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Following previous research studies of the effect of silver nanoparticles (AgN) on digestive microbiota in pigs, we aimed to study the microbial changes induced by the addition of AgN on the digestive tract site (ileum or caecum) in weaning piglets and its influence on fermentation. Sixteen piglets weaned at 28 days (7.08 kg average weight) were given a prestarter diet, without (CT, n=6) or with 20 ppm metallic AgN (SIL, n=10) for 14 days. Then, piglets were slaughtered and their ileal and caecal contents sampled for their 16s rRNA sequencing using llumina MiSeq. Taxonomic assignment was performed using BLASTN against a RDP database data and analysed using R and JMP statistical packages. Ileal (6.60 vs. 6.65) and caecal (5.57 vs. 5.58) pH did not differ between CT and SIL. Volatile fatty acid concentration at the ileum was low, but in the caecum molar proportion of acetate was higher (0.577 vs. 0.461), and propionate lower (0.236 vs. 0.318), in CT than SIL. Addition of AgN decreased the ileal richness (P=0.002) but increased Lactobacillus sp. (P=0.07) in the ileum and reductions in Clostridium sp. (P=0.09 in ileum and P=0.03 in caecum) were observed when AgN were added. Taxa most influenced by addition of AgN included Treponema porcinum and Acitenobacter sp. at ileum and Desulfovibrio sp. and Ruminococcus albus at caecum. Spearman correlations between fermentation parameters and relevant taxa in both ileum and caecum also differed when AgN was added. Silver nanoparticles exert a differential effect on the microbial population depending on the digestive site (research supported by the project POCTEFA EFA-183/16).

A total of 200 Duroc cross (Landrace×Large White) pigs, 50% barrows and 50% gilts, of 26.3±0.55 kg body weight (BW) were used to study the effect of Lysine (Lys) restriction in the grower period on subsequent performance, serum metabolites and fatness. Four diets with Lys contents of 11.0, 9.1, 7.8 and 5.2 g/kg were offered to animals during the grower phase (45 d) in a two (sex)×four (diet) randomized block factorial design with five pens (replicates) per treatment and five pigs each. At the end of the restricted period, one pig per pen (five pigs per treatment) was slaughtered and the rest were fed a common finishing diet with 9.1 g/kg Lys until slaughter at 123 kg±2.35 kg BW. During the grower phase, Lys restriction reduced average daily gain (ADG) ( P P =0.008) and feed conversion ratio (FCR) ( P =0.003). The responses were quadratic and similar for both sexes. At the end of this period, restricted pigs showed lower backfat thickness ( P P =0.001) and cholesterol (quadratic; P =0.039). Also, serum albumin decreased quadratically ( P= 0.004) with Lys restriction while urea increased with the highest level of restriction. During the finisher phase, ADG increased linearly ( P P= 0.0.97), resulting in a linear increase of FCR ( P =0.002). However, the compensatory growth was incomplete and, during the overall period, there was a reduction of ADG (quadratic; P= 0.041) and of FCR (linear; P =0.001) as dietary Lys content decreased, whereas fat depth at the gluteus medius (GM) muscle increased linearly ( P =0.004). This entailed a delay to reach the slaughter BW of 1.8±0.43 d per g Lys restriction/kg of diet which was related to worse FCR by 0.034±0.0095 and to an increase of fat thickness at GM muscle of 0.51±0.168 mm. At the end of the trial, barrows grew faster, ate more feed and were fatter than gilts ( P

The effect of the solid by-product from the olive oil industry (olive cake) on digestibility, growth performances, and carcass, meat and fat characteristics was studied in sixty Duroc×(Landrace×Large White) gilts, of 69.5 ± 5.02 kg of body weight and 126 ± 3 days of age. Increasing levels of olive cake (0, 50, 100 and 150 g/kg of feed) were included in the diet by replacing the same proportion of barley. Five pens with three pigs per treatment were assayed, considering the pen as replicate. The trial lasted 35 days, and animals were slaughtered with 96.7 ± 7.45 kg of body weight. Daily feed intake increased (P=0.04) and daily gain tended to increase (P=0.06), both quadratically, with olive cake inclusion reaching the maximum values at 100 g olive cake/kg. The daily apparent digestible energy intake also increased quadratically (P=0.04) on increasing dietary olive cake content. The feed conversion ratio was not affected by diet. Also, the apparent organic matter digestibility tended to decrease quadratically (P=0.06) and energy digestibility decreased linearly (P

