Short Lactation Length Research Articles

Evaluation of parity and its interaction effect with season of calving, period of calving on production and reproduction traits in Hardhenu (Bos taurus × Bos indicus) dairy cattle

AbstractThis study investigated the impact of parity, period of calving, and season of calving on various production and reproduction traits in Hardhenu cattle. Third‐parity cows outperformed first and second‐parity cows, exhibiting significantly higher total milk yield (TMY), 305 days milk yield (305d MY), peak yield (PY), and artificial insemination per conception (AIPC) (p < .01). The Lactation length (LL) was inversely related to parity, with first‐parity cows having extended lactations (p < .05). The period of calving had a substantial influence on production traits. The season of calving was critical, affecting production traits differently across parities. First‐parity cows had the highest TMY and 305d MY during winter and summer calving, with summer calving associated with shorter LL (p < .05). Second‐parity cows showed higher TMY and 305d MY during summer calving, while third‐parity cows had higher TMY in winter (p < .01). PY followed similar patterns to TMY, with LL affected by the season of calving. Additionally, the study explored interactions between parity, period of calving, and season of calving on reproduction traits. Third‐parity cows had higher AIPC compared to first and second‐parity cows (p < .01). Reproduction traits were also significantly affected by the period of calving, with cows calving in the 2017–2021 period displaying longer service period (SP), calving interval (CI), dry period (DP), and AIPC (p < .01). These findings highlight the complex interplay of biological, environmental, and management factors in shaping the productivity and reproductive efficiency of Hardhenu cattle, emphasizing the need for multifaceted considerations to optimize herd performance.

Breeding pure and crossbreeds of European cattle breeds for milk production improvement under tropical climate conditions-a review.

The aim of this review was to present the breeding status of pure or crossbreeds of European cattle with African indigenous cattle in order to improve milk yield in African tropical conditions. As the African indigenous breeds are characterized by small size, low body weight (300-450 kg) and low production performances (less than 1000 kg per lactation), short lactation length (205-240 days), etc., the crossbreeding with pure European cattle was done in order to ameliorate production performances especially milk and beef production. As results, it was seen that F1 offspring improved output productions than their parents of tropical origin. Also, it was seen that F1 offspring showed disease and heat resistance than their parents of temperate climate origin. However, at different degrees of crossbreeding, it was seen that the offspring can demonstrate bad production performances than their parents and therefore, the crossbreeding has to respect a certain degree. Other consequences are that the crossbreeding of local and pure European cattle breeds has resulted in calving complications in African local cattle. In African indigenous cattle, the selection as an improvement tool was given less emphasis as a solution to improve output production. That is why, the implementation of a well-prepared selection programs could be practiced in African indigenous cattle in order to preserve African cattle genotypes, as they are endangered of extinction due to various crossbreeding with exotic cattle breeds.

A three-year comparison of once-a-day and twice-a-day milking in seasonal-calving pasture-based systems

Globally, the majority of dairy cows are milked twice a day (TAD); however, in pasture-based production systems, such as in Ireland, the idea of milking once a day (OAD) is being considered for reasons such as improved work-life balance. The immediate effects within a lactation, as well as the multilactation consequences of OAD, compared with TAD milking, require understanding. The objective of this randomized experiment was to compare OAD and TAD milking, over a 3-yr period, by examining the differences in milk production and composition, body weight (BW), body condition score (BCS), dry matter intake (DMI), udder characteristics, locomotion score, and milking time. Over the 3-yr period, 83 cows were enrolled in the experiment; 32, 44, and 48 cows in yr 1, 2, and 3 of the experiment, respectively. Each year, 23% of the herds were primiparous animals, while the remainder were second lactation or greater in parity. All cows were milked in the morning at 0700 h; only cows milked TAD were milked a second time each day at 1600 h. Cows rotationally grazed pastures for the duration of the lactating period and were housed during the nonlactating period. Milking cows OAD reduced cumulative milk yield by 26%, and milk solids yield (kg of fat + kg of protein) by 21%, across the 3 yr of the experiment when compared with cows milked TAD which produced 4,126 and 365 kg/cow, respectively. A contributory factor to the reduced production was a shorter lactation length (9.7 d) of the cows milked OAD compared with TAD (294 d). Milk fat percent of cows milked TAD was similar for all 3 yr of the study (5.05%), whereas milk fat percent of the cows milked OAD increased year on year, with each year being greater than the previous year (5.02%, 5.32%, and 5.70% for yr 1, 2, and 3; respectively). Milk protein percent was greater (+0.19%) for cows milked OAD compared with TAD which was 3.78%. Compared with cows milked TAD, total DMI for cows milked OAD was 22% less at the start of lactation (<167 d), but as the lactation progressed (>167 d) we observed no difference in DMI between treatments. Similar to the literature, milking cows OAD significantly increased average somatic cell score, both during (+16%) and at the end of lactation (+19%), compared with milking cows TAD which were 4.69 and 4.79, respectively. We detected positive aspects associated with OAD milking such as greater BW, BCS, and fertility performance. Milking OAD reduced both milking time per cow per day (reductions ranged from 34% in the first 4 mo of lactation to 43% during mo 5-9 of lactation) and milking time per liter of milk (-3.5 s/L) throughout lactation, leading to less labor inputs on-farm which can have positive implications for farmer work-life balance. The significant time saving and potential savings in costs (e.g., electricity) need to be considered in conjunction with the milk production reduction when considering OAD milking for the entire lactation.

