Jens Hindhede

Resting and social behaviour of dairy heifers housed in slatted floor pens with different sized bedded lying areas

Abstract The hypothesis that an increase in the straw bedded resting area for group housed heifers would increase synchronization of resting behaviour and decrease aggressive and abnormal behaviour was tested. An experiment was conducted on two Danish commercial dairy farms with 20 Danish Friesian heifers (approximately 400 kg) from November 1994 to April 1995. The experimental pens were constructed on existing slatted floor and contained a total area of 27 m 2 per pen with five heifers in each pen. Three different sizes of lying area (1.8, 2.7 and 3.6 m 2 per heifer) bedded with straw were established in each pen for three consecutive periods of 5 weeks. Resting and social behaviour were recorded using direct observations for 24 h at the end of each 5 week treatment period. The synchronization of resting behaviour was reduced ( P = 0.002) when the heifers were offered 1.8 m 2 bedded lying area per heifer compared with 2.7 or 3.6 m 2 per heifer, and the heifers were more aggressive, as more butting ( P = 0.007) and forcing another heifer to stand up ( P = 0.02) were seen. The frequency of leaning against other heifers was highest ( P = 0.05) at the lowest space allowance in the bedded area. The results indicate that increasing the resting area from 1.8 m 2 to 2.7 or 3.6 m 2 per heifer improved the welfare of group housed dairy heifers.

Association between resting behaviour and live weight gain in dairy heifers housed in pens with different space allowance and floor type

The hypothesis that daily gain is associated with resting behaviour in heifers is tested in this paper. The test is based on two experiments conducted on Danish commercial dairy farms with Danish Friesian heifers (300–400 kg) in the winter periods. Group size was 5–6 heifers per pen. Experiment A, with 80 heifers, investigated the effect of different space allowances (1.5 or 3.0 m2 per heifer on fully slatted floor) and different floor types (fully slatted or with access to bedding). Experiment B, with 70 heifers, investigated the effect of space allowance in the deep bedding area (1.8; 2.7 and 3.6 m2 resting area per heifer). Data from experiment A showed a tendency towards a positive correlation between lying periods and daily gain for heifers housed on fully slatted floor but not when housed with access to bedding. There tended to be a positive correlation between number of lying periods and daily gain at a low but not at a high space allowance. The data from experiment B showed a tendency towards a positive correlation between lying time and daily gain at a low space allowance in the deep bedding area and not at a high space allowance. Among heifers in the pens with access to bedding in experiment A, it was found that one particular heifer in each of the four pens lay significantly more on the slatted floor and this heifer had an average daily gain which was less than the others.

Expert opinions of strategies for milk fever control

Dairy cows have several risk factors for milk fever. The most-suitable strategy to control milk fever in a specific herd will depend on herd-specific circumstances such as the attitude and skills of the farmer, the opportunities available in the production system and the economic consequences of a certain strategy. To develop feasible strategies in a modern loose-housing dairy herd, we carried out an expert opinion study. Animal husbandry advisors and veterinary practitioners were used as experts. The experts quantified the effect on milk fever and time needed by the farmer for two preselected options: Ca-gel fed orally peripartum and a low dietary cation-anion-difference in the dry-cow ration. The estimated mean relative risk (compared to no strategy) was 0.45 and 0.42, respectively, and the median time needed by the farmer was 7 and 33 min, respectively, per cow year. The experts also suggested 12 control strategies. The two control strategies, which were predicted to be the most, relevant were Ca-gel fed orally peripartum used alone and used in combination with a low Ca dry-cow diet.

Effect of space allowance in deep bedding systems on resting behaviour, production, and health of dairy heifers

An experiment was conducted on three Danish commercial dairy farms using 70 Danish Friesian heifers over a period of 141 to 162 days beginning in November. Average body weight of the heifers was 315 kg at the beginning of the experiment. Fourteen experimental pens were established with a flock size of five and different space allowance in the deep bedding area: 1.8, 2.7, and 3.6 m2 resting area per heifer. The total space allowance inclusive of an unstrawed area at the feed manger was 3.6, 4.5, or 5.5 m2 per heifer in herd 1, 3.6 or 4.5 m2 per heifer in herd 3, and 3.0 or 4.9 m2 per heifer in herd 2. Eating space was standardized within pens to 60 cm per animal. Feed was available ad libitum. At 1.8 m2 resting area per heifer, the heifers were unable to synchronize their resting behaviour, and the variance of the daily lying time was higher compared with heifers at 2.7 or 3.6 m2 resting area. None of the heifers were lying on the unstrawed area. Total lying time was not affected by the space allowance of ...

Effect of Space Allowance, Access to Bedding, and Flock Size in Slatted Floor Systems on the Production and Health of Dairy Heifers

Abstract An experiment was conducted on seven Danish commercial dairy farms with 200 Danish Friesian heifers (315 kg) in 152 days from the month of November. Founded on existing slatted floor systems, 32 experimental pens were established with Low (L) or High (H) space allowance (1.5 vs. 3.0 m2 per animal), different type of separate lying area (Slatted (S) vs. Bedded (B) floor) and different flock size (6 vs. 12 animals). Eating spaces were standardized to about 50 cm per animal. Ad libitum feeding was practised and rations contained a maximum 30% concentrates (dry matter). An increase in space allowance from 1.5 to 3.0 m2 per animal in pens with fully slatted floors increased the live weight gain by 174 g day−1 or 31% (P = .04) and net energy intake per kg live weight gain was reduced by 23% (P = .04). Heifers housed in small pens lay down less than heifers in large pens. Access to bedding affected number of lying periods. Production, however, was not influenced by access to a bedded lying area. Flock s...

