PRIMER REPORTE DE Cryptosporidium parvum EN TERNEROS HOLSTEIN (Bos taurus) DE MANIZALES, CALDAS, COLOMBIA / FIRST REPORT OF Cryptosporidium parvum IN HOLSTEIN CALVES (Bos taurus) FROM MANIZALES, CALDAS, COLOMBIA

El objetivo de este estudio fue identificar especies o genotipos del protozoario parásito Cryptosporidium presentes en heces colectadas de terneros Holstein del municipio de Manizales, Departamento de Caldas, Colombia. El ADN fue extraído a 80 muestras de materia fecal, de las cuales 11 fueron diagnosticadas positivas para Cryptosporidium spp., mediante reacción en cadena de la polimerasa (PCR). El análisis PCR-RFLP del locus 18S ADNr, identificó la presencia de Cryptosporidium parvum en todas las muestras positivas analizadas. Este hallazgo sugiere que el ganado puede ser una fuente potencial de infección por Cryptosporidium en humanos y se constituye en el primer reporte publicado de C. parvum en bovinos de Manizales, Caldas.

The objective of this study was to identify species or genotypes of Cryptosporidium parasite present in feces collected from Holstein calves in Manizales city, Caldas Department, Colombia. DNA was extracted from 80 fecal samples, which 11 were diagnosed positive for Cryptosporidium spp., by the Polymerase Chain Reaction method. PCR-RFLP analysis of 18S rDNA locus identified the presence of Cryptosporidium parvum in all samples tested positive. This finding suggests that cattle may be a potential source of human infection by Cryptosporidium, and it becomes the first published report of C. parvum in cattle in Manizales, Caldas.

Low progesterone concentration during the development of the first follicular wave reduces pregnancy per insemination of lactating dairy cows.

Objectives were to determine the effect of progesterone (P4) concentration on fertility of lactating dairy cows induced to ovulate follicles of the first follicular wave. Lactating dairy cows (n=989) at 38±3d postpartum were balanced by parity and body condition score and randomly assigned to 3 treatments: first follicular wave (FFW), first follicular wave with exogenous P4 (FFWP), or second follicular wave (SFW). All cows had their estrous cycle presynchronized with 2 injections of prostaglandin (PG) F(2α) given 14 d apart. Cows in the FFW and FFWP treatments started the ovulation synchronization protocol 3 d after the last PGF(2α) of the presynchronization protocol, whereas SFW cows received a GnRH injection (100 µg of gonadorelin diacetate; Cystorelin, Merial Ltd., Duluth, GA) 3 d after the last PGF(2α) of the presynchronization protocol and started the synchronization protocol 7 d later. The synchronization protocol consisted of GnRH on d -10, PGF(2α) on d -3, and GnRH concurrent with timed artificial insemination (AI) on d 0. Cows in the FFWP treatment received 2 controlled internal drug release inserts containing 1.38 g of P4 from d -8 to -3. Progesterone concentration was determined on d -10, -8, -6, -3, and 0 from all cows and at 7, 14, and 21 d after AI from a subsample of cows (n=170). Cows (n=715) had their ovaries scanned by ultrasound on d -10, -3, and 7 d. Pregnancy was diagnosed at 38 and 66 d after AI. Concentration of P4 from study d -8 to -3 was lowest for FFW cows (1.4±0.1 ng/mL) and similar between SFW (3.7±0.2 ng/mL) and FFWP (3.7±0.1 ng/mL) cows. Diameter of the dominant follicle on study d -3 was greater for FFW cows (16.5±0.3 mm) than for SFW cows (15.4±0.3 mm), but diameter of the dominant follicle of FFWP cows was not different (15.9±0.3 mm) compared with that of SFW and FFW cows. The incidence of multiple ovulation was largest for FFW cows (SFW=19.5, FFW=33.6, FFWP=19.0%), but pregnancy per AI (P/AI) at 66 d was smallest for FFW cows (SFW=38.9, FFW=22.3, FFWP=32.0%). Anovular cows in the SFW (19.4 vs. 42.8%) and FFWP (22.1 vs. 37.2%) treatments had reduced P/AI compared with cyclic cows, despite having similar or greater P4 concentration from study d -8 to -3, respectively. Estrus and ovulation synchronization protocols for lactating dairy cows must result in growth of ovulatory follicle under P4 concentration >2 ng/mL to ensure high P/AI.

Resynchronization strategies to improve fertility in lactating dairy cows utilizing a presynchronization injection of GnRH or supplemental progesterone: I. Pregnancy rates and ovarian responses.

