Effects of short period frequent milking on milk yield and udder health in Turkish Saanen goats

The major purpose of this study was to investigate whether increasing milking frequency for a short period (21 days) increases milk yield and milk components and improves udder health throughout lactation in Turkish Saanen goats. Two groups were formed (control, n = 14, treatment, n = 14); balanced by parity, bodyweight and birth type to make them homogenous. Feeding and management practices were the same for both groups. The treatment group was milked four times a day (4×) for 21 days after weaning whereas the control group was milked twice a day (2×). All the animals were milked twice daily thereafter. The pyronin methyl green stain method was used to estimate the somatic cell count (SCC), which is an indication of udder health. This method provided a count that excluded RNA and background noise while including cells with DNA. Repeated measures analyses indicated that overall differences between the 2× and 4× groups were significant for the morning, evening and total test day milk yields, in that values for the 4× group were increased 14.7, 8.8 and 12.1%, respectively. Differences between the groups for SCC were not significant. The results of this study indicate that increasing milking frequency to 4×, even for a short time (21 days), increases overall milk yield throughout lactation in dairy goats.     

The effect of body condition on ovarian activity of free ranging tropical jennies (Equus asinus)

Serial ultrasonography was performed on seven jennies to study the effect of seasonally fluctuating body condition on ovarian activity during the dry, short rainy and long rainy seasons. Kendall Tau correlations and differences of least square mean values were compared. A distinct seasonal pattern was observed both in body condition and ovarian activity. The mean (+/-SD) Body Condition Score (BCS) was lowest during the dry season 2.6 +/- 0.45 when compared with 3.5 +/- 0.52 and 3.9 +/- 0.58 during the short and long rainy seasons, respectively. The mean (+/-SD) number of total follicles was also proportionally low 7.3 +/- 1.6 during the dry season compared with 9.6 +/- 2.4 and 11.3 +/- 3.3 found during the short and the long rainy seasons, respectively. The BCS was positively correlated to the total number of follicles and the diameter of the largest follicle during all seasons. Periods of increasing BCS and transition between seasons with both increasing and decreasing body conditions were strongly correlated to the number and size of ovarian follicles. Seasonal fluctuation in the body condition was found to be the result of variation in feed resource and ovarian activity was also closely following this seasonal pattern. The improvement in body condition has generally, a positive impact on emergence of small growing follicles there by having influence on the total count of ovarian follicles.     

Application of ultrasonography in the study of the reproductive system of tropical jennies (shape Equus asinus)

The use of high-frequency (5 MHz) ultrasonography was studied in 11 jennies (7 non-pregnant and 4 pregnant) to characterize the reproductive organs and follicular activities at different stages of reproduction. The result showed close similarity with the mare. The visibility of endometrial folds increased towards ovulation. A positive correlation (p < 0.001; τ = 0.79) was found between the score of the folds and the size of the dominant follicle. The diameter of the uterus and the size of the dominant follicle were significantly correlated (p < 0.001; τ = 0.80). In pregnant jennies, an embryonic vesicle was detectable at 14 days. Follicular growth was characterized by more than one wave. The smallest ovarian follicle was 2 mm and the largest 40 mm. Depending on the reproductive stage, up to 13 follicles were detected per ovary. After monitoring 84 cycles, a mean (±SD) diameter of 34.4 ± 3.6 mm (27.5–40.2 mm) of the preovulatory follicle and 67.85% incidence of single ovulation were found. The mean (±SD) interovulatory interval was 25.7 ± 6 days. This study proved that high-frequency ultrasonography is highly effective in characterizing the reproductive organs and follicular activity of jennies and could be useful in the reproductive management of donkeys.     

Cutaneous habronemiasis in horses and domestic donkeys (Equus asinus asinus)

Cutaneous habronemiasis in 15 horses and 5 donkeys is described. The lesions were distributed in many parts of the body involving the medial canthus, shoulder and pectoral regions, knee and fetlock joints, abdominal wall and prepuce. Some animals had more than one lesion. The lesions were ulcerative and filled with soft light red granulation tissue. When curretted, the deeper layers revealed a dense fibrous tissue with calcified foci. Close examination of the lesions showed that the superficial layer of this dense fibrous tissue contained small caseated and necrotic foci. The same features prevailed in lesions involving the muscular areas, but the deeper layers consisted of a dense granuloma with no evidence of cicatrization. Curretted material digested in potassium hydroxide revealed fragments of larvae of the nematode suggestive of Draschia or Habronema. The histopathological changes were severe and comprised: necrotic foci in a dense fibrous stroma infiltrated with eosinophils, macrophages and few giant cells. Sections of the larvae surrounded by eosinophils were encountered in lesions of the muscular areas. Curretting and excision of the lesion were effective and produced complete healing of the wound by scar tissue formation.     

