The effects of stationary periods and external temperature and humidity on thermal stress conditions within sheep transport vehicles.

AIM: To identify the contributions of stationary periods and external climatic environments to thermal stress conditions for sheep on livestock transport vehicles during journeys in summer. METHODS: Two livestock transport vehicles carrying sheep, operating under commercial conditions in New Zealand, were monitored during February and March 2002. Temperature and humidity were logged in five pens inside each vehicle, as well as externally. From these data, the temperature-humidity index (THI) was calculated. Global positioning equipment was used to log the location of the vehicle and whether it was moving or stationary. Regression analysis was used to identify factors that made a significant contribution to the THI within the vehicle. Regression models included the effects of vehicle, journey, initial ambient temperature or THI, pen position and duration of each stationary period. RESULTS: The THI in the livestock pens generally increased when vehicles were stationary. The highest THI value (95) was recorded in a vehicle on an enclosed deck of a Cook Strait ferry. Ambient conditions, the initial THI of a pen, and duration of the stationary period were all significant contributors to increases in the THI. Some increases in the THI occurred in stationary vehicles despite ambient conditions being mild, suggesting that lack of airflow was a critical factor. During stationary periods, 34% of THI readings exceeded 75, and, on average, the THI increased by 0.16 for every minute of a stationary period. CONCLUSIONS: Increases in the THI that could be detrimental to the welfare of sheep could occur on stationary sheep transport vehicles at most daytime ambient temperatures during summer. For a given stocking density and vehicle design, the THI of a pen increased in proportion to the duration of the stationary period. Mild ambient conditions (<25 degrees C) provided some protection against excessive THI increases if the duration of the stop was limited, but drivers are best advised to park their vehicles where there is airflow, and to minimise the duration of stops where possible. Livestock transport vehicles during summer should not be placed on enclosed ferry decks where airflow is absent or minimal.

Effects of surgical or banding castration on stress responses and behaviour of bulls.

OBJECTIVE: To compare the effects of surgical and latex banding methods of castration in 14- and 9-month-old bulls. DESIGN: Two randomised, controlled experiments. PROCEDURE: In Experiment 1, following administration of local anaesthetic, 14-month-old bulls were castrated by either surgical or banding methods, or left entire. Behavioural, plasma cortisol, plasma haptoglobin and bodyweight responses were recorded. A group of steers from the same mob was used as an additional comparison for bodyweight data. In Experiment 2, following administration of local anaesthetic, 9-month-old bulls were castrated by either surgical or banding methods and cortisol, haptoglobin and bodyweight responses were recorded. Entire bulls from the same group were used as an additional comparison for bodyweight data. RESULTS: In Experiment 1, surgical castrates exhibited more leg stamping and tail swishing than banded or entire animals in the hours after castration. Surgical castrates in both experiments also showed an increase in plasma haptoglobin, which resolved after 4 days. Plasma cortisol was generally not affected by castration. Surgical castrates grew more slowly than entire bulls, but faster than banded animals, in the 56 days after treatment. In Experiment 1, after 56 days, the bodyweights of surgical and banded castrates were not different from the bodyweights of the steers. Fourteen-month-old banded cattle developed persistent wounds above the latex band which remained for several weeks after scrotal dehiscence, but this did not occur in the 9-month-old animals. CONCLUSION: The banding procedure produced fewer acute effects, but a greater suppression of growth than surgical castration and induced prolonged wound formation in the older age group, suggesting that this procedure may not be as suitable for yearling cattle.

Effects of bovine oviductal proteins on bull spermatozoal function.

The effects of bovine oviductal proteins on bull sperm viability, acrosome reaction and motility were studied. Motile frozen/thawed spermatozoa from Percoll gradients were incubated with 1.0 mg/mL oviductal proteins (>8 kDa) extracted by ammonium sulphate precipitation from oviductal extract (OE) or serum-free oviductal epithelial cell-conditioned media (CM), treated in the presence (CM+) or absence (CM-) of 1 microg/mL 17beta-estradiol. Inclusion of oviductal proteins had a significant beneficial effect on sperm viability (76.3 to 80.6%+/-5.3) compared with the control (without oviductal proteins; 57.8%+/-5.3) immediately after the commencement of incubation. After 5 h, viability was significantly higher for CM- and OE treatments than for the control, although no differences were observed at 24 h. Acrosomal status only differed among treatments after 24 h, when higher percentages of acrosome- reacted spermatozoa were found in the control (46.0%+/-2.5) than in the oviductal protein treatments (33.1 to 38.2%+/-2.5). No differences in percentages of motile spermatozoa occurred within the first hour of incubation, although inclusion of CM proteins decreased sperm velocities, beat cross frequency, linearity, and straightness but increased values for mean angular displacement. These findings suggest that proteins secreted by oviductal epithelium promote viability, delay the acrosome reaction and suppress the motion of spermatozoa.