Objectives were to evaluate 3 resynchronization protocols for lactating dairy cows. At 32+/-3 d after pre-enrollment artificial insemination (AI; study d -7), 1 wk before pregnancy diagnosis, cows from 2 farms were enrolled and randomly assigned to 1 of 3 resynchronization protocols after balancing for parity, days in milk, and number of previous AI. All cows were examined for pregnancy at 39+/-3 d after pre-enrollment AI (study d 0). Cows enrolled as controls (n=386) diagnosed not pregnant were submitted to a resynchronization protocol (d 0-GnRH, d 7-PGF2alpha, and d 10-GnRH and AI) on the same day. Cows enrolled in the GGPG (GnRH-GnRH-PGF2alpha-GnRH) treatment (n=357) received a GnRH injection at enrollment (d -7) and if diagnosed not pregnant were submitted to the resynchronization protocol for control cows on d 0. Cows enrolled in CIDR treatment (n=316) diagnosed not pregnant received the resynchronization protocol described for control cows with addition of a controlled internal drug release (CIDR) insert containing progesterone (P4) from d 0 to 7. In a subgroup of cows, ovaries were scanned and blood was sampled for P4 concentration on d 0 and 7. After resynchronized AI, cows were diagnosed for pregnancy at 39+/-3 and 67+/-3 d (California herds) or 120+/-3 d (Arizona herds). Cows in the GGPG treatment had more corpora lutea than CIDR and control cows on d 0 (1.30+/-0.11, 1.05+/-0.11, and 1.05+/-0.11, respectively) and d 7 (1.41+/-0.14, 0.97+/-0.13, and 1.03+/-0.14, respectively). A greater percentage of GGPG cows ovulated to GnRH given on d 0 compared with CIDR and control cows (48.4, 29.6, and 36.6%, respectively), but CIDR and control did not differ. At 39+/-3 d after resynchronized AI, pregnancy per AI (P/AI) was increased in GGPG (33.6%) and CIDR (31.3%) cows compared with control (24.6%) cows. At 67 or 120+/-3 d after resynchronized AI, P/AI of GGPG and CIDR cows was increased compared with control cows (31.2, 29.5, and 22.1%, respectively). Presynchronizing the estrous cycle of lactating dairy cows with a GnRH 7 d before the start of the resynchronization protocol or use of a CIDR insert within the resynchronization protocol resulted in greater P/AI after resynchronized AI compared with control cows.

Effect of increasing amounts of supplemental progesterone in a timed artificial insemination protocol on fertility of lactating dairy cows.

The objectives were to evaluate the effect of supplemental progesterone during a timed artificial insemination (TAI) protocol on pregnancy per insemination and pregnancy loss. Lactating dairy cows from 2 dairy herds were presynchronized with 2 injections of PGF(2alpha) 14 d apart, and cows observed in estrus following the second PGF(2alpha) injection were inseminated (n = 1,301). Cows not inseminated by 11 d after the end of the presynchronization were submitted to the TAI protocol (d 0 GnRH, d 7 PGF(2alpha), d 8 estradiol cypionate, and d 10 TAI). On the day of the GnRH of the TAI protocol (study d 0), cows were assigned randomly to receive no exogenous progesterone (control = 432), one controlled internal drug-release (CIDR) insert (CIDR1 = 440), or 2 CIDR inserts (CIDR2 = 440) containing 1.38 g of progesterone each from study d 0 to 7. Blood was sampled on study d 0 before insertion of CIDR for determination of progesterone concentration in plasma, and cows with concentration <1.0 ng/mL were classified as low progesterone (LP) and those with concentration > or =1.0 ng/mL were classified as high progesterone (HP). From a subgroup of 240 cows, blood was sampled on study d 3, 7, 17 and 24 and ovaries were examined by ultrasonography on study d 0 and 7. Pregnancy was diagnosed at 38 +/- 3 and 66 +/- 3 d after AI. Data were analyzed including only cows randomly assigned to treatments and excluding cows that were inseminated after the second PGF(2alpha) injection. The proportion of cows classified as HP at the beginning of the TAI protocol was similar among treatments, but differed between herds. Concentrations of progesterone in plasma during the TAI protocol increased linearly with number of CIDR used, and the increment was 0.9 ng/mL per CIDR. The proportion of cows with plasma progesterone > or =1.0 ng/mL on study d 17 was not affected by treatment, but a greater proportion of control than CIDR-treated cows had asynchronous estrous cycles following the TAI protocol. Treatment with CIDR inserts, however, did not affect pregnancy at 38 +/- 3 and 66 +/- 3 d after AI or pregnancy loss.

Delayed disaccharidase development in a rabbit model of intrauterine growth retardation.

Intrauterine growth retardation (IUGR) affects almost 10% of infants born in the United States. It may be responsible for delayed gastrointestinal function and is an important cause of perinatal morbidity and mortality. The New Zealand White rabbit provides an optimal model for the study of naturally occurring IUGR. At term, birth weight is determined by fetal position within the bicornuate uterus. The small intestinal disaccharidase enzymes are indicators of bowel maturity and function. To examine potential differences in disaccharidase development between normal and IUGR fetuses, this rabbit model was investigated. Jejunum was harvested at multiple stages in rabbit development including the third trimester fetus, neonate, and adult. Lactase, maltase, and sucrase enzyme activity, as well as total protein content, was determined. Results were analyzed by the 2-tailed t test and ANOVA. Lactase activity appeared in the mid-third trimester, peaked in the early neonatal period, then declined to adult levels. Maltase activity appeared in the early third trimester and gradually rose to adult levels. Sucrase remained at trace levels until the mid-neonatal period, reaching adult levels by weaning. Both lactase and maltase activity were depressed in IUGR fetuses compared with their normal littermates. This pattern of disaccharidase depression continued into the neonatal period until catch-up growth occurred at 2 wk when levels equalized. This report describes differential small intestinal disaccharidase development between normal and growth-retarded rabbit fetuses in a naturally occurring model of IUGR.

