Ellen C. Jongman

The aversiveness of carbon dioxide stunning in pigs and a comparison of the CO2 stunner crate vs. the V-restrainer

Using aversion learning techniques, the relative aversiveness of CO(2) to pigs in comparison to a shock with an electric prodder, and the aversiveness of a CO(2)-stunner crate in comparison to the aversiveness of a V-belt restrainer used for electric stunning were examined. The results showed that 90% CO(2) was considerably less aversive than an electric shock with a prodder. However, during exposure to 90% CO(2) all pigs lost conscious, which may have affected their memory of the procedure. The pigs remained conscious after exposure to 60% CO(2) and again showed virtually no aversion towards the stunner crate, while an electric shock with a prodder appeared highly aversive. The aversion to the V-restrainer belt and the CO(2) crate were similar.

Milking regimes to shorten milking duration.

Four milking regimes using automatic cluster removers (ACR) were tested over a 19-week period, from mid to late lactation. Each treatment group consisted of 16 slow-milking cows. The milking regimes used were: an ACR setting of 200 ml/min (Control); raised ACR setting from 200 to 500 in steps of 100 ml/min (Raised ACR); raised ACR as above in conjunction with pre-milking teat stimulation (Raised ACR+Stim); and terminating the milking when an ACR threshold of 200 ml/min was reached or when a predetermined maximum milking duration was reached (Timer). All incremental treatments were applied in blocks of 6 or 7 weeks duration. ACR thresholds were raised from 200 to 500 ml/min without observed loss of milk production when compared with controls. However, even up to an ACR setting of 500 ml/min there was little reduction in the group milking duration even when used with teat stimulation. In contrast, the Timer treatment resulted in a 34% reduction of the maximum milking duration for the group without significant loss of milk yield. For all groups, including Control, strip yield was occasionally very high and highly variable. Willingness of cows to enter the milking platform, behaviour during milking, teat condition and incidence of mastitis were similar for all treatment groups. The results indicated that simple truncation of milking at a predetermined maximum duration could be a most potent and inexpensive method of milking a herd more quickly. Such a method could be employed by using a simple timer in any dairy regardless of the level of sophistication of the milking system.

The influence of conditions at the time of mating on reproduction of commercial pigs

The objective of this study was to compare a new mating system, called the Detection-Mating Area (DM Area), and a conventional mating system on the long-term reproductive performance of commercial pigs. The DM Area treatment basically involved detecting oestrous females in an arena closely surrounded on two sides by boars and mating these females in this arena. This mating system was designed to improve the physical and sexual environments of the pigs at mating. In contrast, the conventional treatment involved conducting oestrus detection and mating in the boars accommodation pen. The study was conducted over an 18-month period at a commercial farm that housed 2400 breeding female pigs. In order to control for the effects of the stockperson, an analysis was conducted on the reproductive performance of female pigs in which one stockperson assisted the matings in both treatments over a 12-month period. Gilts mated in the DM Area treatment had a higher (P 0.05). There were no significant (P>0.05) differences found between the reproductive performance of sows in the two treatments; however this comparison was confounded by sows in the DM Area treatment having a lower number of matings per oestrus than those in the other treatment. Observations on the sexual behaviour of pigs at 145 matings indicated that the boars in the DM Area treatment displayed a higher (P<0.05) number of bouts of courting behaviour directed towards the female than boars in the conventional treatment (8.3 and 6.4, respectively). These very limited observations on sexual behaviour suggest that changes in the courting behaviour of bears may be associated with changes in litter size. While there was some indication from the results of progesterone analysis of blood samples taken from unmated gilts that there may have been some differences between treatments in the sexual age of gilts at matings, these differences are unlikely to explain the differences in litter size between treatments. Further research is required to identify the component (s) of the DM Area treatment that are responsible for the improvement in litter size in gilts and to further examine the effects of the two treatments on the reproductive performance of sows.

Space allowance and barriers influence cow competition for mixed rations fed on a feed-pad between bouts of grazing

The objective of this experiment was to evaluate how feeding space allowance and provision of feed barriers interact to affect feeding and social behavior of dairy cows fed a partial mixed ration on a feed-pad. The treatments were factorial with 3 feeding space allowances (0.6, 0.75, or 1.0m of trough space per cow) and feed troughs that were either open or had head barriers that physically separated adjacent cows to reduce interactions during feeding. One hundred and forty-four Holstein-Friesian cows in mid lactation were allocated into 12 groups of 12 cows, with 1 of 6 treatments (3 × 2) randomly assigned to 2 groups out of 12. Treatments were changed weekly over 3 wk according to a row-column, crossover design, with week corresponding to rows and group corresponding to columns. Thus, the design included 2 replicated groups per treatment in each week. Grazed pasture intake was approximately 6.1 kg of dry matter (DM)/cow per day, supplemented with 3.5 kg of DM/cow per day of wheat (Triticum aestivum) grain fed during milking and 10.7 kg of DM/cow per day of a mixed ration offered on the feed-pad after each milking. The experiment comprised a 7-d pre-experimental period followed by a 21-d experimental period. The social hierarchy within each group was determined before the experiment commenced. Feeding and social behaviors of cows were analyzed using video recordings and the changes in heart rate and heart rate variability were determined using heart rate monitors. Data were analyzed using mixed effect models by REML. When feeding space allowance was increased, we observed an increase in the time a cow spent feeding and a decrease in the number of feeding bouts in relation to the total time feed was available, particularly in subordinate cows. The number of aggressive behaviors and displacements decreased when space allowance increased. In addition, HR was reduced and the reduction was more pronounced in subordinate cows compared with dominant cows. Use of feed barriers increased cow feeding time and decreased the number of feeding bouts in relation to the total time feed was available, particularly in subordinate cows, and reduced the number of cow displacements during feeding. We conclude that increasing the feeding space from 0.6 to 0.75 to 1.0m reduces aggressive interactions and improves cow feeding behavior, with the effects being greatest for subordinate cows. The use of feed barriers further reduces competition at the feed trough in a partial mixed ration feeding system.

