Efficiency of measuring corpus luteum crosssectional areas by ultrasonography for detecting early pregnancy in cattle

The obj e ctive of this study was to examine the efficiency of a novel method of early pregnancy diagnosis in cows. This method was based on cross - sectional area change s of corpora lutea measured by t ransr ectal ultrasonography. One hundred forty one Japanese Black cows were artificially inseminated and divided into four groups according to examination days . Corpora l utea of all cow s in each group were measured twice at 7 days apart, on days 13 and 20 (n = 1 8 ), 14 and 21 (n = 40 ), 15 and 22 (n = 37 ) and 16 and 23 (n = 46 ) post - insemination. Confirmation of pregnancy was performe d by ultrasonography on day 30 post - insemination . All non - pregnant cows showed clear regression of t heir c orpora l utea at rates of 35. 8 , 43.7 , 51. 3 , and 56.2 % on days 20, 21, 22 , and 23 post - insemination, respectively . Some ovarian disorders were discovere d in 9% of non - pregnant cows. In conclusion, the present method was hig hly sensitive (100%) in detecting ear ly non - pregnancies in the field , and also helpful in detecting ovarian disorders at an early stage, which gives reason to use it for better economic management and benefit.(AU)

Efficiency of measuring corpus luteum crosssectional areas by ultrasonography for detecting early pregnancy in cattle

The obj e ctive of this study was to examine the efficiency of a novel method of early pregnancy diagnosis in cows. This method was based on cross - sectional area change s of corpora lutea measured by t ransr ectal ultrasonography. One hundred forty one Japanese Black cows were artificially inseminated and divided into four groups according to examination days . Corpora l utea of all cow s in each group were measured twice at 7 days apart, on days 13 and 20 (n = 1 8 ), 14 and 21 (n = 40 ), 15 and 22 (n = 37 ) and 16 and 23 (n = 46 ) post - insemination. Confirmation of pregnancy was performe d by ultrasonography on day 30 post - insemination . All non - pregnant cows showed clear regression of t heir c orpora l utea at rates of 35. 8 , 43.7 , 51. 3 , and 56.2 % on days 20, 21, 22 , and 23 post - insemination, respectively . Some ovarian disorders were discovere d in 9% of non - pregnant cows. In conclusion, the present method was hig hly sensitive (100%) in detecting ear ly non - pregnancies in the field , and also helpful in detecting ovarian disorders at an early stage, which gives reason to use it for better economic management and benefit.

Progesterone concentrations measured by radioimmunoassay in blood plasma and in fat-free milk of Gir breed cows iBos indicus). Determinations during oestrus cycle. Early pregnancy diagnosis. / Níveis de progesterona determinados por radioimunoensaio em plasma sangüíneo e leite desnatado de vacas da raça Gir (Bos indicus). Avaliações durante o ciclo estral. Diagnóstico precoce de gestação.

Progesterone concentrations were measured by radioimmunoassay in 137 fat-free milk and in 138 blood plasma samples obtained three times weekly during 17 estrous cycles from 12 zebu Gir cows, raised in range conditions at the "Centro Intraunidade de Zootecnia e Indústrias Pecuárias Fernando Costa", Pirassununga, State of São Paulo, Brazil. Profiles of progesterone concentrations for early pregnancy diagnosis were also examined on samples taken 23 days after natural service. Correlations were found between frozen and cooled milk samples (r = 0.92), as well asbetween milk and blood plasma progesterone levels (r = 0.63). Variations during estrous cycle were detected, with lower values in folicular phase (less than 1.49 nmol/l in plasma and 2.61 nmol/l in milk) and peak values in luteal phase (from 15.60 to 21.30 nmol/l in plasma and 5.91 to 11.37 nmol/l in milk). All pregnancy and non pregnancy diagnosis were confirmed by rectal palpation, when 9.54 nmol/l in plasma and 3.18 nmol/l in milk discriminations values were utilized. From the combined data of 24 oestrus observations and progesterone profiles (29 oestrus) it was found that 17.2% of failure occured in oestrus detection.

Foram estudados 17 ciclos estrais de 12 vacas da raça Gir, mantidas em regime extensivo de pastagens no Centro Intraunidade de Zootecnia e Indústrias Pecuárias "Fernando Costa", em Pirassununga, Estado de São Paulo. Para o estudo dos níveis de progesterona através de RIE, foram colhidas, 3 vezes por semana e aos 23 dias após a cobertura, amostras de leite e de plasma sangüíneo, totalizando, respectivamente, 137 e 138 amostras. Os resultados obtidos indicaram correlação entre amostras refrigeradas e congeladas de leite desnatado (r = 0,92), assim como entre leite desnatado e plasma sangüíneo (r = 0,63). Verificaramse, ainda, variações dos níveis de progesterona durante o ciclo estral, com baixos valores na fase folicular (inferiores a 1,49 nmol/l de leite desnatado) e picos de 15,60 a 21,30 nmol/l no plasma e 5,91 a 11,37 nmol/l, no leite desnatado durante a fase luteínica. Todos os resultados de prenhez e não prenhez, baseados na análise de progesterona, utilizando níveis discriminatórios de 9,54 nmol/l no plasma e 3,18 nmol/l no leite, foram confirmados por palpação retal. As falhas de detecção de cio foram da ordem de 17,2% (24 cios observados em 29 ocorridos)