Reproductive characteristics of a free-ranging population of Cape mountain zebra (Equus zebra zebra).
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In a population of free-ranging Cape mountain zebra, median age at first foaling was 67 months (range 38-105 months), median foaling interval was 25 months (range 13-69 months) and annual foaling rate was 32%. Foaling rates of younger and older mares were similar. Foals were born all year round with a peak corresponding to the rainy season (summer). Conception occurred later in the season when the spring was dry. (+info)
Effect of source of dietary energy and energy restriction during lactation on sow and litter performance.
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The effects of source of energy and energy restriction during lactation on sow and litter performance were investigated in an experiment with 90 primiparous sows. At parturition, the sows were randomly assigned to diets containing either tallow or cornstarch as a major energy source. Energy intake was restricted to 8 Mcal of metabolizable energy X sow-1 X d-1 during a 28-d lactation. All sows received equal amounts of crude protein, vitamins and minerals daily, which met or exceeded standard recommendations. Sows fed the diet with tallow lost more weight (P less than .05) during lactation than those fed the diet with cornstarch. Litter size at d 28 was greater (P less than .07) for sows fed cornstarch than for sows fed tallow. However, pig and litter weights on d 14 and 28 of lactation were similar between dietary treatments. Sows were bled on d 110 of gestation and d 14 and 28 of lactation and blood plasma was analyzed for urea. A significant treatment X time interaction was found for plasma urea. Sows fed the diet with tallow appeared to catabolize more protein than those fed the diet with cornstarch. Energy digestibility was lower (P less than .01) in the diet containing tallow, but protein digestibility was not affected by source of energy. Percentages of sows in estrus by 7, 14 and 70 d post-weaning were not different between treatments. (+info)
Effects of number of lambs suckled and supplemental protein source on lactating ewe performance.
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Effects of number of lambs suckled and supplemental protein source on ewe performance were determined. Lactation performance of ewes nursing twin or triplet lambs was compared in Exp. 1 and 2. In Exp. 1, ewes giving birth to and nursing triplets produced 21% (P less than .05) more milk/unit metabolic body weight, were 10% more efficient in the conversion of feed to milk and produced 26% (P less than .05) more kg of lamb/ewe on d 42 of lactation than did ewes giving birth to and nursing twins. In Exp. 2, lactation performance of ewes giving birth to triplets and rearing only two lambs was compared with performance of ewes giving birth to triplets and rearing three lambs. Ewes rearing three lambs produced 28% (P less than .08) more milk and were 26% (P less than .05) more efficient in converting feed to milk than were those rearing two lambs. This suggests that direct nursing stimulation of the mammary gland is responsible for the improvement in milk production observed when ewes nurse additional lambs. The efficacy of slowly degradable protein sources for improved lactation was studied in Exp. 3 and 4. When blood meal was fed to twin-rearing ewes at 3.30% of the diet (25% of total dietary protein), milk production was greater (3,176 vs. 2,506 g/d, P less than .05) and efficiency of milk production was greater (1.05 vs .79 g milk/g feed, P less than .05) than when ewes were fed supplemental soybean meal. Ewes in this experiment fed supplemental meat and bone meal also tended to produce more milk than those fed soybean meal.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Serotyping of Campylobacter jejuni, Campylobacter coli, and Campylobacter laridis from domestic and wild animals.
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By using 50 unabsorbed antisera, we were able to serotype 272 (65.7%) of 414 thermotolerant campylobacters from wild and domestic animals, on the basis of heat-stable antigens identified by means of passive hemagglutination. Forty-two serotypes were recognized. The pattern of serotypes detected in the various animal species was compared to human clinical isolates by using the Czekanowski index (proportional similarity index). The highest degree of similarity to the clinical isolates was observed for the poultry isolates, followed by strains from wild birds, flies, and pigs (in order of decreasing similarity). The serotypes recovered most frequently from poultry (LAU 1 and LAU 2) were also most prevalent in Norwegian patients. In contrast, serotype LAU 35/44, the predominant porcine serotype, was never recovered from human clinical specimens. Flies captured in chicken farms and in piggeries harbored serotypes which were also commonly seen in chickens and pigs, respectively. Nine of the strains included in this study could not be ascribed to any defined species. All of these were resistant to nalidixic acid and did not produce H2S. (+info)
Vitamin A during lactation: relationship of maternal diet to milk vitamin A content and to the vitamin A status of lactating rats and their pups.