Effect of Restricted Suckling on Shortened Lactation Length and Performance of Sahiwal Cattle

Background: Sahiwal cattle write is more prone to lactation failure and short lactation. The present study was conducted to study effects of restricted suckling on productive (with special reference to lactation length) and reproductive performance of Sahiwal cows, who had short lactation length. Methods: A total of 24 multiparous Sahiwal cows of 2nd-4th parity were selected based on their previous history of short lactation length (70-190 days). Cows were randomly divided into 3 weaning groups i.e. zero day weaning group (G1, n=8), restricted suckling up to 90 days (G2, n=6) and restricted suckling up to 150 days (G3, n=6). Recording of peak yield (PY), lactation milk yield (LMY) and lactation length (LL), udder morphometry, somatic cell count (SCC), milking behaviour and reproduction parameters was done. Blood plasma levels of prolactin (ng/ml), growth hormone (mg/ml) and cortisol (ng/ml), were also studied. Result: Lactation MY (kg) was found highest in G2 followed by G3 and G1. Lactation length was found significantly (p≤0.05) longer in group-3. Temperament scoring, days to first heat and service period of cows found significantly higher in RS groups. Overall improvement in lactation length was 38.27% in G2 and 37.28% in G3 as compared to their previous LL. So, the study indicated that the restricted suckling method seems to be more efficient compared to an immediate calf separation since this avoided the cow becoming dry prematurely, improved milk yield, lactation length and growth rate of calves.

Prevalence and Associated Risk Factors of Postpartum Anestrus in Dairy Cows of Sylhet District, Bangladesh

The objectives of current study were to assess the prevalence and risk factors associated with postpartum anestrus in lactating dairy cows in Sylhet region, Bangladesh. A total of 420 postpartum cows of different breed and age were selected randomly from different dairy farms in studied area. Structured questionnaire was used to collect data from farm owner on prevalence and risk factors for postpartum anestrus. Observed heat within 60 days after parturition was considered as normal cyclic cows and others were considered as postpartum anestrus. The prevalence of postpartum anestrus was 36.20%. The study shows that older cows take relatively more time for ovarian resumption. Cow’s having first parity shows cyclicity within 60 days of parturition, and postpartum anestrus increases significantly with the advancement of parity. Postpartum anestrus was significantly higher (P&lt; 0.001) in cows with poor (≤1.0) and excessive (&gt;3) body condition scores (BCS), respectively, compared to those with moderate/optimal BCS (2–3). The postpartum cyclicity in cows within 60 days with a history of normal placental expulsion was significantly higher than in the cows with RFM. Ovarian cyclicity was highest (75.92%) among the cows that were maintained in adequate hygienic conditions and lowest (43.51%) in a poor environment. The highest percentage (88.10%) of cows showed postpartum cyclicity with a history of short lactation length (0-150 days) and resumption of postpartum estrous cycle increases significantly with lactation length. Resumption of postpartum estrus cycles in cows takes more time with a history of minimal (&lt;15 liters) daily milk production than the cow with medium (&gt;15-25 liters) daily milk production. Cows get an adequate feed supply (both concentrate and green grass), which shows a positive effect on postpartum cyclicity. Pre and postpartum complications have a significant (p&lt;0.001) effect on the postpartum cyclicity of cows. Endometritis (81.25%) followed by pyometra (75.76%) were recorded as major reproductive obstacles in ovarian resumption, whereas uterine prolapse (70.59%) followed by abortion (61.54%), milk fever (58.33%), stillbirth (58.33%) and dystocia (57.63%) were the major recorded complications in post-partum phase. The study also revealed that the non-restricted suckling period has a significant (p&lt;0.001) negative effect on ovarian resumption. The risk factors including parity, BCS, placental expulsion, hygienic condition, lactation length, daily milk production and management system were significantly (P&lt;0.01) influenced the postpartum cyclicity. Maintaining optimal BCS of cows, proper hygienic and good management practice, and farmer's training on management of cattle reproduction would improve the number of cows for breeding by 60 days postpartum.

