Hasil untuk "Cattle"

Zenon Nogalski, Martyna Momot

The quality of beef fat depends on both intramuscular fat (IMF) content and fatty acid (FA) composition, which can be modulated by finishing diets. This study evaluated the effects of silage type and feeding intensity on IMF deposition, FA profile, desaturase indices, and lipid quality indices in finishing Holstein–Friesian bulls. Thirty-two bulls were assigned to a 2 × 2 factorial design (n = 8/group) and fed total mixed rations for 120 days based on grass silage or maize silage, under intensive (≈50:50 forage:concentrate, DM basis) or semi-intensive feeding (≈70:30). FA composition of <i>longissimus lumborum</i> lipids was determined by GC-FID, and lipid quality indices were calculated, including the atherogenic index (AI), thrombogenic index (TI), and the hypocholesterolemic/hypercholesterolemic ratio (h/H). Feeding intensity increased IMF content (<i>p</i> = 0.001) and the absolute amounts of major FA classes (g/100 g meat). Silage type primarily affected FA composition by increasing n-3 PUFA and lowering the n-6/n-3 ratio in grass silage diets (<i>p</i> = 0.042). Several FAs showed silage type × feeding intensity interactions (<i>p</i> < 0.05), indicating that the response to dietary energy supply depended on the forage base. Overall, feeding intensity mainly regulated lipid deposition, whereas silage type modulated the nutritional profile of intramuscular fat.

İbrahim Cihangir Okuyucu, Ahmet Akdağ, Hüseyin Erdem

Confinement-based intensive production of water buffalo (Bubalus bubalis) raises challenges for sustainable milk production, milk quality and consumer apprehensions about animal welfare and food safety. Despite the fact that the reactivity of buffaloes to machine milking constitutes a new scientific field, it is a new phenomenon that is the subject of current debate. This review aims to provide a comprehensive understanding of water buffalo cow behaviour and physiological responses that are relevant to optimizing milking management and animal welfare in these systems. It focuses on the relationships between udder characteristics, milking temperament, human-animal interactions, and management strategies. Our literature review suggests that: i) species-specific milking techniques are essential due to udder differences between buffaloes and cattle, ii) minimizing stress optimizes milk ejection and yield, iii) gentle handling improves buffalo welfare, and iv) a holistic approach integrating udder physiology, behaviour, and management is crucial for sustainable production.

Le Van Trong, Ha Thi Phuong, Le Thi Huyen

The ability to accurately identify key growth stages is critical for proper rice management, Since management practices are directly tied to plant developmental processes, a sound understanding of rice growth is essential for effective cultivation. This study was conducted to evaluate the growth and yield performance of seven rice varieties (BT, CUDH1, NU986, ST25, TBR225, TX111, and VNR20) during different growth stages (Root establishment and Greening up,Tillering, Panicle initiation, Flowering, and Dough stage) in Thanh Hoa province, Vietnam. Results indicated that CUDH1 and TX111 exhibited superior performance, with greater plant height, higher leaf area index (LAI) throughout most growth stages, and enhanced dry matter accumulation. These characteristics reflect strong photosynthetic capacity and robust growth potential, ultimately leading to the highest recorded yields: CUDH1 (8.25 t ha-1) and TX111 (8.02 t ha-1). The NU986 (7.73 t ha-1) and BT (7.32 t ha-1) also achieved relatively good yields, though improvements in cultivation techniques are recommended to fully exploit their potential. Conversely, ST25 (6.97 t ha-¹), VNR20 (7.05 t ha-¹), and TBR225 (7.18 t ha-¹) exhibited lower plant height and dry matter accumulation, thus making them more suitable for high-quality rice production or areas prone to lodging. the conclusion, varietal selection tailored to specific production goals and local ecological conditions is a critical factor in improving the efficiency and sustainability of rice production systems.

