A survey to identify economic opportunities for smallholder dairy farms in Bangladesh

Identified economic opportunities for planning interventions greatly increase farmers’ compliance with an extension programme. We investigated opportunities for interventions to increase dairy farmers’ income in four areas of Bangladesh, including the districts of Mymensingh, Khulna-Satkhira, Sirajgonj-Pabna and Chittagong. The data were collected from 1440 dairy farms at a one-day visit and were summarized as the difference between management targets and each herd’s calculated management indices. The average number of lactating cows, feed cost as a percentage of income from milk, milk sold as percentage of milk produced, lactating cows as a percentage of mature cows, and lactating cows as a percentage of total cattle varied from 1.5 to 3.4, from 52.5% to 92.1%, from 78.7% to 92.6%, from 81.9% to 86.7% and from 34.3% to 37.7%, respectively. The average age at first calving, calf production interval, lactation length, and milk production were 35.0–44.3 months, 14.0–17.6 months, 249–286 days and 3.5–7.2 litres, respectively, depending on the locality. The average cost for producing 100 litres of milk was 18.9–35.1 US dollars. The production cost increased when daily milk production per cow decreased (r² = 0.43–0.55). Management improvements directed towards increasing average milk production per cow per day, increasing lactation length, decreasing age to first calving, and decreasing calf production interval could expect to yield an average income increase up to a range of 676.3–1730.6 US dollars depending on the milk-producing area.     

Feeding strategies for small-scale dairy systems based on perennial (<Emphasis Type="Italic">Lolium perenne</Emphasis>) or annual (<Emphasis Type="Italic">Lolium multiflorum</Emphasis>) ryegrass in the central highlands of Mexico

Small-scale dairying is an option for campesinos in Mexico. The costs of feeding are high and strategies based on quality forages are a priority. The performance, agronomic variables and feeding costs were evaluated for dairy cows continuously grazing perennial ryegrass–white clover for 9 h/day (PRG) or fed cut herbage from annual ryegrass for 8 weeks followed by 9 h/day for 6 weeks on a tethered rotational grazing pattern (ARG). All cows received 3 kg/day of an 18% crude protein (CP) concentrate. A 14-week split-plot on-farm experiment was designed with 10 cows from two participating farmers, and 1.5 ha per strategy. Milk yield was recorded weekly and milk composition, live weight and body condition score were recorded every 14 days. Net herbage accumulation was greater for ARG (8222 kg organic matter (OM)/ha) than for PRG (5915 kg OM/ha) (p < 0.05), with higher CP in PRG (p < 0.05). Milk yield was 19 kg/cow per day for PRG and 15.9 kg/cow per day for ARG (p > 0.05). Over 14 weeks, PRG produced 1422 kg more milk. There were no differences for live weight or condition score (p > 0.05), but linear regression shows a live weight gain of 0.200 kg/cow per day for PRG. Protein and fat content showed no differences (p > 0.05), but milk fat content in PRG was below standard. ARG had 60% higher costs, and margins were 38% higher in PRG. ARG has a place in rain-fed fields. The results provide viable options for improving these systems that may be suitable in their socio-economic context and their social and personal objectives.     

Early lactation dairy cows: Development of equations to predict intake and milk performance at grazing

The objectives of this study were to examine the effect of parity and days in milk (DIM) on dry matter intake (DMI) and actual milk yield (MY_Act) of grazing spring calving dairy cows in early lactation (< 100 DIM) and to develop equations to predict DMI and milk yield for grass based systems of milk production. A dataset containing 335 observations from 134 Holstein Friesian dairy cows was assembled from two early lactation grazing studies. Observations were available for primiparous (n = 130) and multiparous (n = 205) cows during periods of DMI measurement using the n-alkane technique. Animal performance was divided into two classes of DIM: less than 50 DIM (< 50 DIM) or between 51 and 100 DIM (> 50 DIM). Parity and DIM had a significant effect on grass DMI (GDMI), total DMI (TDMI), MY_Act and milk composition. TDMI increased with parity and DIM and ranged from 13.4 kg/cow per day (primiparous animals, < 50 DIM) to 20.1 kg/cow per day (multiparous animals, > 50 DIM). Actual MY increased with parity and decreased with DIM (range: 24.1 kg/cow per day (primiparous animals, > 50 DIM) to 33.0 kg/cow per day (multiparous animals, < 50 DIM)). Multiparous cows had greater bodyweight (BW) and lower BCS than primiparous cows. In the early lactation period a number of variables had a significant effect on GDMI, TDMI and milk yield. These predictor variables included BW, BCS, potential milk yield (MY_Pot), DIM, daily herbage allowance (DHA; > 4 cm), concentrate level and parity. The equations accounted for 79%, 83% and 86% of the variation in GDMI, TDMI and milk yield, respectively. Actual milk yield was always below the MY_Pot of the cows, the mean difference was 5.8 kg/cow per day. As DHA and concentrate level increased, the difference between MY_Act and MY_Pot reduced. This study supports the concept that immediately post-calving offering a grass based diet with a medium level of concentrate supplementation is sufficient to support high milk production in grazing dairy cows.     