Studies on aromatic amino acid oxidase activity in ram spermatozoa: role of pyruvate as an antioxidant.

Chemical antioxidants and catalase have been shown to be ineffective in improving the motility of ram spermatozoa in a chemically-defined diluent (RSD-1). In an attempt to identify the biochemical basis of this observation, the activity of aromatic amino acid oxidase (AAAO), the enzyme responsible for generation of hydrogen peroxide in ram and bull spermatozoa, has been investigated. Ram spermatozoa contained higher levels of AAAO activity than bull spermatozoa, although the physico-chemical properties of the enzyme were generally similar in both species. Components of the medium had a marked effect upon AAAO activity. In the presence of glutamate and 3-(N-morpholino)propanesulfonic acid (MOPS), AAAO activity was decreased. Pyruvate appeared to increase AAAO activity. This was due to the ability of this substance to destroy hydrogen peroxide. Pyruvate in RSD-1 works as an effective antioxidant and therefore eliminates the need for other antioxidants in the semen diluent.

Motility of ram spermatozoa during storage in a chemically-defined diluent containing antioxidants.

The effects of five antioxidants--Vitamin E (VE), butylated hydroxyanisole (BHA), n-propyl gallate (n-PG), deferoxamine mesylate (Desferal) and catalase (EC 1 . 11 . 1 . 6)--on the maintenance of motility of ram spermatozoa in a chemically-defined ram semen diluent (RSD-1) have been evaluated. VE, n-PG and Desferal inhibited spermatozoal motility. The relative inhibition (i.e., ratio of change in % motility over 24 h between the treatment group and the corresponding control) at equimolar concentrations (100 microM) of Desferal, VE and n-PG were 1.6, 1.8 and 3.6 respectively. BHA had no effect at 10 microM but at lower concentrations, gave a slight improvement in motility in freshly diluted spermatozoal samples and in those stored for 1 day at 15 degrees C. The addition of catalase to RSD-1 was also ineffective in improving the motility of spermatozoa. The lack of beneficial effects of the tested antioxidants suggests that RSD-1 itself may destroy reactive oxygen species and the antioxidant activity of RSD-1 components requires further study.

Use of electronic probes for classifying lamb carcasses.

Three commercially available electronic lamb carcass grading probes (Hennessy Grading Probe, AUS-Meat Sheep Probe, Swedish FTC Lamb Probe) and one developmental probe (Ruakura GR lamb probe) were assessed for accuracy and suitability for use on-line on the lamb dressing chain for objectively classifying lamb carcasses. GR is the total tissue thickness over the 12th rib taken at a distance 11 cm from the mid-line, used to define fatness in lamb carcass grading in New Zealand. Probe measurements were compared with manually measured GR (sometimes used at present) and Toland probe measurements (total tissue depth between the ribs) for accuracy of predicting both GR on the right side of the carcass and also carcass water (indicating muscle) and fat content. Probes were tested on six occasions, each having approximately 50 lambs. All probes combined with carcass weight accounted for over 70% of the variation (R(2)) of GR right, with GR left accounting for 92% of the variation of GR right. Inclusion of a quadratic probe term was not quite as useful as inclusion of carcass weight for predicting GR right. The three commercial electronic probes individually when combined with carcass weight could account for 36-49% of the variation in the percentage of water and fat in the carcass, with the manual GR probe (right) on the chilled carcass accounting for 55% of the variation in water and 58% of the variation in fat percentages. Chilled carcass measurements are expected to give better results than readings on hot carcasses. The use of a quadratic probe coefficient instead of carcass weight with the probe readings gave similar accuracy of prediction of carcass composition. There was little difference between the two sides in the accuracy of prediction. Small differences were found between regressions relating probe readings to GR and composition for the different probing occasions. The electronic probe results from this trial are consistent with overseas results where probes are in use for objectively grading the carcasses of meat animals.