S. Wagura Ndiritu, Castro Ngumbu Gichuki

Pastoralist households in Kenya’s arid and semi-arid lands (ASALs) rely heavily on livestock trade for livelihoods and income. Between 2021 and 2023, the region experienced its worst drought in four decades, marked by six consecutive failed rainy seasons. This study investigates the factors influencing pastoralists’ choice of livestock market channels during this period, focusing on the effects of drought, conflict, and livestock production systems. It also examines how different sources of livestock market information shape trading decisions. Data were collected from 1,053 households using a multistage sampling approach. Analytical methods included Multivariate Probit (MVP) regression and Classification and Regression Tree (CART) analysis. Findings reveal that informal networks, especially neighbours and family, were the most influential sources of market information. In contrast, formal channels such as mobile phone calls and radio had limited impact. Households affected by drought were more likely to sell steers through butcher outlets, reflecting urgent liquidity needs. Conflict significantly reduced participation in local markets, highlighting how insecurity limits access. Across all livestock types, namely steers, heifers, bulls, cows, sheep, and goats, pastoralists engaged in multi-channel marketing strategies shaped by herd size, household demographics, and external shocks. These results underscore the need to strengthen both traditional and digital market information systems that provide timely, localized livestock market intelligence. Supporting livestock marketing cooperatives and Common Interest Groups (CIGs) is also vital to improving coordination and bargaining power. Such interventions are essential for enhancing resilience, market participation, and economic inclusion in Kenya’s drought-prone pastoralist areas.

Francisca O. Eichie, Godstime Taiwo, Modoluwamu Idowu et al.

The study aimed to investigate the impact of Bovine Respiratory Disease (BRD) on the metabolism of beef steers during a 35-d receiving period using plasma metabolomics. In this study, 77 newly weaned crossbred (Angus × Hereford) beef steers (BW = 206 ± 12 kg and age = 180 ± 17 days) were categorized into two groups: Healthy and Sick groups. The Sick group comprised beef steers diagnosed with BRD at any time during the 35-day period (n = 31), while the Healthy group did not show any signs of BRD (n = 46). Blood samples were collected from the coccygeal vessels on day 35, and plasma samples were subjected to targeted metabolomics analysis using Nuclear Magnetic Resonance spectroscopy. Data and statistical analyses, including biomarker and pathway enrichment analyses, were performed using Metaboanalyst 5.0. Results of the growth performance showed that sick steers had lower (p ≤ 0.05) ADG (1.44 vs. 1.64 kg/d) and higher (p = 0.01) feed:gain ratio (3.57 vs. 3.13) compared to healthy steers. A total of 50 metabolites were quantified. The partial least squares discriminant scores plot showed a slight separation between the two groups of steers, indicating some metabolic differences. Furthermore, the plasma concentrations of four metabolites (sarcosine, methionine, dimethyl sulfone, and L-histidine) were greater (p ≤ 0.05) in healthy steers compared to sick steers. Among these metabolites, sarcosine and methionine qualified as candidate biomarkers associated with BRD infection based on an area under the curve &gt;0.70. Additionally, quantitative enrichment analysis revealed that cysteine and methionine metabolism was enriched in healthy steers compared to sick steers. This suggests that these metabolic pathways may play a role in the response to BRD infection. The findings of this study highlight the altered plasma metabolome in steers with BRD during the receiving period. Understanding these metabolic changes can contribute to the development of effective management strategies and nutritional interventions to mitigate the negative impact of BRD on beef cattle health and immune function.

sevil gürbilek, oktay keskin, osman tel

In this study, a Brucella antigen-capture ELISA (Ag-cELISA) prototype was developed. To study the validity of the developed Ag-cELISA, milk samples collected from Brucella-positive goats (n=120) and cattle (n= 64), as well as from unknown Brucella-status cattle (n=105) and sheep (n=65) herds were tested by Ag-cELISA, I-ELISA, and culture method. All Brucella-positive samples were confirmed using PCR. It was found that the developed Ag-cELISA could detect 50-100 bacteria per well (equivalent to 103 to 2×103 cells per mL) as the lowest limit of detection (LOD) and was therefore considered moderately sensitive to detect brucellae in milk. In an infected goat herd, out of 120 milk samples, 41, 32, and 17 were positive by Ag-cELISA, I-ELISA, and culture, respectively. Ag-cELISA detected 15 positive cases out of 17 culture-positive milk samples. Two culture-positive milk samples were not detected in Ag-cELISA. The relative sensitivity and specificity between Ag-cELISA and I-ELISA were 78% and 100%, respectively. In an infected cow herd, out of 64 milk samples, 32, 23, and 11 were found positive by Ag-cELISA, I-ELISA, and culture, respectively. Ten out of 11 culturally positive milk samples were found positive by Ag-cELISA. The relative sensitivity and specificity between the Ag-cELISA and I-ELISA were 71.9% and 100%, respectively. From randomly collected 105 cow and 110 sheep milk samples from herds of unknown Brucella-infection status, three (2.85%) and five (4.5%) samples were found positive using Ag-cELISA, respectively. These results showed that Ag-cELISA could be used to detect brucellae in milk more practically and safely than bacterial culture. On the other hand, this information re-affirms that milk can be an important source of brucellosis and creates a public health risk in humans; therefore, increased public awareness is of utmost importance

Biruk Alemu Gemeda, Barbara Wieland, Gezahegn Alemayehu et al.