Effect of silage from ryegrass intercropped with winter or common vetch for grazing dairy cows in small-scale dairy systems in Mexico

The objective was to determine the effect of including silages of annual ryegrass (Lolium multiflorum) intercropped with winter vetch (Vicia villosa) (ARG-VV) or with common vetch (Vicia sativa) (ARG-VS) compared with maize silage (MS) on milk yield and milk composition of dairy cows grazing cultivated perennial ryegrass–white clover pastures with supplemented concentrate during the dry season. Six Holstein dairy cows with a mean yield of 19.0 kg/cow/day at the beginning of the experiment were randomly assigned to a 3 × 3 repeated Latin square. Treatments were: 8 h/day intensive grazing, 3.6 kg of dry matter (DM) per cow per day of concentrate plus MS, and ARG-VV or ARG-VS ad libitum at a stocking rate of 3.0 cows/ha for three experimental periods of 3 weeks each. Milk yield (MY) and milk composition, live weight and body condition score as well as silage and concentrate intakes were recorded during the third week of each experimental period, and pasture intake was estimated indirectly from utilised metabolisable energy. Economic analysis was obtained by preparing partial budgets. There were no statistical differences (P > 0.10) in MY, milk fat or protein content nor for live weight, but there was significant difference (P < 0.10) in body condition score. There were non-statistical differences in silage DM intake (P < 0.11); however, significant differences (P < 0.10) were obtained for estimated grazed herbage intake whilst no differences for total DM intake. Slightly higher economic returns (10%) were obtained with ARG-VS over MS, and this was 7% higher than ARG-VV. It is concluded that ARG-VS could be an option for complementing grazing for small-scale dairy production systems in the dry season as it is comparable to MS in animal performance and slightly better in economic terms.     

Participatory rural appraisal in smallholder dairy systems in Tunisia

Participatory Rural Appraisal (PRA) was carried out by a multidisciplinary team on a total of 60 smallholder dairy farms in three different geographical areas of Tunisia. Farms with less than three cows were excluded. Those participating had between three and 10 cows. Average milk production ranged between 8 and 32 litres per cow per day. 70% or over of milk produced was sold off the farms. Average inter-calving intervals — measured from month of calving only — ranged from 12.9 months to 19. Age at first calving varied from two to nearly three years. Most work was done by the families. PRA revealed that the farmers in all three regions perceived unbalanced nutrition, which included availability of forages, to be the most important constraint, followed by poor reproductive efficiency. Reseeding with new species was instituted for grazing and hay. Farmers from the different regions were taken on exchange visits to see how these approaches worked. Training in reproductive management and milking hygiene was introduced. Seasonal ration formulation depending on local forage analysis was instituted. Two farms are participating in a programme of evaluation of olive oil extraction by-product as a ruminant feed. Partial budget analysis of these interventions will be carried out.     

