Effects of replacing canola meal with camelina expeller on intake, total tract digestibility, and feeding behavior of beef heifers fed high-concentrate diets

To assess the effect of inclusion of camelina expeller in beef cattle diets, 24 Simmental heifers were used. Two experiments were carried out. In the first, two free-choice tests, one without and another with molasses, were conducted to know the preference of animals for a total mixed ration (TMR) made with a 90 to 10 concentrate to barley straw ratio, where canola meal (CM) or camelina expeller (CE) was used in the concentrate as a protein source. Heifers were allotted in four pens with two independent feedbunks, one for each diet. In the second, a replicated 4 × 4 Latin square design was used to assess the effects of the replacement of CM with CE on intake, digestibility, and sorting and animal behavior. The experiment was performed in four 28-d periods during which groups of three animals were allotted in each pen of 12.5 m 2. Diets were formulated with a 90 to 10 concentrate to barley straw ratio and fed as TMR, and they were designed to contain 1) CM as main protein source and 0% of CE (0CE), 2) 3% of CE replacing CM (3CE), 3) 6% of CE replacing CM (6CE), and 4) 9% of CE replacing CM (9CE). In the free-choice test without molasses, heifers showed a greater preference for CM than for CE (38.6 vs. 8.7 kg/d; P 0.10), and there was no effect of this replacement on DM, OM, CP, and NDF apparent digestibility (P > 0.10). Intake of long particle size increased lineally as CE proportion increased (P = 0.015). In addition, extension of sorting behavior for long particle size tended to increase lineally (P = 0.07), and sorting against this particle size was detected in 0CE and 3CE, but not in 6CE and 9CE (P < 0.05). However, the results recorded for long particle size intake and for sorting behavior against these particles did not translate into more time spent ruminating in heifers fed diets with higher proportion of CE. In conclusion, when canola meal was replaced with camelina expeller at more than 14% of inclusion, heifers preferred the canola meal diet. However, replacing canola meal with camelina expeller up to 9% of inclusion in diets for beef cattle did not affect intake and digestibility but promoted a greater intake of long particle size of barley straw

EVALUACIÓN DE COMPUESTOS FENÓLICOS EN POLLOS DE CARNE SOBRE EL REDEMIENTO PRODUCTIVO Y SU STATUS OXIDATIVO

La oxidación de los lípidos se puede producir por la presencia de una elevada cantidad de radicales libres, debido a un elevado consumo de ácidos grasos poliinsaturados o como resultado de una falta de antioxidantes. En general, se acepta que la oxidación de los lípidos es la principal causa del deterioro de los tejidos y que afecta directamente al valor comercial de la carne de pollo. Este proceso podría prevenirse mediante la suplementación de antioxidantes en las dietas, que minimicen la formación de los radicales libres y aumenten la estabilidad de los lípidos. En la actualidad, diversos compuestos fenólicos están siendo estudiados, debido a su potencial antioxidante. Los compuestos fenólicos son metabolitos secundarios de las plantas, que se caracterizan por minimizar las consecuencias negativas de la oxidación lipídica, pudiendo ser de interés para su uso en alimentación animal. El objetivo global de este estudio es evaluar el efecto de compuestos fenólicos, como fuente natural de antioxidantes, en pollos de carne. Noventa y seis hembras Ross 308 se asignaron al azar a 24 jaulas (4 animales por jaula) y las jaulas se distribuyeron al azar en 4 tratamientos (6 jaulas por tratamiento). Los tratamientos fueron: C-, dieta basal con 3% de aceite de pescado; C+, C- con 250 ppm de vitamina E; Dieta A, C- con 1500 ppm de producto A; Dieta B, C- con 1500 ppm de producto B. El producto A y B son productos con alto contenido de compuestos fenólicos. La suplementación dietética de los productos evaluados en este estudio, no modificó los parámetros productivos, el perfil lipídico ni el grado de oxidación de la sangre (P> 0.05). Hacen falta más estudios para valorar la efectividad de estos productos a diferentes dosis de incorporación así como la concentración y combinación de sus principios activos.<br /