A survey of Australian dairy farmers to investigate animal welfare risks associated with increasing scale of production

Although large herds (more than 500 cows) only represent 13% of Australian dairy farms, they represent more than 35% of the cows milked. A survey of Australian dairy farmers was conducted to assess relationships between herd size and known or proposed risk factors for adverse animal welfare outcomes in Australian dairy herds in relation to increasing scale of production. Responses from 863 Australian dairy farms (13% of Australian dairy farms) were received. Increasing herd size was associated with increases in stocking density, stock per labor unit, and grain fed per day-all of which could reasonably be hypothesized to increase the risk of adverse welfare outcomes unless carefully managed. However, increasing herd size was also associated with an increased likelihood of staff with formal and industry-based training qualifications. Herd size was not associated with reported increases in mastitis or lameness treatments. Some disease conditions, such as milk fever, gut problems, and down cows, were reported less in larger herds. Larger herds were more likely to have routine veterinary herd health visits, separate milking of the main herd and the sick herd, transition diets before calving, and written protocols for disease treatment. They were more likely to use monitoring systems such as electronic identification in the dairy, computerized records, daily milk yield or cell count monitoring, and pedometers or activity meters. Euthanasia methods were consistent between herds of varying sizes, and it was noted that less than 3% of farms make use of captive-bolt devices despite their effectiveness and ready availability. Increasing herd size was related to increased herd milking time, increased time away from the paddock, and increased distance walked. If the milking order of cows is consistent, this may result in reduced feed access for late-milking-order cows because of a difference in time away from the paddock. More than 95% of farmers believed that their cows were content most of the time, and cows were reported as well behaved on more than 90% of farms. Although the potential animal welfare issues appear to be different between herd sizes, no evidence existed for a relationship between herd size and adverse welfare outcomes in terms of reported disease or cow contentment levels.

Reduced space allowance for adult sheep in lairage for 24hours limits lying behaviour but not drinking behaviour

The key lairage requirements for livestock include sufficient space to lie down, sufficient time to allow recovery from travel, and access to water to allow recovery from dehydration. Current recommendations for lairage of adult sheep include that holding pens should provide no less space than 0.6 m2 per sheep. Particularly during periods when large numbers of sheep are culled, space allowances may be limited to 0.3 m2 or less, which may reduce the ability of individual sheep to lie down or access water. Adult Merino-cross sheep were allocated to one of four space allowance treatments during unloading from commercial transport vehicles at a commercial abattoir after an average transport time of 3 h. The treatments were 0.3, 0.45, 0.6 and 1.0 m2/sheep and each pen measured 18 m2. Differences in space allowance were achieved by varying the number of sheep per pen, with pens holding 18 (1 m2), 30 (0.6 m2), 40 (0.45 m2) and 60 (0.3 m2) animals. In each pen, eight focal sheep were randomly selected and marked on the back for identification on video records. The sheep remained in the lairage treatments for 24 h and were continuously recorded on video using low light cameras. The data were subsequently analysed for both lying and drinking behaviours after 8 and 24 h in lairage. There were five replicates of all treatments over a 3-week period. A space allowance of 0.3 m2/sheep reduced the time sheep spent lying and the proportion of sheep that lay down at least once, compared with greater space allowances. Space allowances between 0.3 and 1 m2/sheep showed a linear relationship with the time sheep spent lying during the first 24 h. Optimal space allowance may be greater than 1 m2, based on lying behaviour. Drinking behaviour was not affected by space allowance in a 24 h period in lairage although overall 20% of sheep were not observed to drink after 24 h in lairage.