Genetic survey in smallholder dairy production system of Southern province of Zambia.

Milk production among the smallholder dairy farmers in Zambia is reported to be low despite improvements in milk collection infrastructure and unmet demand by the populace. This study was conducted to characterize cattle breeds and the breeding strategies of the smallholder dairy production system in the Southern province of Zambia. The study was conducted using questionnaires to obtain responses from identified respondents in six districts considered the main dairy cattle producing areas. One hundred and twenty questionnaires were administered and available for descriptive statistical analysis. The cattle genetic groups included local (Tonga and Angoni) breeds and their crosses (40.0%); beef (Boran and Brahman) breeds and their crosses (23.3%); Friesian breed and its crosses (28.8%); Jersey breed and its crosses (4.9%); and Fleckvieh breed (3.0%). Calving rate was found to be to be between 36% and 50% for the dairy herds. Compared to the other genetic groups, it was noted that Friesian and its crosses had higher milk production (3.55 L vs. 1.4L). The low milk yield reported could be attributed to the period of study, which coincided with the long dry season between April and October. The Friesian and its crosses recorded earlier age at first calving (2.65 vs. 2.8 years), shorter longevity (10.5 vs. 12.25 years), and shorter lactation length (7.5 vs. 9.25 months). Jersey and its crosses, on the other hand, had an above average performance for all indices of economic importance such as milk production, lactation length, age at first calving, longevity, and number of calves produced. The results indicated natural mating was practised by 85% of the farmers. Farmer-preferred traits include size and conformation (23%); performance and colour (16% and 15%, respectively) in the choice of a bull. Selection by farmers were thus based on simple observation without pedigree or performance-based genetic evaluation. It was apparent that the smallholder dairy production system is in a shifting trend to transform the mainly local and beef breed animals into dairy herds through crossing with exotic dairy breeds. The production system is, however, faced with the challenges of water and feed supply to meet nutritional requirements, and high disease burden. Jersey breed was found to be a logical choice for the resource poor smallholder dairy farmers. The development and management of the smallholder dairy breeding schemes should be all-inclusive and directed at the prevalent production systems with the aim of also improving the feeding and management practices.

Performance Evaluation of Arsi, Kereyu and Their Crossbred Cattle Under Current Climate Change in Mid Rift Valley of Oromia, Ethiopia

The study was conducted in Fentale and Boset districts, East Shoa Zone, Oromia Region, Ethiopia. The objective of this study was to identify morph metric variation between cattle breeds of Arsi, Kereyu and their crossbred, and to evaluate adaptive, productive (milk yield) and reproductive performance of these cattle breeds, and their crossbred in the mid rift valley of Oromia Region. Three PA’s from each district, a total of Six PA (Huluka, Kawa, Barchota, Benti, Kobo and Dakaedu) were selected purposively. Respondents’ were identified using purposive sampling technique. Kereyu, Arsi and crossbred cattle of the two were reared for, milk production, risk aversion and source of income. The major production constraints identified were feed shortage, water scarcity, disease and coverage of grazing land by invasive plants. Arsi cattle’s have long age at first mating (3.87±.17), age at first calving (4.66±0.2) and calving interval (1.50±0.125) than Kereyu (3.78±0.23, 4.52±0.25, 1.39±0.19) and crossbred (3.86±0.11, 4.64±0.12, 1.49±0.14) in both study location while the crossbred cattle have medium Values respectively. Arsi cattle have short Lactation length than kereyu and Crossbred (6.36, 7.51, 7.11months for Arsi, kereyu and crossbred respectively also similar for daily milk yield (1.26, 1.71 and 1.43). The farmers in the two district prefer Kereyu breed due to their ability to tolerate drought, disease and highly adaptable to the area where as Arsi breed of cattle was susceptible to feed shortage, water scarcity and disease than other breed in the area. This study revealed that the Arsi community in the study area prefers to mate breeding female of Arsi with bull of Kereyu breed.

