Suckling Calves Research Articles

Influence of different water access status of suckling calves on performance, water intake behavior and some blood metabolites

This study was conducted to determine the effects of water accessibility of pre-weaning calves during milk feeding meal on performance, water intake behavior and some blood metabolites. Forty-eight Holstein calves (39.2 ± 5.8 kg of BW) were assigned to 4 treatments, which consisted of different water accessibility: 1) Ad libitum water (AW), 2) Water not available (WNA), 3) Water available after milk feeding (WAM) and 4) Water available before milk feeding (WBM). Resulted showed different water accessibility changed water consumption of calves. The water intake of AW (1.03 kg/d) and WBM (1.07 kg/d) treatments were higher than others. Starter intake of WBM decreased (P<0.05) as compared with others. Calves of WBM had higher (P<0.05) activity of serum AST. Blood Cl and K did not show the difference (P<0.05) among treatments. Serum TAC levels were higher (P<0.05) in WNA and WAM calves. Serum protein and HDL in WNA calves were higher (P<0.05) than others. These groups had higher (P<0.05) serum Na concentration than others. The different water accessibility of calves had no significant effects on health score, respiratory, fecal score and growth parameters. Treatments did not affect behaviors parameters. But the number of visiting water bucket of AW and WBM were higher than other groups. Acetic acid and propionic acid of AW calves significantly increased (P<0.05) as versus other treatments. Drinking water around milk feeding meal change water consumption, performance and improve some blood metabolites and rumen parameters of calves but did not influence growth parameters.

Youngstock health: Effective disease prevention today ensuring tomorrow's profitable herd

Foreword Proactive youngstock health management is critical not only to optimise animal welfare and production efficiency and profitability, but also to minimising the environmental impact of livestock production. The morbidity and mortality rates tolerated by some producers, and at times even accepted by their vets, are often far too high. Whether it is the loss of dairy bull calves, who may have little monetary value but nevertheless contribute to both the carbon footprint and other environmental impacts of a dairy if not utilised for food production, dairy heifers with the additional loss of the best genetics in the herd or a beef suckler calf representing the only product of the cow that year, we need to do all we can to prevent death and disease. Even where calves do not die, managing sick animals is costly in treatment and labour and antibiotic use in these animals to treat, and on some farms still to prevent disease, is very likely to contribute to antimicrobial resistance. The only logical conclusion that one can come to is that if cattle units are to remain viable and produce sustainable milk and meat, we need to redouble efforts to prevent disease. Sometimes we talk of new science, while at other times we find ourselves repeating ‘the same old message’. The need for adequate colostrum management is one such case, the messages may not be new but far too many calves still fail to receive enough maternally derived antibody, making the article in this supplement on colostrum vital reading. Don't assume you, or more importantly your clients, know everything there is to know about colostrum. After ensuring calves have received initial protection via maternal derived antibody from colostrum then we need to ensure they are protected from infections as they grow, particularly respiratory diseases. Despite having had good vaccines for over 20 years, their uptake in the national herd I believe is still suboptimal, far too many calves still receive antimicrobials, and poor growth rates are common due to chronic lung damage. Ellie Button explains well in her article ‘Calf disease: an immunological perspective’ the calf's innate and acquired immunity and describes how an understanding of the calf's developing immunity can be used to enhance disease prevention. Finally, Kat Hart and colleagues discuss communication and promoting behaviour change in ‘How to engage farmers in youngstock care: a clinical forum’, something that in the past we have often forgotten. It's not good enough for vets to understand the science and turn a blind eye to poor on farm practices, or to simply tell clients what to do and walk away expecting them to do as they have been told! We often need to motivate clients towards real lasting change, and to do that we all need to communicate better. Together the three articles in this supplement are a powerful combination, the challenge is to read them and then effect valuable changes on your clients’ farms.