Behavioural responses of lambs to plastic clips as an alternative procedure to mulesing

OBJECTIVE Compare the effects on the behaviour of lambs of applying occlusive plastic clips, as an alternative procedure to surgical mulesing, with tail docking, surgical mulesing and a control treatment. PROCEDURE We allocated 48 6-7-week-old Merino lambs to four treatment groups: plastic clips (Clip); surgical mulesing (Mules); tail docking with a rubber ring (Tail ring); no treatment (Control). For each posture and behaviour observed on each of the 4 days post-treatment, a Dunnetts multiple comparison test was used to simultaneously compare the Clip treatment with each of the comparator treatments (Control, Tail ring and Mules treatments). RESULTS Most of the significant differences (P < 0.05) detected between the comparator treatments occurred on day 1. For four of these measurements, the Clip treatment differed (P < 0.01) from the Mules treatment, but from not the Control and Tail ring treatments: the Clip lambs spent less time standing immobile not interacting with ground, hay or feeder, less time standing immobile head down not interacting with ground, hay or feeder, more time walking and more time interacting with ground, hay or feeder. CONCLUSION These behavioural results, together with previous behavioural and physiological research, indicate that the effect on lamb welfare of applying occlusive clips is less than that of surgical mulesing.

The effects of direct and indirect road transport consignment in combination with feed withdrawal in young dairy calves

Male dairy calves may be transported from their farm of origin at a young age. This process may involve an extended period off feed and indirect consignment through an intermediate facility, prompting potential welfare concerns. To assess the impact of transport, 59 male Holstein-Friesian dairy calves (5-9 d old) were either (1) held in situ on farm (control); (2) transported for 6 h; (3) transported for 12 h; or (4) transported for 1 h to a holding facility where they were kept for 6 h and then transported for 5 h. All treatments included a 30-h period of feed (milk) withdrawal, and calf responses were measured over time from before their last feed until the completion of the study after the transport and feed withdrawal periods. Apart from increases in serum creatine kinase in calves transported for 12 h, transported calves generally did not differ in blood concentrations of glucose, beta-hydroxybutyrate, lactate, total protein or in packed cell volume, compared with controls (P>0.05). Calf responses to the indirect consignment treatment did not differ from those of other transported calves. Withdrawal of feed for 30 h caused calves to lose 6% of body weight; blood glucose varied from 3.96 mmol/l immediately before daily feeding to 5.46 mmol/l at 3 h post feeding, and then declined to 3.43 mmol/l at 30 h. Calves lay down for 22-32% of the time during transport, and did not show a rebound effect in lying behaviour post arrival in comparison with controls. Best practice transport of 6-12 h duration, including indirect consignment via a holding facility, did not significantly affect calf blood biochemistry and metabolism in comparison with untransported animals. However, extending the time off feed beyond the daily feeding interval resulted in reduced blood glucose concentrations, suggesting that time off feed needs to be carefully managed in young transported dairy calves.

Short communication: Milking order consistency of dairy cows in large Australian herds

We used on-farm records from dairy infrastructure to examine the consistency of the milking order over 150 d in 5 Australian dairy herds that were milking more than 500 cows as a single group. Within a single day the difference in milking order rank position was less than 20 percentage points for 72% of cows. The correlation coefficient comparing milking rank position in the morning and afternoon was 0.72, with the position of cows at the beginning and end of the milking order being more consistent than cows toward the middle of the milking order. Over a period of 150 d, cows with a mean position in the first and last 20% of the milking order maintained their position more consistently than cows in the middle of the milking order. Milking position of cows between one month and the next was highly correlated (r = 0.88). In large herds, subpopulations of cows are regularly milked toward the beginning and the end of the milking order. It is common for cows to be collected from the paddock as a group, to wait as a group in the dairy yard to be milked, and to return individually to the paddock or feed pad immediately after they have been milked. Thus, cows milked later in the milking order are likely to be away from the paddock for several hours longer than cows milked earlier in the milking order. This may affect their welfare though differences in time available for lying down, equality of pasture eaten, and time spent standing in the dairy yard.

The impact of a shaded pre-milking yard on a pasture-based automatic milking system

During hot weather cows typically reduce feed intake and actively seek shade and water to reduce the metabolic stress on their bodies. This can have a negative impact on the occurrence of voluntary milking visits to an automatic milking system (AMS) operating with voluntary traffic, thus reducing milking frequency. Shade is known to be effective in alleviating heat stress in dairy cattle; however, the impact of providing shade at the milking facility of a pasture-based AMS on time taken to voluntarily enter a milking unit is unknown. A herd of ~300 lactating cows milked in a pasture-based AMS were divided into two groups during the summer of 2016. Each group spent 4 weeks in a SHADE (predominately shaded pre-milking yard) and a NO-SHADE (predominantly non-shaded pre-milking yard) treatment, with two periods in a crossover design. Cow respiration rates, time spent in pre- and post-milking areas, concentrate consumption and milk yield were recorded. On average, cows in the SHADE treatment were found to take longer to enter the milking unit than did cows in the NO-SHADE treatment (SHADE = 11.40 min, NO-SHADE = 8.70 min, P < 0.001). SHADE was also associated with lower average respiration rates (SHADE = 68 breaths per minute (bpm), NO-SHADE = 73 bpm, P < 0.001), increased concentrate consumption (SHADE = 6.50 kg/cow.day, NO-SHADE = 6.39 kg/cow.day, P = 0.03) and increased milk yield (SHADE = 11.44 kg/cow.milking, NO-SHADE = 10.95 kg/cow.milking, P < 0.001). Overall, SHADE made available to the cows pre-milking appeared to improve cow performance and comfort (as indicated by reduced respiration rates).