74,122 research outputs found
Phenotypic effects of calving ease on the subsequent fertility and milk production of dam and calf in UK Holstein-Friesian heifers
The effect of calving ease on the fertility and production performance of both dam and calf was studied in approximately 50,000 and 10,000 UK Holstein-Friesian heifers and heifer calves, respectively. The first objective of this study was to estimate the effect of a difficult calving on the subsequent first-lactation milk production by estimating lactation curves using cubic splines. This methodology allows the estimation of daily milk, protein, and fat yields following calvings of differing degrees of difficulty. Losses in milk yield after a difficult calving have been quantified previously; however, estimates are generally restricted to the accumulated yields at specific days in lactation. By fitting cubic splines, gaps (in which the shape of the lactation curve can be merely guessed) between estimations were avoided. The second objective of this study was to estimate the effect of a difficult birth on the subsequent performance of the calf as an adult animal. Even though the calving process is known to involve cooperation between dam and calf, the effect of a difficult calving has, until now, only been estimated for the subsequent performance of the dam. Addressing the effects of a difficult birth on the adult calf strengthens the importance of calving ease as a selection trait because it suggests that the benefit of genetic improvement may currently be underestimated. The effect of calving ease on the subsequent reproductive performance of dam and calf was analyzed using linear regression and with calving ease score fitted as a fixed effect. Dams with veterinary-assisted calvings required 0.7 more services to conception and 8 more days to first service and experienced a 28-d longer calving interval in first lactation compared with dams that were not assisted at calving. Effects of calving ease on the reproductive performance of the adult calf in first lactation were not detected. Losses in milk yield of the dam were significant between d 9 to 90 in milk subsequent to a veterinary-assisted calving, creating a loss of approximately 2kg of milk per day, compared with a nonassisted calving. Calves being born with difficulties showed a significant reduction in milk yield in first lactation, demonstrating the lifelong effect of a difficult birth. Compared with nonassisted calves, veterinary-assisted calves showed a loss of 710kg in accumulated 305-d milk yield, which was significant from 129 to 261 d in milk. This suggests that from birth to production, physiological effects of a bad calving are not negated. Results furthermore suggest a beneficial effect of farmer assistance at calving on the milk yield of both dam and calf, when moderate difficulties occurred
Influence of group housing, lactation system and floor type on performance and injuries in rabbit does
To evaluate the effect of group housing, lactation system, and floor type, 40 crossbred multiparous pregnant rabbit does were transferred to individual pens (0.5 m x 1.0 m); 8 does were kept individually during all the trial (I; n=8); the other 32 does were kept in 8 collective pens (2.0 m x 1.0 m, by joining 4 individual pens) in stable groups of 4 individuals (G; n=8) from 8 d until 2 d before kindling and from 2 d until 33 d after kindling. Half pens had wire net floor covered with plastic mats (W; n=8) and the other half plastic slatted floor (P; n=8). Within G does, in half pens (n=4) each doe nursed its own litter (fixed lactation, F); in the remaining half, each doe randomly nursed the litters of the group (random lactation, R). Doe performance at kindling and during lactation, litter performance from standardization until weaning (33 d), and skin injuries on G does (5, 12, 19, 26 and 34 d after kindling) were controlled. The effect of the housing system on performance was tested by PROC GLM of SAS. Within G does, the effect of the lactation system and floor type was evaluated by PROC MIXED (pen as random effect); the injury frequency was analysed by PROC FREQ according to observation day, lactation system, and floor type. Housing system did not affect doe kindling or lactation performance; litter weight at standardization was higher for G than I does (680 vs 619 g, P<0.05), but differences disappeared at weaning. The lactation system showed some residual effects when controlled lactation finished, nests were opened, and kits free of moving. In fact, from 19 to 33 d after kindling, does and litters had higher feed intake (679 g/d vs 602 g/d; P<0.05) and, at 33 d, kits were heavier (775 vs 748 g, P<0.05) in R than in F pens. Floor type (W vs P pens) affected milk production (244 vs 225 g/d; P=0.06), and kit weight at the end of controlled lactation (301 vs 290 g; P<0.05), without residual effects at weaning. The injury frequency changed after the group formation: 34% at 5 d, 47% at 12 d, 13% at 19 and 26 d, and 10% at 34 d of lactation (P<0.05). In conclusion, under our conditions, group housing did not negatively affect doe performance; lactation system and floor type had minor effects; aggressiveness among does was evident after group formation during early lactation but decreased in the late lactation. Further recordings on more reproductive cycles would be necessary to confirm the present results
