Use and limitations of alternative feed resources to sustain and improve reproductive performance in sheep and goats

A Circular Economy Approach to Integrate Divergent Ruminant Production Systems: Using Dairy Cow Feed Leftovers to Enhance the Out-of-Season Reproductive Performance in Goats

Based on a circular economy approach, we evaluated the possible effect of targeted supplementation with leftover feed from dairy cows (i.e., intensive system) on the reproductive performance of crossbred/rangeland goats (i.e., extensive system) in arid Northern Mexico. During the deep-anestrous season (i.e., March-April, 25° North), multiparous goats (n = 38) with a similar body weight (BW) and body condition score (BCS) were randomly assigned to two groups: (1) supplemented group (SG; n = 19; BCS: 1.76 ± 0.07; BW: 43.7 ± 1.8 kg), receiving 400 g goat d-1 of dairy-cow-feed leftovers prior to grazing; and (2) non-supplemented group (NS; n = 19; BCS: 1.76 ± 0.06; BW: 44.3 ± 2.5 kg). Both groups were directed to the rangeland for a period of ≈8 h. While the experimental period lasted 36 d, the experimental breeding considered 11 d (d0-d10). The anovulatory status of goats was ultrasonographically confirmed on days -20, -10, and -1 prior to male-female interaction. Previously, bucks were separated for 3 weeks from the experimental females and received exogenous testosterone every third day (i.e., 50 mg i.m.) prior to mating. With respect to the response variables, namely BW, BCS, blood glucose levels (BGLs), estrus induction (GIE, %), latency to estrus (LTE, h), estrus duration (ED, h), and luteal tissue volume (LTV, mm), no differences (p > 0.05) occurred between experimental groups. However, the response variables, namely goats ovulating (GO, %; 78.9 vs. 47.3), total number of corpuses luteum (TNCL, n; 27 vs. 13), ovulation rate (OR, n; 1.42 vs. 0.73), multiple ovulation (MO, %; 73.3 vs. 55.5), and pregnancy rate on d 36 (PRd36, %, 68.4 vs. 36.8), favored (p < 0.05) the SG over the NS goats. Our results demonstrate that connecting the circularity of two divergent ruminant production systems (i.e., cow-intensive and goat-extensive) by using dairy cows' feed leftovers as a targeted supplementation strategy in anestrous goats under a marginal-rangeland production system enhanced out-of-season reproductive outcomes (i.e., ovulation rate and pregnancy rate), thus benefiting marginal goat producers and their families.

Impact of the nutritional quality of barley on growth rate, biometric and biochemical parameters and plasma concentration of androgens during puberty in the Ouled-Djellal lambs

Puberty is part of physiological processes including growth, adrenarche, menarche, energy balance and metabolism. This study describes the dynamic between both metabolic and reproductive statutes during pubertal growth in Saharan breed sheep. Once weaned (3 months age), two lots of lambs are made up and each one receive a barley supplementation ration of 250 vs 500 g/head/day in addition to season's diet. Biometric measurements and blood samples are collected once a month from 3 to 12 months of age in order to evaluate biochemical and sexual hormonal status. Results show a significant weight gain and growth level in the double dose lot. Changes in biochemical parameters are closely related with age at least for glycemia and total proteinemia. Androgenic profile shows individual fluctuations (0.02 to 3.47 μg /ml) due to age, season and feeding ratio. In accordance with our findings, the diet effect is clearly evidenced between the two batches, it's noted that plasma concentration of androgens is the lowest (<0.30 ng /ml) at 3 months and increases to 0.53 vs 0.76 ng /ml between 4 and 6 months confirming the pre-pubertal phase. Also, biometric and biochemical parameters are tightly correlates with plasma androgen changes, depending on whether the animal be pubescent or not. In conclusion, although interesting this study shows no early puberty onset in the barley supplemented lambs as was reported in other sheep breeds; nevertheless, the testis activity as well as the body fitness have clearly be enhance. The synergy between biochemical profiles and biometric measurements explain the metabolic function of testicular androgens at puberty.