A virtual dairy herd as a tool to teach dairy production and management

The objective of this project was to develop and test a web-based virtual dairy herd to help students understand the structure and functioning of a dairy herd, and to promote active learning. At the beginning of the course, the instructor defines the profiles of herds to be assigned to students (e.g., herd size, production, diets, fertility). Each student has a unique herd and engages in decision-making for desired management practices in the herd. Modeled events are based on cow physiology and normal dairy herd management practices. Students' activities and decisions include heat detection, insemination, pregnancy diagnosis, dry-off, diet specifications, feeding groups, colostrum and milk-replacer feeding, weaning, treatment of diseases, and milk withdrawal from the tank if antibiotics are used, among others. The daily output provides information on technical indexes, economic performance, counters of incorrect decisions as feedback for students, and score. Time in class can be devoted to discussions of dairy management issues. Additional exercises based on students' own herds (e.g., calculating required space for cows, land for forage production, manure management) can also be implemented. Students' performance in the virtual dairy farm was monitored over 3 years. The average score (n = 326) was 87.8 ± 1.1 over 100 points, suggesting that self-learning with the virtual dairy farm was highly successful. At the end of each semester, students (n = 277) responded to a survey on the experience of working with the virtual dairy herd. Most students (>87%) agreed that the virtual dairy herd was more effective and motivating than traditional lectures and helped them understand dairy production better. In an unannounced test conducted at least 2 wk before the final exam, students (n = 207) were asked 14 questions on dairy cattle and 14 similar questions on other species taught in the same class through traditional lectures. A similar test on the same students (n = 142) was conducted in their fifth semester (2 years later). Results were better in dairy compared with other species questions in the first (9.6 vs. 3.7) and fifth (8.0 vs. 3.8) semesters. The virtual dairy herd is an effective tool for teaching introductory courses in dairy production. The program can be accessed at www.virtualdairyfarm.org, and a manual and videos with instructions for instructors and students are available online

Effects of the feed : Water mixing proportion on diet digestibility of growing pigs

Funding: This research was funded by Spanish Ministry of Science and Innovation (CDTI project IDI-20110003), and TEM 2010 research grant form "Comissionat per a Universitats I Recerca del Departament d'Innovació, Universitats I empresa form Generalitat de Catalunya (AGAUR).The effect of different water-to-feed ratios on apparent total tract digestibility of energy and nutrients were evaluated in growing-finishing pigs. In trial 1 (26 d), 16 female pigs (46.7 ± 1.98 kg of body weight, BW) were individually assigned to four treatments (n = 4). In trial 1, pigs were fed a control diet in dry form (CON) and in blend form with water-to-feed ratios of 0.6:1, 2.1:1 and 2.7:1. In trial 2 (26 d), rearranged animals (65.4 ± 3.14 kg of BW) were assigned a control diet in dry form (CON) and ratios of 1.35:1, 2.7:1 and 3.5:1. In trial 1, pigs fed on ratios of 2.1:1 and 2.7:1 had a higher organic matter digestibility (OMd) and gross energy digestibility (GEd) than CON. In trial 2, pigs fed on ratios of 1.35:1, 2.7:1, and 3.5:1 had a higher OMd and GEd than CON. Quadratic regressions showed the maximum dilution rate to reach higher digestibility coefficients at 1.83:1 and at 2.7:1 for trials 1 and 2, respectively. During trial 1, pigs on the 0.6:1 dilution rate had higher weight gain than those on CON. The water-to-feed ratio that optimized OM and GE digestibility may increase with the age of the pigs

Efficacy of medium-chain fatty acid salts distilled from coconut oil against two enteric pathogen challenges in weanling piglets