The effect of Holstein-Friesian genotype and feeding system on selected performance parameters of dairy cows on grass-based systems of milk production in Ireland
End of project reportThe overall objective of this project was to assess, the effect of strain of Holstein-Friesian dairy cow, pasture-based feed system (FS) and their interaction on animal performance in terms of milk productivity and lactation profile, body weight (BW), body condition score (BCS), feed intake and energy balance (EB), reproductive performance and overall economic profitability
Organic dairy cows: milk yield and lactation characteristics in thirteen established herds and development of a herd simulation model for organic milk production
As a consequence of organic standards and principles, organic dairy producers are frequently faced with a different set of management considerations than those found in conventional dairy systems. The broad objective of this study was to examine in detail the production characteristics of 13 well-established organic dairy herds, and to relate these to the specific conditions that exist within organic dairy farming.
Monthly milk records for 13 organic herds for three years were collected and converted into a Microsoft Access database, using InterHerd™ (Agrisoft Plc., UK) herd management software. The data were sorted and analysed using the InterHerd-herd management, Excel for Windows™ and Statistix for Windows software programmes. Estimated parameters were used to examine the importance of two important indicators: lifetime yield/lactation length and economic efficiency. To assess the first, a spreadsheet model based on the Wood's lactation curve was developed. With regard to the latter, a model calculator was used. Five herds were chosen for case studies, that examined the farm performance by using InterHerd™-generated data and by interviewing the producer retrospectively and asking him to comment on the data.
Results
Milk yield and lactation characteristics
The 13 established, organic herds were characterised with relatively low yields, but herd variation was great: from a total lactation yield of 5,100 kg to 7,000 kg. Milk fat and protein content, lactation length and individual cow SCC means were similar to those reported in conventional, milk recorded herds.
Lactation yields increased up to the third lactation, whereas persistency of lactations decreased up to the third lactation. This pattern followed similar patterns reported in conventionally managed herds. Similarly, somatic cell counts increased with parity, mimicking similar phenomenon reported in conventionally managed dairy cows.
Length of lactation and lactation persistency were associated with month of calving, with autumn calving cows tending to have shorter lactations with better persistency. This phenomenon was, however, confounded with parity.
Fertility
It is concluded that fertility performance in terms of culling for fertility and mean calving intervals were better in the organic survey herds when compared with existing data from conventionally managed UK dairy herds. Good fertility performance even in the highest yielding organically managed cows suggests that early lactation energy deficit may not be a major problem in these herds. It is also suggested that financial impact of high number of services per conception, as observed in majority of the survey herds, may be insignificant as the main losses caused by poor fertility are attributable to culling and prolonged calving intervals.
Herd models
Herd productivity indices were generated, using an existing model based on a measure of feed conversion efficiency at the herd level. The advantage of using this approach in the estimation of productivity is that it takes full account of the entire feed input to the system, including forage.
The production index was closely and independently associated with yield and calving rate. Culling was not independently associated with the production index but once calving rate and lactation yield are taken into account, culling rate also becomes a significant factor.
Case studies
Case studies demonstrated the usefulness of recorded data analysis, using herd management software and observation of seasonally adjusted lactation curves to examine feeding management. In all five herds, apparent and reoccurring seasonal feeding and grazing management shortcomings were detected.
Recommendations
Further research would need to be carried out to establish financial consequences of poor fertility in organic systems with different milk pricing and cow values. Similarly, further research is needed to establish causes for high numbers of services per conception in these herds and to establish whether this phenomenon exists in other organically managed herds.
