Effect of Yerba Mate Extract as Feed Additive on Ruminal Fermentation and Methane Emissions in Beef Cattle.

The inclusion of plant extracts that contain secondary compounds with the potential to modulate rumen fermentation and improve animal performance has gained attention in recent years. The aim of this study was to evaluate the effect of the inclusion of yerba mate extract (Ilex paraguariensis ST. Hilaire) (YME) on the ruminal parameters. Eight castrated cattle were divided into four groups, a control without YME (0%) and three treatment groups with 0.5, 1 and 2% inclusion of YME in the dry matter. The inclusion of YME did not show differences in ruminal methane emissions (CH4), and total apparent digestibility (p = 0.54). Likewise, YME did not modify ruminal pH, but positively affected NH3-N, which decreased linearly as the extract level in the diet increased (p = 0.01). No short chain fatty acids (SCFA) were influenced by YME, except isovaleric acid (p = 0.01), which showed a lower concentration in the inclusion of 2% YME. Our results show that up to 2% YME does not affect digestibility, ruminal fermentation parameters, or the concentration of short-chain fatty acids in the rumen.

An agent-based simulation model to compare different reproductive strategies in cow-calf operations: Technical performance.

The objective of this study was to create a stochastic, agent-based simulation model of a synthetic population of beef cattle, and then use it to compare the technical performance of different reproductive strategies. The model was parameterized using data from a real beef cattle herd and from the peer-reviewed scientific literature to represent a Nelore cattle herd in the state of São Paulo, Brazil. Ten scenarios were evaluated: natural mating (NM) only (ONM); one timed artificial insemination (TAI) plus NM (1TAI + NM); two TAI plus NM, with 24, 32, and 40 days between inseminations (2TAI/24 + NM, 2TAI/32 + NM, and 2TAI/40 + NM, respectively); three TAI without NM, with 24, 32, and 40 days between TAI (3TAI/24, 3TAI/32, and 3TAI/40, respectively); and three TAI plus NM, with 24 and 32 days (3TAI/24 + NM and 3TAI/32 + NM, respectively). NM began 10 days after the last TAI and was performed until the end of the breeding season. The size of the female herd was set to contain up to 400 individuals. The bull population was established at 0, 7, or 15 bulls depending on the used scenario. Simulation was performed for 5000 days. The outcomes for each scenario are means ± S.E. assessed on 32 farms at 1-day time intervals and on an animal-by-animal basis after steady state was reached (1825 days). The 3TAI/24 + NM scenario resulted in a greater number of births (279.85 ± 0.47 births), while the ONM scenario had the least value (202.38 ± 0.43 births). The heaviest males and females at weaning belonged to 3TAI/24, with 190.85 ± 0.17 kg for males and 173.89 ± 0.13 kg for females. The ONM scenario had the lightest males (166.84 ± 0.18 kg) and females (151.75 ± 0.16 kg). The greatest and least total pregnancy rates were found in 3TAI/24 + NM (0.91 ± 0.00) and ONM (0.62 ± 0.00), respectively. The ONM scenario required 52.5 days more than scenarios that included TAI to reach 50% of pregnancy. The greatest ages at culling for cows was 3TAI/24 + NM (3658.88 ± 10.41 days). In contrast, the lowest age at culling was found in ONM (2823.93 ± 8.28 days). We concluded that the proposed model represents the main interactions of a real beef cattle herd. It has all the advantages of a physical experiment, but does not require incurring significant expenses nor altering the real system. This study offers evidence that the scenarios that present the best technical performance are those that used TAI with a 24-day interval between inseminations.

Effect of dietary copper sources on performance, gastric ghrelin-RNA expression, and growth hormone concentrations in serum in piglets.