Weight gain of free-ranging beef cattle grazing in the boreal forest of south-eastern Norway

Young forest stands and clearcuts in the boreal forest created by modern forestry practices along with meadows of abandoned summer farms may contribute as feeding areas for beef cattle. The patchy distribution and varying quality and diversity of forage on such unimproved lands may affect cattle productivity. Weight gain of 336 beef cows and 270 calves free-ranging during three summer grazing seasons was monitored in boreal forests of south-eastern Norway, stocked at either high (0.16 cows ha-1) and low (0.04 cows ha-1) stocking densities. We used linear mixed effect models for assessing intrinsic correlates of weight gain in cows and calves in the two areas. Habitat use and home range size of a subsample of 53 cows were monitored by using GPS collars programmed to log locations at 5 min. intervals during the grazing season. Additional extrinsic correlates of weight gain for the subsampled cows using a linear mixed model were also tested.Average weight gain of beef cows grazing at the low stocking density was positive among cows of early maturing breeds (represented by Hereford) gaining 24 ± 2.8 kg (± SE), while cows of late maturing breeds (mainly represented by Charolais) had an average weight loss of 9 ± 8.4 kg. The average weight gain was negative for beef cows of both early (Herefords) and late maturing breeds (mainly represented by Charolais but also Limousin and Simmental) at the high stocking density. Within both breed groups, there was a negative relationship between breed-specific average weight of cows at turnout and weight gain during the grazing period, while a prolonged grazing period was slightly positively related to weight gain. There was no relationship between weight gain and home range size and proportion of grazing habitat for the 53 cows fitted with GPS collars.Higher weight gains in calves of the low compared to the high stocking density area was found. However, there was no breed effect of weight gain in calves. Across study areas, spring-born suckler calves gained more weight than autumn-born calves (92 ± 1.7 kg vs. 65 ± 4.4 kg). Also, there were higher weight gains for spring-born bull-calves than spring-born heifers (100 ± 2.4 kg vs. 94 ± 2.2 kg).Overall, the results indicate that it is possible to achieve acceptable weight gains for cattle grazing coniferous forest by finding breeds suitable for these extensive areas and stocking at moderate densities.

Spontaneous and experimental poisoning by Froelichia humboldtiana in cattle

ABSTRACT: The aim of this work was to describe the epidemiological, clinical and pathological aspects of two outbreaks of spontaneous poisoning caused by Froelichia humboldtiana in cattle in Pernambuco, northeastern Brazil and reproduce experimentally this poisoning in cattle. Spontaneous poisonings of primary photosensitization occurred in two farms at the municipalities of Cachoeirinha and São Caetano and affected twenty-two adult bovines and two suckling calves after the rainy season. All bovines have recovered 21 days after they were removed from the pasture. To reproduce experimental poisoning, three cows and a calf were maintained in a pasture with 1ha composed by F. humboldtiana during 14 days. Clinical signs and skin lesions were similar in both spontaneous and experimental poisoning and consisted of cutaneous itching and hyperemia of non-pigmented areas of skin that evolved into edema, exudative dermatitis and extensive areas of skin necrosis. Serum levels of aspartate aminotransferase (AST), gamma glutamyltransferase (GGT), total, direct and indirect bilirubin were normal in all cattle examined. Histologically, lesions consisted of epidermal necrosis, hyperkeratosis with large amounts of degenerate neutrophils and acanthosis. In the dermis, edema and inflammatory infiltrate composed of eosinophils, lymphocytes and plasma cells mainly around the blood vessels were observed. In the experimental group, clinical signs of photosensitization were observed after the third day of F. humboldtiana consumption. The suckling calf displayed mild clinical signs of photodermatitis on the 8th day of the experiment. It was estimated that the average consumption of F. humboldtiana necessary to initiate clinical signs in each adult bovine was 78kg.

Determination of milk intake by calf suckling during lactation in Kankrej cows

The research work was carried out on Kankrej cattle at Livestock Research Station, S. D. Agricultural University, Sardarkrushinagar, Gujarat. The quantity of milk suckled by the calves was estimated by weigh-suckle-weigh technique (Williams et al ., 1979). Kankrej calves were selected for the present study (for the period of lactation maximum up to 305 days). A total of 741 observations were considered for analysis. The results revealed that overall suckling allowance was 725.9 liters per lactation. The average milk suckled by the calves in a single time was 1.26±0.04, 1.20±0.06, 1.11±0.05, 1.13±0.05, 1.18±0.05, 1.12±0.05, 1.22±0.08, 1.38±0.09, 1.33±0.08, 1.17±0.08 and 1.19 ±0.02 liters during first, second, three, four, five, six, seven, eight, nine, ten month of age and during lactation, respectively. According to the milk production capacity of dam, milk suckled by the calves per time was 1.21±0.05, 1.20±0.02, 1.13±0.05 liters in the cows producing 0-3, 3-6 and more than 6 liters of milk per time, respectively. Similarly, milk suckled by the calves at one time during early, mid and late lactation was 1.20±0.03, 1.14±0.03 and 1.32±0.05 liters, respectively. While, as per the body weight of the calves (up to 50 kg, 50 to 100 kg and more than 100 kg) the milk suckled was 1.21±0.03, 1.15±0.03 and 1.27±0.05 liters, respectively. The milk suckled by the calves in this study was comparatively higher than other Indian cattle breeds, because of powerful mothering instincts of Kankrej cows which ultimately responsible for the least calf mortality in this breed. From the above study, it is concluded that the average milk suckled by the calves per time is 1.19 ±0.02 litres and total 725.9 liters per lactation which could be added to the milk collected in pail while calculating total lactation yield in Kankrej cattle while comparing the production potential especially with crossbreds.

