Concentrate feeding strategy in lactating dairy cows: metabolic and endocrine changes with emphasis on leptin.

This study aimed to evaluate metabolic and endocrine adaptations to energy intake in multiparous Holstein cows (n = 90; mean 9434 kg energy-corrected milk yield/305 d) over the first 20 wk postpartum and to assess the association of leptin with metabolic, endocrine, and zootechnical traits. Concentrates were fed automatically for 24 h at 30% (C30) or 50% (C50) of total dry matter intake (DMI) from wk 1 to 10 postpartum and at linearly reduced amounts thereafter. Roughage was fed for ad libitum intake. The DMI was measured over 24 h; milk yield and body weight (BW), twice/d; milk composition, 4 times/wk; and milk acetone, weekly. Blood samples for determination of metabolite, hormone, and electrolyte concentrations and enzyme activities were obtained at wk 2 prepartum, and at wk 1 to 16 and at wk 20 postpartum from 0730 to 0900. Body condition scores (BCS) and backfat thickness were measured postpartum and during wk 1, 4, 8, 12, 16, and 20. Energy balance (EB) was considerably lower, but milk yield only slightly lower, in C30 than C50. Metabolic stress was more marked in C30 than C50, expressed by lower, glucose, insulin, insulin-like growth factor-1 (IGF-1), triiodothyronine, milk protein, and lactose concentrations, higher nonesterified fatty acid, beta-hydroxybutyrate, growth hormone, and milk acetone concentrations, and an accelerated decrease in BCS and backfat thickness. Nevertheless, C30 adapted successfully and thus maintained high milk yields despite negative EB. Leptin concentrations were lower in C30 than in C50 over the first 20 wk postpartum and were positively associated with BCS, EB, BW, cholesterol, albumin, insulin, and IGF-1; negatively associated with DMI and triiodothyronine; and were higher in cows calving in spring than in fall. Leptin is one among several factors involved in the regulation of energy metabolism and may be important for overall homeostatic and homeorhetic control of metabolism and thus for maintenance of performance.

Effect of calf age and dam breed on intake, energy expenditure, and excretion of nitrogen, phosphorus, and methane of beef cows with calves.

The effects of calf age and dam breeds of different milk yield potential on turnover of energy and nutrients were followed in 16 Simmental and 16 Angus beef cows with Angus-sired calves. Calf ages investigated were 1, 4, 7, and 10 mo. The forage offered for ad libitum access consisted of hay for the calves and of a constant mixture of grass silage, meadow hay, and straw (1:0.7:0.3 on a DM basis) for the cows. Calves of 10 mo of age received an additional 2.6 kg DM/d of crushed barley. The animals were kept in groups of four cows and four calves except in the respiration chambers, where only one cow (tethered) and her calf (loose) were grouped together. Indicator techniques were applied to obtain individual data on feces and urine volumes during group housing. In the Simmental cows, heavier on average by 22 kg, voluntary DMI was higher than in the Angus cows (14.0 vs 12.3 kg/d). In calves, DMI from supplementary feeds was 1.6, 3.9, and 6.3 kg/d, on average, at 4, 7, and 10 mo of age, respectively. Dam breed had no significant effect on DMI and ADG of calves and on BW changes of cows. System retention of energy, N, and P showed a curvilinear development with calf age. System energy expenditure, which linearly increased with calf age, was higher with Simmental than with Angus dams (11%), even when adjusted for metabolic BW (8%). Energy loss through methane linearly increased with NDF intake and, consequently, with calf age from 18 to 30 MJ/d (446 to 751 L/d) for cows and calves together. Similarly, fecal and urinary N excretion and fecal P excretion steadily increased with calf age. In calves, the easily volatile N percentage of manure N rapidly decreased from very high levels in young calves. The resulting changes in inclination to gaseous N loss during manure storage for 8 wk were more than compensated by alterations in N intake of the calves, resulting in an increased total system N loss with progressing lactation. Overall, the present results indicate a difference between Angus and Simmental in efficiency of nutrient and energy utilization that might be explained by the difference in amount of delivery of nutrients to the calves via milk vs forage. Suggestions are made as to how the emissions of N, P, and methane, which were excessive in relation to productivity, could be reduced by nutritional means.