The objective of this study was to characterize the distribution of antimicrobial resistance (AMR) of <i>Escherichia coli</i> (<i>E. coli</i>) isolated from livestock feces and soil in smallholder livestock systems. A cross-sectional study was carried out sampling 77 randomly selected households in four districts representing two agroecologies and production systems. <i>E. coli</i> was isolated and the susceptibility to 15 antimicrobials was assessed. Of 462 <i>E. coli</i> isolates tested, resistance to at least one antimicrobial was detected in 52% (43.7–60.8) of isolates from cattle fecal samples, 34% (95% CI, 26.2–41.8) from sheep samples, 58% (95% CI, 47.9–68.2) from goat samples and 53% (95% CI, 43.2–62.4) from soil samples. AMR patterns for <i>E. coli</i> from livestock and soil showed some similarities, with the highest prevalence of resistance detected against streptomycin (33%), followed by amoxycillin/clavulanate (23%) and tetracycline (8%). The odds of detecting <i>E. coli</i> resistance to ≥2 antimicrobials in livestock fecal samples were nearly three times (Odd Ratio—OR: 2.9; 95% CI, 1.72–5.17; <i>p</i> = 0.000) higher in lowland pastoral than in highland mixed crop–livestock production systems. These findings provide insights into the status of resistance in livestock and soil, and associated risk factors in low-resource settings in Ethiopia.

Jinghang Zhou, Jinghang Zhou, Liyuan Liu et al.

Copy number variants (CNVs), which are a class of structural variant, can be important in relating genomic variation to phenotype. The primary aims of this study were to discover the common CNV regions (CNVRs) in the dual-purpose XinJiang-Brown cattle population and to detect differences between CNVs inferred using the ARS-UCD 1.2 (ARS) or the UMD 3.1 (UMD) genome assemblies based on the 150K SNP (Single Nucleotide Polymorphisms) Chip. PennCNV and CNVPartition methods were applied to calculate the deviation of the standardized signal intensity of SNPs markers to detect CNV status. Following the discovery of CNVs, we used the R package HandyCNV to generate and visualize CNVRs, compare CNVs and CNVRs between genome assemblies, and identify consensus genes using annotation resources. We identified 38 consensus CNVRs using the ARS assembly with 1.95% whole genome coverage, and 33 consensus CNVRs using the UMD assembly with 1.46% whole genome coverage using PennCNV and CNVPartition. We identified 37 genes that intersected 13 common CNVs (&gt;5% frequency), these included functionally interesting genes such as GBP4 for which an increased copy number has been negatively associated with cattle stature, and the BoLA gene family which has been linked to the immune response and adaption of cattle. The ARS map file of the GGP Bovine 150K Bead Chip maps the genomic position of more SNPs with increased accuracy compared to the UMD map file. Comparison of the CNVRs identified between the two reference assemblies suggests the newly released ARS reference assembly is better for CNV detection. In spite of this, different CNV detection methods can complement each other to generate a larger number of CNVRs than using a single approach and can highlight more genes of interest.

E.I. Shornikov

Background. As it turns out it’s not an easy task to promote the concept of “Peasant revolution in Russia, 1902–1922” in order it could gain a worthy place in the Rus-sian literature on agrarian history. Meanwhile, this theoretical approach has a great explana-tory power being applied to most important political events in Russia of that historical pe-riod. The purpose of the article is to confirm this ability by analyzing the social conflict that occurred in Tambov province at the initial stage of the Revolution. Materials and methods. The article draws the attention of historians to the works of the researchers which delibe-rately and purposely apply the methodology of Peasant Studies when observing social con-flicts at the initial and subsequent stages of the peasant revolution in Russia. The analysis of the conflict between peasants and landlords recorded in the collection of documents of peasant movement in Russia 1901–1904 is presented in the frames of this methodology: from the point of view of peasants themselves and their traditional understanding of justice and truth. Results. It is argued that the primary cause of the peasant unrest was not the class struggle of peasants against landlords, but the struggle of the communities against the evo-lution of many landlords towards compliance with formal legislation and submission to market laws and regularities. The peasants did not just defend the right to graze their cattle on the land of the landowner or to use the forest which the both parties considered to be theirs. They struggled for preserving the old order, for the primacy of customary law over official law. Conclusions. The reasons for the riots which tended to turn into real terror, at least if we talk about the events of the very beginning of the twentieth century, should be sought in the field of the conflict between “formal” law, written legislation of the post-reform period, and customary law of the peasants, their “moral economy” and “subsistence ethics”.