Meta-analysis of the effects of on-farm management strategies on milk yields of dairy cattle on smallholder farms in the Tropics

Although East Africa is home to one of the most advanced dairy industries in Sub-Saharan Africa, regional annual milk production is insufficient to meet the demand. The challenge of increasing milk yields (MYs) among smallholder dairy cattle farmers (SDCFs) has received considerable attention and resulted in the introduction of various dairy management strategies (DMSs). Despite adoption of these DMSs, MYs remain low on-farm and there is a large discrepancy in the efficacy of DMSs across different farms. Therefore, the present study sought to: (1) identify on-farm DMSs employed by East African SDCFs to increase MYs and (2) summarize existing literature to quantify the expected MY changes associated with these identified DMSs. Data were collected through a comprehensive literature review and in-depth semi-structured interviews with 10 experts from the East African dairy sector. Meta-analysis of the literature review data was performed by deriving four multivariate regression models (i.e. models 1 to 4) that related DMSs to expected MYs. Each model differed in the weighting strategy used (e.g. number of observations and inverse of the standard errors) and the preferred model was selected based on the root estimated error variance and concordance correlation coefficient. Nine DMSs were identified, of which only adoption of improved cattle breeds and improved feeding (i.e. increasing diet quality and quantity) consistently and significantly (P < 0.05) increased daily MYs across the available studies. Improved breeds alongside adequate feeding explained ≤50% of the daily MYs observed in the metadata while improved feeding explained ≤30% of the daily MYs observed across the different models. Conversely, calf suckling significantly (P < 0.05) reduced MYs according to model 2. Other variables including days in milk, trial length and maximum ambient temperature (used as a proxy for heat stress) contributed significantly to decreasing MYs. These variables may explain some of the heterogeneity in MY responses to DMSs reported in the literature. Our results suggest that using improved cattle breeds alongside improved feeding is the most reliable strategy to increase MYs on-farm in East Africa. Nevertheless, these DMSs should not be considered as standalone solutions but as a pool of options that should be combined depending on the resources available to the farmer to achieve a balance between using dairy cattle genetics, proper husbandry and feeding to secure higher MYs.

Giraffe males have longer suckling bouts than females

Abstract In polygynous mammals, females are expected to bias maternal investment in favor of male calves. The mother should invest more in males to enhance their reproductive success in adulthood, or the males require greater investment as they are bigger and stronger than females. In this study, we used nursing duration to compare the difference in the amount of maternal investment provided by females. We compared differences according to sex of the offspring and the influence of calves’ identification by sniffing, using captive giraffes (Giraffa camelopardalis) as a model. Since a high intensity of allonursing (nursing of a nonfilial calf) was reported in giraffes, we also focused on the difference between filial and nonfilial calves. We observed 22 nursing females and 47 suckling calves in four zoological gardens in the Czech Republic from 2007 to 2011. Nursing duration was longer for male calves than for female calves and for calves sniffed by the nursing female regardless whether the calves were filial or nonfilial. We conclude that male calves are more demanding for the amount of investment received and they are more successful in this effort than female calves. Since females provided investment in the same way to filial and nonfilial calves, selection for higher demand for investment by male than by female offspring should be important for their future development. Our results also demonstrate the importance of sniffing for the identification of the suckling calf by the female.