Background: The search for alternatives to antibiotics in pig production has increased the interest in natural resources with antimicrobial properties, such as medium-chain fatty acids (MCFA) as in-feed additives. This study evaluated the potential of a novel blend of MCFA salts (DIC) from distilled coconut oil with a lauric acid content to reduce enteropathogens and control intestinal diseases around weaning. Two experimental disease models were implemented in early-weaned piglets, consisting of two oral challenges: Salmonella Typhimurium (1.2 × 10 CFU) or enterotoxigenic Escherichia coli (ETEC) F4 (1.5 × 10 CFU). The parameters assessed were: animal performance, clinical signs, pathogen excretion, intestinal fermentation, immune-inflammatory response, and intestinal morphology. Results: The Salmonella challenge promoted an acute course of diarrhea, with most of the parameters responding to the challenge, whereas the ETEC F4 challenge promoted a mild clinical course. A consistent antipathogenic effect of DIC was observed in both trials in the hindgut, with reductions in Salmonella spp. plate counts in the cecum (P = 0.03) on d 8 post-inoculation (PI) (Salmonella trial), and of enterobacteria and total coliform counts in the ileum and colon (P < 0.10) on d 8 PI (ETEC F4 trial). When analyzing the entire colonic microbiota (16S rRNA gene sequencing), this additive tended (P = 0.13) to reduce the Firmicutes/Bacteroidetes ratio and enriched Fibrobacteres after the Salmonella challenge. In the ETEC F4 challenge, DIC prompted structural changes in the ecosystem with increases in Dialister, and a trend (P = 0.14) to increase the Veillonellaceae family. Other parameters such as the intestinal fermentation products or serum pro-inflammatory mediators were not modified by DIC supplementation, nor were the histological parameters. Only the intraepithelial lymphocyte (IEL) counts were lowered by DIC in animals challenged with Salmonella (P = 0.07). With ETEC F4, the IEL counts were higher with DIC on d 8 PI (P = 0.08). Conclusions: This study confirms the potential activity of this MCFA salts mixture to reduce intestinal colonization by opportunistic pathogens such as Salmonella or E. coli and its ability to modulate colonic microbiota. These changes could explain to some extent the local immune cell response at the ileal level

Una granja virtual, o como aprender jugando

Les jornades d'innovació docent a la Facultat de Veterinària tenen per objectiu l'intercanvi d'experiències docents entre el professorat de la Facultat com a punt de partida per reflexionar sobre l'estat actual de la docència i estimular la inclusió de noves activitats d'innovació als estudis de grau. Aquestes jornades estan organitzades pel Grup d'Innovació Docent de la Facultat de Veterinària amb el suport de la Unitat de Formació i Innovació Docent (OQD) de la Universitat Autònoma de Barcelona

Modificación de la fermentación microbiana ruminal mediante compuestos de aceites esenciales