Sow-related factors affecting the postweaning feed intake in Landrace × Large White females.

During the weaning-to-estrus interval (WEI), a high feeding level is usually offered to recover losses due to lactational catabolism. However, several factors can affect the appetite, possibly impairing the efficacy of this strategy. This study aimed to investigate the effect of sow-related factors on average daily feed intake (ADFI) during WEI in 142 primiparous and 458 multiparous sows. After weaning, the sows received 4.3 kg/day of feed and the wastage was recorded. The ADFI after weaning was lower in primiparous than multiparous sows, and on estrous day than in 2 and 3 days preceding estrus (P ≤ 0.05). In primiparous sows, lower ADFI was observed if they had higher backfat thickness at 112 days of gestation (BFT ≥ 11.5 mm) or higher reserves at weaning (BFT ≥ 10.5 mm, caliper units ≥ 12 or ≥ 157 kg; P ≤ 0.05). Higher body reserves at the end of gestation (caliper units ≥ 12, BFT ≥ 11.0 mm, or BCS ≥ 3.0) or weaning (caliper units ≥ 13, BFT ≥ 12.5 mm) negatively affected the ADFI in multiparous sows (P < 0.04). Weaned litter size ≤ 11 piglets (P = 0.06) and shorter lactation length (P< 0.01) decreased the ADFI in primiparous sows. Greater loss in caliper units during lactation tended to reduce ADFI in primiparous and multiparous sows (P ≤ 0.07). Multiparous sows with greater losses in BFT and BCS had lower ADFI (P ≤ 0.03). The ADFI during WEI is reduced when sows are in estrus or if they have greater body reserves.

Unraveling the actual background of second litter syndrome in pigs: based on Large White data

Second litter syndrome (SLS) in sows is when fertility performance is lower in the second parity than in the first parity. The causes of SLS have been associated with lactation weight loss, premature first insemination, short lactation length, short weaning to insemination interval, season, and farm of farrowing. There is little known about the genetic background of SLS or if it is a real biological problem or just a statistical issue. Thus, we aimed to evaluate risk factors, investigate genetic background of SLS, and estimate the probability of SLS existing due to the statistical properties of the trait. The records of 246 799 litters (total number born, TNB) from 46 218 Large White sows were used. A total of 15 398 sows had SLS. Two traits were defined: first a binominal trait if a sow had SLS or not (biSLS) and second a continuous trait (Range) created by subtracting the total number of piglets born in the first parity (TNB1) from the piglets born in the second parity (TNB2). Lactation length, farm, and season of the farrowing had significant effects on SLS traits when tested as fixed effects in the genetic model. These effects are farm management-related factors. The age at first insemination and weaning to insemination interval were significant only for other reproduction traits (e.g., TNB1, TNB2, litter weight in parity 1 and 2). The heritability of biSLS was 0.05 (on observed scale), whereas heritability of Range was 0.03. To verify the existence of SLS data with records of 50 000 sows and 9 parities was simulated. The simulations showed that the average expected frequency of SLS across all the parities was 0.49 (±0.05) while the observed frequency in the actual data was 0.46 (±0.04). We compared this to SLS frequencies in 67 farms and only 2 farms had more piglets born in the first parity compared to the second. Therefore, on the individual sow level SLS is likely due to statistical properties of the trait, whereas on the farm level SLS is likely due to farm management. Thus, SLS should not be considered an abnormality nor a syndrome if on average the herd litter size in parity 2 is larger than in parity 1.