Efecto de la suplementación sobre el peso del ternero y la preñez y condición corporal de vacas del Bajo Chaco Paraguayo

&lt;p&gt;El objetivo del estudio fue evaluar el efecto de la suplementación de terneros lactantes sobre su ganancia de peso, así como el porcentaje de preñez y condición corporal de las vacas. La investigación fue realizada en un establecimiento ubicado en el Departamento Presidente Hayes, en el Bajo Chaco Paraguayo. Se utilizaron treinta terneros de 2 a 3 meses de edad, crías de vacas adultas multíparas, que se agruparon en dos tratamientos (T) de 15 terneros y 15 vacas por cada uno (T1: terneros no suplementados y T2: terneros suplementados, ambos pastando sobre una pradera nativa en forma continua). El suplemento utilizado fue un concentrado con 20% de proteína bruta y 3 Mcal/kg de energía metabolizable, que se ofertó durante 120 días. En cada T se asignó un toro tipo Brangus para el servicio de las vacas, por 70 días. La ganancia diaria promedio de peso de los terneros fue de 0,464 y 0,708 kg para T1 y T2 respectivamente, siendo la diferencia estadísticamente significativa (p&amp;lt;0,05); no así el porcentaje de preñez, que fue idéntico en ambos grupos (7%). Sin embargo, en T2 aumentó la cantidad de vacas con la condición corporal final más alta (CCF3), diferencia que fue estadísticamente significativa (p&amp;lt;0,05). Se concluye que los efectos más importantes fueron la mejoría en la ganancia diaria de peso de los terneros que recibieron la suplementación y el aumento de la cantidad de vacas con CCF3.&lt;/p&gt;

203 Development and evaluation of a dynamic simulation model of farm management strategies affecting the reproductive performance of a suckled beef cow herd

Abstract Reproductive output in suckled beef cow systems is underpinned by a combination of genetics and the impact of efficient animal management strategies which given their cumulative nature, are difficult to evaluate. A dynamic simulation model (Grange Reproductive Management Model; GReMM) was developed replicating the reproductive performance of a suckled beef cow herd over multiple production cycles using the Stella Architect dynamic modelling platform (isee systems, Ventana, Lebanon, USA). Model inputs for farm parameters include dates and duration of breeding seasons in addition to nutrition and management of the periparturient beef cow. Specific management parameters pertaining to the duration of the postpartum anoestrus interval (PPAI), such as the body condition score of the cow at calving (BCSc), level of postpartum nutrition (PPN), management of the suckling calf and bio-stimulation of the dam pre-breeding are modelled. Outputs are displayed in the form of shifts in calving distribution, calving rates and calves per cow per year. Scenario analysis consisted of the implementation of a BASE scenario representative of current industry best practice (Normal reproductive management; NRM: BCSc, 2.75; PPN, 100 MJ ME/d; ad libitum suckling). Two further scenarios were developed representing a more intensively managed herd, with high levels of nutrition pre and post calving in addition to alternative reproductive management strategies (Intensive reproductive management; IRM), and a herd with a low level of nutritional management pre and postpartum (Poor reproductive management; PRM). Outputs generated in terms of calving distribution over six production cycles, indicated that a shift in the calving spread towards later in the calving season occurred in the PRM scenario, and a small improvement in reproductive efficiency evident in the IRM scenario over NRM. The model developed offers a decision support tool with the capability of evaluating practical on-farm management decisions on herd reproductive performance.

EFFECT OF CHLORELLA VULGARIS ALGAE SUPPLEMENTATION ON GROWTH PERFORMANCE OF SUCKLING FRIESIAN CALVES

Twenty newly born male and female Friesian calves with an average live body weight (LBW) of 30.40±0.36 kg were divided into five similar groups (2 male + 2 female in each group) and continued in a feeding trial until weaning to study the effect of supplementing the algae on suckling calves growth performance. Diet of cows and their suckling calves in G1 did not supplemented with algae and served as a control diet. Whereas, cows and their suckling calves were supplemented with algae and their media at levels of 2 ml (G2) and 4 ml (G3) / kg LBW, as low and high levels, respectively. While, cows in G4 and G5 were unsupplemented with algae, but their suckling calves were supplemented with Chlorella vulgaris algae and their media at the same above levels. Results showed that groups supplemented with high level of algae (G3 and G5) were recorded significantly (P<0.05) the highest digestibility of all nutrients and feeding values followed by groups supplemented with low level of algae (G2 and G4), while control group (G1) had the lowest values. The DMI were the same for different groups, while the intake of TDN and DCP were significantly (P<0.05) higher for G3 and G5 compared to those of control one (G1), but the low levels of algae rations (G2 and G4) were insignificant higher than those of control ration as well. Mostly, blood serum measurements (total protein, globulin and albumin) in addition of creatinine and liver enzymes activity (AST and ALT) were markedly improved versus to those of control group (G1). Moreover, the concentrations of immunoglobulin fractions (IgA, IgM and IgG) were increased significantly (P<0.05) with chlorella supplementation and increased with increasing the level of chlorella supplement. Weaning weight and average daily gain of suckling calves increased significantly (P<0.05) with chlorella algae supplementation as well as with increasing supplementation level. Chlorella supplementation improved significantly (P<0.05) feed conversion, being decreased the amounts of DM, TDN and DCP required per one kg live weight gain. Also, chlorella supplementation improved economic efficiency, which decreased feed cost per one kg live weight gain and increased the total and net revenue of live weight gain and economic efficiency.

