.81 kg, 120 days of age), were distributed in randomised blocks with 4 treatments and 7 replicates. Four diets were formulated replacing ground corn with PP (0, 33, 66, and 100%) on a roughage: concentrate ratio of 30:70 on a dry matter basis. The feedlot period lasted for 60 days, and the animals were slaughtered consecutively. The replacing of ground corn with PP reduced the intakes of ether extract and metabolisable energy, digestibility of dry matter, organic matter, crude protein, ether extract, neutral detergent fibre, total digestible nutrients, isovalerate, and omental + mesenteric fat, while it increased the digestibility of non-fibrous carbohydrates, carcass finishing, and the yields of rumen, reticulum, and omasum (p < 0.05). A quadratic effect was observed for the time of chews per rumen bolus, number of rumination chews per day, number of rumination chews per bolus, and number of rumination chews per minute, propionate (p = 0.002), butyrate (p < 0.01) and total short chain fatty acids (SCFA) (p < 0.05) according to the increase in PP levels replacing ground corn in diets offered to lambs. The rumen pH was reduced and the NH₃-N increased according to the evaluation period (p < 0.05). The highest concentration of total SCFA was observed in the collection carried out at 09 h (p < 0.05). The use of up to 100% PP in diets offered to lambs is recommended as it provides nutrient intake, weight gain, and carcass yield similar to ground corn.

This experiment was carried out to evaluate the effect of endo-1,4-beta-xylanase with traces of endo-1,4-beta-glucanase on the performance of 240 piglets (Landrace × Yorkshire × Duroc) with an initial body (BW) of 5.90 ± 0.6 kg. The mixed sex piglets were randomly assigned to 3 treatments with 10 replicates per treatment, and 8 heads per replicate pen. The dietary treatments include (1) corn-wheat-soybean meal (SBM) basal diet without xylanase (XYL) enzyme as positive control (PC), (2) corn-wheat-SBM diet deprived -90 kcal/kg metabolizable energy without XYL enzyme (NC), and (3) corn-wheat-SBM diet deprived -90 kcal/kg metabolizable energy + 0.02 XYL (DG2). The diets were administered in mash form for 42 d (split into 2 phases) as phase 1, d 0-21, and phase 2, d 22-42. All the experimental diets were designed to fulfil the nutrient requirement by NRC 2012. The results show XYL supplementation significantly increased (p < 0.05) final body weight and overall average daily gain (ADG) while enhancing feed efficiency (G/F) compared to the negative control group (NC). Nutrient digestibility was notably improved, with significant increases (p < 0.05) in gross energy (GE), xylan, and non-starch polysaccharides (NSP) digestibility in both phases. The incorporation of XYL also increased monosaccharide and xylooligosaccharide levels in the ileum and caecum, indicating enhanced carbohydrate breakdown. Additionally, XYL supplementation improved the gut microbiota profile by showing higher tendency (p = 0.066) for beneficial bacteria like Lactobacillus with a tendency (p = 0.052) for lower Escherichia coli counts. Overall, XYL supplementation effectively enhanced growth performance and nutrient digestibility in weanling pigs on a low-energy diet.

An experiment was conducted to assess the effects of the BCAA and their interactions on performance, carcass composition, lipid metabolism, liver health, and intestinal morphometry in broiler chickens. Male chickens (n = 1080) were randomly assigned into floor pens in a 3 × 3 factorial design with 3 dietary ratios of SID Leu:Lys (110, 150, and 190%), and 3 dietary ratios of SID Ile-Val:Lys (68-77, 78-87, and 88-97%). Performance parameters were assessed from 1 to 35 days of age. Additionally, blood parameters, carcass composition through DEXA analysis, and intestinal morphometry of the small intestine were evaluated in birds at 35 days of age. Data were subjected to ANOVA and the Tukey Test was used to determine differences between treatments (p ≤ 0.05). Feed intake, feed conversion ratio, and body fat of birds were reduced when SID Ile-Val:Lys increased from 68-77 to 88-97% (p < 0.05). Serum glucose, total cholesterol, and triglycerides were influenced by BCAA interactions (p < 0.05). Alkaline phosphatase and gamma-glutamyl transferase levels were reduced when SID Leu:Lys ratio increased from 110 to 190% (p < 0.05). However, the alanine aminotransferase levels increased when both SID Leu:Lys and SID Ile-Val:Lys increased from 110 to 190%, and 68-77 to 88-97%, respectively (p < 0.05). The highest SID Leu:Lys ratio of 190% resulted in the highest villus height-to-crypt depth ratio in all three portions of the intestine, whereas the highest SID Ile-Val:Lys ratio of 88-97% resulted in the highest ratio only in the jejunum and ileum (p < 0.05). In conclusion, the results of this study provide valuable insights into the inclusion of BCAA in broiler diets and their effects on performance, body fat content, intestinal morphometry, lipid metabolism, and liver health.