Effect of Replacing Sorghum Stubble with Tillandsia recurvata (L.) on Liveweight Change, Blood Metabolites, and Hematic Biometry of Goats

Tillandsia recurvata is an epiphyte that grows on the canopy of many trees in tropical and subtropical areas of America. The objective of this study was to evaluate the effect of partial or complete substitution of sorghum stubble with T. recurvata on liveweight change, metabolic profile, and complete blood count of goats fed increasing levels (0, 30, and 60%, dry matter basis) of T. recurvata. Thirty non-pregnant three-year-old, non-lactating, healthy mixed-breed goats, ten animals per treatment (T0, T30, and T60), were adapted to diets and facilities for 14 days (d-14). Blood samples were collected at d-15, 28, and 56. At the last phase of the trial (from days 67 on), control goats tended to gain more (p = 0.09) weight than their counterparts consuming T. recurvata. Plasma protein, glucose, triglycerides, calcium, and phosphorus concentrations did not differ among dietary treatments (p > 0.05). Dietary treatment influenced red blood cells (higher for T60; p < 0.01), white blood cells (higher for T30; p < 0.05), mean corpuscular volume (higher for T0; p < 0.001), and mean corpuscular hemoglobin concentration (higher for T0; p < 0.01), although not the rest of the blood variables (p > 0.05). The hematocrit percentage tended to be higher (p = 0.06) in T30 than T0 and T60. It was concluded that replacing sorghum stubble with T. recurvata did not modify the metabolic status and maintained live weight of goats. Nevertheless, the use of T. recurvata as feed for goats would improve the nutrition of these animals in the dry season compared to the current diet obtained from an arid rangeland, reducing production costs, and would alleviate the damage caused by this aggressive epiphyte to host trees.

The Performance and Carcass Characteristics of Black Baladi Kids Fed Diets with Graded Quantities of Sweet Lupin Grain (Lupinus angustifolius)

A study was conducted to examine how lupin grains (LUPs) feeding affected nutritional intake, digestibility, growth, and carcass characteristics in kids. A total of 24 growing black kids (initial body weight (BW) = 16.4 ± 0.49 kg) were allocated to one of three diets at random. Lupin was included in the diet at a rate of 0 (control; CON), 100 (LUP100), or 200 g/kg (LUP200) of total dry matter (DM). The trial lasted for 91 days divided into 7 and 84 days to be used for adaptation and data collection, respectively. Feed intake was evaluated daily throughout the study. At the commencement and the end of the study, each kid’s body weight was measured to determine its average daily gain (ADG). On day 70, 5 kids were chosen at random from each group to investigate nutrient in vivo digestibility and N balance. At the end of the study, all of the kids were slaughtered to examine carcass features. Nutrient intakes (neutral detergent fiber, acid detergent fiber, and ether extract) were higher (p ≤ 0.01) in LUP-containing diets than in the CON diet. The average daily gain was greater (p ≤ 0.03) in diets containing lupin grains than in the CON diet. Cost of gain ($US/kg growth) was lower (p = 0.004) in kids fed diets containing lupin than the CON diet. Dry matter and CP digestibility rates were greater (p ≤ 0.03) in lupin diets. Retained N was higher (p = 0.04) in lupin-containing diets than in the CON diet. Cold carcass weight was higher (p < 0.05) for kids consuming the LUP100 diet than the CON diet. In lupin diets, carcass cut weights were higher (p < 0.05). Results of the current study indicate that feeding black kids diets containing lupin grains at 100 or 200 g/kg DM basis is cost effective and would increase profitability.