Esta tesis doctoral se planteó debido a la necesidad de evaluar la capacidad de los aceites esenciales y de sus compuestos como aditivos ruminales. En el primer estudio se utilizaron 8 fermentadores (1320 ml) de doble flujo continuo en dos períodos (8 d) para estudiar el efecto de una mezcla de compuestos de aceites esenciales (BEO, CRINA? RUMINANTS) sobre la fermentación microbiana y el flujo de nutrientes. Los tratamientos se distribuyeron en un diseño factorial 2 x 2, donde el tipo de ración (alta en concentrado: 90% concentrado y 10% paja; vs alta en forraje: 60% heno de alfalfa y 40% concentrado) y la adición de BEO (0 mg/l vs 1.5 mg/l) fueron los efectos principales. La adición de BEO no afectó a la digestibilidad de MS, MO, FND, FAD y PB, pero incrementó la concentración de AGV totales (122.8 vs 116.2 mM) sin modificar significativamente las proporciones individuales de AGV o el metabolismo nitrogenado. El segundo estudio consistió en varias pruebas experimentales diseñadas para estudiar el efecto de la dosis y del periodo de adaptación a la adición de BEO sobre el metabolismo nitrogenado de los microorganismos ruminales. En la primera, se utilizaron de nuevo 8 fermentadores de doble flujo continuo (1320 ml) en dos períodos (6 d de adaptación y 3 de muestreo) para estudiar el efecto de la dosis de BEO sobre la fermentación microbiana ruminal. Los tratamientos fueron: CTR (sin adición de BEO), D5 (5 mg/l de BEO), D50 (50 mg/l de BEO) y D500 (500 mg/l de BEO). En la segunda prueba experimental se utilizaron 8 ovejas (peso medio de 57 kg) para estudiar el efecto de una adaptación larga del líquido ruminal a la adición de BEO sobre la fermentación ruminal. El tratamiento CTR (sin adición de BEO) se asignó al azar a 4 ovejas, y las otras 4 ovejas se adaptaron a BEO (110 mg/d de BEO) durante 4 semanas (ADBEO). La adición de 5 mg BEO/l de líquido ruminal en cultivo continuo incrementó la concentración de AGV totales y la relación acetato:propionato después de 6 d de fermentación, pero los cambios sobre el metabolismo N sólo aparecieron en el líquido ruminal de ovejas alimentados con BEO durante 28 d.En el tercer estudio se evaluaron los efectos de cinco compuestos de aceites esenciales sobre la fermentación microbiana ruminal. En la primera prueba experimental, los efectos de 4 dosis crecientes (5, 50, 500, y 5000 mg/l) de 5 compuestos de aceites esenciales se evaluaron en incubaciones in vitro de líquido ruminal durante 24 h con dos dietas diferentes: una dieta 60:40 forraje:concentrado (18% PB; 30% FND) y la otra 10:90 forraje:concentrado (16% PB; 25% FND). Los tratamientos fueron: control (CTR), eugenol (EUG), guaiacol, limoneno, timol (TIM), y vanillin. En la segunda prueba experimental se utilizaron 8 fermentadores de doble flujo continuo (1320 ml) en 3 periodos (6 d de adaptación y 3 d de muestreo) para estudiar el efecto del TIM y del EUG sobre la fermentación microbiana ruminal y el flujo de nutrientes. Los tratamientos fueron: CTR (control negativo), MON (control positivo, 10 mg/l de monensina), T5 (5 mg/l de TIM), T50 (50 mg/l de TIM), T500 (500 mg/l de TIM), E5, E50 y E500, y se asignaron aleatoriamente a los fermentadores dentro de cada periodo. La mayoría de estos compuestos de aceites esenciales a dosis elevadas demostraron poseer actividad antimicrobiana disminuyendo la concentración total de VFA. Sin embargo, EUG en incubaciones de 24 h y T5 en cultivo continuo modificaron el perfil de AGV sin inhibir la concentración total de AGV, y EUG disminuyó la concentración de