Effect of milking interval on milk yield and quality and rate of recovery during subsequent frequent milking

Forty mid-lactation, pasture-fed dairy cows were used to study the effects of milking interval on milk yield and quality and whether effects could be reversed during a short period of subsequent frequent milking. Following a 2-day pre-experimental period of normal twice-daily milking (TDM), cows were milked again after 6, 12, 18, 24 or 30 h, with each milking interval followed by 24 h of frequent milking (i.e., every 6 h). Milk yield increased linearly until 18 h and then started to plateau. Similarly, milk quality (serum albumin and proteolytic enzyme activity) became adversely affected after 18 h. These changes coincided with increased permeability of mammary tight junctions (TJ), starting after a milking interval of 18 h. A brief period of frequent milking helped restore milk yields to pre-experiment levels, even after the longest milking interval.     

Comparative endocrinological responses to short transportation of Equidae (Equus asinus and Equus caballus)

In order to evaluate the effects of short transportation on β‐endorphin, adrenocorticotropic hormone (ACTH) and cortisol changes, 12 healthy stallions of Equidae (Equus asinus and Equus caballus) were studied before and after transportation of 50 km. Blood samples were collected 1 week before transportation in basal conditions, immediately before loading and after transportation and unloading, on their arrival at the breeding station. Compared to basal and before values, donkeys showed an increase in circulating ACTH (P < 0.001) and cortisol (P < 0.0005) levels after transportation and higher ACTH (P < 0.01) levels than horses after transportation. A positive and significant correlation (r = 0.885; P < 0.01) between ACTH and cortisol levels after transportation was found. No significant differences were observed for β‐endorphin levels. Compared to basal and before values, horses showed higher cortisol (P < 0.005) levels after transportation and no significant differences were observed for ACTH and β‐endorphin levels in donkeys. Horses facing forward (direction of travel) showed higher (P < 0.01) β‐endorphin levels after transportation than donkeys; horses facing backward (the opposite direction of travel) showed lower (P < 0.05) ACTH levels after transportation. The results indicate that short transportation induces a preferential activation of the hypothalamus‐pituitary‐axis (HPA), with significant release of ACTH and cortisol in donkeys and only of cortisol in horses, suggesting that transportation for donkeys may be more stressful than horses.     

Effect of setting a maximum milking time,from peak lactation,on production,milking time and udder health

Abstract

AIM: To examine the effect of setting a maximum milking time, from peak lactation until drying-off, on production, duration of milking, and udder health of dairy cows.

METHODS: Forty cows were assigned in twin-pairs to be either milked until cups were removed at a milk flow-rate threshold of 0.35 kg/minute (Control), or until cups were removed at a milk flow-rate threshold of 0.35 kg/minute, or maximum time, whichever came first (MaxT). The maximum time was set by determining the milking time of the 70th percentile cow when ranked from fastest to slowest, irrespective of yield. The milking routine was typical of that practised on dairy farms in New Zealand, and involved no pre-milking preparation. The study began at peak lactation (68 (SD 7) days in milk; DIM) and continued for 26 weeks. Duration of milking and milk yield were measured for each milking. Composition of milk was determined from weekly herd tests, and milk quality from fortnightly somatic cell counts (SCC). Completeness of milking and teat condition were assessed during the study. The bacterial status of quarter milk samples was determined at the beginning and end of the study, and all treated cases of clinical mastitis recorded. ANOVA was used to examine the effect of treatment group on variables of interest.

RESULTS: Total milk, fat and protein yields during the study period did not differ between treatments. On average, 30.3% of the morning and 27.6% of the afternoon milkings of MaxT cows reached the maximum time at which cups were removed, and were therefore shortened. While the average milking time of the slowest-milking cow was longer for the Control compared with MaxT group in Weeks 1–18, the average milking time did not differ between treatments. There was no difference in overall SCC, and the incidence of clinical mastitis, or the percentage of infected quarters at drying-off, was similar for the MaxT and Control cows.

CONCLUSION: The results show that setting a maximum milking time can reduce the milking time of slower-milking cows in a herd without compromising overall herd production and udder health.

CLINICAL RELEVANCE: Although the numbers of cows in the study were small there was no evidence of a major increase in SCC, or subclinical or clinical mastitis when a maximum milking time was set for slower-milking cows.     

Nutritional Requirement of Adult Donkeys (Equus asinus) during Work and Rest

Tropical Animal Health and Production -     

Strongylus vulgaris in donkeys (Equus asinus) from the highveld of Zimbabwe

Strongylus vulgaris populations in the cranial mesenteric arteries, caecum and colon were studied in 14 donkeys obtained from a communal area of the Zimbabwean highveld during July and November, 1986, and January and April 1987. Adult parasites were present in all animals and larvae in the cranial mesenteric arteries of 12 animals. Aged animals had high worm burdens. The number of adult parasites varied from 63 to 1255 (mean 382) and of larvae in the arteries from 0 to 181 (mean 69). The mean adult worm burdens were highest in July (400) and November (488), and lowest in April (107). The mean arterial larval burden was highest in July (130) and lowest in November (21). These observations indicate that infection with S. vulgaris takes place during the rainy season resulting in the heavy arterial larval population from January onwards and the heavy adult population during the dry season.     