Productive and reproductive performance of crossbred and indigenous dairy cows at smallholdings in selected towns of Jimma Zone, Ethiopia

Context Evaluation of the performance of dairy cows kept in different production systems is essential for the development of appropriate breeding strategies. Aims To examine milk production and reproductive performance of crossbred (CB) and indigenous (I) dairy cows, farmers’ traits preference for CB and I breeding females, and factors affecting the performance of dairy cattle on smallholdings in selected towns of Jimma Zone, Ethiopia. Methods In total, 52 smallholder dairy cattle farmers were randomly sampled and data were collected through individual face-to-face interviews by using structured questionnaires. The traits studied were daily milk yield (DMY), lactation milk yield (LMY), lactation length (LL), age at first service (AFS), age at first calving (AFC), calving interval (CI), days open (DO), and number of service per conception (NSC), all being factors affecting performance of dairy cattle and farmers’ preferred dairy traits. Results On average, CB cows had significantly (P &amp;lt; 0.05) higher DMY (6.0 ± 0.33 vs 1.8 ± 0.07 L/cow), LMY (1466.7 ± 1.13 vs 376.0 ± 21.02 L (L)), LL (8.1 ± 0.41 vs 6.9 ± 0.22 months), and lower AFS (2.69 ± 0.1 vs 3.3 ± 0.07 years), AFC (3.7 ± 0.13 vs 4.3 ± 0.07 years) and CI (21.2 ± 1.37 vs 29.8 ± 1.30 months) than did I cows. However, DO and NSC were not significantly (P &amp;gt; 0.05) affected by genotype. In order of perceived importance, high milk yield (mean rank = 0.306), LL (0.292) and fertility (0.199) were farmers’ most preferred traits for CB breeding cows, and the corresponding preferred traits for I cows were high milk yield (0.253), adaptability (0.229) and LL (0.192). The most important factors perceived by farmers affecting the performance of dairy cattle were breed, nutrition, diseases, breeding and management practices Conclusions The findings of the study indicated that even though CB cows performed better, the performance of both breeds of dairy cows in the study area was found to be generally low due to delayed AFS, late AFC, long CI, shorter LL, low daily and LMY and high NSC. Implications The study highlighted that there is a potential for increasing the performance of dairy cows in the study area, through improved management strategies leading to shorter AFS, AFC, CI and lower NSC. Furthermore, future breed-improvement programs should take into consideration farmers’ trait preferences in design of sustainable improvement programs.

PHYSIOLOGY AND ENDOCRINOLOGY SYMPOSIUM: Factors influencing follicle development in gilts and sows and management strategies used to regulate growth for control of estrus and ovulation1.

Factors that affect follicle health and growth can influence estrus, ovulation, conception, and litter size. Since the majority of the breeding herd is composed of sows, production schedules are established based on synchronized follicle growth following weaning. Insemination of sows over a 3- to 4-d period after weaning facilitates farrowing over fewer days and helps improve the uniformity of pigs at weaning. Synchronized inseminations of the group are reduced when disturbance to the follicular phase results in delayed estrus. The failure of >15 follicles to uniformly progress beyond the 6.0 mm size within 4 d during the follicular phase is associated with delayed estrus and ovulation, reduced ovulation rate, and reduced farrowing rate. In sows, the follicular phase is initiated at weaning by removal of the suckling inhibition, whereas in cycling gilts, luteolysis and clearance of progesterone begins the process. The timing and patterns of follicle-stimulating hormone and luteinizing hormone stimulation to the ovary determine follicle health and selection for ovulation. Interestingly, abnormal wean-to-estrus intervals in sows and deviations from a 19- to 22-d estrous cycle in gilts are associated with reduced fertility. However, in both cases, it is not entirely clear whether the abnormal intervals are a direct result of problems occurring prior to or only during the follicular phase. In prepubertal gilts, the signal for initiating the follicular phase remains elusive, but could reside in differential sensitivity and response to hormone signals at the level of the ovary and brain. Although the mechanisms are not clear, factors such as boar exposure, stress, feed intake, growth rate, and birthweight have been shown to stimulate an early follicular phase. In contrast, inhibitors to follicle growth have been associated with season, heat stress, photoperiod, negative energy balance, poor body condition, slow growth, fewer parities, and short lactation length. Hormonal aids for inducing and delaying the follicular phase, as well as for inducing ovulation are available to aid in synchronized breeding schedules.

