Energy requirements for growth of pubertal female Saanen goats

Previous research on energy requirements of female Saanen goats, using the factorial approach, has not considered the specific requirements for maintenance and growth during the pubertal phase. Thus, the purpose of this study was to estimate energy requirements for maintenance (Trial 1) and growth (Trial 2) of non‐pregnant and non‐lactating female Saanen goats at the pubertal phase from 30 to 45 kg. In Trial 1, the net energy requirements for maintenance (NE_m) were estimated using 18 female Saanen goats randomly assigned to three levels of intake: ad libitum, and 70% and 40% of ad libitum intake. These animals were pair‐fed in six slaughter groups, each consisting of one animal for each level of intake. In Trial 2, the net energy requirements for growth (NE_g) were estimated using 18 female Saanen goats, which were fed ad libitum and slaughtered at targeted BW of 30, 38 and 45 kg. The NE_m was 52 kcal/kg^0.75 of BW. The NE_g increased from 3.5 to 4.7 Mcal/kg of BW gain as BW increased from 30 to 45 kg. Our results suggest that the guidelines of the major feeding systems for the entire growth phase may not be adequate for females at pubertal phase.     

Organic matter and macromineral digestibility in domestic rabbits (Oryctolagus cuniculus) as compared to other hindgut fermenters

It is generally assumed that animal species differ in physiological characteristics of their digestive tract. Because investigating digestive processes is often labour‐intensive, requiring lengthy adaptation and collection periods, comparisons are often made on the basis of data collated from different studies. We added a new data set on dietary crude fibre (CF) and macromineral (Na, K, Ca, P, Mg) composition and apparent digestibility (aD) of organic matter (OM) and macrominerals in rabbits (Oryctolagus cuniculus; a total of 180 measurements with 12 individuals and 10 different diets) to a literature data collection for rodents and domestic horses (Equus caballus). Significant negative relationships between dietary CF and aD OM were obtained, but the significant difference in digestive efficiency between rabbits and guinea pigs (Cavia porcellus) reported from studies where both species had been investigated under identical conditions were not detectable in the larger data collection. However, the 95% confidence interval of the negative slope of the CF–aD OM relationship did not overlap between domestic horses on the one hand, and rabbits and guinea pigs on the other hand, indicating a less depressing effect of CF in horses. Akaike's information criterion indicated that aD of a macromineral did not only depend on its concentration in the diet, but also on the individual and various other diet characteristics and the presence of other macrominerals, indicating complex interactions. The data indicate similar mechanisms in the absorption of macrominerals amongst rabbits, rodents and horses, with the exception of Na and K in guinea pigs and Ca in chinchillas (Chinchilla laniger) that should be further corroborated. In particular, the occurrence of high aD Ca in hindgut fermenters, regardless of whether they employ a digestive strategy of coprophagy or whether they have fossorial habits, suggests that this peculiarity might represent an adaptation to hindgut fermentation in general.     

Mineral absorption in the black rhinoceros (Diceros bicornis) as compared with the domestic horse

To test whether mineral recommendations for horses are likely to guarantee adequate mineral provision for black rhinoceroses (Diceros bicornis), we investigated the apparent absorption (aA) of macro- and microminerals in eight black rhinoceroses from three zoological institutions in a total of 32 feeding trials with total faecal collection, with additional data from three unpublished studies (18 feeding trials). Feeds and faeces were analysed for Ca, P, Mg, Na, K, Fe, Mn, Cu, Zn and Co. The resulting aA coefficients, and the linear relationships of apparently absorbable dietary mineral content to total dietary mineral content [per 100 g dry matter (DM)], were compared with data for domestic horses. Rhinoceroses had significantly higher aA coefficients for Ca and Mg (because of a higher calculated 'true' absorption), and lower ones for Na and K (because of calculated higher endogenous faecal losses). High absorption efficiency for divalent cations is hypothesized to be an adaptation to a natural diet of particularly high Ca:P ratio (approximately 14:1); an effective removal of Ca from the ingesta guarantees sufficient P availability at the fermentation site in the hindgut. Higher faecal losses of Na and K are hypothesized to be linked to a higher faecal bulk per DM intake in black rhinoceroses as compared with horses because of a generally lower digestive efficiency. There were no relevant differences in the absorption patterns of microminerals. In particular, there were no discernable differences in Fe absorption within the rhinoceroses for diets with and without tannin supplementation. Several of the zoo diets assessed in this study were deficient in Cu, Mn or Zn, and most contained excessive levels of Fe when compared with horse requirements. The findings of this study indicate that differences in mineral absorption between occur even between species of similar digestive anatomy; that in particular, Ca absorption might vary between hindgut fermenters with Ca:P ratio in their natural diet; that Na might be a particularly limiting factor in the ecology of free-ranging rhinoceroses; that moderate doses of tannins do not seem to markedly influence mineral absorption; and that diets for captive animals should contain adequate, but not excessive mineral levels.     