Two performance studies were conducted to investigate the effects of 3 different sources of Cu on production parameters of piglets. A total of 256 piglets weaned at 24 ± 2 d were randomly allocated into 4 treatments with 10 or 8 replicates per treatment of 4 or 3 piglets per pen in Exp. 1 and 2, respectively. The experimental period was divided into 3 feeding phases: Phase 1 (24 to 35 d), Phase 2 (36 to 49 d), and Phase 3 (50 to 70 d). Treatments included a Control group (fed 10 mg/kg of Cu from CuSO4), a group fed 160 mg/kg of either CuSO4 (CuSO4-160) or tri-basic copper chloride (TBCC), and a group fed Cu methionine hydroxy analogue chelated (Cu-MHAC) at 150, 80, and 50 mg/kg in Phases 1, 2, and 3, respectively. The methionine value of Cu-MHAC was accounted during diet formulation to achieve the same levels of methionine across treatments. Phases 1 and 2 diets contained 2,200 and 1,500 ppm of ZnO, respectively; and antibiotics were used as growth promoters. Performance parameters were analyzed as completely randomized block design, in which each experiment was considered as a block. In trial 2, blood serum and mucosal samples, from the fundic region of the stomach, were collected from 1 piglet per replicate at day 70 and tested for serum growth hormone levels (GH) and ghrelin mRNA expression, respectively. The contrast between Cu-MHAC vs. CuSO4-160 + TBCC showed that piglets fed Cu-MHAC exhibited better feed conversion ratio (FCR) in all feeding phases compared with feeding inorganic Cu (P < 0.05). Overall, feeding Cu-MHAC improved body weight (BW), BW gain, feed intake (FI), and FCR vs. Control diet fed piglets; yet, it improved BW and FCR vs. TBCC fed piglets, and improved BW, BW gain, and FI vs. CuSO4-160 fed piglets (P < 0.05). Feeding TBCC promoted similar performance than feeding CuSO4-160, regardless of age (P > 0.05). Both ghrelin expression and growth hormone serum levels were significantly increased by feeding Cu-MHAC vs. Control diet fed animals (P < 0.01). Feeding CuSO4-160 upregulated ghrelin expression vs. Control (P < 0.01) while GH serum levels and ghrelin expression did no change by feeding TBCC compared with Control diet fed animals (P > 0.05). It was concluded that feeding Cu-MHAC at the levels tested herein can improve growth performance of piglets beyond feeding 160 ppm of either CuSO4 or TBCC, which may be partially explained by the increased expression of ghrelin and GH serum levels.

Correction: Effects of dietary aflatoxin B1 on accumulation and performance in matrinxã fish (Brycon cephalus).

[This corrects the article DOI: 10.1371/journal.pone.0201812.].

Effects of dietary aflatoxin B1 on accumulation and performance in matrinxã fish (Brycon cephalus).

Aflatoxins (AF) can be cumulative in fish tissues and can influence weight, length, feed intake and survival depending on the species. The aim of this work is to measure performance and aflatoxin levels in tissues of matrinxã (Brycon cephalus) fish chronically exposed to aflatoxin. Aflatoxin was incorporated into fish diets at the following levels: Control Feed + 0 µg AFB1 kg-1; A. Feed + 10 µg AFB1 kg-1; B. Feed + 20 µg AFB1 kg-1; C. Feed + 50 µg AFB1 kg-1. It was used one tank per treatment, each one with 150 juvenile fish, and three replicates within each tank were used for sampling, that was carried out monthly over a period of six months. Aflatoxin was quantified by HPLC in fish liver and muscle after clean up using immunoaffinity columns. Performance was evaluated by using weight, length, consumption and survival rate. Muscle and liver aflatoxin levels were below the limit of detection in all control samples. Aflatoxins B2, G1 and G2 were not detected in any tissues. Traces (values between limits of detection and quantification) of AFB1 were observed in liver tissue in treatment A from day 30 through 90, reaching 0.32 µg AFB1 kg-1 at 150 days of exposure. Treatment B presented traces up to day 60 and had, with a maximum level of 0.39 µg AFB1 kg-1 at 150 days of exposure. Treatment C had aflatoxin residues after day 30, with values ranging from 0.17 to 0.61 µg AFB1 kg-1 during exposure. Muscle samples only had traces of AFB1 in all treatments. Fish was affected by exposure to AFB1 with higher values (P<0.05) for weight and length in treatments A, B and C relative to controls. Therefore, results indicate that matrinxã do not accumulate AFB1 residues in edible tissues, but chronic exposure affects the species.

Effect of microencapsulated Jabuticaba (Myrciaria cauliflora) extract on quality and storage stability of mortadella sausage.

The aim of the present study was to add microencapsulated Jabuticaba aqueous extract (MJE) to mortadella as a natural dye and to evaluate its possible antioxidant and antimicrobial activity during refrigeration. Anthocyanins in the extract were quantified and identified. Three treatments of mortadella were prepared: without dye (Control), with cochineal carmine (Carmine) and with the addition of 2% MJE. We determined the chemical composition of mortadella, along with pH, instrumental color, lipid oxidation, microbiological characteristics (Escherichia coli, Staphylococcus aureus, Salmonella, sulphite-reducing Clostridium, aerobic mesophiles, aerobic psychrotrophics and lactic acid bacteria) and sensory acceptance during storage at 4 °C for 56 days. MJE showed high content of anthocyanins, with prevalence of cyanidin-3-glucoside. MJE improved sensory acceptance of texture and flavor of mortadella (P < 0.05), but we observed a slight decrease in color and aroma attributes (P < 0.05). Lipid oxidation of mortadella was not influenced by MJE or cochineal carmine. MJE also displayed a minor effect on physicochemical and microbiological characteristics during storage. As MJE did not alter most of mortadella sausage's evaluated characteristics, it could be used as a natural dye in order to make better use of agro industry waste and to create a meat product enriched with natural antioxidants.