Dairy Cows Productivity and Socio-Economic Profile of Dairy Smallholder’s Communities in Yogyakarta, Indonesia

The objective of this field questionnaire survey was to describe the dairy cow productivity and socio-economic profile of dairy cattle farmers in Daerah Istimewa Yogyakarta smallholder farming communities which have been targeted dairy development policy. The study was conducted on 190 Friesian Holstein (FH) cows maintained under smallholder’s management system in Daerah Istimewa Yogyakarta, Indonesia. A total of 83 farmers were randomly selected and interviewed with structured questionnaire to assess the socio-economic dairy farmer and productivity performance of dairy cows. The number of dairy productivity performance within the normal. Shortages as well as high cost of feed, occurrence of disease, scarce information about feeding and high medicament cost were the main constraints which might have contributed considerably to delayed age at first service, late age at first calving, long calving interval, short lactation length and low milk production. Therefore, strategies designed to solve the existing problem should be important by involving all stakeholders in the formulation and implementation of improvement strategiesor dairy development policy was being implemented and necessary respect to environmental factors affecting agricultural activities such as a constraint on land use and access to water resources.

Management strategies to improve reproductive performance of Brahman cross cattle (Bos indicus) in East Java, Indonesia

&lt;p class="abstrak2"&gt;The demand for meat in Indonesia cannot be supplied by domestic cattle production, and so breeder cattle stock are imported from abroad overseas to increase domestic production. A commonly imported breed is Brahman cross bred (Bx). Smallholder farmers have reported a wide range of problems associated with Bx cow reproductive performance. The purpose of this study was to identify changes in the reproductive performance of Bx cows by providing advice to farmers on improved management strategies, such as: maintaining body condition score (BCS) of cow&amp;gt; 3, appropriate estrous detection and weaning at 5- 6 months. This study was conducted from October 2011 – December 2013 by using 189 Bx cows and 151 farmers. The research was conducted in two sub districts of Lamongan district (East Java), Modo and Sambeng. Cattle were fed diets based on crop residues and were supplemented with green feeds, by-products (rice bran) and concentrate during the last 2 months of pregnancy and early lactation. The reproductive performance of cows improved during the study, there were a shorter lactation length/early weaning (reduced from 188 days to 153 days) and improved BCS (from 3.0 to 3.3). The length of postpartum anestrous interval (PPAI) decreased from 198 days to 98 days. Cycling to conception decreased from 75 days to 64 days and days open decreased from 217 days to 118 days over the length of the study. This was associated with improvement in BCS of cows at calving (from 3.0 to 3.3) and a shorter lactation length (reduced from 188 days to 153 days). There was no change in the average birth weight of calves (31.8 kg). There was no change in average weaning weight of calves over the year and average daily gain of calves while suckling 0.7 kg/day. The pre weaning calf mortality rate was decreased during this study (from 13% to 6%). This project demonstrated that Brahman cross cows can successfully be kept by smallholder farmers in Indonesia if appropiate management is used. It can be concluded that improving management, such as maintaining body condition score of cow &amp;gt;3, estrous detection, appropiate mating and weaning at 5-6 months can improve reproduction performance of Brahman cross.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Key Words&lt;/strong&gt;: Reproduction, Cattle, Brahman Cross&lt;/p&gt;

Comparative expression profiling of insulin-like growth factor binding protein-5 in milk of Bos indicus and Bubalus bubalis during lactation

Insulin-like growth factor binding protein-5 (IGFBP-5) is a key molecule in mammary gland development, which facilitates the removal of mammary epithelial cells (MECs) by apoptosis that takes place during remodeling of the mammary gland during involution. IGFBP-5 binds with IGFs for their bioavailability. IGFBP-5 has been reported to perform pleiotropic roles such as cellular apoptosis, proliferation and differentiation. To understand the role of IGFBP-5 during lactation and clinical mastitis, expression profiling of IGFBP-5 at the protein level was performed in both indigenous cows (Bos indicus) and buffaloes (Bubalus bubalis) belonging to two different breeds – Sahiwal cows and Murrah buffaloes. Reverse-transcriptase PCR (RT-PCR) of IGFBP-5 mRNA confirmed its expression in milk somatic cells and MECs of Sahiwal cows. ELISA was performed for quantitative measurement of IGFBP-5 concentrations in milk during different days (0, 50, 100, 150, 200, 250 and 300) of lactation, during the involution period and in animals exhibiting short lactation and clinical mastitis. The highest concentration of IGFBP-5 in milk was observed during the involution period followed by colostrum, late and early lactation, respectively, in both cattle and buffaloes. No significant difference in the concentration of IGFBP-5 was observed during the first 150 days of lactation between cows and buffaloes. However, higher concentration of IGFBP-5 was observed in cows during late lactation (200 to 300 days) in comparison with buffaloes. To validate the ELISA data, quantitative real-time PCR was performed in MECs of Sahiwal cows. The relative mRNA abundance of IGFBP-5 was found to be significantly (P<0.05) higher on day 15 than between 50 and 150 days of lactation in case of Sahiwal cows. Highest mRNA expression of IGFBP-5 was observed around 300 days of lactation followed by 200 and 250 days (P<0.05), respectively. Murrah buffaloes showed low levels of IGFBP-5 protein in milk as compared with Sahiwal cows during lactation in ELISA. Animals having history of short lactation length (short lactating animals) showed higher levels of IGFBP-5 expression (at protein level) in comparison with normal lactating animals. We propose that higher level IGFBP-5 expression may have functional significance in lactation persistency. As a pro-apoptotic molecule, higher expression of IGFBP-5 was observed to be inversely related to lactation length and milk production.