Effects of exogenous equine somatotropin on mineral balance in two-year-old horses in race training

This study examined the effects of exogenous equinesomatotropin (eST — Equigen) administration on mineral absorption and retention in two-year-old horses in race training. Sixteen Quarter Horse geldings were paired by age (ave.age=794 d), and one horse from each pair was assigned at random to either the eST treatment group or the control. The experiment was conducted over 112 days during which the horses were gentled to ride and trained on a dirt track in a regimen typical for race horses in training. At 28-day intervals, collections of total fecal and urinary output were made to determine effects on Ca, inorganic P, Mg, Cu and Zn mineral balance.Due to marginal and slightly deficient amounts (P<01)of Ca, P, Mg and Zn intake by days 84 and 112, a result of reduced feed intake to maintain a constant body condition in the presence of a decreased workload, mineral balance for the aforementioned minerals was only examined through day 56. In contrast to the previous minerals, Cu intake appeared adequate. Ca, P, Mg, Cu and Zn intake did not differ (P>.05) by treatment. The eST-treated horses increased (P<.05) Ca retention as a percent of Ca absorbed, had greater (P<.05) overall apparent efficiency of P absorption and greater (P<.05) apparent retention of P on day 56 than the control horses. The eST-treated horses had greater (P<.05) apparent Cu absorption on day 56, greater (P<.05) apparent Cu absorption efficiency on days 56 and 84, and there was a trend (P<.1) for the eST-treated horses to retain more Cu on day 56 than the control horses. Finally, the eST-treated horses retained a greater percent (P<.1) of absorbed Zn on day 56.     

饲料镁和鲈鱼幼鱼的生长及鱼体镁含量相关性研究

为研究饲料中不同镁含量对鲈鱼(Lateolabrax japonicus)的影响,试验在基础饲料中分别添加0、500、1250、3750、5250、8750 mg/kg MgSO4,配制镁含量分别为167、284、491、959、1327、1759 mg/kg的6种试验饲料,饲养初始体重为(12.31±0.02)g的鲈鱼56 d。结果显示:日粮中适当添加镁显著影响鲈鱼的增重率、特定生长率和饲料效率(P <0.05),其中D4组(镁含量959 mg/kg)鲈鱼的增长率和特定生长率均显著大于其他各组(P <0.05)。饲料镁含量显著影响鲈鱼全鱼水分(P <0.05)。随着饲料镁含量增加,肝脏中天冬氨酸转氨酶(GOT)和丙氨酸转氨酶(GPT)呈下降趋势,GOT与GPT比值和肝脏谷氨酸脱氢酶(GDH)也出现显著变化(P <0.05)。通过回归分析增重率得出,本试验中鲈鱼生长的最适饲料镁含量为846 mg/kg。     

Serum IgG,blood profiles,growth and survival in goat kids supplemented with artificial colostrum on the first day of life

The objective of this study was to compare serum IgG concentrations, blood metabolites indicative of nutritional status, weight gain and mortality rate in goat kids fed a commercial colostral supplement containing immunoglobulins against several pathogen microorganisms, prior to the ingestion of the mother colostrum, and goat kids ingesting natural colostrum only. There was no difference in serum IgG concentrations between 27 kids fed a colostrum supplement (20 g, derived from cow lacteal secretions) prior to the kids’ first meal (658 ± 703 mg dl⁻¹) and 21 kids ingesting maternal colostrum freely (1011 ± 1140 mg dl⁻¹) at 24 hours of birth. Hematocrit values, serum glucose and urea concentrations at 24 hours and 5 days of age were unaffected by treatment. Serum total proteins were 14% higher (P < 0.05) in the unsuplemented group than in the supplemented group at 5 d of age. There was no significant difference between the supplemented and unsupplemented kids in daily weight gain from birth to 70 days of age (92 ± 4.8 vs 102 ± 5.1 g day⁻¹). Mortality was 4% for kids receiving the colostrum supplement as compared with 0.0% for kids ingesting maternal colostrum only. Results suggest that, in intensively managed non-dairy goats with kiddings in summer, the supplementation of this commercial colostrum derived from cow lacteal secretions and containing antibodies against diverse pathogens organisms did not enhanced growth, survival or immunity under the farming conditions of this study.     