Effect of group composition and feeding system on behaviour, production and health of dairy heifers in deep bedding systems

An experiment was conducted in eight Danish commercial dairy herds, using 168 Danish Friesian heifers for 5 months, from November 1995. Three groups were established in each herd: two small, homogeneous groups (SHom) with five light heifers (130-250 kg) or five heavy heifers (250-380 kg) and one large, heterogeneous group (LHet) with ten light and heavy heifers (130-380 kg). The space allowance per heifer was 4.5 m2 including a 2.7-m2 resting area (deep litter). Four herds were fed restrictive amounts of concentrate per pen and ammonium-treated straw ad libitum (RCS) and four herds were fed one ration of either silage or total mixed ration (TMR) ad libitum (OR). The group composition had no general affect on the live weight gain (LWG). When using the RCS feeding system, the daily LWG in the LHet groups compared with the SHom groups decreased by 95 g for the light heifers, whereas it increased by 31 g for the heavy heifers. The average feed intake was 7% lower in the LHet groups than in the SHom groups (P=...

Technical and economic effects of feeding one vs. multiple total mixed rations estimated by stochastic simulation under different dairy herd and management characteristics

Abstract The objectives of the present study were: (1) to estimate technical and economic effects of using one vs. multiple TMR feeding groups under different dairy herd and management characteristics (feed level, daily milk yield thresholds for group change, production potential and reproduction and culling for replacement management strategy); and (2) to establish optimum energy content of mixed rations when feeding one TMR all cows in milk (TMR-1). TMR refer to total mixed rations and defines ad libitum feeding of a mixed ration of all feeding ingredients except water. Data were simulated using a mechanistic, dynamic, stochastic simulation model. Equal feed intake per cow per year was obtained with a significantly lower energy content of the initial ration when feeding TMR-1, and the effect of the daily milk yield thresholds used to decide group change were higher than the effect of feeding two vs. three groups. Production and economic effects of the feeding strategies were generally explained by feed intake per cow per year with TMR-1 being inferior at high feed intake due to higher concentrates intake and lower milk production per cow. Optimum energy content according to total net revenue when feeding TMR-1 was affected by milk and concentrate prices, production potential, and reproduction and culling management strategies. Optimum energy content was affected significantly when evaluated as net revenue per kg energy corrected milk (ECM) produced instead of total net revenue (ECM = kg milk (0.383 fat% + 0.242 protein% + 0.7832)/3.140).

Incidence of Milk Fever and Description of Applied Control Strategies for Preventing Milk Fever/Subclinical Hypocalcaemia in Large Dairy Herds

Farmers choice of feasible strategies for preventing milk fever/subclinical hypocalcaemia amongst several options is motivated and influenced by many factors. When developing strategies for milk fever control in modern dairy herds it is relevant to know what strategies are currently preferred in the herds; but this knowledge is scarce. During the year 1998/99 a cohort study was performed among a selected group of 38 modern Danish dairy herds on the farmers use of relevant and feasible strategies for preventing milk fever. The requirements to be met by the farms were, that a. The cows should be stalled in loose housing systems b. The herd size should be at least 100 dairy cows and c. The farmer should be member of the National Danish Milk Recording Scheme. In addition to this some variation between farms were wanted concerning breed, milk yield per cow, housing, feeding etc. A technician from DIAS visited each farm four times during 1.5 year for data collection: recordings and interviews. The farmer continuously recorded all cases where he observed clear milk fever symptoms and subsequently treated by himself. The herds in the survey were relatively large (> 120 dairy cows) and most practised TMR and group feeding. Dry cows were grouped separately in all 38 herds. The average milk fever incidence for all parities in all 38 herds was 5.3% (0 - 21%). The incidence was lowest for cows in first and second parity, but increased progressively with higher parity, thus 17.0% for cows in 4th or later lactation. There was a large variation in incidences between herds also in same parity, thus from 0 to 3 % in first parity, 0 to 13 % in second parity and 0 to 47 % for cows in 4th or later lactation. Options for control of milk fever/subclinical hypocalcaemia were used systematically in 32 of the 38 herds. The proportion of herds using various options was following: 1. Low Calcium content in rations for dry cows 21 % 2. Low Ca/P-ratio in rations for dry cows

Effect of Space Allowance and Access to Bedding in Slatted-floor Housing Systems During Second-year Rearing on Subsequent Milk Production of Primiparious Dairy Cows

An on-farm experiment was conducted for 152 days on seven Danish commercial dairy farms with Danish Friesian heifers housed in pens with low or high space allowance (1.5 vs. 3.0 m2 per heifer) on a slatted floor, or with high space allowance and different floor types in the lying area (slatted vs. bedded). At the beginning of the experiment, the heifers weighed 315 kg on average. Data from 105 heifers indicated the tendency that an increase in space allowance was associated with a decline in milk production in the first 84 days post partum. Access to bedding compared with a fully slatted floor tended to increase milk production 84 days post partum. No effect of housing during rearing was found on later somatic cell count per ml milk.