There is scarce information regarding the effects of probiotics in the diet of lactating ewes on milk yield and composition as well as on metabolite concentrations and enzyme activities in blood. Sixteen Sanjabi ewes, kept under the same feeding and management practices, were divided in two equal groups. The ewes in the first group were fed a diet without probiotics, while the ewes of the second group were fed the same diet supplemented with two grams of commercial probiotics (PrimaLac® 454 Feed grade, containing Lactobacillus acidophilus, 2.5 × 107 CFU/g; Lactobacillus casei, 2.5 × 107 CFU/g; Bifidobacterium thermophilum, 2.5 × 107 CFU/g; Enterococcus faecium, 2.5 × 107 CFU/g). Milk yield measurements, milk composition and blood plasma analyses were carried out at the fourth, eighth and twelfth week of lactation. Probiotics had no effects (p>.05) on any of the examined variables during the first two-thirds of lactation. In the last third of lactation, probiotic supplemented ewes showed an increase (p<.05) of aspartate aminotransferase activity in blood plasma (209 versus 98 U/L) as well as higher (p<.05) yields of milk (503 versus 312 g/d), fat (34.8 versus 22.2 g/d), protein (33.1 versus 20.3 g/d) and lactose (22.4 versus 13.9). In conclusion, probiotics barely affected blood plasma metabolite contents and enzyme activities, but positive effects on milk yield and its components were observed during the last third of lactation. Further research would be needed to determine whether the supplementation of ewe diet with probiotics is advisable for sustainable livestock farming systems.
Milk fat composition can be modulated by the inclusion of lipid supplements in ruminant diets. An interaction between the lipid supplement and the forage to concentrate ratio or the type of forage in the rations may affect milk fat composition. However, little is known about the effects of the starch-to-non-forage NDF ratio in the concentrate and lipid supplementation of goat diets. The aim of this work was to determine the role of dietary carbohydrates in goats rations supplemented with linseed oil on animal performance and milk fatty acid (FA) profile. A total of 16 dairy goats were allocated to two simultaneous experiments (two treatments each), in a crossover design with four animals per treatment and two experimental periods of 25 days. In both experiments alfalfa hay was the sole forage and the forage to concentrate ratio (33:67) remained constant. The concentrate in experiment 1 consisted of barley, maize and soybean meal (concentrate rich in starch), whereas it included soybean hulls replacing 25% of barley and 25% maize in experiment 2 (concentrate rich in NDF). As a result, the starch-to-non-forage NDF ratio was 3.1 in experiment 1 and it decreased to 0.8 in experiment 2. Both concentrates were administered either alone or in combination with 30 g/day of linseed oil. Animal performance parameters were not affected by experimental treatments. In contrast, major changes were observed in milk FA profile due to lipid supplementation and the type of concentrate. Linseed oil significantly raised vaccenic and rumenic acids as well as α-linolenic acid and its biohydrogenation intermediates while decreased medium-chain saturated FA (12:0 to 16:0) in milk fat. Milk fat contents of odd and branched-chain FA and trans-10 18:1 responded differently to linseed oil supplementation according to the concentrate fed.
The aims of the present work were to determine by meta-analysis the responses of broiler performance to increasing dietary levels of black soldier fly larvae meal (BSFLM) and to develop prediction models of the apparent metabolisable energy corrected to zero nitrogen balance (AMEn) of BSFLM. Eighteen studies from 12 countries that sum up to 20 experiments and involved a total of 63 treatments with 468 replicates and 4229 birds fulfilled the requirements for the meta-analysis. Four papers from three countries that investigated eight different samples of BSFLM were selected for development of AMEn prediction by means of regression analysis or artificial neural network (ANN) modelling. Growth performance results were not affected (p > .05) by the presence of BSFLM at levels of 5.7 ± 2.3 and 15.5 ± 6.0% in the diet. Multiple linear regression and ANN models showed high precision and accuracy, were unbiased and performed almost identically in the evaluation dataset (R2 = 0.856 and 0.858 and root mean square error of prediction as percentage of the observed mean = 5.216 and 5.241%). Feeding broilers with diets containing 15% BSFLM is not expected to have negative effects on growth performance. The following regression model could be useful for the estimation of AMEn in BSFLM: AMEn = 4.08 (± 0.330) + 0.295 (± 0.0158) × GE + 0.186 (± 0.0021) × EE; where AMEn and gross energy (GE) are MJ/kg dry matter and crude fat (EE) is % dry matter.
2 January 2019 in Italian Journal of Animal Science
The feed utilisation of young chicks is characterised by a suboptimal fat digestibility, which can be improved by means of dietary emulsifiers. The objective of this study was to evaluate the effect of dietary Globin on the energy efficiency and digestibility of starter feeds and on the production performance of broilers throughout the whole rearing cycle. A total of 224-day-old ROSS 708 chickens (14 birds/pen, 8 replicates/treatment) were fed ad libitum with either a basal diet (C) or a basal diet with the addition of 0.05% Globin during the starter (d1–10), growing (d10–25) and finisher (d25–35) periods. Nutrient digestibility (aD), protein metabolisability (aMCP), energy efficiency (EE) and net energy for production (NEp) were assessed during the starter period. The average daily feed intake (ADFI), average daily gain (ADG), feed conversion ratio (FCR) and protein efficiency ratio (PER) were measured of each growth period. Globin significantly decreased FCR (p = .020) and increased aDfat (p = .021), EE (p = .028) and NEp (p = .011) during the starter period. aMCP (p = .049) and PER (p = .039) were higher in the Globin group than in the Control group. The increased availability of energy from dietary fat, as a result of Globin supplementation, possibly shifted the use of the absorbed amino acids towards an anabolic metabolism, and this could explain the increased aMCP and PER but similar aDCP. The overall performance was similar between groups, although Globin tended to increase PER (p = .064) overall.
9 November 2023 in Italian Journal of Animal Science
This work aimed to determine if the milk fat contents of odd- and branched-chain fatty acids (OBCFA) could be linked to the diet composition in goats, by canonical discriminant analysis (CDA). The OBCFA contents of 32 milk fat samples from two feeding trials (two treatments per trial) were used. In both experiments, the goats were fed a diet, with the same forage/concentrate ratio and nutritive value, which was supplemented or not with 30 g/d of linseed oil. The starch/non-forage NDF ratio of the diet was 3.1 in the first experiment and was lowered to 0.8 in the second experiment by replacing part of the cereals in the concentrate with soybean hulls. Milk fat composition analyses were grouped into four classes in the CDA. Stepwise backward selection identified C13:0 iso, C14:0 iso, C17:0 anteiso, C18:0 iso and C17:0 + cis-9 C17:1 as valid predictors. The first two discriminant functions (DF) explained 82.2 and 13.9% of total variance. DF1 and DF2 differentiated milk samples by the non-forage NDF content and linseed oil supplementation of the diet, respectively. C14:0 iso and C17:0 anteiso were indicative of the diets with high non-forage NDF and starch contents, respectively. C17:0 + cis-9 C17:1 and both C18:0 iso and C13:0 iso contributed to identify the diets with and without added linseed oil, respectively. In conclusion, CDA allowed to identify which milk OBCFA were the best indicators of the starch/non-forage NDF ratio and the presence of linseed oil in the diets fed to dairy goats.