The herd productivity calculator model (LPEC) showed to be a good and robust measure of productivity. Next logical step in this analysis would be to gain data on purchased feeds, so that the productivity index can be expressed in terms of a gross margin per unit of forage input. This would allow the full importance of forage to organic dairy systems to be expressed, and would also allow productivity to be evaluated in terms economic margin per unit of input produced on-farm.
The LPEC generated indices could also be utilised to examine the potential impact of changes to systems before an intervention is implemented, by including costs of intervention and assumed values of production post-intervention. Sensitivity analyses may be conducted to identify the relative importance of individual production parameters to overall herd productivity.
Careful assessment of lactation characteristics in a herd is needed to predict the overall impact of extended calving intervals. It is likely that in most organic herds feeding management would need to be adjusted in order to produce lactations with low late lactation decline to avoid financial losses caused by longer calving intervals.
Analysis of seasonally adjusted lactation curves as a monitoring and decision support system for feeding management is likely to be a useful for organic herds, particularly during conversion period when new feeding systems need to be introduced in a herd
Effects of Chickpea in Substitution of Soybean Meal on Milk Production, Blood Profile and Reproductive Response of Primiparous Buffaloes in Early Lactation
This study aimed to evaluate the effects of the use of chickpea meal in substitution of soybean meal on plasma metabolites, reproductive response, milk yield and composition and milk coagulation traits of primiparous buffaloes in early lactation. Eighteen primiparous buffaloes were blocked by age, body weight and days in milk and equally allotted to two experimental groups from 10 to 100 days of lactation. The experimental diets consisted of the same forage integrated with two different isonitrogenous and isoenergetic concentrates containing either 210 g/kg of soybean meal or 371 g/kg chickpea. The use of chickpea meal had no negative effects on dry matter intake (p = 0.69), body condition score (p = 0.33) and milk yield (p = 0.15). Neither milk composition nor blood metabolites were influenced by dietary treatments (p > 0.05), but an increment of urea concentrations in milk (p 0.05) of the dietary treatment was highlighted on milk coagulation traits as well as buffalo reproductive responses. We concluded that soybean meal can be replaced by chickpea meal in the diet for primiparous dairy buffaloes in the early lactation period without impairing their productive and reproductive performance
Genetic Relationship of Body Energy and Blood Metabolites with Reproduction in Holstein Cows
Body condition score (BCS), energy content (EC), cumulative effective energy balance (CEEB), and blood serum concentrations of glucose, beta-hydroxybutyrate (BHBA), and nonesterified fatty acids ( NEFA) were measured throughout first lactation in 497 Holstein cows raised on a large commercial farm in northern Greece. All these traits are considered to be indicators of a cow's energy balance. An additional measure of BCS, EC, and blood serum glucose, BHBA, and NEFA concentrations were taken approximately 2 mo (61 +/- 23 d) before first calving. During first lactation, first service conception rate, conception rate in the first 305 d of lactation, interval from calving to conception, number of inseminations per conception, incidence of metritis, and incidence of reproductive problems of these cows were recorded; interval between first and second calving, and second lactation first service conception rate were also recorded. Random regression models were used to calculate weekly animal breeding values for first lactation BCS, EC, CEEB, glucose, BHBA, and NEFA. Single trait animal models were used to calculate breeding values for these traits measured on pregnant heifers before calving. Reproductive records were then regressed on animal breeding values for these energy balance-related traits to derive estimates of their genetic correlations. Several significant estimates were obtained. In general, traits that are known to be positively correlated with energy balance (BCS, EC, CEEB, and glucose) were found to have a favorable genetic relationship with reproduction, meaning that increased levels of the former will lead to an enhancement of the latter. On the other hand, traits known to be negatively correlated with energy balance (BHBA and NEFA) were found to have an unfavorable genetic association with reproductive traits. Body condition score, BHBA, and NEFA recorded early in lactation, and glucose concentrations measured in pregnant heifers had the highest genetic correlation with future reproductive performance. Results suggest that genetic selection for body energy and blood metabolites could facilitate the genetic improvement of fertility and overall reproductive efficiency of dairy cows.</p