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We have investigated the effects of maternal vitamin A intake during pregnancy and lactation or during lactation alone on the concentration of vitamin A in rat's milk and on vitamin A levels in plasma and liver of dams and their pups. Groups of Sprague-Dawley rats were fed diets having either a high vitamin A content [15 retinol equivalents (R.E.)/g diet] or a low vitamin A content (0.6 R.E./g) for 42 d, including 7-8 d prior to pregnancy, pregnancy, and for 14 d of lactation. The concentration of vitamin A in milk on d 14 of lactation was significantly greater on the high vitamin A diets [114 +/- 16 micrograms/dl (mean +/- SEM; n = 8) versus 52 +/- 7.3 micrograms/dl (n = 11), P less than 0.005]. However, milk vitamin A concentration on d 1 of lactation did not vary with maternal vitamin A intake during pregnancy. In a second study in which supplementation with vitamin A (30 R.E./g diet) was begun on d 1 postpartum, the milk vitamin A content increased progressively with duration of lactation. Maternal plasma vitamin A concentrations did not differ between rats fed the higher or lower vitamin A diets. However, liver vitamin A concentrations both of dams and of their 14-d-old pups were significantly higher when dams were fed the higher vitamin A diets during pregnancy and/or lactation. The results of these studies indicate that the transfer of vitamin A from mother to offspring by milk and the vitamin A status of dams and their suckling neonates is influenced by maternal vitamin A intake during lactation.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Postnatal development of intestinal bile salt transport. Relationship to membrane physico-chemical changes.
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The postnatal development of intestinal bile salt transport in the rat was examined using the villus technique. Jejunal uptake of taurocholate was linear with respect to incubation concentration at all study ages. Ileal uptake was linear with taurocholate concentration during the first 2 postnatal weeks; a curvilinear relationship indicating the presence of saturable transport appeared during the third week. With the appearance of ileal active transport at age 3 weeks, the Km (app) was constant at 0.49 mM, 0.59 mM, and 0.50 mM in 3-week, 4-week, and adult animals, respectively. The V(app) was 14.65 nmol X mg-1 (dry wt) X min-1 at 3 weeks and declined with age to 11.40 and 10.51 nmol X mg-1 (dry wt) X min-1 in 4-week and adult animals, respectively. The role of physico-chemical changes in the microvillus membrane in the development of ileal active transport was examined. With increasing postnatal age, microvillus membrane cholesterol content rose while the phospholipid content remained unchanged in both ileum and jejunum. Corresponding rises in the cholesterol/phospholipid ratio were observed in both sites. Simultaneously, the microvillus membrane fatty acid composition was changing from predominantly saturated to unsaturated species in both ileum and jejunum. The microvillus membrane fluorescence anisotropy (r) increased with postnatal age in jejunum when measured at 25 degrees C and 37 degrees C and ileum when measured at 25 degrees C; however, no change was noted in ileum when measured at 37 degrees C. Ileal active bile salt transport develops during the third postnatal week, and is associated with concurrent changes in membrane lipid composition and fluidity when measured at 25 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Suckling behavior in range beef calves.
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The number and duration of suckling incidences were recorded during eight 24-h observation periods in a herd of spring-calving Polled Hereford and percentage Simmental cows in 1980 and 1981. The average number of suckling events per calf in 24 h was 5.0 +/- .1 and the average time spent suckling in 24 h was 46 +/- 1 min. Peaks in suckling activity occurred from 0500 to 0700, 1000 to 1300 and 1700 to 2100 h. The most suckling events in a single hour occurred between 0500 and 0600 h and the least between 2200 and 2300 h. Day of the estrous cycle did not influence the number or duration of suckling events. Cows that gave more milk nursed less frequently and heavier calves suckled less frequently (P less than .01). Age, breed and sex of the calf did not influence (P greater than .1) suckling frequency or duration. (+info)
An inherited mild middle-aged adiposity in wild mice.
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In a warfarin-resistant population of wild mice reared in the laboratory, a dominant gene for adiposity, Ad, was found to segregate. The onset of obesity is at 4--6 months, and adipose mice suffer from hyperinsulinaemia; the sexes differ in penetrance, males having greater penetrance then females. Linkage backcrosses show the gene to be situated on chromosome 7 with about 25% recombination with the closely linked warfarin-resistance genes War, and frizzy, fr. The finding of adipose in two other wild populations also carrying War is discussed as an ecological and physiological problem. (+info)