Protein supply to ruminants relies mainly on the flow of microbial crude protein (MCP) from the rumen, which is commonly assumed to primarily depend on energy supply. This study evaluated this assumption with recent data and tested if ruminally fermented organic matter (FOM) was a better predictor of MCP flow than total-tract digestible organic matter (DOM) and if more variables could improve the prediction of MCP flow. A previously published data set was extended by additional studies resulting in a data set of 139 studies including 407 treatment means, typical to Central European rations. Either DOM or FOM had to be reported and estimates of MCP were all based on gastrointestinal measurements. Dietary treatments were restricted to a maximum concentrate proportion of 0.6 and a CP concentration from 10% to 20% of dietary dry matter (DM). Treatments with more than 1% of animal by-products were excluded. Mixed models with "study" as random effect were used to test the ratios between MCP and DOM or FOM. Dietary characteristics including DM intake, OM digestibility (OMD), OM fermentability (OMF), and ruminal N balance and dietary concentrations of CP, rumen-degraded CP (RDP), rumen-undegraded CP (RUP), neutral detergent fibre, starch, and ether extract were evaluated as additional variables to improve prediction accuracy. Regression of MCP flow against DOM (n = 324) or FOM (n = 349) revealed estimates of 139 g ± 36 g and 164 g ± 40 g of MCP for each kg of DOM or FOM, respectively. The best-fitting mixed model estimating MCP/DOM [g/kg] was 312-2.75 · OMD - 0.229 · RUP + 0.290 · RDP whereas MCP/FOM [g/kg] may be calculated as 294-2.80 · OMF + 0.401 · RDP, with OMD and OMF in [%] and RDP and RUP in [g/kg DM]. Microbial CP flow [g/d] was most accurately described as 1896 + 110 · DOM - 23.7 · OMD - 0.164 · RUP + 0.153 · RDP, with DOM in [kg], OMD in [%] and RDP and RUP in [g/d]. Predictions based on DOM were at least as precise as FOM-based predictions and comparison with published models revealed that the presented models were of similar accuracy as the ones from literature.

The effect of ensiling sorghum grains harvested at different dates on pig nutrient digestibility and fermentability was evaluated using in vitro approaches. A sorghum crop was divided following a randomised complete block design and distributed in 3 treatments: 1) grain harvested 113 d after sowing (40% moisture) and ensiled for 180 d (high moisture, HMG), 2) grain harvested 159 d after sowing (15% moisture), rehydrated to 40% moisture and ensiled for 180 d (reconstituted, REC), and 3) sorghum grain harvested 159 d after sowing (15% moisture) and stored dry (dry, DG). Starch content was lower in ensiled grains (HMG and REC) (p = 0.019), and lower for HMG (p = 0.043). The resistant starch fraction was lower (p < 0.001), and the predicted glycaemic index was higher (p = 0.029) in ensiled grains. In vitro DM, OM and starch digestibility were greater in ensiled grains (p < 0.001 for all parameters). Ensiled grains had lower in vitro gas production [ml/g DM] (p = 0.002), but the rate of gas production [ml/h] was higher (p = 0.025). Finally, ensiled grains had lower butyrate and higher branched-chain fatty acids concentration [mol/L] (p < 0.001 and p < 0.003, respectively). The ensiling process improved in vitro digestibility and changed fermentation parameters and short-chain fatty acids profile, regardless of DM at harvest.

Two experiments were conducted to determine net energy (NE) values of wheat bran ingredients and develop a prediction equation for NE of wheat bran. In each experiment, 12 multiparous pregnant sows were allocated to two 3 × 6 Youden squares with three consecutive periods and six diets in each square. The study consisted of six diets, including a corn-soybean meal basal diet and five diets formulated with 29.2% wheat bran. Each period lasted for 10 d, with 5 d allocated for adaptation and followed by 5 d for heat production measurement. Sows were provided feed at 604 kJ/kg BW^0.75·d^-1. On day 10, sows underwent fasting to measure fasting heat production. Results indicated that the inclusion of wheat bran in the diets significantly reduced digestibility of energy and nutrients in (p < 0.05). The average net energy (NE) content of wheat bran was determined to be 8.8 MJ/kg DM. A regress equation NE = 7.968 + 0.28 × CP + 0.607 × EE - 0.782 × ash - 0.05 × hemicellulose (R² = 0.98, p < 0.01) was found to accurately predit the NE value when feeding pregnant sows with wheat bran-based diets. In conclusion, the net energy content of wheat bran fed to pregnant sows ranged from 7.24 to 10.67 MJ/kg DM and can be effectively estimated using proximate analysis methods.