Patrón de riesgo de la incidencia de diarrea y mortalidad en terneros de lechería en Córdoba, Argentina

El objetivo de este estudio fue determinar la incidencia de diarrea y mortalidad en terneros de 2 a 65 días de edad y los factores de riesgo asociados. En una cohorte retrospectiva de un establecimiento de la zona rural de Córdoba, Argentina, 957 terneros Holstein provenientes de 5 lecherías fueron seguidos hasta los 65 días de vida. Sexo de los terneros, paridad de la madre, dificultades en el parto, ingestión de calostro, lechería de origen y estación al nacimiento fueron evaluados como predictores de la incidencia de diarrea y la mortalidad con un modelo de regresión de Cox. Cuarenta y ocho por ciento (48,59%) de los terneros experimentaron al menos un episodio de diarrea, mientras que 20,17% murieron antes de los 65 días de edad. La incidencia de diarrea alcanzó el máximo valor a los 10 días de edad, y la mortalidad estuvo concentrada alrededor de los 15 días de vida. Terneros nacidos en el otoño (HR = 0,239, IC 95%: 0,180- 0,317) y paridad de la madre (vaquilla vs vaca HR = 1,871, IC 95%: 1,130- 3,098) estuvieron asociados al riesgo de diarrea. Lechería de origen, estación de nacimiento (verano y otoño) e ingestión de calostro (deficiente vs adecuado HR = 1,645, IC 95%: 1,186- 2,283) estuvieron asociados al riesgo de muerte. La Fracción Atribuíble Poblacional (FAP) para la mortalidad debida a la ingesta de calostro deficiente fue 9% (IC 95%: 0,965- 16,332%). Los factores identificados pueden ayudar a introducir intervenciones para reducir la diarrea y mortalidad bajo las condiciones productivas de Argentina

Performance and Health of Group-Housed Calves Kept in Igloo Calf Hutches and Calf Barn

Group-reared calves are usually housed in common buildings, such as calf barns of all sorts; however, there are concerns about this practice due to problems such as an increased incidence of diseases and poor performance of the calves. Group calf rearing using igloo hutches may be a solution combining the benefits of individual and group housing systems. The aim of this study was to evaluate group-reared calves housed in Igloo-type hutches compared with those housed in common calf barns. The experiment was carried out on a large private dairy farm located in Vorpommern, Germany. A total of 90 Deutsche-Holstein bull calves were assigned to 2 treatment groups: the calf-barn group, with calves grouped in pens in a building, and the Igloo-hutch group, with calves housed in outdoor enclosures with an access to group igloo-style hutches. Calves entering the 84-day experiment were at an average age of about three weeks, with the mean initial body weight of about 50 kg. The calves housed in the group Igloo hutches attained higher daily weight gains compared to those housed in the calf barn (973 vs 721 g/day), consumed more solid feeds (concentrate, corn grain and maize silage): (1.79 vs 1.59 kg/day), and less milk replacer (5.51 vs 6.19 kg/day), had also a lower incidence of respiratory diseases (1.24 vs 3.57%) with a shorter persistence of the illness

Effects of Carica papaya seed (Linn) meal on health and performance of Jersey calves