互助县山羊唾液中五种无机离子浓度的测定

对互助县30只山羊的唾液钠、钾、钙、磷、氯五种无机离子浓度进行了测定。结果:唾液钠为120.0±23.5mmolL,唾液钾为14.95±5.07mmolL,唾液钙为2.32±0.02mmolL,唾液无机磷为1.55±0.44mmolL,唾液氯为113.3±2.1mmolL,唾液钠钾比为8.7±2.3,唾液钙磷比为1.5±1.0。     

Effects of excessive or restricted phosphorus and calcium intake during early life on markers of bone architecture and composition in pigs

Sufficient supply of pigs with calcium (Ca) and phosphorus (P) is essential for animal health and welfare during the growth period. However, the P content in animal manure is considered as a cause of massive environmental problems in soil and aquatic ecosystems. To complement previous findings, the objective of this study is the investigation of effects of a reduced and increased Ca and P supplementation on bone mineralization and bone structure compared with the current dietary recommendation. Another aim is to find possible serum markers that would allow the assessment of adequacy of P supply for bone health during growth. The result validated that the recommended Ca and P supply is sufficient, without the addition of microbial phytases. However, addition of P has no further beneficial effects on bone stability, while P supplementation below the recommended level affects bone development and growth performance. Reduced P levels have consequences for cancellous bone density and trabecular architecture. Further fine-tuning of the P supply in conjunction with an appropriate Ca supply will contribute to a reduction in P waste and associated environmental impact while maintaining animal health and welfare.     

Milk casein and fatty acid fractions in early lactation are affected by nutritional regulation of body condition score at the beginning of the transition period in primiparous and multiparous cows under grazing conditions

The objective was to evaluate the effect of body condition score (BCS) at 30 days before calving (−30 days) induced by a differential nutritional management, parity and week of lactation (WOL) on milk yield and composition, and milk casein and fatty acid composition. Primiparous and multiparous Holstein cows with high BCS (PH, n = 13; MH, n = 9) and low BCS (PL, n = 9; ML = 8) under grazing conditions were sampled at WOL 2 and 8 (before and after peak of lactation). Milk yield was greater in multiparous than in primiparous cows and tended to decrease from WOL 2 to 8 only in ML cows. Milk protein, fat and casein yields were greater in multiparous than in primiparous cows and decreased from WOL 2 to 8. Milk casein concentration in milk protein was greater in MH cows than in ML, PH and PL cows at WOL 2. Milk κ‐casein was greater, and β‐casein was less in multiparous than in primiparous cows. As lactation progressed, proportion of casein fractions were not altered. Only κ‐casein fraction was affected by BCS at −30 days as PL showed a higher concentration than PH. The de novo (4:0–15:1) and mixed‐origin fatty acids (16:0–16:1) in milk fat increased, whereas preformed fatty acids (≥17:0) decreased from WOL 2 to 8. Saturated (SAT) fatty acids tended to be greater and monounsaturated fatty acids (MUFA) were less in multiparous than in primiparous cows. High‐BCS cows had greater concentrations of polyunsaturated (PUFA), conjugated linoleic acid (CLA) as well as n‐6 and n‐3 fatty acids in milk fat than low‐BCS cows. The results indicate that casein and fatty acid fractions in milk were affected by parity and may be modified by a differential nutritional management during the pre‐calving period (BCS at −30 days) in cows under grazing conditions.     

Low protein provision during the first year of life,but not during foetal life,affects metabolic traits,organ mass development and growth in male mink (Neovison vison)

Low protein provision in utero and post‐partum may induce metabolic disorders in adulthood. Studies in mink have mainly focused on short‐term consequences of low protein provision in utero whereas the long‐term responses to low protein (LP) provision in metabolically programmed mink are unknown. We investigated whether low protein provision in utero affects the long‐term response to adequate (AP) or LP provision after weaning in male mink. Eighty‐six male mink were exposed to low (19% of ME from CP; crude protein) or adequate (31% of ME from CP) protein provision in utero, and to LP (~20% of ME from CP) or AP (30–42% of ME from CP) provision post‐weaning. Being metabolically programmed by low protein provision in utero did not affect the response to post‐weaning diets. Dietary protein content in the LP feed after weaning was below requirements; evidenced by lower nitrogen retention (p < 0.001) preventing LP mink from attaining their growth potential (p < 0.02). LP mink had a lower liver, pancreas and kidney weight (p < 0.05) as well as lower plasma IGF‐1 concentrations at 8 and 25 (p < 0.05) weeks, and a higher incidence of hepatic lipidosis at 25 weeks (p < 0.05). Furthermore, LP mink had a higher body fat (p < 0.05) and lower body CP content (p < 0.05) at 50 weeks of age. It is concluded that some effects of low protein provision in utero can be alleviated by an adequate nutrient supply post‐partum. However, long‐term exposure to low protein provision in mink reduces their growth potential and induces transient hepatic lipidosis and modified body composition.     