Efficacy of dairy on-farm high-temperature, short-time pasteurization of milk on the viability of Mycobacterium avium ssp. paratuberculosis

Feeding pasteurized milk to suckling calves is a popular practice used increasingly on dairy farms. Waste milk is frequently fed to calves because of its high nutritional value and economic benefits compared to milk replacement products. However, one of the disadvantages of feeding waste milk is the potential for exposure to a high number of bacterial contaminants, which may lead to serious illnesses or infections in calves. One of these contaminants is Mycobacterium avium ssp. paratuberculosis (MAP), the causative agent of Johne's disease (paratuberculosis). The transmission and distribution of paratuberculosis in dairy herds occurs mostly through the feeding newborn calves with contaminated colostrum or milk, because this age group is believed to be most susceptible to infection. To reduce the risk of transmission of pathogens, on-farm pasteurization of milk has become increasingly popular. In this study, we analyzed the efficacy of a new commercial high-temperature, short-time pasteurizer (73.5°C for 20 to 25 s) in terms of MAP inactivation under experimental on-farm conditions. The pasteurizer uses a newly developed steam-heating technique, allowing for the pasteurization of the transition milk without clumping. In 3 independent trials, we spiked fresh raw milk samples to a level of 107 or 104 viable MAP cells/mL before pasteurization. We examined the thermal inactivation and viability of MAP using culture and a D29 bacteriophage-based assay. To verify the identity and number of MAP cells, we also performed PCR assays. Pasteurization of the inoculated milk (107 and 104 MAP cells/mL) resulted in a remarkable reduction in viable MAP cells. The mean inactivation rate of MAP ranged from 0.82 to 2.65 log10 plaque-forming units/mL, depending on the initial MAP amount inoculated and the addition of conservative agents to the pasteurized milk. Nevertheless, approximately 103 MAP cells/mL remained viable and could be transferred to calves after high-temperature, short-time pasteurization of milk.

Bovine Cryptosporidium parvum field isolates differ in cytopathogenicity in HCT-8 monolayers

Suckling calves are prone to Cryptosporidium infection. The variable degree of clinical disease is influenced by keeping conditions and immune status of the host, but diversity of isolate virulence may also contribute. The aim of the current study was to evaluate the cytopathogenic effects of 26 C. parvum field isolates by using a MTT assay in HCT-8 cell monolayers. Cell viability of monolayers inoculated with oocysts of the field isolates varied considerably with values of 17.7% (± 5.1%) to 99.5% (± 7.1%). A standard deviation of 18.6% was detected for cell viability of the in house reference strain, which were tested alongside in every assay. Field isolates were grouped in three categories of cytopathogenicity. Probably the length of storage has an effect on the level of the cell destruction category detected post infection in vitro. The applied tool may help to better understand the variable course of cryptosporidiosis in the field.

PSI-15 Factors affecting circulating metabolites and postnatal growth in spring-born neonatal beef calves