Productive and reproductive performance of strategically supplemented free grazing prepartum Bunaji cows in the agropastoral farming system

The effects of prepartum supplementary feeding on the productive and reproductive performance were investigated using grazing gestating Bunaji cows with an average initial body weight of 294.50 ± 3.75 kg. Twenty cows were allocated to a completely randomized design, with five animals per treatment. The treatments were: A, range grazing (RG); B, RG + 100% corn bran (CB); C, RG + 60% CB + 40% palm kernel cake (PKC), and D, RG + 60% CB + 40% dried brewer’s grains (DBG). The average daily gains (ADG) and body condition scores (BCS) of supplemented cows were significantly better than the non-supplemented cows. Postpartum weight loss was markedly reduced in supplemented cows compared to their non-supplemented counterparts. Mean milk offtake and mean milk yield per lactation were significantly lower in non-supplemented cows than the supplemented ones. Among the supplemented cows, ADG, BCS, mean milk offtake and milk yield per lactation were significantly better for cows on treatments C and D than those on treatment B. Though insignificant, longest lactation length (LL) and shortest calving interval were obtained for supplemented cows. Calf’s birth weight was similar among the treatments. Milk yield was significantly influenced (R² = 0.8601) by cow’s weight, BCS and LL.     

An economic opportunity survey of small dairy farms in Paraguay

Participatory rural appraisal (PRA) in 15 small farms and an economic opportunity survey (EOS) in 13 were carried out in the Cordillera basin of Paraguay to identify production constraints and the best ways to achieve economic gain. PRA showed farmers’ perception was that nutrition was the main constraint. The EOS showed that over 70% of the milk produced was sold in the neighbourhood. The average number of adult cows (lactating and dry cows) per farm ranged from 15 to 120, of which 62.2% to 80% were lactating cows. Milk production per cow on one day ranged from 8.5 to 18.2 litres and average lactation length was more than 300 days. Average age at first calving varied from 31 to 39 months. The highest economic opportunity was observed for increased milk production. Age at first calving and calf production interval were also found to be important constraints. Ultrasonography survey of the ovaries 20 maiden heifers over six months showed inadequate activity. Partially budgeted interventions were instituted to improve nutrition and management of maiden heifers, in-calf cows and those in early lactation. More forages were grown. PRA and EOS were shown to be useful tools in identifying production constraints.     

Radioimmunoassay of milk progesterone as a tool for fertility control in smallholder dairy farms

This study focused on the use of radioimmunoassay of progesterone in milk for the diagnosis of post-partum ovarian cyclicity and accurate detection of oestrus and non-pregnancy in cows in the artificial insemination (AI) programme in Bangladesh. In Investigation 1, milk samples were collected on day 0 (day of AI), day 9–13 and day 21–24 from 444 milking cows of various breeds presented for the first post-partum insemination by 413 farmers living at 182 villages/regions in Mymensingh District from 6 AI centres and sub-centres. Each cow was then examined three times after each AI until it stopped returning to oestrus. Sixty to 90 days after the last AI, the cows were examined per rectum to confirm the pregnancy. Milk progesterone data on day 21–24 contributed to a clear diagnosis with respect to non-pregnancy in 100% cows, indicating a possible use of this progesterone assay for identifying non-pregnant cows in AI programmes. In Investigation 2, milk progesterone was monitored two times in a month with a 10-day interval in 88 cows. The samples were taken between 10 days after calving and the first detected oestrus, followed by two more samples 10 days apart. The proportion of cows accurately detected in oestrus was 30%. Another 30% were stated to be in oestrus when they were not (false positive) and 40% were not detected when they were in oestrus (false negative). The mean intervals between calving and oestrus and between calving luteal activity were 40 to 362 days (median = 120, n = 82) and 34 to 398 (median = 111, n = 64) days, respectively. The body condition scores at calving and at the initiation of luteal activity influenced the interval between calving and luteal activity (p < 0.05). Cows suckled twice daily initiated luteal activity earlier than their counterparts suckled several times daily (p < 0.05). Determination of progesterone in milk on day 21–24 is a good means for detecting non-pregnant cows.     