Barley, rice, maize and peas as starch sources were tested to study if differences in glycemic index may affect feed utilization, productive performances and quality traits for growing pigs. Four experimental diets were formulated to include 420 g starch/kg, provided by barley, barley/broken rice, barley/maize or barley/peas combinations (diets coded B, R, M and P, respectively). A 45% of total starch from diets R, M and P was provided by broken rice, maize or peas. The in vitro characterization of feeds showed that the rapidly digestible starch fraction was highest for R (P

Nutritional strategies are being researched in pigs to increase fatness and then to improve quality of dry-cured products. A total of 160 Duroc × (Landrace × Large White) pigs, 50% barrows and 50% gilts, were used in a trial. During the growing period (73-118. d of age), four feeds were formulated with decreasing levels of crude protein (CP; 21.6, 17.7, 14.7 and 13.5%) to achieve 1.10, 0.91, 0.78 and 0.52% of total Lysine, respectively. From 118. d until slaughter, at 123. kg (183, 181, 178 or 192. d of age, respectively), a common diet was provided (17.7% CP and 0.91% Lysine). Barrows had fatter carcasses than gilts but intramuscular fat (IMF) proportion was similar for both. Dietary CP restriction promoted wider backfat depth and pork with higher IMF percentage which was more monounsaturated and less polyunsaturated. We conclude that CP restriction during the grower period improves desirable carcass and meat traits in barrows and gilts intended for dry-cured products.

The authors regret that there were errors in Table 1 in the original article. The analyzed composition of some nutrients (total ash, crude protein, ether extract and neutral detergent fiber) of diets and also the calculation of the ideal protein were erroneous. They were initially expressed in dry matter and they should be expressed in fresh matter which does not affect the rest of the paper. Correct Table 1 is shown below. The authors would like to apologise for any inconvenience caused.

A proportion of dietary starch reaches the hindgut, being fermented there. The characteristics of in vitro caecal fermentation and microbial community in pigs given different sources of starch were studied. Twenty-four Duroc × (Landrace × Large White) gilts given diets based on barley (B), broken rice (R), maize (M) or peas (P) (n=6) for five weeks were slaughtered with 93.6 ± 6.41 kg. No differences (p>0.10) were recorded in caecal pH, total short chain fatty acid (SCFA) and total bacterial concentration, nor in in vitro gas production from caecal contents, indicating the lack of a quantitative dietary effect on caecal environment. This could be partly due to the length of fasting time before slaughter (around 10 h). Molar SCFA proportions did not differ among diets; however, relative proportion of Lactobacillus sobrius/amylovorus as the species-type in starch digestion in hindgut of pigs, was highest with P diet (p = 0.010), and gas production from potato starch as substrate with P diet was highest at 2 h incubation (p = 0.012), and higher than B and R diets at 4 (p = 0.055) and 6 (p = 0.10) h incubation. Caecal bacterial biodiversity was higher for M and R diets than for P and B diets (Shannon index, p = 0.003). Sources of resistant or slowly digestible starch such as peas promote a microbial community with a different profile and higher capacity to ferment the starch arriving to the organ than other sources which are mostly digested in the small gut.

Sixty Duroc × (Landrace × Large White) gilts of 93.5 of body weight (BW) were used to investigate the effect of increasing dietary net energy content (2280, 2350, and 2420 kcal/kg) on growth performance and carcass, meat, and fat characteristics. Animals were intended for dry-cured ham production. Therefore, pigs were slaughtered at 130 kg BW and a minimum fat thickness at Gluteus medius muscle (m. GM) was required. No effect was detected on daily gain or energy intake but feed intake decreased and feed conversion ratio tended to improve as energy increased. Fat depth at m. GM was wider and the proportion of suitable carcasses tended to be greater when energy increased. The treatment had scarce effect on meat and fatty acids. We conclude that 2350 kcal of net energy per kg of feed would optimize the productive and quality responses in gilts when are intended for dry-cured ham production.