Abstract The objective of this experiment was to evaluate relationships of dam parity and calf suckling within 4 h postnatal with neonatal circulating metabolite concentrations, neonatal environment, and postnatal growth. For the experiment, 36 Angus, Hereford, and crossbred dams (age = 4.0 ± 1.74; multiparous (n = 5) and primiparous (n = 31); BCS = 6.5 ± 1.04; average calving date = April 4, 2018) were used. Calves were observed using a digital video recording system for 4 h after birth to determine suckling success [S = suckled (n = 27) or NS = did not suckle (n = 5) ≤ 4 h]. Jugular blood samples were obtained from calves at 24 (24.4 ± 1.73) and 48 to 72 (54.7 ± 9.08) h of age to determine serum blood urea nitrogen (BUN), glucose, non-esterified fatty acids (NEFA), and total protein (TP). Postnatal growth measures were collected at 50.4 ± 13.6 d and 162 ± 19.7 d of age. Calf BW was greater (P ≤ 0.02) at 50 and 162 d of age and ADG (0 to 162 d) was greater (P = 0.04) for S than NS calves, however birth BW was not different (P = 0.69). Ambient temperature at parturition was colder (P = 0.03) for NS calves than S calves. Serum glucose at 24 and 72 h was greater (P ≤ 0.03) in S calves than NS calves, however NEFA, BUN, and TP were not affected (P ≥ 0.09) by suckling success at either sampling time. Dam parity had no effect (P ≥ 0.12) on calf circulating metabolites at 24 and 72 h postnatal. In conclusion, the success of beef calves to suckle within 4 h of birth is associated with greater circulating glucose, warmer ambient temperature at birth, and greater postnatal BW and ADG.

PSI-14 Relationships of neonatal beef calf vigor with metabolic status

Abstract The objective of this study was to evaluate the relationships of neonatal beef calf behavior with calf serum metabolites. Angus, Hereford and crossbred beef females (n = 36; age = 4.0 ± 1.74; BCS = 6.5 ± 1.04; primiparous =5, multiparous = 31; calving date = April 4, 2018) and their calves were monitored continuously from 0 to 4 h post-parturition using a digital video recording system from March to May 2018. Jugular blood samples were obtained from calves at 24 (24.4 ± 1.73) and 48 to 72 (54.7 ± 9.08) h postnatal to determine serum blood urea nitrogen (BUN), glucose, non-esterified fatty acids (NEFA), and total protein (TP). Video was analyzed for behavior latencies calculated from time of birth to time when calf shakes head, kneels, attempts to stand, stands, and suckles. Time to stand had a weak positive correlation (P = 0.03) with time to suckle. Time to shake head had a moderate positive correlation (P ≤ 0.04) with both time to attempt to stand and time to stand, but did not correlate (P = 0.99) with time to suckle. Dam parity (multiparous or primiparous) did not affect (P ≥ 0.20) calf vigor measures. Time to suckle had a moderate negative correlation (P ≤ 0.05) with both serum glucose and total protein at 24 and 72 h, however did not correlate (P ≥ 0.31) with BUN or NEFA serum concentrations. In conclusion, the initial calf vigor measures were poor predictors of time to suckle; however, time to stand may be a viable vigor measure used to predict calf suckling. Further analysis of immunoglobulin G concentrations in calf serum will be used to determine if these vigor measures have a relationship with passive immune transfer in beef calves.

Growth of rumen papillae in weaned calves is associated with lower expression of insulin-like growth factor-binding proteins 2, 3, and 6.

This study aimed to characterize the relationship between the growth of rumen papillae in calves and the mRNA expression of insulin-like growth factor-binding proteins (IGFBPs) in the rumen papillae. The length of rumen papillae, the mRNA expression of IGFBPs in rumen papillae by quantitative real-time PCR, and the presence of insulin-like growth factors I and II (IGF-I and II) by immunohistochemistry (IHC) were analyzed in nine Holstein calves divided into three groups: suckling (2weeks, n=3), milk-continued (8weeks, n=3), and weaned (8weeks, n=3). The length of rumen papillae was greater (p<0.01) in weaned calves than in suckling and milk-continued calves, whereas the expressions of IGFBP2, IGFBP3, and IGFBP6 genes were lower (p<0.05) in the rumen papillae of weaned calves than in milk-continued calves. Thus, rumen papillae length and IGFBP2, 3, and 6 expressions were negatively correlated. The IHC analysis showed that IGF-I and IGF-II were present in the rumen epithelium of calves. These results suggested that the growth of rumen papillae after weaning is associated with the induction of IGFs by the low levels of IGFBP2, IGFBP3, and IGFBP6.