Energetic efficiency of milk synthesis in dual-purpose cows grazing tropical pastures

The aim of this study was to assess the energetic efficiency of milk synthesis by grazing dual-purpose cows with or without a starch-based supplement in tropical South Mexico. Forty-six Holstein × Zebu cows were used in a 2 × 2 × 2 factorial design. Factors analysed were diet (supplemented, unsupplemented), age (young: 1–2 calvings, mature: >3 calvings) and day of lactation (21 and 84 days post-calving). The supplement represented about 30% of estimated dry matter (DM) intake. Grass intake was measured using the n-alkane technique at 21 and 84 days post-calving when calculations of efficiency were performed. Efficiency for milk synthesis was reported as feed conversion efficiency (FCE, kilograms of milk per kilogram of DM intake), gross energetic efficiency (GEE, milk energy output/metabolisable energy (ME) intake) and efficiency of ME use for lactation (k _l, adjusted to zero energy balance). There were no interactions between factors. FCE and GEE were not different between diets, but supplemented cows had a lower (p < 0.01) k _l value (0.62) than unsupplemented cows (0.67), suggesting a diverted partition of nutrients towards body tissue. Mature cows were more efficient (p < 0.001) than young cows in terms of FCE (1.13 vs 0.87) and GEE (0.34 vs 0.26), but equal in terms of k _l (0.65). FCE (1.10 vs 0.90) and GEE (0.34 vs 0.27) were both higher on day 21 compared with day 84 post-calving, with a trend for a higher k _l in early lactation. Dual-purpose cows used tropical grasses efficiently for milk synthesis, and higher milk yield observed in supplemented cows was due to a higher intake of nutrients rather than a higher energetic efficiency.     

Comparison of two milk pricing systems and their effect on milk price and milk revenue of dairy farms in the Central region of Thailand

A study was conducted to investigate determinates of how milk pricing system, farm location, farm size, and month and year affected farm milk price (FMP), farm milk revenue (FMR) and loss in FMR of dairy farms in the Central region of Thailand. A total of 58,575 milk price and 813,636 milk yield records from 1034 farms were collected from November of 2004 to June of 2006. Farms were located in the districts of Muaklek, Pak Chong, Wang Muang, and Kaeng Khoi. A fixed linear model was used to analyze milk price of farms. Two pricing systems were defined as 1 = base price plus additions/deductions for milk fat percentage, solids-non-fat, and bacterial score, and 2 = same as 1 plus bulk tank somatic cell count (BTSCC). Farm size (small, medium, and large) was based on the number of cows milked per day of farms. Results showed that FMP were lower (P < 0.05) in pricing system 1 than pricing system 2. Most small farms had higher (P < 0.05) milk prices than medium and large farms across both pricing systems. Large farms lost more milk revenue due to deductions from bacterial score and BTSCC than small and medium farms.     

Husbandry Factors and the Resumption of Luteal Activity in Open and Zero‐Grazed Dairy Cows in Urban and Peri‐Urban Kampala,Uganda

The study investigated the influence of selected husbandry factors on interval to resumption of post‐partum cyclicity among dairy cows in urban and peri‐urban Kampala. A prospective study of 85 day post‐partum period of 59 dairy cows in open (n = 38) and zero grazing (n = 21) systems was conducted on 24 farms. Cows of parity 1–6 were recruited starting 15–30 days post‐partum. Progesterone (P4) content in milk taken at 10–12 day intervals was analysed using ELISA. The cow P4 profiles were classified into ‘normal’ (< 56 days), ‘delayed’ (> 56 days), ‘ceased’ or ‘prolonged’ (if started < 56 days but with abnormal P4 displays) resumption of luteal activity and tested for association with husbandry and cow factors. Of the 59 cows, luteal activity in 81.4% resumed normally and in 18.6%, delayed. Only 23.7% maintained regular luteal activity, while the others had ceased (10.2%), prolonged (37.3%) or unclear luteal activity (20.3%). There were no differences between open and zero‐grazed cows. Milk production was higher (p < 0.05) in zero than open grazing, in urban than peri‐urban and in cows fed on brew waste (p < 0.001) compared with mill products and banana peels. Results suggest that luteal activity resumes normally in a majority of cows, although only a minority experienced continued normal cyclicity once ovulation had occurred, in the two farming systems irrespective of feed supplements or water, and that supplementing with brew waste is beneficial for milk production.     