Israel García-Cano, Po-Wei Yeh, Diana Rocha-Mendoza et al.

β-Lactoglobulin (β-LG) is believed to be a common allergen in bovine milk. Buttermilk (BM) powder has abundant contents of milk fat globule membrane and phospholipid, both of which have been demonstrated to have positive effects on brain and cognitive development during early infancy. This study focused on modifying β-LG in BM via supercritical CO2 (ScCO2) treatment to modify its reactivity to antibodies and thus reduce its antigenicity. Buttermilk powder was treated in a supercritical fluid extraction system with food-grade CO2 at 100, 150, 200, 250, 350, and 400 bar at 2 temperatures, 50 and 75°C. All analyses were completed in a 10% BM suspension (wt/vol). The BM proteins were examined using sodium dodecyl sulfate (SDS)-PAGE, Western blot, ELISA, and periodic acid staining methods. Semi-purified β-LG was used to evaluate the cytotoxicity, viability, and inflammatory response in the Caco-2 cell line by means of the lactate dehydrogenase assay, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium] assay, and IL-8 production, respectively. The SDS-PAGE showed that the signal intensity of β-LG bands was reduced by up to 50% after being processed at 250 bar and 75°C for 30 min. Lighter and more diffuse signals were found by Western blot, indicating modification of the protein structure. The ELISA demonstrated that ScCO2 treatment could significantly change β-LG antigenicity in BM. Sugar moieties in bands corresponding to β-LG were revealed by periodic acid staining, indicating glycosylation only in samples treated with ScCO2. Caco-2 cells treated with whey proteins had high viability, 24.9% lower inflammation, and no evidence of cytotoxicity compared with untreated cultures. These results showed that reduced antigenicity of β-LG was caused by lactosylation, which has been reported as a possible pathway to reduce the allergenicity in foods. The denaturation of β-LG by supercritical fluid processing is a promising way to address milk allergy, which remains a problem requiring more attention and further research.

Tandiwe Katswara, Samson Mukaratirwa

Abstract Background African tick bite fever (ATBF) caused by Rickettsia africae and transmitted by Amblyomma spp. ticks is one of the zoonotic tick-borne fevers from the spotted fever group (SFG) of rickettsiae, which is an emerging global health concern. There is paucity of information regarding the occurrence and awareness of the disease in endemic rural livestock farming communities living in livestock-wildlife interface areas in South Africa. Methods The purpose of the study was to assess the level of knowledge, attitudes and practices on ticks and ATBF infection from a community living in livestock-wildlife interface areas in South Africa. A focus group discussion (FGD) was carried out followed by verbal administration of a standardized semi-structured questionnaire a month later to 38 rural livestock farmers (23 from Caquba area and 15 from Lucingweni area where A. hebraeum was absent). An FGD was conducted in Caquba (situated at the livestock-wildlife interface where Amblyomma hebraeum was prevalent on cattle and infected with Rickettsia africae) in the O.R. Tambo district of the Eastern Cape province of South Africa. Results Results from the FGD and questionnaire survey showed that participants from the two rural communities were not aware of ATBF and were not aware that ticks are vectors of the disease. Respondents from Caquba reported of having frequent exposure to tick bites (91.3%, 21/23) specifically from the anthropophilic A. hebrauem which they were able to identify as Qwelagqibe in IsiXhosa (their vernacular). Thirteen out of 15 (86.7%) of respondents from Lucingweni reported that they had never been bitten by ticks, which corresponded with the absence of A. hebraeum from their locality as evidenced from results of a concurrent study on prevalence of ticks on livestock in the area. Both communities confirmed to being “very concerned” of tick bites and we presume this was more related to the localized wounds from the bites than to the diseases transmitted by the ticks. Conclusions We recommend future studies encompassing seroprevalence of ATBF in Caquba and other communities at risk in South Africa including establishing surveillance systems to monitor the seasonal infection rates in ticks, cattle and humans.

Md Rezanur Rahaman, Helen Marshall, Adriana Milazzo et al.

