Intake, nutrient apparent digestibility and ruminal constituents of sheep fed diets with canola, sunflower or castor oils

The objective in this experiment was to determine the effects of feeding diets with canola, sunflower or castor oils on intake, nutrient apparent digestibility and ruminal constituents of crossbred Dorper x Santa Ines sheep. Four rumen-cannulated animals of 90.2 +/- 11.4 kg average body weight were assigned to a 4 x 4 latin square. Animals remained individually in cages for the metabolism assay and were fed diets containing roughage at 500 g/kg and concentrate based on ground corn and soybean meal also at 500 g/kg. No oil was added to the control diet, whereas the others had canola, sunflower or castor oils at 30 g/kg (DM basis). There was no difference for the intake of DM and nutrients, except for ether extract, which was greater when animals received oil. The digestibility coefficients of dry matter, organic matter, crude protein, non-fiber carbohydrates and neutral detergent fiber were not changed; however, the addition of oil increased the ether extract digestibility. The values of total digestible nutrients (TDN, g/kg of DM), digestible energy (DE, Mcal/kg of DM), TDN intake and DE intake also did not change with the addition of lipids. Concerning the ruminal constituents, the addition of vegetable oils reduced the concentrations of acetate, butyrate and total short-chain fatty acids. Adding canola, sunflower or castor oils at 30 g/kg in diets with 500 g roughage/kg and 500 g concentrate/kg does not impair the intake or digestibility of nutrients in sheep, although it reduces the concentration of short-chain fatty acids in the rumen.

Contribution to economic evaluation of systems that value animal welfare at farm

The demand for "welfare friendly" products increases as public conscience and perception on livestock production systems grow. The public and policy-makers demand scientific information for education and to guide decision processes. This paper describes some of the last decade contributions made by scientists on the technical, economical and market areas of farm animal welfare. Articles on animal welfare were compiled on the following themes: 1) consumer behavior, 2) technical and economical viability, 3) public regulation, and 4) private certification policies. Most studies on the economic evaluation of systems that promote animal welfare involved species destined to produce export items, such as eggs, beef and pork. Few studies were found on broilers, dairy cows and fish, and data regarding other species, such as horses, sheep and goats were not found. Scientists understand that farm animal welfare is not only a matter of ethics, but also an essential tool to gain and maintain markets. However, it is unfortunate that little attention is paid to species that are not economically important for exports. Studies that emphasize on more humane ways to raise animals and that provide economic incentives to the producer are needed. An integrated multidisciplinary approach is necessary to highlight the benefits of introducing animal welfare techniques to existing production systems.

Liberação de peróxido de hidrogênio por fagócitos de glândulas mamárias bovinas hígidas e infectadas

O objetivo do presente estudo foi avaliar a capacidade de liberação de peróxido de hidrogênio (H2O2) por fagócitos oriundos de glândulas mamárias bovinas sadias e infectadas. Desse modo, 73 amostras de leite provenientes das glândulas mamárias foram classificadas em sadias e infectadas de acordo com a cultura bacteriológica e a contagem de células somáticas (CCS). Após o isolamento das células do leite, procedeu-se à contagem diferencial de leucócitos e determinação da liberação de H2O2 pela oxidação da solução de vermelho fenol. Foi observada menor liberação de H2O2 pelos fagócitos oriundos dos quartos mamários infectados, assim como houve correlação negativa entre a liberação de H2O2 por fagócitos e a CCS (r=-0,34; P=0,0025), e a porcentagem de neutrófilos (r=-0,24; P=0,04). Além disso, houve tendência de menor liberação de H2O2 pelos fagócitos estimulados por forbol 12-miristato 13-acetato nas glândulas mamárias infectadas. Entretanto, observou-se maior liberação de H2O2 pelos fagócitos em 1mL de leite nos quartos mamários infectados, ao considerar a CCS mL-1. Pode-se concluir que fagócitos de quartos mamários infectados apresentaram menor liberação de H2O2, o que indica menor capacidade microbicida. Por outro lado, observou-se maior liberação de H2O2 pelos fagócitos em 1mL de leite nos quartos infectados, fato que pode contribuir com o maior recrutamento de leucócitos para a glândula mamária e/ou a persistência do processo inflamatório.