Productive response of grazing dairy cows to fresh chopped maize supplementation under a small farming system in the Mexican Highlands

The aim of this study was to evaluate the animal performance of late lactating grazing dairy cows in response to fresh chopped maize (FCM) supplementation under a small farming system. Twenty-four multiparous Holstein dairy cows were used in a rotational grazing on a mixed alfalfa–orchard grass sward. Three treatments were evaluated: 0, 4, and 8 kg dry matter (DM) of FCM cow⁻¹ day⁻¹. The experimental design was a crossover, with three periods lasting 19 days each. There were no differences on individual milk production nor on milk composition. Herbage DM intake decreased (P < 0.0001) from 8.4 to 5.2 and 3.1 kg DM when increasing FCM from 0 to 4 and 8 kg DM, respectively. Total DM intake increased (P < 0.0001) with 8 kg DM of FCM, averaging 14.8 kg. Substitution rate was 0.75 and 0.67 kg of pasture per kilogram of FCM with 4 and 8 kg DM of FCM, respectively. Consequently, stocking rate (STR) increased (P < 0.0001) from 3.8 to 6.2 and 8.8 cows ha⁻¹, and milk production per hectare increased (P < 0.0001) from 39.3 to 64.5 and 95.5 kg of milk, with 0, 4, and 8 kg DM of FCM, respectively. This means that STR increases 0.63 cows ha⁻¹, and 0.75 kg of milk ha⁻¹ when FCM is increased in 1 kg of DM. In conclusion, offering FCM as supplement to grazing dairy cows in their final lactation stage had no benefits in individual milk production or milk composition, but had benefits on milk production per hectare.     

Milk production and calf rearing practices in the smallholder areas in the Eastern Cape Province of South Africa

Farmer perceptions on milk production and calf rearing practices on communal rangelands in the smallholder areas of the Eastern Cape Province, South Africa were evaluated on a total of 218 cattle farmers using structured questionnaires, semi-structured interviews with key informants and personal observations. Nearly 70% of the households in the small-scale areas milked twice a day compared to 60% in the communal areas. About 62% of the interviewees weaned calves between 6 and 12 months of age. Milk yield/cow/day (7.5 ± 0.5 litres), fresh milk consumption/household/day (3.2 ± 0.5 litres) and sales/household/day (3.1 ± 1.1 litres) were highest in the sour-veld, small-scale farms (P < 0.05). Sour milk consumption/household/day (2.6 ± 0.2 litres) and sales/household/day (0.8 ± 0.2 litres) were significantly high in communal farms with a sour-veld. It was concluded that, calf rearing practices were poor and milk yield, consumption and sales were generally low and varied with production system and rangeland type. Further research is required to improve calf management practices, cow nutrition, milk yield and quality and how milk production can be used as a toll for rural development in the smallholder areas of South Africa.     

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.     

Post-grazing sward height imposed during the first 10 weeks of lactation: Influence on early and total lactation dairy cow production,and spring and annual sward characteristics

Increasing the proportion of grazed grass in the diet of the dairy cow is the main target of grass-based milk production systems. Imposing a severe post-grazing sward height (PGSH) in early lactation is one strategy to increase grass utilisation. A grazing experiment was undertaken to investigate the direct and carryover effects of PGSH imposed in early lactation on sward and dairy cow lactation performance. Ninety Holstein–Friesian dairy cows (mean calving date: February 13) were randomly assigned to one of three target PGSH treatments: 2.7 cm (severe; S), 3.5 cm (low; L) and 4.2 cm (moderate; M) from February 14 to April 24, 2011 (period 1; P1). This was followed by a carryover period (period 2; P2) during which cows were randomly re-assigned within their P1 treatment across two PGSH treatments: 3.5 or 4.5 cm until November 13. Sward utilisation (>2.7 cm) during P1 was significantly improved by decreasing PGSH from M (0.74) to L (0.82) and further to S (0.94). At the end of the entire grazing season, the M treatment swards had produced +1.4 t dry matter (DM)/ha than the S and L treatment swards which had similar total DM yields (14.1 t DM/ha). Treatment had no immediate or carryover effect on the proportions of leaf, stem and senescent material in the sward or the quality of herbage selected by the animals. During P1 the cows in S had greater bodyweight loss (−18 kg), reduced milk (−2.1 kg/day) and milk solids yields (−0.21 kg/day) as well as lower grass DM intake (−1.7 kg DM/day) compared with the cows in L and M, which performed similarly (−5 kg, 24.1 kg/day, 1.94 kg/day, and 13.0 kg DM/day, respectively). There was no carryover effect of early lactation PGSH on milk and milk solids yields, fat and protein concentrations during P2. This indicates that cows restricted in P1 were able to adjust production in accordance with the higher PGSH imposed during the remainder of the lactation. The S treatment had numerically lower, though not significantly lower, total lactation milk and milk solids yields, reflecting their significantly reduced yields in early lactation. It was concluded that grazing to 2.7 cm in early lactation is too restrictive for dairy cows. Cows in L and M had very similar total cumulative production performance. As a result, grazing to 3.5 cm during the first 10 weeks of lactation contributes to achieving both high milk output from pasture and high grass utilisation.     