Effect of zinc supplementation on development and growth of Chilean infants.

OBJECTIVE: To evaluate the effect of zinc supplementation on growth and development during infancy. DESIGN: We randomized 150 term neonates of low socioeconomic status to receive supplemental zinc 5 mg/d (SG) or a lactose placebo (PG); 112 completed a 1-year follow-up. All were breast-fed and given cow milk formula after weaning; solid foods and iron were added at 5 months. Anthropometry measured monthly, psychomotor development (PDI), mental development (MDI), and behavior including motor quality factor were assessed by Bayley Scales at 6 and 12 months. The groups were comparable in maternal characteristics, birth weight, home environment, and mother-infant interaction. RESULTS: No effects of zinc on weight, length, and weight for length at 12 months were found controlling for sex and breast-feeding. The mean PDI (SG: 84.5 +/- 11.5 vs PG: 87.6 +/- 9.9) and MDI (90.9 +/- 10.5 vs 88.9 +/- 9.1) were similar; however, 46 of 52 infants in the PG scored <100 in MDI vs 42 of 57 in the SG (P <.05). A smaller proportion of the SG, 2 of 57, scored low in motor quality factor at 6 months compared with the PG, 8 of 52 (P =.02). The mean at 12 months for the SG was 31.9 +/- 2.8 and for the PG 30.8 +/- 2.9 (P <.05); zinc supplementation entered the multiple regression at 12 months (P =.037). CONCLUSIONS: Zinc supplementation may have a beneficial effect on mental development and motor quality behavior of healthy term infants.

Effect of esophageal ligation on the development of fetal rabbit intestinal lactase.

To investigate the effect of normal fetal swallowing and amniotic fluid ingestion on small intestinal disaccharidase development, 13 pregnant New Zealand White rabbits underwent operation on day 24 of a normal 31-day gestation. The right ovarian fetus in the bicornuate uterus underwent esophageal ligation (EL), while the contralateral left fetus underwent cervical exploration only, and served as the control (C). Rabbits were sacrificed on gestational day 31, fetal somatic measurements obtained, and the midjejunum removed for determination of disaccharidase activity and protein content. There was one maternal death, and 9 of 12 fetal pairs survived the entire study period (75%). Results are reported as mean +/- SEM, analyzed by two-tailed Student's t testing with P < .05 being considered significant. Fetal weight was decreased in EL (48.6 +/- 2.7 g) versus C (51.4 +/- 3.2 g) (P = .06). Small intestinal length decreased in EL (49.2 +/- 2.0 cm) versus C (54.9 +/- 1.1 cm) (P = .01). Midjejunal protein content (mg/mL homogenate) was also significantly decreased in EL (38.4 +/- 3.4) versus C (46.2 +/- 3.7) (P = .05). Sucrase activity was not detectable in either group. Lactase activity in jejunal mucosa was not effected when expressed as units of enzyme per milliliter of homogenate (EL = 0.357 +/- 0.03 v C = 0.373 +/- 0.04; P = .70) and units enzyme per gram of protein (EL = 38.8 +/- 4.2 v C = 34.2 +/- 4.6; P = .44). We have confirmed previous studies demonstrating decreases in somatic growth, small intestinal length, and mucosal nutrient transport in rabbit fetuses following esophageal ligation.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of transamniotic administration of epidermal growth factor on fetal rabbit small intestinal nutrient transport and disaccharidase development.

As fetal swallowing is documented in utero, supplementation of the ingested amniotic fluid with nutrients or hormones has been postulated as a potential prenatal treatment for intrauterine growth retardation (IUGR). To study the effect of epidermal growth factor (EGF) on the developing fetal small intestine, 12 pregnant rabbits underwent operation on day 24 of a normal 31-day gestation. Bilateral ovarian end fetuses underwent catheterization of their respective amniotic cavities with attachment to a miniosmotic pump. Study fetuses received recombinant human EGF at approximately 300 micrograms/kg/d for 1 week; controls received carrier solution only at an equivalent rate. On gestational day 31, fetuses were delivered by cesarean section and somatic measurements were recorded. The small intestine was harvested and proximal, middle, and distal regions were analyzed for lactase and maltase enzyme activity. Additionally, the uptake of radiolabeled glucose and proline was measured by a standard everted mucosal sleeve technique for each segment. Results were analyzed by Student's paired t test and reported as mean +/- SEM. Nine fetal pairs survived (75%). Small intestinal (SI) length was increased in EGF fetuses (54.8 +/- 1.9 cm) versus control (50.4 +/- 2.7 cm) (P = .02). Lactase activity, reported as UE/g protein, was significantly increased in the proximal segments in the EGF-infused fetuses; maltase was significantly increased in both the proximal and middle segments (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)