Effects of Aspergillus spp. exogenous fibrolytic enzymes on in vitro fermentation of tropical forages

BACKGROUND: Cellulose and hemicellulose are quantitatively the most important structural carbohydrates present in ruminant diets. Rumen micro-organisms produce enzymes that catalyse their hydrolysis, but the complex network formed by structural carbohydrates and lignin reduces their digestibility and restricts efficient utilisation of feeds by ruminants. This study aimed to produce two enzymatic extracts, apply them in ruminant diets to determine the best levels for ruminal digestibility and evaluate their effects on in vitro digestibility. RESULTS: In experiment 1 a two-stage in vitro technique was used to examine the effects of different enzymatic levels of Aspergillus japonicus and Aspergillus terricola on tropical forages. Enzyme addition had minor effects on corn silage at the highest enzymatic level. In experiment 2 an in vitro gas production (GP) technique was applied to determine apparent in vitro organic matter digestibility and metabolisable energy. The addition of enzymes in GP showed interesting results. Good data were obtained using sugar cane and Tifton-85 hay supplemented with extracts of A. japonicus and A. terricola respectively. CONCLUSION: Overall, the study suggests that addition of crude extracts containing exogenous fibrolytic enzymes to ruminant diets enhances the effective utilisation of ruminant feedstuffs such as forages. Copyright (c) 2012 Society of Chemical Industry

Glycerol as a by-product of biodiesel production in Brazil: Alternatives for the use of unrefined glycerol

On January 1 2008, Brazil included yet another element into its energy matrix: biodiesel. The predominant biodiesel production process involves a phase of transesterification that yields glycerol as a by-product. The use of this glycerol is limited since it is considered an unrefined raw material that must be refined for its various types of use. Several studies have addressed identification of possible uses for unrefined glycerol. Given the diversity of uses, an overview is necessary. The purpose of this work is to present alternatives currently being considered for the use of unrefined glycerol as a by-product of biodiesel production, aiming to contribute to the sustainable consolidation of the biofuel market. Exploratory research was carried out to identify these viable alternatives for the use of this by-product. The possibilities include the production of chemical products, fuel additives, production of hydrogen, development of fuel cells, ethanol or methanol production, animal feed, co-digestion and co-gasification, and waste treatment among others. The present research reveals that there are promising possibilities for the use of unrefined glycerol, which may help consolidate the sustainability of the biofuel market. (C) 2012 Elsevier Ltd. All rights reserved.

Different herbage allowances and milk yield in crossbred Holstein x Gir

The objective of this study was to evaluate different herbage allowances in stargrass (Cynodon nlemfuensis Vanderyst var. nlemfuensis), on the herbage disappearance rate (HDR) and milk yield in crossbred Holstein x Gir cows. Thirty animals were assigned to three different herbage allowances (HA), ranging from 10.0, 12.5 and 15.0% BW. There was effect of HA on the HDR ( P<0.001). Increasing the HA in one unit had effect on the HDR increasing by 140.0kg ha(-1) day(-1). There was effect of leaf: stem ratio on milk yield (P<0.05). The increasing in supplying herbage allowances did not resulted in increased milk yield because the management for herbage allowance and herbage growth.

Validation of models for predicting milk urea nitrogen concentrations, estimating dry matter intake by the NRC (2001)

The objective of this study was to validate three different models for predicting milk urea nitrogen using field conditions, attempting to evaluate the nutritional adequacy diets for dairy cows and prediction of nitrogen excreted to the environment. Observations (4,749) from 855 cows were used. Milk yield, body weight (BW), days in milk and parity were recorded on the milk sampling days. Milk was sampled monthly, for analysis of milk urea nitrogen (MUN), fat, protein, lactose and total solids concentration and somatic cells count. Individual dry matter intake was estimated using the NRC (2001). The three models studied were derived from a first one to predict urinary nitrogen (UN). Model 1 was MUN = UN/12.54, model 2 was MUN = UN/17.6 and model 3 was MUN = UN/(0.0259 × BW), adjusted by body weight effect. To evaluate models, they were tested for accuracy, precision and robustness. Despite being more accurate (mean bias = 0.94 mg/dL), model 2 was less precise (residual error = 4.50 mg/dL) than model 3 (mean bias = 1.41 and residual error = 4.11 mg/dL), while model 1 was the least accurate (mean bias = 6.94 mg/dL) and the least precise (residual error = 5.40 mg/dL). They were not robust, because they were influenced by almost all the variables studied. The three models for predicting milk urea nitrogen were different with respect to accuracy, precision and robustness.