Trace minerals for improved performance: a review of Zn and Cu supplementation effects on male reproduction in goats

Minerals are required in small amounts but play significant roles in many physiological functions related with growth, reproduction, and health of goats such as biochemical, molecular systems, and optimized enzymatic activities due to their roles as co-factors to metalloenzymes. Among them, zinc (Zn) and copper (Cu) are leading essential elements in goat nutrition, because of their role across several biological functions. The proportion of these minerals availability and absorption from the ingested feed is usually less, because of their complexities with un-degradable parts of feed resources. Hence, their exogenous supplementation is required for normal animal functions. On this background, this review presents findings associated with supplementation of these minerals in organic form as a way for improving the fertility of male goats with special focus on physico-chemical-kinetics of the semen for improving the application of reproductive technologies. This review emphasizes the organic sources of these minerals to replace the inorganic sources, based on their significance in improving semen qualities, antioxidant protection, and mediation of molecular activities. This review also discusses salient routes of Zn and Cu absorption and identifies the need for molecular exploration for positive outcomes with supplementation of these minerals as an area of the future goat nutrition-reproduction improvement strategy.

Characterization of Phytoestrogens in Medicago sativa L. and Grazing Beef Cattle

Phytoestrogens are plant-produced bioactive secondary metabolites known to play an integral role in plant defense that frequently accumulate in times of stress and/or microbial infection. Phytoestrogens typically belong to two distinct chemical classes; flavonoids (isoflavones) and non-flavonoids (lignans and coumestans). Upon consumption by livestock, high concentrations of phytoestrogens can cause long-term disruption in reproduction due to structural similarities with mammalian estrogens and their tendency to bind estrogen receptors. Wide variation in phytoestrogen concentration has been reported in pasture legumes and corresponding silage or hay. Lucerne is a common perennial pasture legume in temperate climates, but information on phytoestrogen production or accumulation in grazing livestock is currently limited. Therefore, metabolic profiling using UHPLC-MS-QToF was performed to identify and quantitate key phytoestrogens in both fresh and dried lucerne fodder from replicated field or controlled glasshouse environments. Phytoestrogens were also profiled in the blood plasma of Angus cattle grazing field-grown lucerne. Results revealed that phytoestrogens varied quantitatively and qualitatively among selected lucerne cultivars grown under glasshouse conditions. Fresh lucerne samples contained higher concentrations of coumestans and other phytoestrogenic isoflavones than did dried samples for all cultivars profiled, with several exceeding desirable threshold levels for grazing cattle. Coumestans and isoflavones profiled in plasma of Angus heifers grazing lucerne increased significantly over a 21-day sampling period following experimental initiation. Currently, threshold concentrations for phytoestrogens in plasma are unreported. However, total phytoestrogen concentration exceeded 300 mg·kg⁻¹ in fresh and 180 mg·kg⁻¹ in dried samples of selected cultivars, suggesting that certain genotypes may upregulate phytoestrogen production, while others may prove suitable sources of fodder for grazing livestock.

Causes and Flock Level Risk Factors of Sheep and Goat Abortion in Three Agroecology Zones in Ethiopia

A cross-sectional survey was conducted to estimate the incidence of small ruminant abortion and identify its major causes and potential risk factors in goat and sheep flocks in three agroecology and production systems of Ethiopia. Information on pregnancy outcomes and management risk factors were collected for 299 goat and 242 sheep flocks. Blood samples were collected from 133 sheep and 90 goat flocks and tested for Coxiella burnetii, Brucella spp., Chlamydia abortus, and Toxoplasma gondii. A causal diagram outlined relationships between potential predictor variables and abortion in the flock. The effect of management and exposure to infectious causes on the number of abortions in the flock across agroecology was tested using zero-inflated negative binomial regression. Results showed that 142 (58.68%) goats and 53 (17.73%) sheep flocks reported abortions in the 12 months before the survey. The mean annual flock abortion percentages were 16.1% (±26.23) for does and 12.6% (±23.5) for ewes. Farmers perceived infectious diseases, extreme weather conditions, feed shortage, physical traumas, and plant poisoning as the most important causes of abortion. A higher proportion of abortion was recorded during the short rainy season (March to May) and start of the short dry and cold season (June to August) in the lowland mixed crop-livestock and pastoral agroecology and production system, respectively. Overall, 65.41% sheep and 92.22% goat flocks tested positive for one or more abortion causing agents, namely, C. burnetti, C. abortus, Brucella spp., and T. gondii; mixed infection was found in 31.58% sheep and 63.33% goat flocks. Spending the night in a traditional house and providing supplementary feed for pregnant dams were important management factors which significantly (p ≤ 0.05) decreased the risk of abortion by 2.63 and 4.55 times, respectively. However, the presence of other livestock species and dogs in the household and exposure of the flock to Brucella spp. or anyone of the four tested infectious agents significantly (p ≤ 0.05) increased the risk of abortion in sheep and goat flocks. In general, abortion is a challenge for small ruminant production in the study area especially in lowland agroecology and calls for improvement in husbandry practices, health care and biosecurity practices.

