Water is an important nutrient for livestock production and is often provided on rangelands directly from ponds or dugouts. Cattle may defecate and urinate into the water thereby adding nutrients and reducing palatability. A study was conducted to examine the effects of water source on cattle production and behavior, to determine the relationship of selected chemical and biological constituents on the observed response and to test the effect of fecal contamination on water consumption. Four dugouts or ponds were selected at 4 sites: 2 in the Fescue Prairie near Stavely in southwestern Alberta, 1 in the Mixed Prairie at Onefour in southeastern Alberta, and 1 in the Palouse Prairie near Kamloops, British Columbia. Yearling Herefords were tested at 3 sites and Hereford cow-calf pairs at 1 Stavely site. At each site, three paddocks radiated from the pond that were stocked with 10 yearlings or cow-calf pairs randomly assigned to either clean water (water delivered to a trough from a well, river, or pond), pond water pumped to a trough $(\text{pond}_{\text{trough}})$ , or direct access into the pond $(\text{pond}_{\text{direct}})$ . The trials were repeated at each site for 3 to 6 years. Observations were made on cattle weight gains, cow backfat thickness, and activity budgets. Fecal samples were analyzed for selected parasites and pathogens. Other experiments were conducted to determine the effects of manure-contaminated water on feed and water consumption and water selection. Calves, with cows drinking clean water, gained 9% more (P < 0.10) weight than those with cows on $\text{pond}_{\text{direct}}$ but cow weight and backfat thickness were not affected. Yearling heifers having access to clean water gained 23% (P = 0.045) and 20% (P = 0.076) more weight than those on $\text{pond}_{\text{direct}}$ and $\text{pond}_{\text{trough}}$ , respectively. Cattle avoided water that was contaminated with 0.005% fresh manure by weight when given a choice of clean water. Cattle that had access to clean water spent more time grazing and less time resting than those that were offered $\text{pond}_{\text{trough}}$ or $\text{pond}_{\text{direct}}$ . Cattle management must consider water quality together with forage conditions in order to achieve optimal production from rangeland. /// El agua es un nutriente importante para la producciÃ_n ganadera y se provee a menudo directamente en los agostaderos de las charcas o de los aguajes. El ganado puede defecar y orinar en el agua y de ese modo agregar nutrientes y reducir la palatabilidad. Un estudio fue conducido utilizando ganado vacuno de la raza Hereford para examinar los efectos de la fuente de agua en la producciÃ_n y el comportamiento del ganado, para determinar la relaciÃ_n de componentes quÃ_micos y biolÃ_gicos seleccionados en la respuesta observada y para probar el efecto de la contaminaciÃ_n fecal en la consumiciÃ_n del agua. Cuatro aguajes o charcas (charca) fueron seleccionados en cuatro sitios: dos en la pradera de Festuca cerca de Stavely en el sudoeste de Alberta, uno en la pradera mixta en Onefour en el sudeste de Alberta y uno en la pradera de Palouse cerca de Kamloops en la Colombia Británica. Vaquillas de un año fueron utilizadas en tres sitios y pares de vacas con terneros en un sitio de Stavely. En cada sitio, tres potreros salieron en forma radiada de la charca conteniendo diez vaquillas de un año o diez vacas con terneros al pie, asignadas al azar al agua limpia (agua llevada a un bebedero de un pozo, un rÃ_o, o una charca), agua de la charca bombeada a un bebedero (charca bebedero), o acceso directo a la charca (charca directo). Los estudios fueron repetidos en cada sitio de 3 a 6 años. Se realizaron observaciones de aumentos de peso del ganado, el espesor de la grasa del lomo de las vacas y vaquillas y el tiempo que pasaron en diferentes actividades. Fueron analizadas muestras fecales de parásitos y patÃ_genos seleccionados. Otros estudios fueron conducidos para determinar los efectos del agua contaminada con abono en la consumiciÃ_n del pienso y del agua y la selecciÃ_n del agua. Los terneros, con las vacas bebiendo el agua limpia, ganaron un 9% más (P < 0.10) de peso que aquellos con las vacas en charca directo, pero el peso de las vacas y el espesor de la grasa del lomo no fueron afectados. Las vaquillas de un año que tenÃ_an acceso al agua limpia ganaron un 23% (P = 0.045) y un 20% (P = 0.076) más de peso que aquellas en charca directo y charca bebedero, respectivamente. El ganado evitÃ_ el agua que estaba contaminada con 0.005% de abono fresco de peso cuando tenÃ_a acceso al agua limpia. El ganado que tenÃ_a acceso al agua limpia pasÃ_ más tiempo pastando y menos tiempo descansando que el que fue ofrecido el agua charca directo o el agua charca bebedero. Los administradores del ganado deben considerar la calidad del agua junto con las condiciones del forraje para lograr la producciÃ_n Ã_ptima de la pradera.