Condição corporal ao parto e produção de leite sobre o desempenho reprodutivo de vacas holandesas em lactação

O objetivo, neste estudo, foi avaliar os efeitos da condição corporal ao parto e da mudança de condição corporal sobre o desempenho reprodutivo de vacas leiteiras após o parto. Para tanto, 51 vacas holandesas, de 30 dias pré-parto até 150 dias após o parto, foram distribuídas aleatoriamente de acordo com a condição corporal ao parto nas classes 1 (condição corporal maior ou igual a 3,25) e 2 (condição corporal menor ou igual a 3,0). Dentro das classes de condição corporal ao parto, os animais foram distribuídos quanto à mudança de condição corporal (Categoria 1, igual ou menor que -0,50 e Categoria 2, igual ou maior que -0,75) e à média da produção de leite ajustada para 3,5% aos 150 dias (Grupo 1 = 22,61 e Grupo 2 = 31,65 kg/dia). Não houve diferenças da condição corporal ao parto e da produção de leite ajustada para 3,5% sobre o intervalo parto primeiro estro, intervalo parto primeiro serviço, período de serviço, número de serviço / concepção e taxa de gestação aos 150 dias de lactação. Vacas que ao parto apresentaram média de escore de condição corporal de 3,40 e 2,79 tiveram semelhante desempenho reprodutivo pósparto. Em relação à produção de leite ajustada para 3,5%, vacas com produção média de 22,61 e 31,65 apresentaram similares resultados. A mudança de condição corporal não influenciou o intervalo parto primeiro serviço, o período de serviço e o número de serviço por concepção, mas apresentaram maior intervalo parto primeiro estro e menor taxa de gestação

Hair: a tool to evaluate the HPA axis activity

Hair cortisol is a novel marker to measure long-term secretion cortisol free from many methodological caveats associated with other matrices such as plasma, saliva, urine, milk and faeces. For decades hair analysis has been successfully used in forensic science and toxicology to evaluate the exposure to exogenous substances and assess endogenous steroid hormones. Evaluation of cortisol in hair matrix began about a decade ago and have over the past five years had a remarkable development by advancing knowledge and affirming this method as a new and efficient way to study the hypothalamic-pituitary-adrenal (HPA) axis activity over a long time period. In farm animals, certain environmental or management conditions can potentially activate the HPA axis. Given the importance of cortisol in monitoring the HPA axis activity, a first approach has involved the study on the distribution of hair cortisol concentrations (HCC) in healthy dairy cows showing a physiological range of variation of this hormone. Moreover, HCC have been significantly influenced also by changes in environmental conditions and a significant positive correlation was detected between HCC and cows clinically or physiologically compromised suggesting that these cows were subjected to repeated HPA axis activation. Additionally, Crossbreed F1 heifers showed significantly lower HCC compared to pure animals and a breed influence has been seen also on the HPA axis activity stimulated by an environmental change showing thus a higher level of resilience and a better adaptability to the environment of certain genotypes. Hair proved to be an excellent matrix also in the study of the activation of the HPA axis during the perinatal period. The use of hair analysis in research holds great promise to significantly enhance current understanding on the role of HPA axis over a long period of time.

Tenovaginoscopic approach to the common digital flexor tendon sheath of adult cattle: technique, normal findings and preliminary results in four clinical cases

The aim of this study was to describe the tenovaginoscopic approach to the bovine common digital flexor tendon sheath (CDFTS). A comparative anatomical, ultrasonographic and endoscopic study was undertaken using 26 healthy cadaver feet from adult dairy cows. Tenovaginoscopy was performed using a rigid, 30 degrees arthroscope (length 18 cm; outer diameter 4mm) enabling a direct view of the synovial cavity and the following structures: digital flexor tendons, digital annular ligaments, lateral and medial pouches, three mesotendons, the vinculum of the superficial digital flexor tendon, and a slot-shaped opening in the manicaflexoria of the hind feet. Additionally, four clinical cases of septic tenosynovitis treated with lavage under tenovaginoscopic control were examined. Tenovaginoscopy represents a feasible, minimally invasive method for the diagnosis and treatment of septic tenosynovitis of the CDFTS, which allows the degree of alterations of the normal structures to be evaluated.