Polyphenols in Farm Animals: Source of Reproductive Gain or Waste?

Reproduction is a complex process that is substantially affected by environmental cues, specifically feed/diet and its components. Farm animals as herbivorous animals are exposed to a large amount of polyphenols present in their natural feeding system, in alternative feed resources (shrubs, trees, and agro-industrial byproducts), and in polyphenol-enriched additives. Such exposure has increased because of the well-known antioxidant properties of polyphenols. However, to date, the argumentation around the impacts of polyphenols on reproductive events is debatable. Accordingly, the intensive inclusion of polyphenols in the diets of breeding animals and in media for assisted reproductive techniques needs further investigation, avoiding any source of reproductive waste and achieving maximum benefits. This review illustrates recent findings connecting dietary polyphenols consumption from different sources (conventional and unconventional feeds) with the reproductive performance of farm animals, underpinned by the findings of in vitro studies in this field. This update will help in formulating proper diets, optimizing the introduction of new plant species, and feed additives for improving reproductive function, avoiding possible reproductive wastes and maximizing possible benefits.

Sustainable goat production: modelling optimal performance in extensive systems

Context Strategies for achieving greater ruminant livestock productivity are essential to meet the food demands of growing populations, but sustainable changes are difficult to identify given the inherent complexity of such systems. Systems models can address this issue by allowing the impact of potential changes to be explored. Aims To develop a holistic systems model for goat production in an extensive Mediterranean environment which could allow changes in key management factors influencing the system to be investigated. Methods Initially, a conceptual comprehensive stock-and-flow model of a representative Mediterranean goat production system was constructed. This was used to identify informative indicators that would represent the overall technical and economic performance of the system. Sub-models were then assembled to build the full systems model. The model was parameterised with data collected over 3 years for goat holdings in northern Morocco. Scenario analysis techniques are used to explore the strategies that optimise performance under climate and feed price challenges. Key results Meat production is particularly important during periods of drought when increased meat yields can counteract the expected reduction in milk yields, to protect human food security, prevent excessive rangeland degradation and preserve natural nutritional resources. Feed price shocks during drought can have significant negative impacts on the system and zero feed input is shown to be a more sustainable strategy than reliance on high price feed during drought. Any alternative feed sources need to have a high forage component to reduce grazing periods significantly and promote rangeland preservation. Implications A diverse management strategy with a mixed meat and dairy semi-intensive production is more stable than specialised dairy systems and allows goat production and financial viability of intensification to be maintained under climatic stress; maintaining meat production was necessary to optimise performance. Conclusions The model allows improved insight into management strategies which could optimise animal husbandry performance in goat subsistence systems. However, the work also demonstrates the difficulty of constructing a truly holistic model since, to be practical, such constructs must necessarily be bounded; parameter selection and the limits to the boundaries imposed are inevitably critical.

Extracts of forage plants affect the developmental competence of ovine oocytes in vitro