Background: Livestock farmers are at risk of Q fever, a zoonotic disease transmitted to humans from animals such as cattle, sheep and goats. Australia bears substantial Q fever burden, particularly among farmers. A One Health approach engages cross-sectoral collaboration among animal, human and environmental health and is the preferred framework for Q fever prevention. Methods: Cattle, sheep and goat farmers were invited to participate in an online survey in 2019 to gauge perceptions about Q fever and its prevention. Participants were recruited via membership newsletters and social media. Descriptive analyses and logistic regressions were performed. Results: A total of 351 farmers completed the survey. Most respondents (80%) had been farming for ≥20 years, with sheep and beef cattle their primary stock. 71% reported knowledge of Q fever, and 85% identified transmission through contaminated dust inhalation was highly likely. The majority of respondents (97%) were aware of Q fever vaccine, and 95% agreed it was effective in preventing disease, yet 42% remained unvaccinated. Reported barriers to vaccination included poor access to a trained doctor and time and cost related to vaccination. Most farmers (≥91%) believed that subsidized vaccination and improved awareness would promote higher uptake. Conclusion: While Q fever knowledge among respondents was good, their practices related to airborne transmission prevention were poor. Livestock farmers would benefit from adherence to dust and aerosol transmission prevention practices. One Health partnership between government and industry is needed to promote Q fever awareness and address low vaccination rates among livestock farmers by funding vaccination programs.

Mohammadi Mahdieh, Harth Kirsten, Puzyrev Dmitry et al.

Passages of people or cattle through narrow entrances or exits occur in manifold situations. They are difficult to study experimentally, because one has to carefully separate objective, physical parameters from subjective, individual motivations, manners and temperament. Mechanically excited physical model systems can help to discriminate some of these classes of parameters. We characterize active and passive particles of equal shape and mass on a vibrating plate and study their bottleneck passage dynamics. They show fundamentally different scaling behavior.

João P. S. Roseira, Rasmo Garcia, Tâmara C. da-Silveira et al.

Background: Coffee hulls obtained from dry processing, have the potential to be used in ruminant diets. Objective: To evaluate the chemical composition and in situ degradability of dry matter (DM) and neutral detergent fiber (NDF) of coffee hulls treated with calcium oxide (CaO) in different environmental conditions (EC). Methods: Coffee hulls were subjected to treatments distributed in a 2 × 2 factorial arrangement, consisting of two levels of CaO (0 and 5%, on a DM basis) and two environmental conditions (aerobiosis and anaerobiosis) in a completely randomized design with four replicates, totaling sixteen experimental units. Five-gram samples were incubated in the rumen of two male cattle for 0, 3, 6, 9, 12, 24, 48, 72, 96, and 120 h. Results: Regarding dry matter degradation kinetic parameters, except for fraction b, the potential and effective degradability was affected (p<0.05) by a CaO × EC interaction. As for estimated fiber degradation parameters, the potentially degradable fraction b was affected (p<0.05) by CaO and EC. Treatment with CaO increased fraction b in 4.08 percentage points. Conclusions: The use of CaO in the treatment of coffee hulls increases the effective and potential degradability of DM and reduces the undegradable fiber fraction. Anaerobic condition is the best environment for the treatment of coffee hulls with CaO.

Juan Carlos Pinilla León, Natalia Da Silva Borges

Cystoisospora suis en un protozoario de distribución mundial que puede provocar pérdidas económicas significantes debido a que ocasiona diarrea y deshidratación en lechones lactantes. Entre septiembre 2015 y agosto 2016, se condujo una investigación con la finalidad de determinar aspectos de la dinámica de infección por Cystoisospora suis en lechones lactantes de una granja piloto ubicada en la parroquia Güigue, municipio Carlos Arvelo, estado Carabobo, Venezuela. Para la determinación parasitaria se colectaron 480 muestras fecales de camadas (cuarenta muestras mensuales) y se aplicó una encuesta epidemiológica en cada muestreo. Todas las muestras se cultivaron en dicromato de potasio al 2,5% y posteriormente fueron procesadas con una técnica de flotación-centrifugación, utilizando una solución saturada de NaCl enriquecida con solución azucarada (1 L de solución saturada de NaCl + 500 g de azúcar). Los resultados señalan que C. suis se encontró presente durante todo el período de estudio con 52,08% de prevalencia, y sus mayores valores en lechones con dos semanas de vida. Con respecto al mes de muestreo, no se encontró significancia estadística (P> 0,05) entre las constantes meteorológicas y la prevalencia por C. suis, lo que podría indicar que estas variables ambientales no tuvieron efecto sobre la presencia del protozoario. Con respecto a la encuesta, se encontró correlación estadísticamente significativa (P< 0,05) entre la prevalencia y la presencia veterinaria, protocolo N° 3 y empleo de Baycox al 5%. Se concluye que C. suis estuvo presente durante el periodo de estudio, y sus mayores valores de prevalencia fueron obtenidos en lechones con dos semanas de vida, no encontrándose significancia estadística entre las constantes meteorológicas y la prevalencia de C. suis, lo que podría indicar que las condiciones meteorológicas registradas durante el periodo estudiado, fueron óptimas para que ocurriese el proceso de esporulación, y por tanto, mantener viables ooquistes durante todo el año.