Twenty four Jersey calves were randomly blocked according to sex and birth date, to determine the effects of supplementing Carica papaya seed (Linn) meal (CPSM) on health and growth performance of calves. In the first study, calves were fed CPSM for only 2 days to determine faecal pathogen population. In the second study; calves were randomly assigned at birth to three treatments and fed until weaning at 42 days. Each treatment had six calves. Treatments were; 1) a control group, which did not receive additive; 2) a group that was supplemented 5 g/d of Carica papaya seed meal (CPSM) and 3) the last group that was supplemented 5 g/d of a commercial product containing Lactobacillus acidophilus (Lact). After receiving milk with colostrum from their dams for 3 consecutive days after birth, calves had commercial starter pellet and fresh water ad lib. Treatments were added to whole milk from day 4 and fed to calves before being allowed to suckle from the dams for 30 min three times a day (08:00; 12:00 and 17:00). Calf starter dry matter intake (DMI) was evaluated daily while body weight (BW) and body structural growth were measured weekly. Faecal samples were collected directly from the rectum on day 7 and 10, before and after receiving CPSM respectively. The DMI; DMI/BW; BW and BWG of calves did not differ among treatments, and averaged 305.4 g/d; 7.7 g/d per BW; 39.4 kg and 32.1 kg, respectively. The initial BW, 22.2 ± 1.49 kg did not differ among groups, but the weaning BW was higher (p<0.05) for CPSM fed calves compared to control diet fed calves. It did not differ between control and Lact calves. Calves in Lact and CPSM treatments had similar average daily gain (ADG) and heart girth (HG), which were higher (p<0.05) than calves fed the control treatment. Calves fed CPSM had higher (p<0.05) hip width (HW) and shoulder height (SH) than control calves. There were effects of time (p<0.001) for starter DMI/BW, ADG and all structural body parameters, and effects (p<0.05) of interaction between time and treatments for only starter DMI/BW, ADG and HG. The CPSM treatment reduced faecal coliforms and E. coli (p<0.05) by 93.6% and 96.1%, respectively; and tended to reduce Enterobacteriaceae (p=0.056) by 96.4%. The present study revealed that feeding CPSM to calves during the pre-weaning period increased growth performance by improving average daily gain, feed efficiency and enhancing health status due to low faecal pathogen countAgriculture, Animal Health and Human EcologyM. Sc. (Agriculture

Diagnosis and molecular epidemiology of bovine rotavirus and coronarvirus in Brazil

Rotavirus and coronavirus are the two most common viral causes of neonatal calf diarrhea and their presence causes a lot of economic damage to the farmers as well as suffering to the animal. By getting better knowledge about the viruses we may help in tracing transmission and in producing new vaccines. This paper served to study the molecular epidemiology of rotavirus and coronavirus in fecal samples collected from two different farms in the state of São Paulo, Brazil. These samples have been studied with focus on the gene VP4, VP7, NSP4 in rotavirus and the gene S1 in coronavirus. From the first farm the screening PCR showed that 12/48 samples were positive for rotavirus and 4/48 positive for coronavirus. No determination of genotypes of rotavirus was achieved and the sequences retrieved did not match any known rotavirus. Nor was any amplification and sequencing of the positive samples of coronavirus successful. From the second farm 14/22 samples tested positive for rotavirus and 2/22 samples positive for coronavirus. Initial genotyping PCR for determination of G- and P-genotype identified 3 samples as G6, 5 samples as P[1] and 1 sample as P[11]. Successful sequencing confirmed that the 3 samples were of genotype G6 but identified the, by genotyping PCR determined, P[1] samples as P[5]. From the coronavirus positive samples one sequence which clustered within the genus betacoronaviruses were retrieved.Rotavirus och coronavirus är de två vanligaste virala orsakerna till neonatal diarré hos kalvar och orsakar stora ekonomiska skador för djurägare samt ett lidande för djuren. Genom att få mer kunskap om hur dessa virus är uppbyggda på RNA-nivå kan man hjälpa i smittspårning och i utveckling av nya vacciner. Detta är en studie på molekylär epidemiologi hos dessa virus i fekala prover insamlade från två olika gårdar i delstaten São Paulo, Brasilien. Dessa prover har undersökts med fokus på generna VP4, VP7, NSP4 hos rotavirus samt genen S1 hos coronavirus. I proverna från första gården var 14/48 prover positiva för rotavirus och 4/48 positiva för coronavirus. Genotypning av rotavirus lyckades inte i denna uppsättning och de sekvenser som erhölls liknade inte några andra kända sekvenser av rotavirus. Amplifiering och sekvensering av coronavirus i denna uppsättning lyckades inte. Från den andra gården var 14/22 prover positiva för rotavirus och 2/22 positiva för coronavirus. I genotypande PCR för G- och P-genotyp identifierades 3 prover som G6, 5 prover som P[1] och 1 prov som P[11]. Sekvensering av dessa prover konfirmerade genotypningen som G6 men visade att de tidigare genotypade P[1] istället var av genotyp P[5]. Sekvensering av genen S1 i ett av de två positiva proverna av coronavirus lyckades och denna sekvens placerades i genus betacoronavirus vid en fylogenetisk analys