Effects of exogenous melatonin on prolactin secretion, lactogenesis and reproductive seasonality of adult female red deer (Cervus elaphus).

The effects of administration of exogenous melatonin to pregnant red deer hinds on prolactin secretion, lactogenesis and reproductive seasonality were studied. Mature hinds (n = 23) were allocated to one of four treatments. Hinds in treatment 1 (n = 6) each received two subcutaneous melatonin implants (Regulin) at monthly intervals starting on 2 October, about 80 days before expected parturition. Hinds in treatment 2 (n = 6) received similar treatment starting on 2 November, about 40 days before calving, whereas hinds in treatment 3 (n = 5) received treatment starting on the actual day of calving (about 10 December). Final implants were delivered on 1 February, with overall treatment durations of 150, 120 and 90 days for treatments 1-3, respectively. Hinds in treatment 4 (n = 6) served as controls and received no melatonin treatment. Blood samples were taken twice a week from September to May, and plasma was analysed for progesterone and prolactin. Mammary development was assessed by palpation score (0-5) twice a week from October to April inclusive, and liveweights were recorded at least every two weeks throughout the trial. Calving occurred between 28 November and 24 December, with no significant differences among treatments (P > 0.10). Hinds in treatment 1 exhibited significant retardation of mammary gland development and liveweight gain leading up to parturition (P < 0.01). Furthermore, sex-adjusted calf birth weights were on average 3 kg lighter for treatment 1 (P < 0.05), with all calves either removed for bottle-rearing or having died within a few hours of birth.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of animal sex and size on effort when pelting lambs.

Pelting load data were collected and analysed for 304 lambs (comprising 46% ewes, 26% cryptorchids and 28% rams), all of which came from one farm. Although typically about 24% more impulse (Ns) had to be applied for pelting ram lambs than for ewe or cryptorchid lambs, only one-third of this increase was attributable to the distinct sexual category of rams; the rest was due to rams being heavier. Carcass size had a much greater effect on pelting load than animal sex: a change in dressed carcass weight of slightly less than 1 kg has the same effect on impulse requirement as the net sex effect. These findings suggest that the differences in pelting effort associated with animal sex are of relatively minor significance compared with the large differences occurring over the range of lamb size normally processed.

Carcass composition and meat quality of brush-tail possums (Trichosurus vulpecula).

One-hundred-and-thirty-nine possums, balanced as far as possible for sex (68 male, 71 female) and age (1 year, 42; 2-4 years, 61; 5+ years, 36), were slaughtered and the dissected carcass composition, muscle, and cooked meat composition measured. Possums were slaughtered at time in captivity TIC 0 (n = 58), TIC 14 days (n = 20) and TIC 28 days (n = 61). Compared with the 5+ years (mature) age group the 1 year olds (juveniles) were 67% and the 2-4 year olds (immature) 96% of the live weight of the mature possums. Carcass composition was characterised by high lean (78-80%) and low fat (around 1-2%). The cooked meat from possums is very high in protein (∼ 25%) and low in fat, suggesting it should be a valuable source of animal protein with a low total fat, high unsaturated fat content. In all cases cooked meat was rated as tender, based on shear force values, despite having a pH of around 6·3.

The effect of sporidesmin toxicity on ovine serum vitamin B12 levels.

A field outbreak of facial eczema occurred during a vitamin B12 response trial in young growing sheep. Pasture cobalt levels were in the low range for sheep (<0.08 mg/kg, 1.358 micromol/kg) and mean (of 3) liver vitamin B12 levels in the sheep were low (<400 nmol/kg) during the period in which facial eczema occurred. Mean serum vitamin B12 levels of the untreated group were low (<485 pmol/l) for the two months (January and February) preceding the period of facial eczema. However, levels showed an approximate 3.5 fold increase in both cobalt supplemented and unsupplemented groups with the onset of facial eczema in March. From February to March the mean serum vitamin B12 and glutamyl transferase (GGT) activity showed parallel increases with a positive correlation (r = 0.73) between log serum vitamin B12 and log serum GGT activity during the period January to July for both groups. This finding suggested that the increase in serum vitamin B12 was due to sporidesmin induced liver damage. The diagnostic implication is that, in areas where facial eczema is a problem, liver is the sample of choice for determining vitamin B12 status. because sporidesmin toxicity can elevate low serum vitamin B12 levels to diagnostically normal levels.