Between-year variation in the effects of phosphorus deficiency in breeder cows grazing tropical pastures in northern Australia

Breeder herd productivity can be severely reduced by dietary phosphorus (P) deficiency. The performance of small groups of P-deficient (Pdefic) or P-supplemented (Psupp) breeder cows was studied over 5 annual cycles while grazing C4 grass-Stylosanthes pastures at a site in the seasonally dry tropics of northern Australia. Soils contained c. 4 ppm of bicarbonate extractable P. Plasma inorganic P concentrations (PIP) during the wet season indicated that the Pdefic cows were deficient in P in 4 years and marginal in one year. Annual liveweight (LW) changes ranged widely between annual cycles from −71 to +13 kg in Pdefic cows and from +4 to +44 kg/head in Psupp cows. The LW responses to increased dietary P ranged from −9 to +115 kg, were greatest in years when LW losses by the Pdefic cows were greatest, and were associated with low-rainfall years. LW gains of calves suckling Psupp cows (mean 0.86 kg/d) tended to be higher (range 0.01–0.17 kg/d; mean 0.09 kg/d) than those of calves suckling Pdefic cows, but were significantly (P = 0.03) higher in only one year. Reconception appeared to be higher in Psupp than Pdefic cows during the 2 years of lower rainfall. Overall, the results indicated that responses to P supplementation by breeders grazing P-deficient pastures can vary widely between years. Therefore, the response in any one year may not reliably indicate responses in the longer term.

Behavioural characteristics of yaks grazing summer and winter pastures on the Qinghai-Tibetan Plateau

The yak is the primary herbivore grazing on the Qinghai-Tibetan plateau, an area characterized by extremely harsh conditions and a very short vegetation growing season. Herbage quantity and quality peak in summer when it is lush and green, but is dry and withered in winter when it is scarce and of poor quality. Traditionally, yaks graze only natural pasture all year without supplements and have adapted well to the extreme winter conditions. Grazing behaviour has been used as an indicator for grazing management decisions and, in this study, was measured in five 4 to 8 years old yak cows suckling calves during summer and winter on the Qinghai-Tibetan plateau. The diurnal behavioural patterns were similar in the two seasons. Grazing time and jaw movements per hour increased at dawn (07:00), remained relatively steady and then decreased at dusk (19:00), whereas ruminations, mastications and boluses per hour exhibited an opposite trend and decreased at dawn, and then increased after dusk. Seasonally, with a decrease in herbage quality from summer to winter, yaks decreased grazing and ruminating times and walking distance (P < 0.05) and increased drinking and idling times (P < 0.05). Air temperature was the primary meteorological variable affecting yak behaviour and was correlated positively with grazing time, ruminating time, the rate of mastications while ruminating, boluses formed and mastications per bolus (P < 0.05). In addition, wind velocity and precipitation significantly influenced the grazing behaviour of yaks (P < 0.05). We concluded that both meteorological and forage conditions affected the grazing behaviour of yaks and that the general reduction in grazing activities in winter could have been a strategy to reduce exposure to the harsh conditions and, consequently, reduce energy expenditure for foraging and for thermoregulation.

Diversity of Parasitic Diarrhea Associated with Buxtonella Sulcata in Cattle and Buffalo Calves with Control of Buxtonellosis.

Simple SummaryWe investigated the relationship between parasitic infections as a cause of diarrhea in suckling and post-weaning cattle and buffalo calves and Buxtonella sulcata infection, which remains an important pathogenic factor of diarrhea in Egypt. B. sulcata mono-infection was found more frequently associated with other parasitic infections that cause diarrhea. Drug treatment exhibited a higher efficacy than treatment with garlizine, a natural product in the treatment of buxtonellosis.The association between parasite isolates, including Buxtonella sulcata, in suckling and post-weaning calves and diarrhea was studied with the aim to control diarrhea caused by B. sulcata. A total of 1100 diarrheic fecal samples were collected from 609 suckling calves and 491 post-weaning calves with diarrhea. Salt floatation and modified Ziehl–Neelsen techniques were applied for the microscopic examination of the presence or absence of parasite eggs and oocysts/cysts. The microscopic findings revealed that 20.36% of the calves had parasitic diarrhea, with a prevalence rate of 19.54% in suckling calves and 21.38% in post-weaning calves. The most frequently detected parasites according to morphological characters were Eimeria species, Buxtonella sulcata, Toxocara vitulorum, Cryptosporidium species, and Moneizia species. In suckling calves, Eimeria species, B. sulcata, and T. vitulorum had the highest prevalence rates of infection, corresponding to about 37.14%, 32.86%, and 20.00%, respectively. However, in post-weaning calves, B. sulcata infection was more prevalent (30.15%) than infections with Eimeria species and T. vitulorum. The highest parasite score density was found in multiple infections with B. sulcata, Eimeria species, and T. vitulorum; however, the score density of B. sulcata when present alone in the fecal specimens was higher than in specimens co-infected with other parasites. The risk factors affecting the prevalence rate of parasitic diarrhea, such as sex, season, housing system, and feed stuff, are discussed. Concerning the treatment of diarrhea caused by B. sulcata in post-weaning cattle calves, 20 calves were divided into 4 equal groups. Group A was given sulphadimidine sodium (1.0 g/10 kg body weight) and metronidazole (500 mg/40 kg body weight); group B was treated with oxytetracycline hydrochloride (500 mg/45 Kg of body weight) and metronidazole (500 mg/40 kg body weight); group C was daily administered garlizine (allicin), 2 g/ L in drinking water; group D was the untreated control group. All medications were administered orally for four successive days. The results showed that the cyst count was significantly lower in the drug-treated groups, and the metronidazole + oxytetracycline hydrochloride and metronidazole + sulphadimidine combinations achieved 98.77% and 96.44% efficacy, respectively. Garlizine had 72.22% efficacy. Intriguingly, B. sulcata infection was associated with other parasitic infections, but B. sulcata mono-infection was the most common cause of diarrhea. Moreover, the combinations of oxytetracycline hydrochloride or sulphadimidine with metronidazole are recommended to control buxtonellosis in calves. Further studies are recommended to investigate the bacterial, viral, and fungal infections associated with B. sulcata infection.