Leandro Nahuel Fariña, Leonel Andrés Lugano, María José Pérez et al.

RESUMEN   En los actuales sistemas de producción porcina, la tasa de reposición de hembras es elevada. Conocer el momento óptimo del servicio es importante, permite un uso eficiente de las instalaciones. Existen en el mercado fármacos para sincronizar el celo. Altrenogest es un progestágeno similar a la progesterona natural (PN), su administración suprime el ciclo estral y la supresión del tratamiento produce un agrupamiento de los celos entre 4 a 10 días (d) posteriores a la última dosis. En el presente trabajo se propuso: evaluar la eficacia en la concentración de celo de animales tratados con Altrenogest versus un grupo Control. Se utilizaron sesenta cerdas nulíparas semejantes, de 120-130 kg y con un celo previo, agrupadas de a pares y asignadas al azar a un grupo tratado con Altrenogest y a uno Control. Se detectó celo una vez al d en presencia de cerdo macho sin castrar, durante 28 d a partir del inicio del tratamiento. Se consideró exitoso las hembras que entraron en celo entre los d 19-24 pos inicio del tratamiento (dPIT). Los datos obtenidos se analizaron por el test de McNemar que mide el número de divergencias entre las parejas. En 15 parejas (15/30) solo las cerdas tratadas presentaron celo entre los d 19 al 24 dPIT. En 13 (13/30) las control y las tratadas lo presentaron en el mismo dPIT. Solo 2 parejas (2/30) de las no tratadas presentaron celo en ese dPIT. (P= 0,0003). El tratamiento con Altrenoget demostró ser efectivo para la presentación de celo en el periodo deseado. Las cerdas tratadas de este ensayo tuvieron una probabilidad siete veces mayor de concentrar el servicio que los controles no tratados.   ABSTRACT   In the current systems of pig production, the rate of replacement of females is high. It is important to know the optimal time of service to allow efficient use of the facilities in the farm. In the market exist drugs to synchronize estrus in pigs. Altrenogest is a progestagen similar to natural progesterone (PN), its administration deletes the estrus cycle and the removal of the treatment produces a clustering of heats between 4 to 10 days (d) after the last dose. In the present study it was proposed: assess the efficacy in the concentration of estrous of gilts treated with Altrenogest versus a Control Group. Sixty gilts of 120-130 kg, with a previous estrus, grouped of pairs were assigned randomly to a group treated with Altrenogest and a control. Estrus was detected once a d, in the presence of boar, for 28 d from the start of the treatment (dPT). It was considered a success if the animal get into heat between the d 19-24 dPT. The results were analyzed by the McNemar test that measures the number of divergences between couples. Fifteen (15/30) couples treated sows presented heat among the 19 d to 24 dPT. In 13 (13/30) the control and the treated presented estrus it in the same dPT. Only 2 pairs (2/30) of the untreated showed heat in that dPT. (P = 0.0003). Altrenogest treatment shows to be effective for the presentation of estrus in the desired period. Gilts treated in this trial were seven times more likely to concentrate the service than untreated controls.