Use of the Hennessy Grading Probe (GP) for predicting the meat, fat and bone yields of beef carcasses.

Left sides of 36 bulls, 22 cows, 57 steers and 38 heifer carcasses were weighed hot (HCWL) and were probed with the Hennessy Grading Probe (HGP) at five sites to give four subcutaneous fat depths, two M. longissimus dorsi depths and one total tissue depth measurement. A fat depth (GR) over the 10th rib was also measured by ruler probe. The left sides were later separated by knife into saleable eat (90% visual lean), fat trim and bone. Probe readings of subcutaneous fat thickness at the fatter rump sites (BF, 5-7 cm lateral to the perianal region over the M. biceps femoris; SC8, 8 cm lateral to the prominence of the sacral crest) were smaller than ruler measurements at the same sites. Probe eye muscle depth measurements were smaller than measurements taken at the same site by ruler. The BF measurement taken by probe, combined with HCWL, gave the best prediction of percentage fat trim (RSD = 2·0% for steers and 2·2% for heifers) and edible meat yield (RSD = 2·0% for steers and 2·6% for heifers) in the left sides of all the measurements studied, either singly or in combination. A major problem was to find a measurement site where subcutaneous fat was not removed from some carcasses during hide removal.

The effect of bone in meat samples upon analytical results for fat, protein and water by foss Super-Scan type 10600.

Investigations have been made into possible spectral interferences at fat, protein and water wavelengths of the Super-Scan (infra-red meat analyser) due to absorbance by phosphorus (a natural constituent of bone) at the carbohydrate wavelength. Instrument calibration for boneless meat resulted in the need for correction factors to results for bone-in meat of × 0·96, × 1·05 and × 0·97 for % fat, % protein and % water, respectively, to bring them in line with those by standard chemical methods. Comparisons between Super-Scan results for boneless meat to which tricalcium phosphate (the major constituent of bone) has been added showed an interference proportional to the amount of phosphate present and varied in size depending on sample fatness. Calibration with bone-in meat controlled interference adequately for % fat and % water, but still required an empirical correction factor of × 0·97 for protein.

The effects of infant feeding, birth order, occupation and socio-economic status on speech in six-year-old children.

The relationship of breast-feeding to the incidence of clear speech at six years of age was examined for 319 New Zealand children of European descent in samples from Putaruru and West Coast. Children were more likely to be breast-fed if first-born, and less likely if the father's occupational group was business or labouring. Differences in clear speech were associated with birth order and socio-economic status. Controlling for these effects, the association of breast-feeding with clear speech was different for the sexes. It was negligible for girls but strongly positive for boys.

Associations between dry cow therapy, clinical mastitis, and somatic cell count score with milk and fat production in ten New Zealand dairy herds.

Cows in each of 10 dairy herds were assigned to two similar groups on age, breed, production, and previous mastitis history. Only cows in one group received dry cow therapy at the end of their 1977-1978 lactations. Production of all cows was tested at bi-monthly intervals during their 1978-1979 lactations. The composite evening and morning sample for milk fat measurement also was used for somatic cell counting. In the therapy group, 15.4% of cows had clinical mastitis detected by the herd owners during post-treatment lactations compared to a 9% incidence among untreated herd mates. Lactational average milk somatic cell count was higher in cows detected with clinical mastitis but lower in the therapy group. Untreated cows subsequently produced less milk (3706 versus 3966 liters) with this effect most pronounced among untreated cows with higher average cell count scores. Similarly, the depressive effects of detected clinical mastitis on production were most apparent among those cows in which clinical infection was associated with high lactational cell count score. Clinical mastitis depressed production more in Jersey cows than in Friesian-Jersey crossbreds. In these herds selective dry cow therapy may have been preferable to whole herd therapy.