Journal of Range Management, volume 55, pages 452-460

dugouts, ponds, water intake, weight gains

Effects of omega-3 fats for pork

Suggestions for the BC lamb industry.

The objective of this investigation was to provide a comprehensive analysis of the total lipid composition of present-day retail beef meat available at the consumer level and to evaluate the total lipid composition with special emphasis on the nutritional value. For this purpose, 40 beef cuts were obtained from four cattle farms based on either a natural grazing system (NGS) or an intensive production system (IPS). The total lipid composition was analyzed using complementary chemical and chromatographic procedures. The content of n-3 LC-PUFA, CLA, total trans-18:1, and branched-chain fatty acids was significantly higher in NGS beef than in IPS beef. The trans-18:1 and CLA profiles were affected by the different production systems, whereby they can be utilized empirically to differentiate between feeding regimen and production management. Fatty acid ratios that have health implications ( n-6/ n-3, LA/alphaLNA, and AA/EPA) were remarkably beneficial for NGS beef compared with IPS beef. In conclusion, from the human health perspective, beef raised on NGS is clearly superior with regard to a more favorable fatty acid profile in comparison to IPS beef.

Journal of Agricultural and Food Chemistry, volume 56, issue 12, pages 4775-4782

breed, production system, retail beef meat, total lipid composition

(Abstract not available.)

Bovine meat is criticised for the bad nutritional image of its lipids and fatty acids. However, with dairy products, beef is the major source of conjugated linoleic acid (CLA) which could have several human health benefits. The present study compared, from data of five nutritional experiments on bovine animals performed by the laboratory, the impact of factors linked to the animals (breed, age, sex, type of muscle) and to feeding conditions (basal diet, lipid supplements) on the CLA proportion and composition in muscles. Among these factors, linseed supplementation was an efficient way to increase CLA proportion in beef (+22% to +36%) but was highly modulated by the nature of the basal diet, and by intrinsic factors (breed, age/sex, type of muscle) since these ones could modulate CLA proportion in beef from 24% to 47%. Moreover, these factors modified also the proportion of cis,trans-CLA, related to cis,cis- and trans,trans-isomers. Specific biological properties of these latter isomers should be determine to understand the consequences of intramuscular CLA isomer variations for the health of consumers. ?? 2005 Elsevier Ltd. All rights reserved.

Meat Science, volume 73, issue 2, pages 258-268

age, beef, breed, conjugated linoleic acid isomers, diet, gender, muscle

Carcass composition, muscle fatty acids and eating quality of loin chops were examined in ram lambs from four diverse breed x production system groups: pure Welsh Mountain off upland flora, pure Soays off lowland grass, Suffolk crosses off lowland grass and Suffolk crosses off concentrates. The two Suffolk groups had heavier and better muscled carcasses than the others and Soays were particularly lean. Fatty acid composition was different between the groups. The forage-fed lambs all had high concentrations of n-3 polyunsaturated fatty acids (PUFA) including 18:3 ([alpha]-linolenic acid) and 20:5 (eicosapentaenoic acid) compared with Suffolks-concentrates which had high concentrations of the n-6 PUFA 18:2 (linoleic acid) and 20:4 (arachidonic acid). Soays were high in both n-3 and n-6 PUFA. Flavour characteristics in grilled chops were similar in Welsh Mountain and Suffolks-grass which differed from Soays and Suffolks-concentrates. The latter two groups had low scores for lamb flavour and overall liking and high scores for abnormal lamb flavour, metallic, bitter, stale, and rancid. Soays had the highest score for livery. These results extend previous findings of the association between feed, PUFA composition and lamb flavour profile and confirm that forage-fed lamb is preferred by UK taste panellists. They also identify a specific breed effect on the quality of meat from lambs raised on forage. These findings suggest that possibilities exist for the production of meat with specific quality characteristics.

