Experimental lead-poisoning in dogs

Extract

It has long been established that antibodies to the major anaerobic infections in sheep are transferred to the suckled lamb in the colostrum or first milk. Effective absorption of such antibodies from the gastro-intestinal tract takes place during the first fifteen hours of life; hence, in order to acquire protection the lamb must have suckled during this period. The degree of protection available in the colostrum will depend on the success of the immunization procedures in the ewe.     

Post-partum Reproductive Performance of Sanga Cattle in Smallholder Peri-urban Dairy Herds in the Accra Plains of Ghana

The reproductive performance of 76 Sanga cows was studied from February 1995 to July 1996 in smallholder peri-urban dairy systems in the coastal savanna zone of the Accra plains of Ghana. The interval from calving to resumption of cyclic ovarian activity was 101±7 days; that from calving to conception was 152±4 days; gestation length was 292±16 days; and the calving interval was 444±16 days. The effects of location, season of calving, parity, body condition score and sex of calf were studied. Calving to cycling interval was significantly shorter in the dry season than in the wet season, and decreased significantly with increasing body condition score. Calving to conception interval was affected only by location. Gestation length was not affected by any of the variables studied. Calving interval was affected by location, season of calving, parity and body condition score. It is concluded that long post-partum anoestrus leads to prolonged calving intervals and poor reproductive performance. Feed supplementation to improve the nutritional status and body condition score of cows and early weaning of calves could be introduced to enhance reproductive performance.     

Post-partum ovarian activity in Finnhorse mares with special reference to seasonal effects.

In a previous study, times from parturition to the first ovulation were followed in 55 Finnhorse mares on the basis of milk progesterone determinations. Ninety-six per cent of mares had ovulated by day 20 post-partum. If intervals of more than 19 days are excluded from the data, the time from parturition to 1st ovulation was 117 days. However, in cases of foaling before and after the beginning of June the times were 13.0 days and 8.8 days, respectively (p less than 0.001). Long intervals (over 16 days) occurred mainly before 1st May (in 6 out of 7 cases). In a 2nd study, 25 post-partum Finnhorse mares were examined by rectal palpation and ultrasonic scanning. Five and 7 days post partum, but not 2 days post partum there was a statistically significant difference between ovulatory ovaries and non-ovulatory ovaries regarding size of whole ovary and the largest follicle. Six to 8 days before the first post-partum ovulation, the size of the preovulatory follicle was greater in mares which had foaled before the middle of May (32 mm) than in those which had foaled after the middle of May (20 mm) (p less than 0.05). Within 2 days before ovulation there was no statistical difference between the sizes (43 mm and 42 mm, respectively). The growth rate was therefore slower in cases of early foaling (1.8 mm/day) than in cases of late foaling (3.7 mm/day).     

Effect of restricted suckling on milk yield,composition and flow,udder health,and postpartum anoestrus in grazing Holstein cows

The effect of restricted suckling on milk yield and composition, udder health, and postpartum anoestrus in dairy cows in pasture-based systems, was studied in 32 Holstein multiparous cows and their calves. At calving, each cow–calf pair was randomly assigned to one of two treatments: restricted suckling (RS) of the cows by her own or another calf, twice daily for 30 min or artificial rearing (AR) of the calves with milk obtained from the bulk tank, offered twice a day in buckets. Treatments were applied until week 8 after calving. The diet of the cows consisted of direct grazing in improved pastures, corn silage and a commercial concentrate which was offered at milking. Milk production and composition, udder health, body condition score of the cows, body weight and milk intake of the calves were measured weekly, and the first postpartum ovulation was determined three times a week by ovarian ultrasonography. Cows with RS management had a lower machine-milked milk yield (17.9 vs. 24.8 kg/d), a lower fat percentage (3.21 vs. 4.11%) and 4% fat-corrected milk yield (16.2 vs. 25.7 kg/d), and also a lower average milk flow (1.35 vs. 1.76 kg/min) than cows in the AR treatment. There was no effect of treatment on milk protein percentage or udder health as measured by milk electrical conductivity. The interval from calving to first postpartum ovulation was shorter in the AR cows than in the RS cows (18.5 vs. 21.8 days). The RS calves consumed more milk (7.2 vs. 5.4 kg/d), gained more body weight (0.813 vs. 0.656 kg/d), and had a higher body weight at weaning (84.3 vs. 73.3 kg) than AR calves. Restricted suckling of grazing dairy cows had a negative effect on machine-milked milk yield, fat percentage and 4% fat-corrected milk yield, but had no effect on udder health or on improved weight gain and body weight at weaning of the calves.     

