Consequences of dietary energy source and energy level on energy balance,lactogenic hormones,and lactation curve characteristics of cows after a short or omitted dry period

Omitting the dry period (DP) generally reduces milk production in the subsequent lactation. The aim of this study was to evaluate the effect of dietary energy source—glucogenic (G) or lipogenic (L)—and energy level—standard (std) or low—on milk production; energy balance (EB); lactogenic hormones insulin, insulin-like growth factor 1 (IGF-1), and growth hormone (GH); and lactation curve characteristics between wk 1 and 44 postpartum in cows after a 0-d or 30-d DP. Cows (n = 110) were assigned randomly to 3 transition treatments: a 30-d DP with a standard energy level required for expected milk yield [30-d DP(std)], a 0-d DP with the same energy level as cows with a 30-d DP [0-d DP(std)], and a 0-d DP with a low energy level [0-d DP(low)]. In wk 1 to 7, cows were fed the same basal ration but the level of concentrate increased to 6.7 kg/d for cows fed the low energy level and to 8.5 kg/d for cows fed the standard energy level in wk 4. From wk 8 postpartum onward, cows received a G ration (mainly consisting of corn silage and grass silage) or an L ration (mainly consisting of grass silage and sugar beet pulp) with the same energy level contrast (low or std) as in early lactation. Cows fed the G ration had greater milk, lactose, and protein yields, lower milk fat percentage, greater dry matter and energy intakes, and greater plasma IGF-1 concentration compared with cows fed the L ration. Dietary energy source did not affect EB or lactation curve characteristics. In cows with a 0-d DP, the reduced energy level decreased energy intake, EB, and weekly body weight gain, but did not affect milk production or lactation curve characteristics. A 30-d DP resulted in a greater total predicted lactation yield, initial milk yield after calving, peak milk yield, energy intake, energy output in milk, days to conception [only when compared with 0-d DP(low)], plasma GH concentration [only when compared with 0-d DP(std)], and decreased weekly body weight gain compared with a 0-d DP. A 30-d DP decreased both the increasing and the declining slope parameters of the lactation curve and the relative rate of decline in milk yield (indicating greater lactation persistency) compared with a 0-d DP, and decreased plasma insulin and IGF-1 concentration, and EB. In conclusion, feeding a G ration after wk 7 in milk improved energy intake and milk production, but did not affect EB compared with an L ration. For cows without a DP, a reduced dietary energy level did not affect milk production and lactation curve characteristics, but did decrease EB and weekly body weight gain. A 30-d DP increased milk yield and lactation persistency, but decreased milk fat and protein content, EB, and plasma insulin and IGF-1, compared with a 0-d DP.     

Automated body condition scoring of dairy cows using 3-dimensional feature extraction from multiple body regions

Machine vision technology has been used in automated body condition score (BCS) classification of dairy cows. The current vision-based classifications use information acquired from a limited number of body regions of the cow. Our study aimed to improve automated BCS classification by including multiple body condition–related features extracted from 3 viewpoints in 8 body regions. The data set of this study included 44 lactating cows with their BCS evenly distributed over the scale of BCS from 1.5 to 4.5 units. The body images of these cows were recorded over 2 consecutive days using 3-dimensional cameras positioned to view the cow from the top, right side, and rear. Each image was automatically processed to identify anatomical landmarks on the body surface. Around these anatomical landmarks, the bony prominences and body surface depressions were quantified to describe 8 body condition–related features. A manual BCS of each cow was independently assigned by 2 trained assessors using the same predefined protocol. With the extracted features as inputs and manual BCS as the reference, we built a nearest-neighbor classification model to classify BCS and obtained an overall classification sensitivity of 0.72 using a 10-fold cross-validation. We conclude that the sensitivity of automated BCS classification has been improved by expanding the selection of body condition–related features extracted from multiple body regions.     

The effect of furosemide on serum prolactin levels in the postpartum period

Furosemide, in combination with breast binding and milk fluid restriction, seems to inhibit postpartum lactation effectively, but has no effect in reducing serum prolactin levels. Inhibition of milk secretion must therefore be mediated by other mechanisms.     

A standardized method for computed tomography of the orbits

A standardized method for the CT exploration of the orbital region has been searched for. This method makes it possible to visualize the entire orbital region with a minimum of 4 tomographic scans, each section 6 mm thick. The reference line chosen for this exploration is parallel to the optic nerve and joins the projection of the inferior border of the orbit on the lateral view with the upper border of the ear to the scalp. After each tomographic scan the patient is moved so that the new scanning line is still parallel to the reference line but distant by 9 mm from the previous one.     