Forage plants may contain secondary compounds that disrupt reproduction in ruminants so, as ‘duty of care’, proposed new forage species need to be tested for harmful effects on reproduction before industrial release. We evaluated the effects of Bituminaria bituminosa, Medicago sativa, Chicorium intybus, Trifolium subterraneum, Trifolium pratense, Biserrula pelecinus and Eremophila glabra, on the in vitro developmental competence of ovine oocytes. Crude methanolic extracts of each plant were added to the medium (final concentrations: 0, 50 or 100 μg dry extract per mL) used for in vitro maturation of cumulus-oocyte complexes derived from abattoir-sourced adult ewe ovaries. After in vitro fertilisation, we quantified cleavage rate, blastocyst rate, hatching rate, blastocyst efficiency, and total blastocyst cell number (TCN). Extract from B. pelecinus, at 50 μg/mL concentration, increased cleavage rate at (P &lt; 0.05), and at 100 μg/mL, increased blastocyst rate and efficiency (P &lt; 0.05). The other plant extracts did not affect these measures. TCN was affected by stage of development and treatment, but not by the interaction between stage and treatment. Within treatments, TCN was increased by C. intybus (at both 50 and 100 μg/mL) but decreased by M. sativa (at both 50 and 100 μg/mL; P &lt; 0.05). We conclude that methanolic extracts of forage plants, present during in vitro oocyte maturation, did not disrupt subsequent fertilisation and embryo development until the blastocyst stage. On the contrary, B. pelecinus appears to improve fertilisation and embryo development. Overall, these observations suggest that these plants will not disrupt in vivo oocyte maturation but further testing is still required, especially for the other stages of the reproductive process.

Advancement of puberty and enhancement of seminal characteristics by supplementation of trace minerals to bucks

Attainment of puberty in animals is dependent on their age, body weight, nutritional status, genetic and environmental conditions. Nutritionally, organic minerals are suggested to improve semen production, sperm motility and male fertility. In this context, role of organic zinc (Zn) and copper (Cu) in advancing male puberty and semen characters in Osmanabadi goats were studied. Forty one (n = 41) bucks (Aged 5 months) were divided into ten groups and the dietary treatments comprised of a control group (basal diet; without additional trace mineral supplementation) and nine treatment groups that received, in addition to the basal diet, various doses of trace minerals (mg) on per kg dry matter basis, organic Zn as low Zn20, medium Zn40 and high Zn60, organic Cu as low Cu12.5, medium Cu25, high Cu37.5 and combination of organic Zn + Cu as low Zn20 + Cu12.5, medium Zn40 + Cu25, high Zn60 + Cu37.5, respectively fed for a period of 8 months. Bucks fed organic trace minerals reached puberty 28-35 days earlier than control group. In addition, improvement (P < .01) in testosterone hormone (ng/ml) levels (control: 1.63 ± 0.07 VS Zn60: 2.54 ± 0.02; Cu12.5: 6.17 ± 0.05; Cu25: 3.01 ± 0.04; Cu37.5: 2.39 ± 0.06; Zn20 + Cu12.5: 1.94 ± 0.02; Zn60 + Cu37.5: 2.44 ± 0.16 at 240 days), semen production capacity (sperm concentration, volume, mass motility) and semen quality (higher progressive motility, velocity, sperm membrane integrity and acrosome integrity) were observed in supplemented groups (P < .05) than the control bucks. The present study demonstrated that, additional feeding of organic Zn and Cu to growing male goats advanced onset of puberty and improved quantitative and qualitative semen characteristics. The results also implied that the organic Cu had a significant effect on overall performances of bucks as compared to Zn alone or Zn and Cu in combination.

Relationship of organic mineral supplementation and spermatozoa/white blood cells mRNA in goats