Factors affecting milk yield,milk fat,bacterial score,and bulk tank somatic cell count of dairy farms in the central region of Thailand

A study was conducted to determine the effects of season, farm location, and farm size on farm milk yield (FMY), average milk yield per cow (AYC), milk fat, bacterial score, and bulk tank somatic cell count (BTSCC) of dairy farms in the central region of Thailand. Farms were located in the districts of Kaeng Khoi, Muaklek, Pak Chong, and Wang Muang. Collection of data was at the farm level; individual animal records were unavailable. A total of 967,110 daily farm milk yield, 58,575 milk fat and bacterial score, and 24,109 BTSCC records from 1,034 farms were collected from July of 2003 to June of 2006. There were three seasons: rainy, summer and winter. Farms were categorized into small, medium, and large according to the number of cows milked per day. Results showed that FMY and AYC were higher (p <0.05) in winter and lower in the summer and rainy seasons. In addition, the majority of small size farms had higher (p < 0.05) AYC and milk fat values, and lower bacterial score and BTSCC values than medium and large size farms.     

A comparison of production and management between Wisconsin organic and conventional dairy herds

An observational study was conducted in Wisconsin to compare production and management on organic and conventional dairy farms. Thirty organic dairy herds, where antimicrobials are rarely used for calves and never used for cows, were compared with 30 neighboring conventional dairy farms on which antimicrobials were routinely used for animals of all ages. A seven-page questionnaire regarding milk production, milking practices, housing, incidence of the major dairy diseases and medical treatments was used to assess management and production during 2000-2001. Body condition scores (BCS) of lactating cows and environmental and animal sanitation scores (EASS) were also collected on each of two occasions. The organic herds had significantly fewer cattle than did the conventional herds (P=0.017). The average daily milk production per cow in organic dairy herds (20.2 kg/day) was lower than that of conventional herds (23.7 kg/day). The incidence of clinical mastitis (CM) on organic farms (28 cases per 100 cow-years at risk) was not statistically different from that of on conventional farms (32 cases per 100 cow-years at risk). No significant difference in bulk tank somatic cell count (BTSCC) was observed between organic farms (262,000 cells/ml) and conventional farms (285,000 cells/ml). The average annual cull rate was 18.0 cases per 100 cow-years for the conventional farms and 17.2 for the organic farms (P=0.426). Our paired t-test results indicated significantly higher parasite burden on organic dairy farms; however, no significant difference between the two farm types when controlling for season (March and September), grazing intensity (no grazing, little grazing, grazing with access to housing and grazing only) and herd average milk production per cow. There was little evidence of other fundamental differences between the two farm types in other management and production parameters.     

On-farm evaluation of the effect of coffee pulp supplementation on milk yield and dry matter intake of dairy cows grazing tropical grasses in central Mexico

Tropical grasses are the primary nutrient resource for cattle production in the tropics, and they provide low-cost nutrients to cattle. However, its production is constrained by seasonal changes and quality; hence, appropriate usage of relatively inexpensive agricultural by-products is important to profitable livestock production. The objective of the study was to evaluate the effect of supplementing coffee pulp to dairy cows grazing tropical grasses on milk yield and forage intake. Four multiparous crossed Holstein–Brown Swiss–Zebu cows of similar weight and milk yield were used. The effect of 10%, 15% and 20% inclusion of coffee pulp in dairy concentrates on milk yield and forage intake was analysed using a 4 × 4 Latin square design. Results showed that there were no significant effects (P > 0.05) in grass dry matter intake, milk yield, milk composition body weight and body condition score due to the inclusion of coffee pulp in the dairy concentrates. It is concluded that coffee pulp can be included at levels of 20% in the concentrate without compromising significantly (P > 0.05) milk yield, milk composition and grass dry matter intake. It also was concluded that cost of concentrate is reduced in 20% by the inclusion of coffee pulp.     