Plasma leptin and mRNA expression of lipogenesis and lipolysis-related factors in bovine adipose tissue around parturition

The objective was to study changes in plasma leptin concentration parallel to changes in the gene expression of lipogenic- and lipolytic-related genes in adipose tissue of dairy cows around parturition. Subcutaneous fat biopsies were taken from 27 dairy cows in week 8 antepartum (a.p.), on day 1 postpartum (p.p.) and in week 5 p.p. Blood samples were assayed for concentrations of leptin and non-esterified fatty acids (NEFA). Subcutaneous adipose tissue was analysed for mRNA abundance by real-time qRT-PCR encoding for leptin, adiponectin receptor 1 (AdipoR1), adiponectin receptor 2 (AdipoR2), hormones-sensitive lipase (HSL), perilipin (PLIN), lipoprotein lipase (LPL), acyl-CoA synthase long-chain family member 1 (ACSL1), acetyl-CoA carboxylase (ACC), fatty acid synthase (FASN) and glycerol-3-phosphate dehydrogenase 2 (GPD2). Body weight and body condition score of the cows were lower after parturition than before parturition. The calculated energy balance was negative in week 1 and 5 p.p., with higher negative energy balance in week 1 p.p. compared with that in week 5 p.p. On day 1 p.p., highest concentrations of NEFA (353.3 mumol/l) were detected compared with the other biopsy time-points (210.6 and 107.7 mumol/l, in week 8 a.p., and week 5 p.p. respectively). Reduced plasma concentrations of leptin during p.p. when compared with a.p. would favour increasing metabolic efficiency and energy conservation for mammary function and reconstitution of body reserves. Lower mRNA abundance of ACC and FASN expression on day 1 p.p. compared with other biopsy time-points suggests an attenuation of fatty acid synthesis in subcutaneous adipose tissue shortly after parturition. Gene expression of AdipoR1, AdipoR2, HSL, PLIN, LPL, ACSL1 and GPD2 was unchanged over time.

Lipopolysaccharide and lipoteichoic acid induce different immune responses in the bovine mammary gland

Different pathogens, such as Escherichia coli and Staphylococcus aureus, can be responsible for different outcomes of mastitis; that is, acute and severe or chronic and subclinical. These differences in the disease could be related to different mammary responses to the pathogens. The objective of this study was to determine if intramammary challenge with the endotoxins lipopolysaccharide (LPS), from E. coli, and lipoteichoic acid (LTA), from Staph. aureus, induce different immune responses in vivo in milk cells and mammary tissue. To provide a reference level for comparing the challenge and to show the different stimulation of the mammary immune system on a quantitatively similar level, dosages of LPS and LTA were chosen that induced an increase of somatic cells in milk to similar maxima. One udder quarter in each of 21 lactating dairy cows was challenged with 0.2 mug of LPS or 20 mug of LTA. From these quarters and from respective control quarters, milk cells or tissue biopsies were obtained at 0, 6, and 12h relative to the challenge to measure mRNA expression of tumor necrosis factor-alpha (TNFalpha), IL-1beta, IL-8, lactoferrin, and RANTES (regulated upon activation, normal T-cell expressed and secreted). Furthermore, if no biopsies were performed, hourly milk samples were taken for measurement of somatic cell count, lactate dehydrogenase (LDH), and TNFalpha. Somatic cell count increased in all treatments to similar maxima with LPS and LTA treatments. Concentrations of TNFalpha in milk increased with LPS but not with LTA. The activity of LDH in milk increased in both treatments and was more pronounced with LPS than with LTA. The mRNA expression of TNFalpha, IL-1beta, IL-8, and RANTES showed increases in milk cells, and LPS was a stronger inducer than LTA. Lactoferrin mRNA expression decreased in milk cells with LPS and LTA treatments. The measured factors did not change in either treatment in mammary tissue. Challenge of udder quarters with dosages of LPS and LTA that induce similar increases in SCC stimulate the appearance of different immune factor patterns. This dissimilar response to LPS and LTA may partly explain the different course and intensity of mastitis after infection with E. coli and Staph. aureus, respectively.