Causas de diarrea neonatal y mortalidad de terneros en tambos de Uruguay, caracterización de especies y subtipos zoonóticos de Cryptospordium y estimación de pérdidas económicas nacionales por mortalidad de terneras lecheras

Los objetivos de esta tesis fueron: 1) identificar enfermedades infecciosas/protozoarias de terneras/os lecheras/os asociadas al síndrome de diarrea neonatal, a falla en la transferencia pasiva de inmunidad (FTPI) y a mortalidad en rodeos comerciales, 2) caracterizar especies y subtipos de Cryptosporidium detectados en terneras/os neonatas/os de tambos del país para y determinar su eventual potencial zoonótico y su distancia con fuentes de aguas superficiales colectadas por plantas potabilizadoras de agua para consumo humano y 3) estimar las pérdidas económicas nacionales debidas a mortalidad de terneras lecheras durante el período de crianza para el sector primario en Uruguay. Para el primer objetivo se realizó un estudio de casos y controles de terneros diarreicos (n = 264) y no diarreicos (n = 271) de hasta 30 días de edad de 27 establecimientos. Las heces se analizaron mediante un ELISA de captura de antígeno para Cryptosporidium spp., rotavirus, coronavirus bovino y Escherichia coli F5+, y mediante cultivo selectivo para Salmonella enterica. La sangre/suero se analizó por RT-PCR o ELISA para detección del virus de la diarrea viral bovina. El suero de terneros de ≤ 8 días (n = 95) se evaluó mediante refractometría para determinar la concentración de proteínas totales en suero (PTS). Mediante un cuestionario se registró si los terneros muestreados murieron antes del desleche (período de crianza). Cryptosporidium spp. y rotavirus fueron los únicos patógenos que se asociaron estadísticamente con diarrea. Los terneros diarreicos, los terneros infectados con cualquiera de los patógenos y los terneros infectados con rotavirus tuvieron concentraciones significativamente más bajas de PTS, sugiriendo una FTPI. Los terneros diarreicos tuvieron mayor probabilidad de morir antes del desleche que los no diarreicos. Los terneros diarreicos infectados con S. enterica también tuvieron mayor probabilidad de morir. Para el segundo objetivo se seleccionaron heces de 255 terneros (170 diarreicos y 85 no diarreicos) que habían resultado positivas para Cryptosporidium spp. por ELISA de antígeno, y se procesaron mediante PCRs anidadas dirigidas a los genes 18S rRNA y gp60, seguidas de secuenciación para identificar los subtipos de C. parvum. En 166 muestras se detectaron 7 subtipos de C. parvum de los cuales 5 son zoonóticos. El subtipo IIaA15G2R1 fue el más frecuente (53,6%; 89/166), seguido por IIaA20G1R1 (24,1%; 40/166), IIaA22G1R1 (11,4%; 19/166), IIaA23G1R1 (3,6%; 6/166), IIaA17G2R1 (3%; 5/166), IIaA21G1R1 (2,4%; 4/166) e IIaA16G1R1 (1,8%; 3/166). No hubo diferencias significativas en las proporciones de terneros diarreicos y no diarreicos infectados con ninguno de los subtipos. Se detectaron dos conglomerados espaciales, uno de los cuales se superpuso con Montevideo y la principal planta de potabilización de agua (Aguas Corrientes) que abastece esta ciudad a partir del río Santa Lucía. Los terneros infectados en todos los establecimientos se encontraban dentro de los 20 – 900 m de un curso de agua superficial natural que drenaba los campos, 10 de los cuales fluían hacia seis plantas de potabilización de agua ubicadas entre 9 y 108 km aguas abajo. Cuatro de estos cursos de agua fluían río abajo hacia Aguas Corrientes. Para el tercer objetivo se desarrolló un modelo bioeconómico en Excel para simular la vida productiva de una hembra lechera bajo las condiciones de manejo y alimentación promedio de los establecimientos lecheros uruguayos. El costo total de criar una ternera desde el nacimiento hasta el desleche a los 75 días de vida fue de US$129,74 (US$ 1,77 ternera/día) y desde el nacimiento hasta el primer parto a los 33 meses de vida de US$589,89 (US$ 0,58/día), siendo los costos de alimentación y de mano de obra los principales contribuyentes al costo total durante estos períodos. La edad al repago de 52,7 meses de vida. El lucro cesante (costo de oportunidad) de una ternera que muere durante la etapa de crianza fue, en promedio, de US$2678,6, estimándose una pérdida de US$ 64.382.829 a nivel del sector primario en los años 2014 – 2020. Las diarreas neonatales infecciosas/protozoarias y la FTPI se asocian a morbimortalidad. Los terneros lecheros son reservorios de enteropatógenos zoonóticos y representan una potencial vía de contaminación de cursos de agua superficial captada por plantas potabilizadoras de agua para consumo humano y la mortalidad de terneras en la crianza causa pérdidas económicas multimillonarias para el sector primario en Uruguay