Meat Science, volume 55, issue 2, page 141

Fatty acid composition of intramuscular fat in M. Longissimus was measured in four groups of lambs representing two Spanish breeds: Rasa Aragonesa (RA) and Merino (ME) and two British lamb types: the Welsh Mountain breed (WM), whose carcasses were purchased in Spain and typical early lambs (EL) purchased in Britain. The lambs grown in Spain were concentrate fed and slaughtered at a lighter weight and lower age than those grown in Britain. The British lamb carcasses purchased in Spain were of a similar weight to the Spanish lambs but were lighter than the lamb carcasses purchased in Britain. The British lambs were grass fed. Relationships between fatty acid (FA) composition and sensory attributes were examined following sensory testing of all lambs by both British and Spanish taste panels. The production system was shown to be more important than breed in determining FA composition. British lambs had higher percentages, within total fatty acids, of 18:0, 18:3 (n-3) and long chain polyunsaturated n-3 FA and lower percentages of 18:2 (n-6) and long chain polyunsaturated n-6 FA than Spanish lambs. These differences were due to the different feeding systems used. The amounts of these FA in muscle (mg/100 g) were also different between the British and Spanish groups, not only because the British lambs had more total fat. For both taste panels, odour and flavour intensity were positively correlated with the amounts and percentages of 18:0 and 18:3 and negatively correlated with those of 18:2. This was explained by the fact that both panels gave higher odour and flavour intensity scores to the grass-fed British lamb with high 18:3 levels and lower scores to the concentrate-fed Spanish lamb with high 18:2 levels. However, 18:0 and 18:3 were positively correlated with flavour quality and overall appraisal for the British panel and negatively for the Spanish panel. Conversely, 18:2 was a positive contributor to flavour and overall preference for the Spanish panel and was negative for the British panel. The results show that the production system affects muscle fatty acid composition and the flavour of lamb. However, people's preference is determined to a large extent by their past experience.

Meat Science, volume 54, issue 4, pages 339-346

fat quality, lamb, taste panel

The objective of this study was to determine the impact of increasing the rate of carcass growth of steers grazing autumn grass by either supplementing with concentrates or by increasing grass supply on fatty acid composition of triacylglycerols within the M. longissmus thoracis. One hundred and ten steers (567 kg) were assigned to ten dietary treatments in a 3 (daily grass allowances: 6, 12 and 18 kg dry matter (DM)/animal) by 3 (daily concentrate allowances: 0, 2.5 and 5 kg/animal) factorial experiment with a control group offered concentrates ad libitum. Animals were slaughtered after 100 days and lipid extracted from samples of the M. longissmus thoracis for fatty acid analysis. There was an interaction (P < 0.001 ) between grass and concentrate allowance for the proportions of major fatty acid classes which reflected the patterns observed for individual fatty acids. Thus, supplementary concentrates had little effect on total fatty acids when offered with the high grass allowance, but high concentrate supplementation of the low grass allowance decreased the saturated fatty acid (SFA) and increased the monounsaturated fatty acid (MUFA) proportions. The high increment of concentrates at the medium grass allowance decreased the SFA and increased the MUFA proportions compared to the low increment of concentrates. In the absence of concentrates the high grass allowance decreased the proportion of SFA (P<0.001) and increased MUFA proportion (P < 0.001 ). Intra-muscular fat from the positive control group had lower (P < 0.05) SFA and higher (P < 0.05) MUFA proportions than that of animals offered the low grass allowance alone or with 2.5 kg concentrates or the medium grass allowance alone or with 5 kg concentrates. There was an interaction between grass and concentrate allowance for polyunsaturated fatty acid (PUFA): SFA ratio whereby this ratio was higher (P < 0.05) for the first concentrate increment on the medium grass allowance than this grass allowance either unsupplemented or supplemented with the high concentrate allowance. There was no effect of grass or concentrate allowance on the n-3: n-6 PUFA ratio but this ratio tended (P < 0.1) to be higher for all grass-based treatments compared to the control group. It is concluded that similar carcass growth rate can be achieved from an allowance of 18 kg autumn grass DM/day and 5 kg concentrates or from ad libitum concentrates and that muscle from the former ration has a lower fat concentration and a more favorable n-3 and n-6 PUFA profile, from a human health perspective. ?? 2002 Elsevier Science B.V. All rights reserved.