Factors Associated with Farrowing Failure Occurrences in Reserviced Females on Commercial Swine Farms

Of collected 687 U.S.A. farms, 149 farms were selected by the criteria based on accurate 5-year records. Farrowing failure occurrence (%) was defined as the number of females returned to service and failed to farrow divided by the number of females served during a certain period. A service was defined as one or more mating events during a 10-day time period. Of 178, 367 services in 155, 035 parity records of 39, 945 breeding females, 39, 204 females (22.0%) had farrowing failure occurrences in the first service, 23, 332 females (13.1%) were rserviced. Farrowing failure occurrences (%) in the second, and third service or later were also 32.4, and 49.2%, respectively. Using the multiple logistic regression analyses in mixed models of SAS, increased numbers of services were associated with higher farrowing failure occurrences (P 14 days (P<0.05) . In the first service and reservice groups, females serviced from April to September had higher farrowing failure occurrences than those serviced from October to March (P<0.05) . Low or high parity females rserviced during spring and summer seasons after short lactation length should be carefully monitored on commercial farms.

Effects of age and liveweight at first calving on first lactation milk, protein and fat yield of Friesian heifers

This paper reports on both the individual and combined effects of age (AFC) and liveweight (LWFC) at first calving for Australian Holstein–Friesian heifers on first lactation production. One hundred and thirty-five Australian Holstein–Friesian heifers were allocated to 1 of 3 AFC treatments. Within each AFC treatment, heifers were randomly assigned to 1 of 3 LWFC treatments. Heifers in all groups grazed pasture and were supplemented when the quantity and quality of pasture was inadequate to meet growth requirements. Mean AFC and LWFC achieved were 25.1, 29.9 and 33.9 months and 498, 549 and 595 kg, respectively. Mean liveweight gains from 16 weeks of age to calving ranged from 0.45 to 0.71 kg/day, depending on treatment. The heifers calving at 33.9 months of age produced 6.6 and 12.3% more milk, 6.3 and 11.9% more protein and 5.4 and 12.2% more fat than those calving at 29.9 and 25.1 months of age at the end of their first 300 day lactation, respectively. The lower production of the younger cows was associated with decreased daily output rather than by shorter lactation length. Heifers averaging 595 kg at first calving produced 5.5% more milk, 8.4% more protein and 11.4% more fat than those averaging 498 kg in first lactation, respectively. The heifers averaging 621 kg LWFC and 34 months AFC had the highest production of the 9 treatment groups. Production was increased by 5.35 L milk, 0.19 kg protein and 0.23 kg fat for an additional 1 kg LWFC, respectively. For each month delay in AFC, production was increased by 66.7 L milk, 1.87 kg protein and 2.36 kg fat, respectively. The combined effects of AFC and LWFC showed that to offset the negative effects of a 1 month reduction in AFC on milk, protein and fat yields in first lactation, LWFC would have to be increased by 8.1, 4.0 and 4.5 kg, respectively. Under the conditions of this experiment, maximum milk, protein and fat were estimated to be achieved at 559, 563 and 568 kg liveweight at first calving, respectively.