Sow body condition at weaning and reproduction performance in organic piglet production
The objective was to investigate the variation in backfat at weaning and its relations to reproduction results in organic sow herds in Denmark. The study included eight herds and 573 sows. The average backfat at weaning mean�13 mm; SD�4.2 mm) ranging from 10.5 to 17.3 mm among herds shows that it is possible to avoid poor body condition at weaning even with a lactation length of seven weeks or more. No main effect of backfat at weaning on reproduction performance was found, but the probability of a successful reproduction after weaning tended to decrease with decreasing backfat for first parity sows, whereas the opposite was the case for multiparous sows
Effect of non-structural carbohydrate dietary content on the productive performance of Sarda primiparous ewes
Comparison of breed of dairy cow under grass-based spring milk production systems
End of project reportThe objective of this study was to investigate the potential differences among
different dairy cow breeds across two feeding systems on milk production,
udder health, milking characteristics, body weight, body condition score,
hormone parameters, ovarian function, survival and overall reproductive
efficiency. The breeds investigated included Holstein-Friesian (HF),
Montbéliarde (MB), Normande (NM), Norwegian Red (NRF) and Holstein-
Friesian × Montbéliarde (MBX) and Holstein- Friesian × Normande (NMX).
Selection within the HF breed has, until recently, been predominantly for milk
production with little or no direct selection for functional traits other than those
correlated with superior type. The MB and the NM have been simultaneously
selected for both milk and beef production in the past. The NRF were imported
as calves and come from a more balanced total merit index incorporating
production and cow functionality since the early 1970s. The dairy cow breeds
were grouped into blocks of two within breed groups and randomized across
two spring-calving grass-based feeding systems: low concentrate feeding
system (LC) and high concentrate feeding system (HC). Those on LC feeding
system were offered approximately 530 kg/cow over the total lactation, while
those on HC feeding system were offered approximately 1030 kg/cow
Comparative study of lactation curves and milk quality in Holstein versus Swedish Red and White-Holstein Cross Cows
The objective of this study reported in this research paper was to compare the lactation curves of the production of milk, fat, protein, percentages of fat and protein, and somatic cell score in purebred Holstein (H) cows and Swedish Red and White (SRW) - Holstein (SxH) crossbred cows in the south-central region of the province of Cordoba, Argentina. The data set consisted of 32847 herd-test records from 1244 purebred H cows and 310 SRW x H crossbred cows, from three commercial dairy farms with cows of first to fifth or more lactations. The curves were modeled using the fourth-order Legendre orthogonal polynomials. In this study, the data of production of milk, fat production, protein production, percentage of fat, percentage of protein and somatic cell score (SCS) were analyzed. Purebred H cows had significantly higher milk production, more fat production and higher protein production levels than did SxH crossbred cows. However, SxH crossbred cows produced milk that had a higher percentage of fat and a higher percentage protein than did purebred H cows. In none of the lactations did somatic cell score differ significantly between the two breed groups. The results of our study showed that, SxH crossbred cows had significantly higher percentages of fat and protein; however, purebred H cows were significantly superior to SxH crossbred cows for the production of 305-d milk, fat, and protein. Mammary health, expressed in SCS, did not differ significantly between the two breed groups. Thus, suggest that crossbreeding Holstein purebred cows with SRW bulls can improve the composition of milk solids without affecting mammary health and, in this way, compensate substantially for any potential loss in the production and/or quality of the milk of the crossbred cows compared to H purebred cows.Fil: Pipino, Diego. Agroveterinaria Pipino; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; ArgentinaFil: Piccardi, Mónica Belén. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Departamento de Desarrollo Rural. Area de Estadística y Biometría; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lembeye, Felipe. Soprole. Gerencia de Abastecimiento. Departamento Agropecuario; ChileFil: Lopez Villalobos, Nicolas. Massey University; Nueva ZelandaFil: Vazquez, Maria Isabel. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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