[Rumenocentesis: a suitable technique for analysis of rumen juice pH in cattle?]

In the United States, rumenocentesis has been recommended especially for early diagnosis of subacute rumen acidosis (SARA). The objective of the current study was to evaluate health risks due to the technique ofrumenocentesis and to measure pH in ruminal juice using a commercial indicator paper (Pehanon) and a pH electrode (reference method). After 11 dairy cows underwent rumenocentesis, the clinical status of those animals was evaluated daily, and cows were slaughtered as well as pathologically--anatomically examined on day 7. During the observation period, the following pathological clinical signs were evident: forced inspiration (3 cows), transient episode of hyperthermia (2 cows), increased tension of the abdominal wall (8 cows) and positive foreign body tests (3 cows). One cow had to be culled on day 7 because of severe generalised septic peritonitis spreading from the site of rumenocentesis. At slaughter, hematoma formation in the area of the puncture site was found in 9 out of 10 cows. It was concluded that the severe complications encountered with this technique do not legitimate rumenocentesis as a routine procedure for collection of rumen juice samples in cows under Swiss conditions. The correlation between the pH reference method and the commercial indicator paper was the high (r = 0.926).

Differential expression of ABC transporters and their regulatory genes during lactation and dry period in bovine mammary tissue

ATP-binding cassette (ABC) transporters play a pivotal role in human physiology, and mutations in these genes often result in severe hereditary diseases. ABC transporters are expressed in the bovine mammary gland but their physiological role in this organ remains elusive. Based on findings in the context of human disorders we speculated that candidate ABC transporters are implicated in lipid and cholesterol transport in the mammary gland. Therefore we investigated the expression pattern of selected genes that are associated with sterol transport in lactating and nonlactating mammary glands of dairy cows. mRNA levels from mammary gland biopsies taken during lactation and in the first and second week of the dry period were analysed using quantitative PCR. Five ABC transporter genes, namely ABCA1, ABCA7, ABCG1, ABCG2 and ABCG5, their regulating genes LXRalpha, PPARgamma, SREBP1 and the milk proteins lactoferrin and alpha-lactalbumin were assessed. A significantly enhanced expression in the dry period was observed for ABCA1 while a significant decrease of expression in this period was detected for ABCA7, ABCG2, SREBP1 and alpha-lactalbumin. ABCG1, ABCG5, LXRalpha, PPARgamma and lactoferrin expression was not altered between lactation and dry period. These results indicate that candidate ABC transporters involved in lipid and cholesterol transport show differential mRNA expression between lactation and the dry period. This may be due to physiological changes in the mammary gland such as immigration of macrophages or the accumulation of fat due to the loss of liquid in the involuting mammary gland. The current mRNA expression analysis of transporters in the mammary gland is the prerequisite for elucidating novel molecular mechanisms underlying cholesterol and lipid transfer into milk.

Differential expression and localization of lipid transporters in the bovine mammary gland during the pregnancy-lactation cycle

The transport of lipids across mammary gland epithelial cells (MEC) determines milk lipid content and composition. We investigated the expression of lipid transporters and their regulators in comparison to blood metabolites during lactation and dry period (DP) in dairy cows. Repeated mammary gland biopsies and blood samples were taken from 10 animals at 7 stages of the pregnancy-lactation cycle. Expression levels of the specific mRNAs were determined by quantitative reverse transcription-PCR, whereas ABCA1 was localized by immunohistochemistry. Blood serum metabolites were determined by common enzymatic chemistries. Elevated mRNA profiles of ABCA1 and ABCA7 were found during DP as compared with lactation and were inversely associated with blood cholesterol levels. Elevated levels of ABCG2, NPC1, SREBP1, SREBP2, LXR alpha, and PPAR gamma were found postpartum, whereas ABCG1 did not differ between the functional stages of the mammary gland. The ABCA1 protein was localized in MEC and showed differential activity between DP and lactation suggesting a role of ABCA1 in the removal of excess cellular cholesterol from MEC during the DP. The expression profiles of ABCA7 and NPC1 may reflect a role of these transporters in the clearance of apoptotic cells and the intracellular redistribution of cholesterol, respectively. Regulation of lipid transporters in the mammary gland is partially associated with transcription factors that control lipid homeostasis.