The antioxidant properties and the protective role of organic zinc (Zn) and copper (Cu) in white blood cells (WBCs) and spermatozoa were analyzed through quantification of superoxide dismutase 1 (SOD1), catalase (CAT), glutathione peroxidase 4 (GPx4) and nuclear factor erythroid 2-like 2 (NFE2L2) and correlations were determined with sperm functional characteristics in Osmanabadi bucks. Bucks (aged 5 months; n = 40) were divided into ten groups, and the dietary treatments comprised of a control and nine treatment groups as follows: organic Zn as Zn 20, Zn 40 and Zn 60, organic Cu as Cu 12.5, Cu 25, Cu 37.5 and combined organic Zn and Cu as Zn 20+Cu 12.5, Zn 40+Cu 25, Zn 60+Cu 37.5, respectively per kg dry matter for a period of 8 months. The blood (120 and 240 days) and semen (240 days: 40 × 4 = 160) samples were collected from 40 bucks. In WBCs: the relative abundance of mRNA for SOD1, CAT, GPx4, NFE2L2 was greater (P < 0.05) in (120 and 240 days) in majority of the mineral supplemented animals. In spermatozoa: the relative abundance of SOD1, NFE2L2, GPx4 and CAT mRNA was greater (P < 0.05) in selected treatment groups. The abundance of SOD1 mRNA in WBCs was positively correlated (P <  0.05) with sperm mass motility (r = 0.692, P = 0.027). The abundance of GPx4 mRNA was negatively correlated (P <  0.05) with type A sperm (straightness; STR) > 85% and amplitude of lateral head displacement (ALH) > 2.5 μm/ s) (r = -0.711, P = 0.021) and (P <  0.05) positively correlated with sperm viability (r = 0.669, P = 0.035). Organic Zn and Cu supplementation was associated with an increase in the expression of antioxidant defense enzyme genes in bucks.

Effect of increasing levels of wasted date palm in concentrate diet on reproductive performance of Ouled Djellal breeding rams during flushing period

Aim

The aim of the study was to assess the effect of two levels of wasted date (WD) by replacing commercial concentrate on the reproductive performance of Ouled Djellal (OD) rams.

Materials and Methods

Eighteen mature (2-year-old) OD rams were equally allocated to three groups and fed during 11 weeks with one of three different experimental diets, that contained 0% (0 WD), 50% (50 WD), or 75% (75 WD) of WDs in concentrate diet. Live body weight (LBW), body condition scoring (BCS), scrotal circumference (SC), testicular weight (TW), sperm production and quality, plasma testosterone concentration (T), and sexual behavior (reaction time and number of mounts with ejaculation) were regularly recorded from every ram.

Results

LBW, SC, and TW changed significantly among diet groups and during the experimental period (p<0.001), the highest averages were recorded in (0 WD) group. LBW, BCS, SC, TW, semen volume, and percentage of the positive hypo-osmotic swelling test were (p<0.001) positively influenced by flushing period. Nevertheless, sperm concentration showed a significant (p<0.001) decrease at day 30, followed by a return to the initial values afterward. There were no differences (p>0.05) between diet groups for plasma testosterone concentration and semen attributes, except that (50 WD) group expressed the lowest overall value of semen concentration. Furthermore, neither time nor diet affected (p>0.05) sperm motility and reproductive behavior parameters.

Conclusions

It is possible to introduce WD as unconventional local feeding resources in flushing diet of breeding rams without disturbing their reproductive performance.

Free gossypol supplementation frequency and reproductive toxicity in young bulls

The aim of the present study was to analyze seminal quality of young bulls subjected to different frequencies of gossypol supplementation. Forty-eight Nellore bulls, with 19 months of age and weighing 357.8 ± 7.2 kg, were used in this study. Animals were fed with 10.5 kg of standard supplement containing free-gossypol from whole cottonseed (WCS) at the following frequency: 3x/week (G3x), 5x/week (G5x) or 7x/week (G7x - Control). Additionally, a negative control was provided, and the treated animals received only mineral supplement (MM) ad libtum. The experiment lasted for 84 days and semen was collected at the beginning and at the end for analysis and cryopreservation. Fresh semen was used for initial analysis and plasma membrane integrity and sperm morphology were also determined. General motility using computer assisted sperm analysis (CASA), plasma and acrosomal membranes integrity, mitochondrial activity, and induced oxidative stress were assessed in post-thawed semen. The study design was completely randomized. Parametric data were analyzed by ANOVA and non-parametric data by the Wilcoxon test, using the statistical program SAS. Level of significance was set at 5%. Supplementation with WCS, regardless the frequency, increased total (P = .009) and head (P = .005) defects in comparison to animals receiving only forage and mineral supplement. Infrequent supplementation, particularly 5 times in the week (G5X), increased head (P = .026) and midpiece (P = .014) abnormalities. Sperm motility in fresh semen was lower in animals that received daily supplementation than those supplemented on alternate days (P = .021). Additionally, animals supplemented daily showed lower percentage of spermatozoa with intact acrosome compared to those supplemented on alternate days (P = .005). Thus, regardless the frequency of supplementation, free-gossypol supplementation affects sperm quality. Although the amount of free gossypol supplied weekly was the same among treatments, daily supplementation compromised sperm kinetics, differently from infrequent supplementation that led to sperm defects developed during spermatogenesis.