Retrospective analysis of trends and production factors associated with sow mortality on swine-breeding farms in USA

Of the 825 pig farms in USA that mailed in their electronic file containing production records, 604 farms were used to observe breeding-female mortality risk and related factors (herd size, lactation length, parity and season). Multiple regression was used to determine factors associated with annual mortality risk. Analyses of variance were used for comparisons of mortality risks among parity and season groups. Average annual mortality risks during the 1997 period was 5.68%. Average breeding-female inventories and average lactation length on USA farms were 733 and 18.3 days, respectively. Higher annual breeding-female mortality risk was associated with larger herd size, greater parity at farrowing and shorter lactation length ( P<0.02). For example, as herd size increases by 500 females, mortality risk increases by 0.44%. Older parity was associated with higher mortality risks. Summer season was also associated with higher mortality risk. Using five-years’ records on 270 farms, annual mortality risk in 1997 was higher than those of 1993 and 1994, while average breeding-female inventory increased and lactation length decreased. It is recommended that producers, especially in large herds, pay more attention to breeding females.

Assessment of sows mating efficacy during the low productive period after early weaning: A field study

Data on sows bred after weaning (n = 9,540) and their lactation feed intake records (average lactation length <20 d) were obtained from 16 commercial farms. Weaning-to-first-mating intervals (WMI) at 6 to 12 d and 0 to 6 d after weaning were defined as the low and high productive periods, respectively. Of the 9,192 sows mated, 80.5 and 19.5% were mated at 0 to 6 d and 7 to 12 d, respectively. In logistic regression analysis, lower parity, shorter lactation length, lower average daily feed intake (ADFI) during lactation, and a greater number of weaned pigs were associated with mating at 7 to 12 d after weaning (P ≤ 0.045). Exponentiating the coefficients in logistic regression analysis, the odds ratios were 0.79 for parity, 0.84 for ADFI during lactation, 0.85 for lactation length, and 1.05 for weaned pigs, respectively. A sow with a 14-d lactation length is 2.3 (1/0.85 5) times as likely to mate within a 6- to 12-d WMI as a sow with a 19-d lactation length. Thus, the early weaned sows are more likely to mate during the low productive period than the later weaned sows. The odds for parity 0.79 imply that Parity 1 sows were 1.6 (1/0.79 2) times as likely to mate within a WMI 6 to 12 d as Parity 3 sows. For each 1-kg increase in ADFI, a mating occurrence during the low productive period decreased by 0.84 times. Sows are mated during the low productive period because this period is a part of the distribution of WMI in a herd. However, our research suggests that increasing feed intake during lactation and maintaining parity proportion appropriate to the herd can decrease the proportion of sows mated during the low productivity period.

Management factors associated with swine breeding-herd productivity in the United States

A database containing 24 key production measurements was created by abstracting data files of 673 U.S. farms which participated in the PigCHAMP data-share program in 1995. Summary statistics for breeding-herd performance data were presented for the Cornbelt and the South or Eastern regions. Eight models were built to assess the association between production system, operation management factors and productivity outcomes. Lactation length, percentage of multiple matings, parity of culled sows, percent gilts in the breeding-female inventory, and female culling rate were the management factors identified as having important associations with productivity outcomes. For example, shorter lactation length, higher percentage of multiple matings, and lower culling rate were associated with more pigs weaned per mated female per year. In addition, a lower percentage of gilts in the breeding-female inventory and a higher percentage of multiple matings were associated with fewer average non-productive female days. We recommend that producers change their management systems to decrease lactation length, the percentage of gilts in the breeding-female inventory, and female culling rate, and increase percentage of multiple matings in order to improve breeding-herd productivity on swine farms.

An epidemiological investigation of reduced second-litter size in swine

This study was designed to determine if reduced second-litter size is associated with sow genetics, weaning-to-service interval for primiparous sows, or other covariates thought to influence litter size. A database of 135 herds was analyzed retrospectively using analysis of covariance. Of the 135 herds, 40% had fewer pigs born alive in their second litter thanin the first. A large first-litter size was the major determinant of fewer pigs being born alive in the second litter. Based on least-squares means, 6 out of 13 sow genetic groups had fewer pigs born alive in the second litter than in the first; however, the difference depended on the weaning-to-service interval. A short lactation length and a heavy average weaned pig weight was associated with fewer pigs born alive in the second litter than in the first. In conclusion, delaying the breeding of primiparous Large-White (or Yorkshire) × Landrace sows post-weaning was related to an increased number of pigs born alive in their second litter.