Metabolic and luteal function in winter‐calving Spanish beef cows as affected by calf management and breed

This experiment aimed at evaluating the effect of calf management and breed on the metabolic and luteal function of post‐partum beef cows fed at maintenance. Fifty multiparous cows, 22 Parda de Montaña (PA) and 28 Pirenaica (PI), were assigned to either suckling once‐daily for 30 min (RESTR) or ad libitum (ADLIB) from the day after calving. Blood samples were collected to analyse metabolites [non‐esterified fatty acids (NEFA), β‐hydroxybutyrate, total protein and urea)], insulin‐like growth factor‐I (IGF‐I) and progesterone (P4) at different intervals. Cows from RESTR maintained their live‐weight (LW) over the first 3 months post‐partum, whereas ADLIB cows lost nearly 4% LW. Both genotypes showed similar LW gains during this period (p > 0.10). Calf daily gains were lower in RESTR than in ADLIB treatment (p < 0.05), but similar across breeds (p > 0.10). Milk and lactose production were lower in RESTR cows than in ADLIB (p < 0.05). Milk and protein yield were greater in PA than in PI breed (p < 0.05). Serum NEFA, total protein and urea were higher in PI cows suckling ADLIB than in the rest (p < 0.05). Cows from PI breed had greater NEFA values than PA ones on the first week post‐partum (p < 0.001). Circulating IGF‐I was not affected by suckling frequency, breed nor their interaction (p > 0.10). Suckling frequency, but not breed, affected the interval from calving to first ovulation (p < 0.001), being shorter in RESTR than in ADLIB cows. In conclusion, the ad libitum suckling practice improved cow milk yield and offspring gain compared to once‐daily suckling for 30 min from the day after calving, at the expense of impairing the onset of cyclicity. The effect of calf management was confounded with breed on the studied blood biochemical constituents, but any of these metabolites influenced the role of endocrine IGF‐I in these genotypes.     

Some Arthropods Affecting Man and Livestock in New Zealand

Extract

At present, the standard tuberculin test used in New Zealand is the subcaudal intradermal test using 0·1 ml Commonwealth Serum Laboratories Synthetic Medium tuberculin, animals being classified as positive or negative to the test on the presence or absence of any swelling either visible or palpable at the site of the injection at the 96th hour.     

乏情季节诱导山羊同期发情的研究

通过对云阳县栖霞乡放牧 +舍饲条件下的经产母羊 3组 (A组 40只、B组 3 1只、C组 18只 )共 89只分别用孕激素阴道栓同期发情处理 10天 ,其中A组取栓后直接观察发情情况、B和C组取栓后分别注射PGF2α 0 0 5mg/只和 0 1mg/只。结果表明 :A组 2～ 4天内同期发情率为 42 5 0 % ;B组同期发情率为 67 74% ,48小时有羊只发情高峰 ;C组同期发情率为83 3 3 %。取栓至开始发情时间A组明显长于B组和C组 (P <0 0 5 ) ;平均发情持续时间短于B、C组 (P <0 0 1,P <0 0 5 ) ,B、C组之间差异不显著 (P >0 0 5 )。     

Evaluation of different hormonal treatments on oestral and ovarian responses in Moroccan Beni Arouss goats during anoestrus and breeding season

The efficacy of eight combinations of fluorogestone acetate (FGA, 20 or 40 mg as intravaginal device during 11 days), equine chorionic gonadotropin (eCG, 300 or 500 UI injected 48 hr before FGA removal) and prostaglandin F_2α (cloprostenol, 0 or 50 μg injected 48 hr before FGA removal) aiming at induction and synchronization of oestrus and ovulation was evaluated during the anoestrus season in spring and during the breeding season in autumn in adult Beni Arouss goats. Oestrous behaviour was recorded between 12 and 60 hr after FGA removal. Blood samplings allowing to assess onset of the pre‐ovulatory LH surge and increase of progesterone as sign of an active corpus luteum were performed, respectively, between 20 and 60 hr and 3, 5, 8 and 15 days after FGA removal. No season‐related differences (spring vs. autumn) were observed for oestrous response (95% vs. 93%), pre‐ovulatory LH surge (94% vs. 84%) and luteal response after 3–8 and 11–15 days post‐treatment (respectively 92% vs. 66% and 92% vs. 98%). The onset of oestrus (21 [13–53] vs. 32 [12–54] hr) and LH surge (26 [20–60] vs. 38 [22–60] hr) occurred significantly later in autumn. FGA (40 vs. 20 mg) in autumn significantly delayed the onset of oestrus (36 [16–54] vs. 23 [12–47] hr) and LH surge (44 [26–58] vs. 33 [22–60] hr). Significant treatment‐related differences were recorded for onset of LH surge (earliest for 20 mg FGA, 300 IU eCG, 50 μg PGF_2α) and onset of luteal phase (latest for 40 mg FGA, 300 IU eCG, 50 μg PGF_2α). In conclusion, the hormone combinations tested appeared equally effective in terms of oestrous and ovulation rates. Season has influenced significantly the onset of oestrus and LH surge, and the high dose regimen of FGA delayed the ovarian response in autumn.