Estimation of energy balance at the individual and herd level using blood and milk traits in high-yielding dairy cows.

This study aimed to estimate individual and herd-level energy balance (EB) using blood and milk traits in 90 multiparous high-yielding Holstein cows, held on a research farm, from wk 1 to 10 postpartum (p.p.) and to investigate the precision of prediction with successively decreased data sets simulating smaller herd sizes and with pooled samples. Dry matter intake, milk yield, and BW were measured daily from parturition through wk 10 p.p. Milk composition was determined 4 times per week, and milk acetone was measured weekly. Blood samples for the determination of metabolites, hormones, electrolytes, and enzyme activities were taken weekly from wk 1 to 10 p.p. between 0730 and 0900. Body condition scores and ultrasonic measurements of backfat thickness and fat depth in the pelvic area were evaluated in wk 1, 4, and 8 p.p. Concentrations of glucose, cholesterol, urea, insulin, insulin-like growth factor-1, triiodothyronine, and thyroxine (T4) in blood plasma and of lactose and urea in milk were positively correlated with EB, whereas concentrations of nonesterified fatty acids (NEFA), creatinine, albumin, beta-hydroxybutyrate, and growth hormone and enzyme activities in blood, and concentrations of fat, protein, fat:lactose ratio, and acetone in milk were negatively correlated with EB. Leptin concentration was not correlated to EB over the first 10 wk p.p. To estimate EB linear mixed-effects, models were developed by backward selection procedures. The most informative traits for estimation of EB were the fat:lactose ratio in milk and NEFA and T4 concentrations in blood. The precision of estimation of EB in individual cows was low. Using blood in addition to milk traits did not result in higher precision of estimation of herd-level EB, and decreasing sample sizes considerably lowered the precision of EB prediction. Estimation of overall mean herd-level EB over the first 10 wk p.p. using pooled samples was precise even with small sample sizes, but does not consider the level of EB in particular weeks. In conclusion, estimation of herd-level EB at individual weeks using milk traits only has practical implication with herd sizes of > or = 100 cows if calving is highly seasonal and of or = 400 cows if calving is uniformly distributed. Using blood in addition to milk traits does not improve precision of estimation of herd-level EB, regardless of sample size.

[Lung metastasis of a benign giant cell tumor of the skeleton 27 years after resection of a recurrent tumor]. / Lungenmetastase eines gutartigen Riesenzelltumors des Skeletts 27 Jahre nach Resektion eines Tumorrezidivs.

Benign giant cell bone tumors sometimes develop benign pulmonary metastases. Most of these appear 3 to 4 years after the treatment of the primary tumor. Metastases have been diagnosed up to 11 years after the first diagnosis. The following is a case report of a 58-year-old man who developed lung metastases 27 years after the treatment of an aggressive local recurrence.

[Needlestick injuries in hospital personnel and the risk of hepatitis-B infection]. / Nadelstichverletzungen beim Spitalpersonal und Risiko der Hepatitis-B-Infektion.

The risk of employees of the University Hospital of Basel acquiring virus hepatitis B following needle stick injuries (NSI) was evaluated prospectively. Over four years, 555 NSI were reported, resulting in a mean incidence of 48 NSI/1000 persons working/year. Of the injured, 455 (82%) had previously been vaccinated against hepatitis B, 32 (6%) were HBsAg and/or anti-HBc positive, and only 65 (12%) were at risk for HBV infection. The origin of 365 (66%) of the needles implicated in the NSI was identified, and of these 15 (4%) had been contaminated with HBsAg-positive blood. None of the 555 persons with NSI developed hepatitis. We conclude that the risk of HBV infection following NSI is low at our institution, but general measures need to be enforced to reduce the incidence of NSI in view of the potential risk that other infectious diseases may be transmitted by NSI.