Ultrastructure of Sarcocystis spp. from donkeys (Equus asinus) in Egypt

The fine structure of Sarcocystis spp. from donkeys (Equus asinus) in Egypt is described. Sarcocysts were found in the oesophagus, diaphragm and heart of 18 of 20 donkeys. Only one type of mature muscle cyst was found. Sarcocysts were 120-410.6 X 48.4-50.2 microns. The primary cyst wall had numerous 3.3-3.7 microns villi. Each villus contained 20-60 fibrillar elements which extended from the ends and sides of the villi throughout the ground substance, where they became tightly packed. The bundles of fibrillar elements formed junctions with the pellicles of the metrocytes. Ultrastructurally, Sarcocystis spp. of the donkey was similar to sarcocysts previously described from the horse.     

Mitochondrial DNA variation and genetic relationships in Spanish donkey breeds (Equus asinus)

In this study, the mitochondrial DNA diversity of six Spanish donkey breeds and two African donkey populations (one from Morocco and the other from Zimbabwe) was analysed. A total of 79 animals were sequenced for 313 bp of the cytochrome b gene, and 91 individuals for 383 bp of the D‐loop region or control‐region. Sequence comparisons and phylogenetic analyses of both Spanish and African populations revealed low diversity. Only six and seven haplotypes respectively were found in cytochrome b and the D‐loop region. Relatively low nucleotide diversity (π) values were detected in these populations. The π values, from the D‐loop region, ranged from 0.0006 to 0.0169 for the Catalana and Andaluza breeds, respectively. The obtained results seem to confirm the existence of two divergent maternal lineages of African origin (Equus asinus africanus and E. a. somaliensis). In this paper the genetic relationships between these breeds are analysed and compared with those obtained in other European populations. Also, the data on the genetic relationships between the populations, obtained from nuclear DNA (microsatellites) and mitochondrial DNA (cytochrome b and D‐loop region) is argued and interpreted.     

Assessment of Sperm DNA Fragmentation in Stallion (Equus caballus) and Donkey (Equus asinus) Using the Sperm Chromatin Dispersion Test

Sperm DNA fragmentation (sDF) is an important parameter to assessing sperm quality. Information about sperm quality is not available for donkeys, especially in some breeds at risk of extinction. The objectives of this research were to test the four commercial variants of sperm chromatin dispersion test (SCD; sperm Halomax test), originally developed to assess sDF in boars, bulls, rams and stallions, in order to scrutinize their applicability in the study of sDF in a donkey breed at risk of extinction (Zamorano-Leonesa), for which there is no specific test available to analyze sperm at present. Only the SCD test, originally developed for stallions, produced stable and consistent results, and was deemed suitable to assess DNA fragmentation in sperm samples from donkeys. Image analysis was used to compare differences between the SCD methodology applied to stallion and donkey semen samples processed under the same experimental conditions. The extent of SCD in the SCD test was approximately 20% lower in donkey sperm than in stallion sperm. Yet, the ratio of chromatin sperm dispersion achieved in fragmented and unfragmented nuclei did not differ significantly between species. These data suggest that a similar protein depletion treatment can cause differences in protein removal in equivalent cells from different species and that sperm chromatin may be organized differently in stallions and donkeys.     

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.     

Improving working donkey (Equus asinus) welfare and management in Mali,West Africa

Working conditions for cart donkeys in West Africa are often harsh. In collaboration with the Society for the Protection of Animals Abroad, we conducted 3 studies and a welfare assessment. In the first study, we compared behavioral and physiological measures of donkeys (n = 10) driven in 2 standard Malian ways (1 = halter and reins, 2 = no halter and with a stick). In a second study, we assessed pressure associated with harness and cart quality. Pressure was measured according to several different parameters, including type of harness (satisfactory or unsatisfactory), type of cart (satisfactory or unsatisfactory), and weight (no weight or 200 kg of weight). Because education likely plays an important role in enhancing working equid welfare, we conducted a third study aimed at educating paraprofessionals about donkey husbandry (n = 82). We also conducted a welfare assessment on a donkey population in Segou, Mali (n = 54). Among training methods, no significant difference was found in either heart rate variability or behavior. A significant difference in back/wither pressure (P < 0.05) was found for the following parameters: harness type (P = 0.02) and cart with weight (P = 0.009). The welfare assessment examined how body condition scores, age, number of lesions, scarring, lameness, behavior parameters, and dehydration were related. The results indicated a significant effect between body condition score and hydration, that is, donkeys with lower body conditions were often less hydrated (P = 0.01). The relationship of body condition was significant when comparing the behavioral response with the ear test (P = 0.03). Finally, educational workshops were conducted at 2 schools, one in Segou (n = 54 students) and one in Bamako (n = 28 students), to measure donkey management knowledge before and after a husbandry education seminar and practical demonstration were conducted. The average test scores for pre- and post-tests numerically increased at both schools. However, the increase in test scores was not significant (Segou P = 0.15 and Bamako P = 0.06). This study provides additional methods to professionals and paraprofessionals on alternative methods for training, harnessing, and working donkeys in developing parts of the world.