N amoniacal. Una selección cuidadosa de estos compuestos permitiría la manipulación de la fermentación microbiana ruminal.This doctoral thesis was planned to test the potential of essential oils and their compounds as ruminal additives. In the first study, eight dual flow continuous culture fermenters (1320 ml) were used in two replicated periods (8 d each) to study the effects of a specific blend of essential oil compounds (BEO, CRINA? RUMINANTS) on rumen microbial fermentation and nutrient flow. Treatments were arranged in a 2 x 2 factorial design. Main factors were type of diet (10 to 90 vs 60 to 40 forage to concentrate ratios) and the addition of BEO (0 vs 1.5 mg/l of BEO). There were no effects of BEO on DM, OM, NDF, ADF and CP digestion. The use of BEO increased the concentration of total VFA (122.8 vs 116.2 mM) without affecting individual VFA proportions or N metabolism. The second experiment was designed to study the effect of dose of BEO and adaptation time to the addition of BEO on N metabolism of rumen microorganisms. The second study consisted in several tests. In the first, eight dual flow continuous culture fermenters (1320 ml) were used in two periods (6 d of adaptation and 3 d of sampling) to study the effects of increasing doses of a specific blend of essential oils (BEO, CRINA? RUMINANTS) on rumen microbial fermentation. Fermenters were fed with the same high forage ration of the first study and the sampling protocol and processing were identical. Treatments were: CTR (no BEO), D5 (5 mg/l of BEO), D50 (50 mg/l of BEO) and D500 (500 mg/l of BEO). In the second experiment, eight sheep (average body weight of 57 kg) were used to study the effects of long term adaptation of rumen fluid to BEO on ruminal fermentation. Four sheep were assigned at random to the CTR treatment (no BEO) and four sheep were adapted to BEO (110 mg/d of BEO) for four weeks (ADBEO). The addition of 5 mg BEO/l of rumen fluid in continuous culture increased total VFA concentration and acetate to propionate ratio after 6 d of fermentation, but changes in N metabolism were only apparent when using rumen fluid from sheep fed BEO for 28 d.In the third study, several essential oil compounds were evaluated on rumen microbial fermentation. In the first experiment, the effects of 4 different doses (5, 50, 500, and 5000 mg/l) of five essential oil compounds were evaluated in in vitro 24 h batch culture of rumen fluid with two different diets: a 60 to 40 forage to concentrate diet (18% CP; 30% NDF) and a 10 to 90 forage to concentrate diet (16% CP; 25% NDF). Treatments were: control (CTR), eugenol (EUG), guaiacol, limonene, thymol (THY), and vanillin. In the second experiment, eight dual flow continuous culture fermenters (1320 ml) were used in three periods (6 d of adaptation and 3 d of sampling) to study the effects of THY and EUG on rumen microbial fermentation and nutrient flow. Treatments were: CTR (negative control), MON (positive control, 10 mg/l of monensin), T5 (5 mg/l of THY), T50 (50 mg/l of THY), T500 (500 mg/l of THY), E5, E50 and E500, and were randomly assigned to fermenters within periods. Most of these essential oil compounds demonstrated their antimicrobial activity decreasing total VFA concentration at high doses. However, EUG in batch fermentation and T5 in continuous culture modified VFA profile without decreasing total VFA concentration, and EUG decreased ammonia N concentration. Careful selection of these essential oils compounds may allow manipulation of rumen microbial fermentation