Andreas Foskolos, Jon M Moorby

The increased nitrogen (N) use efficiency in cattle farming is proposed as a key action to improve N management and reduce the environmental impact of cattle farming systems. Most attention has been given to lactating cow nutrition, excluding the elements of fertility, disease, and the non-lactating animals within the herd. Therefore, the aim of the current study was to develop a herd-level simulation model incorporating these elements to assess dairy farm N use efficiency. We developed a cattle N use efficiency (CNE) model with six primary compartments: (i) heifer growth, (ii) heifer removal, (iii) pregnancy, (iv) cow removal, (v) disease and fertility, and (vi) milk production. The CNE model calculates N loss or gain for each compartment, and then calculates the lifetime N loss or gain taking into account the replacement rate (rep) and/or the corresponding number of lactations in a herd (Lact = 1/rep). Finally, three N use efficiencies were estimated: (i) ReplNE: replacement cattle N use efficiency, (ii) LactNE: lifetime N use efficiency for lactation, and (iii) LNE: lifetime N use efficiency. The sensitivity of the model to variation in farm- and animal-related input values was evaluated using Monte Carlo simulation. Values for a model dairy farm were used based on published data reflecting typical dairy farming practices in the United Kingdom. To assist reporting net values of main N outputs, a dairy herd of 100 lactating cows was modelled. Productive N outputs (1000s of kg) over the course of an animal's lifetime, partitioned into milk and meat, were dominated by milk production (89% of total N output). We estimated a mean ReplNE of 23.7%, affected most by the last stage of heifer growth. The Monte Carlo sensitivity analysis suggested that variation in time to first calving (T1stCal) might cause larger changes on ReplNE than variation in feed. The sensitivity analysis revealed a strong positive correlation between dietary oriented milk N use efficiency (MNE) and LactNE and LNE (r = 0.99 and 0.97 for LactNE and LNE, respectively). However, our study highlighted two other model variables that affected LNE. Variation in calving interval (CI; r = -0.15) and T1stCal (r = -0.15) may cause measurable reductions of overall LNE. The first is an indicator of lactating cattle fertility, and the second an indicator of replacement cattle growth and fertility efficiency. In conclusion, with the current study we provided a dairy cattle herd model that is sensitive in elements of diet, fertility and health. Lifetime N use efficiency of dairy cattle is dominated by MNE, but we detected specific non-diet related variables that affect ReplNE, LactNE and LNE.

Nadia Aline Bobbi Antoniassi, André Mendes Ribeiro Corrêa, Adriana da Silva Santos et al.

Descreve-se um surto de mortalidade em bovinos por Babesia bovis em abril de 2007, no Município de Picada Café, Rio Grande do Sul. Em um rebanho com 55 novilhas, 28 (50,9%) morreram em cinco dias. A doença iniciou vinte dias após o ingresso dos bovinos na propriedade. Os sinais clínicos incluíam febre, incoordenação, agressividade, anemia, petéquias nas mucosas e morte 1 á 2 dias após. Em 4 animais necropsiados, observaram-se palidez de mucosas, hemorragias múltiplas, esplenomegalia, fígado aumentado e alaranjado, vesícula biliar com parede edemaciada e contendo bile grumosa. Os rins estavam vermelho-escuros e a bexiga continha urina cor de vinho tinto. O encéfalo apresentou cor róseo-cereja externamente e ao corte, mais marcado no córtex telencefálico, cerebelo e corpo estriado, contrastando com a cor branca da substância branca. Na histologia havia nefrose hemoglobinúrica, necrose hepática paracentral, bilestase canalicular, congestão esplênica, além de congestão com grande quantidade de eritrócitos parasitados por estruturas compatíveis com Babesia bovis na região cortical do encéfalo, também observadas em esfregaços teciduais dessas regiões. A morte de 28 bovinos em 5 dias deveu-se, provavelmente, à falta de imunidade contra o parasito. O tratamento foi realizado com dipropionato de imidocarb nos demais animais, havendo recuperação dos bovinos que apresentavam sinais iniciais leves e não ocorrência de novos casos durante um período de dois meses, quando foram enviados para abate.<br>An outbreak of cattle mortality due to Babesia bovis infection in the county of Picada Café, Rio Grande do Sul, southern Brazil, in April 2007 is described. Twenty eight heifers (50.9%) died, out of a herd of 55 animals, in five days. The disease occurred approximately 20 days after heifers were transferred to this farm. The clinical signs included fever, anemia, aggressiveness, incoordination, petechiae in the mucous membranes and death after 1 to 2 days. The necropsy revealed pale mucous membranes, splenomegaly, enlarged and yellowish liver, congested and edematous gall bladder containing viscous granular bile. The kidneys and urine were dark red. The gray matter of cerebrum and cerebellum had a characteristic cherry-pink color. Hemorrhage was seen in the epicardium and endocardium. The histological findings consisted of hemoglobinuric nephrosis, paracentral hepatic necrosis, bile stasis, spleen congestion. The gray matter of the brain exhibited congestion with erythrocytes parasitized by Babesia bovis, which were also seen in the brain impression smear. The death of 28 heifers in 5 days was attributed to inadequate immunity against the parasite. The application of imidocarb dipropionate in animals presenting the initial stage of the disease and in all other animals of the herd was adopted as preventive treatment and no new cases of the disease happened in the next two months, when they were sent to slaughter.

D.M. Pfukenyi, S. Mukaratirwa, A.L. Willingham et al.