Comparison of the performance of Holstein-Friesian and Jersey×Holstein-Friesian crossbred dairy cows within three contrasting grassland-based systems of milk production

The performance of spring calving Holstein-Friesian (HF) and Jersey×Holstein-Friesian (J×HF) dairy cows was examined during three successive years (mean of 35 HF cows and 31 J×HF cows per year). Throughout the experiment cows were managed on one of three grassland-based systems of milk production, namely low concentrate (LC), medium concentrate (MC) or high concentrate (HC). Post-calving, cows were housed and offered grass silage, supplemented with 6.0, 8.0 and 10.0 kg concentrate/cow/d in systems LC, MC and HC, respectively (mean period from calving to start of full time grazing, 69 days). During the grazing period target concentrate feed levels were 0, 2.5 and 5.0 kg/cow/d for systems LC, MC and HC, respectively (mean period from start of full time grazing to start full time re-housing, 206 days). Full lactation concentrate inputs were 530, 1092 and 1667 kg/cow, in systems LC, MC and HC, respectively. There were no significant genotype×system interactions for any of the milk production parameters examined. Food intake during the confinement and grazing periods was unaffected by genotype. Milk yield was highest with HF cows while milk fat and milk protein content were highest with the J×HF cows (P<0.001). Genotype had no effect on fat plus protein yield. Milk yield and fat plus protein yield were higher with systems MC and HC than with LC (P<0.001). HF cows were on average 44 kg heavier than J×HF cows, while the mean condition score of the J×HF cows was approximately 0.2 units higher than that of the HF cows (P<0.001). Live weight and condition score changes during the lactation followed similar trends with both genotypes. The J×HF cows had fewer days to first observed heat (P<0.05), a higher conception rate to first service (P<0.01), first plus second service (P<0.001), and a higher pregnancy rate at the end of the breeding season (P<0.05). Although mean somatic cell score was unaffected by genotype, the proportion of cows with one or more cases of mastitis was lower with the J×HF cows (P<0.05). In summary, while the J×HF cows had improved fertility performance compared to the HF cows, both genotypes exhibited similar levels of tissue mobilisation and deposition throughout the lactation, while there was no evidence of a genotype×grassland system interaction for any of the milk production parameters examined.     

Seroprevalence and potential risk of bovine brucellosis in zerograzing and pastoral dairy systems in Uganda

A cross-sectional study was conducted in Uganda between November 2006 and February 2007 to assess the seroprevalence and risk of brucellosis in zerograzing and pastoral dairy systems; two major sources of milk in Uganda, 80% of which is sold unpasteurized to consumers through informal channels. A total of 723 cattle comprised of 497 animals from the pastoral system and 226 animals from the zerograzing system were tested for antibodies against natural B. abortus infection using the competitive enzyme-linked immunosorbent assay (C-ELISA). Herd-level seroprevalence was 100% in the pastoral system and 5.5% (95% CI: 1.8, 9.2) in the zerograzing system. The animal-level seroprevalence and within-herd range of brucellosis in cattle in the pastoral system were 34.0% (95% CI: 29.9, 38.1) and 8.1–75.9%, while for those in the zerograzing system were 3.3% (95% CI: 0.9, 5.7) and 0–9.0%. Abortion rates of 23% and 0% among seropositive cows vis-à-vis 5.4% and 1.9% among seronegative cows were recorded in the pastoral and zerograzing systems, respectively. The risk of natural B. abortus infection was higher among older cattle (>24 m) (Odds ratio [OR] = 1.83, 95% CI: 1.25–2.67) and dry cows (OR = 2.01, 95% CI: 1.23–3.31) in the pastoral system, and in calves aged 0–6 m (OR = 5.72, 95% CI: 1.04–31.41) in the zerograzing system. Implementing a culling program in the zerograzing system to eliminate the existing low risk of brucellosis and targeting calves in the pastoral systems for vaccination could avert the cost-related limitation of brucellosis control in Uganda.