Livestock Production Science, volume 81, issue 2, pages 307-317

beef, cattle, concentrates, fatty acids, grass

The objective of this work was to evaluate the conjugated linoleic acid content (CLA), the fatty acid profile, and the chemical composition of the Longissimus muscle (LM) of steers and bulls finished in pasture systems. Fourteen 1/2 Nelore ?? 1/2 Aberdeen Angus cattle were studied. The animals were slaughtered at approximately 20 months of age, with an approximate final liveweight of 480 kg. Moisture, ash, fat, crude protein, cholesterol, and fatty acid contents of Longissimus muscle were determined. Steer muscle had a higher lipid content (3.38%) than that of bulls (1.71%). Total n-3 fatty acids were higher in bulls. The amounts of CLA in steer and bull fat were similar, but the CLA content in steer muscle was higher (47.99 mg 100 g -1 in LM) than that in bull muscle (23.24 mg 100 g -1 in LM). ?? 2006 Elsevier Ltd. All rights reserved.

Meat Science, volume 74, issue 2, pages 242-248

cla, fat, meat, nelore

Thesis

Eighty pigs, male and female littermate pairs, were fed a control or a test diet from 25 to 95 kg live weight. The diets, as fed, contained 15.5 g/kg linoleic acid (18:2) and 1.9 g/kg α-linolenic acid (18:3) (control) or 10 g/kg linoleic acid and 4 g/kg α-linolenic acid (test). The test diet, with added linseed, was, therefore, high in the main n-3 polyunsaturated fatty acid (PUFA) 18:3 and low in the main n-6 PUFA 18:2. Making this relatively small change led to a 56% increase in the content of 18:3 in muscle and major increases in the contents of the beneficial longer chain PUFAs EPA (20:5n-3) (100% increase) and DHA (22:6n-3) (35% increase) which are synthesised from 18:3n-3. Levels of EPA and DHA in pigmeat adipose tissue were also increased by the test diet. In liver, the test diet resulted in an 18:3 level 4× higher than in muscle, with 10× more EPA and 20× more DHA. Sausages, analysed after 6 months frozen storage also had high n-3 PUFA levels, due to the contribution of these fatty acids from both muscle and adipose tissue. From a health perspective these results confirm the potential of pigmeat to supply valuable n-3 PUFA to the human diet. The test diet produced a PUFA:saturated FA ratio in muscle of 0.4, close to the minimum recommended value for the diet as a whole and an n-6:n-3 ratio of 5, a significant improvement on the current average for pigmeat (7). It is estimated that the test diet would provide 12 g of long chain n-3 PUFA to the human diet per annum at current pigmeat consumption levels in the UK, about a third of that from oily fish.

Meat Science, volume 55, issue 2, pages 201-212

overview of Argentina beef production

Predicting the binding mode of flexible polypeptides to proteins is an important task that falls outside the domain of applicability of most small molecule and protein−protein docking tools. Here, we test the small molecule flexible ligand docking program Glide on a set of 19 non-α-helical peptides and systematically improve pose prediction accuracy by enhancing Glide sampling for flexible polypeptides. In addition, scoring of the poses was improved by post-processing with physics-based implicit solvent MM- GBSA calculations. Using the best RMSD among the top 10 scoring poses as a metric, the success rate (RMSD â‰_ 2.0 Ã… for the interface backbone atoms) increased from 21% with default Glide SP settings to 58% with the enhanced peptide sampling and scoring protocol in the case of redocking to the native protein structure. This approaches the accuracy of the recently developed Rosetta FlexPepDock method (63% success for these 19 peptides) while being over 100 times faster. Cross-docking was performed for a subset of cases where an unbound receptor structure was available, and in that case, 40% of peptides were docked successfully. We analyze the results and find that the optimized polypeptide protocol is most accurate for extended peptides of limited size and number of formal charges, defining a domain of applicability for this approach.

(Abstract not available.)

Agriculture and Natural Resource Publication, page 4