During the period between January 1999 and December 2000, the distribution and seasonal patterns of Schistosoma mattheei infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Faecal samples of cattle were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of the intermediate host-snail populations and the climatic factors influencing the distribution were also determined at monthly intervals from November 1998 to October 2000, a period of 24 months, in six dams and six streams in the highveld and nine dams in the lowveld communal grazing areas. Monthly, each site was sampled for relative snail density, the vegetation cover and type, and physical and chemical properties of the water. Mean monthly rainfall and temperature were recorded. Snails collected at the same time were individually examined for shedding of cercariae of S. mattheei and Schistosoma haematobium. A total of 16 264 (5 418 calves, 5 461 weaners and 5 385 adults) faecal samples were collected during the entire period of study and 734 (4.5 %) were positive for S. mattheei eggs. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), calves compared to adult cattle (P < 0.01) and the wet season compared to the dry season (P < 0.01). Faecal egg output peaked from October/ November to March / April for both years of the study. Bulinus globosus, the snail intermediate host of S. mattheei was recorded from the study sites with the highveld having a significantly higher abundance of the snails than the lowveld (P < 0.01). Monthly densities of B. globosus did not show a clearcut pattern although there were peaks between March / May and September / November. The mean num ber of snails collected was positively correlated with the water plants Nymphaea caerulea and Typha species. Overall, 2.5 % of B. globosus were shedding Schistosoma cercariae. In the highveld, 2.8 % of B. globosus were infected with schistosome cercariae and 1.5 % in the lowveld, with the figures at individual sites ranging from 0-18.8 % in the highveld and from 0-4.5 % in the lowveld. The cercariae recorded here were a mixture of S. mattheei and S. haematobium since they share the same intermediate host. The transmission of Schistosoma cercariae exhibited a marked seasonal pattern, being more intensive during the hot, dry season (September / November).

Mirella Leme Franco Geraldini Sirol, Janaina Conte Hadlich, Liliane Suguisawa et al.

Foram realizados quatro estudos de simulação para verificar a distribuição de inversas de variáveis com distribuição normal, em função de diferentes variâncias, médias, pontos de truncamentos e tamanhos amostrais. As variáveis simuladas foram GMD, com distribuição normal, representando o ganho médio diário e DIAS, obtido a partir da inversa de GMD, representando dias para se obter determinado peso. Em todos os estudos, foi utilizado o sistema SAS® (1990) para simulação dos dados e para posterior análise dos resultados. As médias amostrais de DIAS foram dependentes dos desvios-padrão utilizados na simulação. As análises de regressão mostraram redução da média e do desvio-padrão de DIAS em função do aumento na média de GMD. A inclusão de um ponto de truncamento entre 10 e 25% do valor da média de GMD reduziu a média de GMD e aumentou a de DIAS, quando o coeficiente de variação de GMD foi superior a 25%. O efeito do tamanho dos grupos nas médias de GMD e DIAS não foi significativo, mas o desvio-padrão e CV amostrais médios de GMD aumentaram com o tamanho do grupo. Em virtude da dependência entre a média e o desvio-padrão e da variação observada nos desvios-padrão de DIAS em função do tamanho do grupo, a utilização de DIAS como critério de seleção pode diminuir a acurácia da variação. Portanto, para a substituição de GMD por DIAS, é necessária a utilização de um método de análise robusto o suficiente para a eliminação da heterogeneidade de variância.<br>Four simulation studies were conducted to verify the distribution of the inverse of variables with normal distribution, relatively to variances, averages, truncation points and sample sizes. The variables simulated were GMD, with normal distribution and representing average daily gain, and DIAS defined as a multiple of the inverse of GMD and representing days to reach a fixed body weight. The SAS® (1990) system was used, for simulation of the data, and for subsequent analysis of the results in all studies. The standard deviations simulated for GMD significantly affected DIAS sampling averages. The regression analyses showed a reduction on the mean and in the standard deviation of DIAS as a function of the increase in the average of GMD. Including a truncation point at about 10 to 25% of the mean value reduced the mean of GMD and increased the mean of DIAS when the coefficient of variation of GMD was above 25%. Size of the groups did not significantly affect averages of GMD or DIAS. Standard deviation and CV of GMD increased with the increase on group size. Due to the dependence between the average and the standard deviation and the variation observed in the standard deviations of DIAS as a function of group size, the use of DIAS as selection criteria may reduce the accuracy of the genetic evaluation. Therefore, in order to substitute GMD by DIAS, it is necessary the use of a method of analysis robust enough to eliminate the heterogeneity of variance.