Milk Production, Marketing and Quality in Meta District of Eastern Hararghe Zone, Ethiopia

The study was conducted in Meta District of Eastern Hararge Zone Oromia Regional State, Ethiopia with the objective to assess milk production and marketing, and to determine chemical composition and microbial quality of raw cow milk. Three Rural Kebeles (RK) namely, Biftu Ganama, Oda Chafe and Waligalte Bali&amp;rsquo;na were purposively selected based on dairy production potential and accessibility. A total of 132 respondents were randomly selected from farmers (122), consumers (6) and milk collection centers (4). Interview was made using semi-structured questionnaire to collect data on milk production, constraints, marketing, milk handling practices and utensils used as milk container. The result of the study indicated that, average daily milk production, milk for marketing and consumption were 1.96&amp;plusmn;0.517 litters/day/cow, 68.9% and 31.1%, respectively. Majority of the respondents ranked feed shortage as the first constraint. Hand milking after calf suckling was practiced by all the farmers. Most of the respondents (56.6%) used a gourd container locally called &amp;ldquo;qabe&amp;rdquo; for milking, and plastic jerry can (81.96%) for milk delivery to milk collection centers. Significantly higher (P &amp;lt; 0.05) figures were recorded for fat, protein, total solids, solids-not-fat and lactose contents at producers level than the consumers and collection centers. Total bacterial count (TBC), coliform count (CC) and yeast and mould count (YMC) of milk samples from milk collection centers were significantly higher (P &amp;lt; 0.05) than milk samples from consumers and producers and did not meet quality standards set by Quality Standard Authority of Ethiopia. Therefore, we can concluded that the chemical composition of milk was satisfactory compared to the standard level, whereas the microbial quality of the milk was poor that suggests the need for better sanitary practices of milking environment and milk utensils.

Sensory and behavioural control of gonadotrophin secretion during suckling-mediated anovulation in cows

A major limiting factor in the resumption of postpartum ovarian cycles in cattle is the inhibitory influence of the suckling calf on central regulatory elements controlling the release of GnRH from the median eminence. This inhibitory influence occurs only as a consequence of specifically defined behavioural interactions between the cow and calf in the presence of a maternal bond, cannot be simulated experimentally using thermal, electrical or mechanical stimuli, and is not dependent upon sensory ennervation within the udder. Indeed, the identity of the calf, either own or unrelated, appears to define the neuroendocrine events that attend the maintenance of the anovulatory state under controlled experimental conditions. Hence, new hypotheses that focus upon the relationship between physiological correlates of maternal behaviour and hypothalamic regulation of LH secretion are currently being tested. Specific aspects of these relationships remain conjectural, but are postulated to include the regulation of opioid tone, intracerebral oxytocin, and modulation of synthetic or excitatory activity of GnRH secretory neurones. Defining the role of the special senses in transduction of signals from calves that influence these neuronal processes may provide insight for developing practical intervention strategies of the future.