Effects at early stage of life of elevated milk replacer feeding on growth rate,plasma IGF‐I concentration and intestinal nutrient transporter expression in Holstein bull calves

In order to evaluate the effects of an elevated amount of modified milk replacer on body weight, daily gain, starter intake, plasma endocrine parameters and expression of nutrient transporters in small intestinal epithelia, Holstein bull calves (n = 24) were fed for 60 days either with the usual amount of 24% crude protein (CP) and 20% fat milk (CF) replacer (C group), or with a double amount of a modified milk replacer of 28% CP and 16% CF (E group). Body weight from D20 to D60 and daily gain before D40 was greater or tended to be greater for the E group than the C group. Plasma concentrations of insulin‐like growth factor‐1 (IGF‐I) and insulin were greater for the E group than the C group on D28 but not on D56, without changing plasma growth hormone levels. Gene expression for sodium‐dependent glucose transporter 1 and fatty acid translocase (CD36) was altered in day‐ and intestine‐dependent manners. From these findings, we conclude that an elevated intake of milk replacer given up to 40 days old is sufficient to enhance body weight, which may be associated with increased plasma IGF‐I concentrations, in Holstein bulls.     

Changes in some blood micronutrients, leukocytes and neutrophil expression of adhesion molecules in periparturient dairy cows.

Dairy cows are highly susceptible to infectious diseases, like mastitis, during the period around calving. Although factors contributing to increased susceptibility to infection have not been fully elucidated, impaired neutrophil recruitment to the site of infection and changes in the concentrations of some micronutrients related with the function of the immune defence has been implicated. Most of the current information is based on studies outside the Nordic countries where the conditions for dairy cows are different. Therefore, the aim of the study was to evaluate changes in blood concentrations of the vitamins A and E, the minerals calcium (Ca), phosphorous (P), and magnesium (Mg), the electrolytes potassium (K) and sodium (Na) and the trace elements selenium (Se), copper (Cu) and zinc (Zn), as well as changes in total and differential white blood cell counts (WBC) and expression of the adhesion molecules CD62L and CD18 on blood neutrophils in Swedish dairy cows during the period around calving. Blood samples were taken from 10 cows one month before expected calving, at calving and one month after calving. The results were mainly in line with reports from other countries. The concentrations of vitamins A and E, and of Zn, Ca and P decreased significantly at calving, while Se, Cu, and Na increased. Leukocytosis was detected at calving, mainly explained by neutrophilia, but also by monocytosis. The numbers of lymphocytes tended to decrease at the same time. The mean fluorescent intensity (MFI) of CD62L and CD18 molecules on blood neutrophils remained constant over time. The proportion of CD62L+ neutrophils decreased significantly at calving. The animals were fed according to, or above, their requirements. Therefore, changes in blood levels of vitamins, minerals and trace elements were mainly in response to colostrum formation, changes in dry matter intake, and ruminal metabolism around calving. Decreased levels of vitamins A and E, and of Zn at calving might have negative implications for the functions of the immune defence. The lower proportion of CD62L+ neutrophils at calving may result in less migration of blood neutrophils into the tissues, and might contribute to the increased susceptibility to infections at this time.     

Effect of selection for growth on normal and reduced protein diets on weight gain, feed intake, feed efficiency and body composition in mice

Mice selected for weight gain from 3 to 9 weeks of age on a normal (N) protein diet containing 19.3% protein and a reduced (R) protein diet with 5.1% protein were reared on both diets in generations 7 and 9. The lines NH, NC, NL, RH, RC and RL (H, high; C, control; L, low) were tested for weight gain on diet N and R and for feed intake and feed efficiency on diet N in generation 7. In generation 9, the lines were tested for body composition traits (fat, protein and water percentage) at 3, 6, 9 and 12 weeks of age on both diets. A significant (p < 0.0001) genotype × environment interaction for growth rate was observed in generation 7. Weight gain at both the protein levels was best improved by selection at the protein level itself. Furthermore, the ranking of the lines on diet N was similar for weight gain, feed intake and feed efficiency. In generation 9 at 9 weeks of age, the ranking of the lines for fat percentage was equal to the ranking for weight gain in generation 7 on both test‐diets. The association between weight gain and protein or water percentage was less pronounced, particularly on diet R. These results suggest that the largest genetic improvement in growth rate is obtained when the protein content of the feed is the same in selection and production. However, when selection is carried out in one environment while the animals have to perform under conditions with varying nutrient protein contents, selection in an inferior environment may be advantageous.