Cholera in Portugal, 1974.I. Modes of transmission

In April-November 1974, Portugal had a cholera epidemic caused by Vibrio cholerae El Tor Inaba with 2467 bacteriologically confirmed hospitalized cases and 48 deaths. Most of the country was affected, with 17 of the 18 districts reporting cases. V. cholerae was isolated from 42 per cent of shellfish tested during the epidemic, and an epidemiologic study found that a history of consumption of raw or poorly cooked cockles was significantly more common among cholera patients than among paired controls. Water from a spring and a brand of commercially bottled water were also found to be vehicles of transmission of cholera. Although night soil was sometimes used on gardens, consumption of raw fruits and vegetables was not associated with illness.     

Superinfection exclusion by bacteriophage T7

Only two of the early genes of bacteriophage T7 were found to play a significant role in exclusion of superinfecting bacteriophage T3 particles; genes 0.3 and 1. Protein synthesis by the preinfecting phage particle was not required for efficient exclusion. These findings are discussed with regard to the known functions of these genes during T7 development.     

Vasopressin administration in the first month of life: effects of growth and water metabolism in hypothalamic diabetes insipidus rats

Rats homozygous for the mutant gene for diabetes insipidus (Brattleboro strain) are stunted in growth compared to rats heterozygous for the mutant gene and normal rats without the mutant gene. The hypothesis was tested that normal growth depends upon the presence of vasopressin. It was expected that replacement therapy of vasopressin rats homozygous for diabetes insipidus would make possible a normal growth rate similar to that of rats heterozygous for diabetes insipidus. Rats heterozygous and homozygous for diabetes insipidus were treated with 0.25 U (Days 0-9) and 0.5 U (Days 10-29) of vasopressin during the first month of life. During the treatment period, vasopressin significantly increased the urine osmolatities of the homozygous rats demonstrating the renal effectiveness of the vasopressin. The results showed that remedial vasopressin administration could not produce normal growth rates in homozygous rats and may be detrimental. Six weeks following vasopressin treatment, homozygous, diabetes insipidus rats which had received vasopressin had increased 24 hr water intakes and decreased urine osmolalities compared to control, homozygous rats, Heterozygous rats also had decreased urine osmolalities resulting from vasopressin six weeks after the cessation of vasopressin treatment.     

Effect of temperature on growth and activity of a methanogenic culture utilising acetate

Studies with a methanogenic culture enriched for use of acetic acid showed that this culture had an optimum growth temperature of 35 degrees C, with only small differences for other temperatures between 30 and 40 degrees C. The optimum temperature was the same when determined on the basis of biomass production rate during the exponential (log) phase of growth (0.08-0.09 day-1, at 35 degrees C), amount of biomass present at the end of the log phase (100 mg/l), activity of the biomass (rate of conversion in millimoles per day per milligram (dry wt.) biomass present, 0.08 at end of log phase), or biomass yield (mg (dry wt.) biomass produced per millimole acetic acid converted, 1.0-1.1). Temperatures outside the range 30 to 40 degrees C caused marked reductions in the above parameters. The maximum temperature for growth was 42-44 degrees C; the minimum, below 15 degrees C, the lowest temperature studied. Acetic acid conversion to methane was 0.8-1.0 mol/mol, and was independent of temperature.     

Characteristics of soluble immune complexes prepared from oligovalent DNP conjugates and anti-DNP antibodies

The stability of soluble immune complexes was investigated after isolation by gel filtration and sucrose gradient ultracentrifugation. Soluble immune complexes were formed between specific goat anti-dinitrophenol (DNP) antibodies and DNP conjugated to a large (19 S) carrier, namely bovine thyroglobulin. The composition and molecular weight of these complexes were determined by ultracentrifugation on calibrated sucrose density gradients and the use of different isotopic markers for antigen and antibody. A good separation of immune complexes containing one, two, or three antigen molecules per complex was obtained by ultracentrifugation while gel filtration was less effective. Ultracentrifugational analysis of fractions isolated by these two procedures showed that large immune complexes containing more than one antigen were relatively labile, whereas small immune complexes containing one antigen were stable. The stability of large immune complexes was dependent on dilution. Because dilution affects the size and composition of soluble immune complexes, it is important to emphasize that for the investigation of a causal relationship between the biological properties and the size and composition of immune complexes, analysis of the immune complexes should be performed in the same dilutions in which they will be used experimentally.