ECONOMIC IMPACT OF CALF MORTALITY ON DAIRY FARMS IN KUWAIT

Objective of this study was to investigate the economic impact of mortality of pre-weaned calves on dairy cattle enterprise in Kuwait. Cost/benefit analysis model was applied to two different situations: in the first situation, a baseline scenario, field survey data without intervention using 1,280 newborn calves was used in first calving season. In the second situation, the intervention scenario (improved management), 665 newborn calves were used in second calving season during the following year. Calving seasons extended for 7 months from September to March. Calf performance studies were conducted from birth to weaning. Economic model was constructed on Microsoft Excel and used to evaluate the impact of calf mortality on calf enterprise. Results showed that gross margins increased from 13 to 35% as a result of implementation of intervention measures during the second calving season over baseline scenario. A significant correlation between increased veterinary expenses and an increase in revenues (r2 = 0.65, P<0.05) was observed. If the intervention measures such as colostrum feeding, nutrition and hygiene had not been implemented, the farms would have lose income from 12 to 51% of the gross revenues. Net income was influenced by costs of feeds, veterinary services and laborers. Discounted cash flow studies on a whole farm basis revealed that the impact of interventions was small (0-3%). Calf mortality could not be isolated from whole farm for assessing its impact on dairy farm economics. Economic studies demonstrated the cost/benefits of using the improved techniques of calf rearing

PERFORMANCE OF PRE-WEANED FEMALE CALVES CONFINED IN HOUSING AND OPEN ENVIRONMENT HUTCHES IN KUWAIT

Objective of the present study was to compare the responses of Holstein Friesian pre-weaned female calves confined in elevated metallic crates in closed-type of housing and polyvinyl hutches in an open environment of Kuwait. A total of 176 newborn Holstein Friesian female calves were randomly distributed to conventional confinement in closed-type calf houses (control) and individual calf hutch in open environment (treatment). These calves were monitored upto the weaning age of 90 days. The average daily live weight gain was significantly higher in calves housed in hutches than conventional housing system (413 versus 113 g/h/d; P≤0.0001). Mean risk rates (RR) for mortality in hutch and conventional housing were 0.017 and 0.23, respectively. The results showed a significant positive impact of hutch housing with respect to growth, mortality and incidence of diseases in Kuwait’s intensive dairy farming syste