Impacts of compost bedded pack barns on the welfare and comfort of dairy cows

Three loose housing systems for lactating cows (compost bedded pack, CBP; conventional bedded pack, BP; and freestalls, FS) were assessed on one farm in terms of cow behavior and welfare. An on-farm welfare assessment based on the Welfare Quality protocols was used four times every three months on 757 cows. Video recordings taken twice over four days were used to assess behavior patterns at resting areas. Cows in CBP and BP were dirtier than those in FS (p < 0.0001). Fewer integument alterations were recorded for CBP and BP than FS (p < 0.001). Cows in BP were quicker to lie down and stand up compared to those in CBP or FS (p < 0.001). Percentages of cows needing more attempts before rising were higher for FS (p < 0.01). However, a higher frequency of kneeling was observed in CBP (p = 0.033). A lower percentage of cows lying in the resting area was recorded for FS (56%) than CBP or BP (97 or 84%, respectively, p < 0.05). Overall, in this study, cows kept in bedded pack barns were dirtier but had fewer integument alterations and spent more time lying down in the resting area than cows housed in freestalls

Evaluación de la eficacia de aditivos basados en aceites esenciales frente a un desafío oral de Escherichia coli K88 en lechones de destete

Phytogenic feed additives are characterized to contain botanic compounds biologically active with organoleptic and medical properties. Globally their use in feeding strategies or as alternative to growth promoters for animal production has increased, especially during the weaning period. The high stress and the abrupt feeding changes experienced by the piglet in this period have a negative impact on voluntary feed intake, which may promote the presence of enteropathies that affect piglet performance and increase mortality rates. The main objective of this study was to evaluate the potential of two phytogenic feed additives in weanling pigs to enhance gut health at early life stages and to fight intestinal pathogens. To achieve the objective, a trial was designed to evaluate the potential of two different phytogenic feed additives in weanling piglets in front of an Enterotoxigenic Escherichia coli K88 (ETEC K88) oral challenge. In brief, 96 weanling piglets were transported to the University facilities from commercial farm with mothers that did not received E. coli vaccination. Animals were distributed in 4 rooms of 8 pens each (32 pens, three animals per pen). The experiment included four treatment groups with eight replicates per each including: (i) a control group with plain diet (T1); (ii) the same plain diet supplemented with ZnO (2500 ppm Zn) (T2); (iii) supplemented with phytogenic 1 (1kg/tm) (T3); (iv) or supplemented with phytogenic 1 (1kg/tm) plus phytogenic 2 (1.5 kg/tm) (T4). Pigs were fed over 16 days ad libitum with the experimental diets. After an adaptation period, animals were orally challenged with ETEC K88 and one animal per pen was euthanized at day 8 post-inoculation (PI). In this experiment, main parameters assessed were animal performance, clinical signs, bacterial loads in the gut, immune response and intestinal morphology. In general terms, we were not able to find significant differences in performance comparing the phytogenic diets to the plain diet, although some trends could be found. ZnO supplementation increased (P = 0.03) average daily gain (ADG) in the 0-4 PI period compared to pigs fed treatment T1, and treatments T3 & T4 showed intermediate values. The same pattern was observed with gain:feed ratio (G:F; P = 0.03) in the same period. Additionally, some significant effects were found in other parameters. The numbers of lactobacilli in feces and colon digesta on day 8 PI were the highest (P = 0.0007; P = 0.03, respectively) with diets supplemented with phytogenics (T3 & T4) and the lowest with the diet including ZnO (T2). The ratio lactobacilli:coliformrs in feces on day 8 PI was significantly increased (P=0.002) by the inclusion of the T3 treatment when compared to T1 and T2, showing T4 intermediate values. Phytogenics did not affect the serological concentration of TNF-α. There was a trend at day 4 PI in Pig-MAP to decrease with T4 (P=0.07). Villus:crypt (VH:CD) ratio was significantly increased (P=0.009) by the inclusion of ZnO and also by the T4 treatment compared to T1, showing T3 intermediate values. In conclusion, both tested phytogenics could help the piglet to fight the ETEC challenges after weaning considering the numerical improvements observed in performance immediately after the challenge. This better response could be due to an improved microbiota balance suggested by the increased ratio of lactobacilli:coliforms observed in feces on day 8 PI, particularly in the T3 treatment. Additionally the phytogenic T4 shows enhanced anti-inflammatory properties with reductions in Pig-MAP serological levels concomitant with an improvement in the intestinal architecture (VH:CD ratio).<br /

Exploring additive, synergistic or antagonistic effects of natural plant extracts on in vitro beef feedlot-type rumen microbial fermentation conditions

Six Essential oils (EO) (tea tree oil-TeTr, oregano oil-Ore, clove bud oil-Clo, thyme oil-Thy, rosemary oil-Ros, and sage oil-Sag) in Experiment 1; and different combinations of selected oils in Experiment 2, were evaluate at four doses in an in vitro microbial fermentation system using ruminal fluid from beef cattle fed a 10:90 straw: Concentrate diet. In Experiment 1, TeTr, Ore, Clo and Thy improved rumen fermentation profile in a direction consistent with better feed utilization. In Experiment 2, TeTr mixed with Thy, Ore, Thy + Ore or Clo at 200 and 400 mg/L increased the molar proportion of propionate and decreased that of acetate, and the acetate to propionate ratio. However, the size of the effect was similar to that obtained with TeTr alone, suggesting that effects were not additive. When Thy, Ore or Thy + Ore where mixed with Clo, most effects on rumen fermentation profile disappeared, suggesting an antagonistic interaction of Clo with Thy and Ore. Results do not support the hypothesis of additivity among the EO tested, and antagonistic effects of Clo mixed with Thy or Ore were demonstrated at least in a low pH, beef-type fermentation conditions