Short-term supplementation with maize increases ovulation rate in goats when dietary metabolizable energy provides requirements for both maintenance and 1.5 times maintenance

This study aimed to evaluate ovarian follicular dynamics in goats submitted to synchronization of estrus and supplemented with diets that differed in the metabolizable energy source and amount of energy. The experiment was carried out using 42 does allocated into three treatments, fed for 9 days with a ration providing 1.0 times maintenance containing maize (1 MM, n = 14) or without maize (1 M, n = 14) or a ration providing 1.5 times maintenance containing maize (1.5 MM, n = 14). Estrus was synchronized with two injections of cloprostenol given 7 days apart. Does were also treated with intravaginal progesterone inserts and eCG. The number of ovulations and size of the follicles were measured using ultrasonography on Days 10, 11, and 12 after the start of the dietary treatment. The interval to estrus and duration of estrus did not differ between treatments (P = 0.382). Does fed with 1 and 1.5 MM had a similar number of ovulations but a greater number of ovulations than goats fed with 1 M (P = 0.028). The mean number of small, medium, large, and total number of follicles on Days 10 to 12 of ultrasound evaluations did not differ (P = 0.204) between treatments, but mean numbers changed over time (P < 0.001). The mean frequency and amplitude of LH pulses and concentrations of glucose, insulin, leptin, and insulin growth factor-1 in plasma were not significantly affected (P > 0.258) by any of the treatments. In summary, the inclusion of maize in the ration can stimulate ovulation rate at maintenance level. Similar results between groups fed diets that included maize and provided metabolizable energy at 1.0 and 1.5 maintenance demonstrate that to increase the ovulation rate when synchronizing estrous cycles in does, dietary supplementation with maize can be restricted to provide a maintenance level of metabolizable energy only, which would reduce dietary costs.

Hormonal concentrations and reproductive performance of Holstein heifers fed Trifolium alexandrinum as a phytoestrogenic roughage

Effects of phytoestrogen isoflavones in Berseem clover on hormonal balance during early pregnancy and fertility of heifers were studied. Holstein heifers (n=26) were divided into two equal homogenous groups. Heifers in the first group (Clover-fed group) were fed Egyptian clover (Trifolium alexandrinum) as oestrogenic roughage; whereas the heifers in the second group (Silage-fed group) were fed maize silage. Concentrations of four isoflavone aglycones (genistein. Daidzein, biochanin A and formononetein) were determined in the two roughages. Treatment lasted for 20 consecutive weeks (5 months) during which blood samples were collected biweekly for determining the metabolic profile of heifers. Heifers were subjected to oestrous synchronisation using a double prostaglandin F2α (PGF2α) based protocol, 14days apart (week 10 and 12), and were artificially inseminated 12h following detection of overt signs of oestrus. Concentrations of serum oestradiol (E2) and progesterone (P4) on the day of insemination (Day 0) and on Days 7, 14 and 21 post-insemination (early pregnancy) were determined and P4 to E2 ratio was calculated. Clover had greater total isoflavone content than maize silage. The dominant isoflavone detected in Berseem clover was biochanin A, whereas the least was formononetein. Metabolic profile was not affected (P>0.05) by the type of roughage and was in the same trend in both experimental groups. The overall mean concentration of serum E2 was greater (P<0.05) in the clover-fed group than in the silage-fed group. The overall mean concentration of serum P4 was less (P<0.05) in the clover-fed group than in the silage-fed group. During the period of early pregnancy (from Day 7-21 post-insemination) the concentration of serum P4 increased in the silage-fed group, however, no change was observed in the clover-fed group. The overall mean of P4 to E2 ratio was greater (P<0.001) in the silage-fed group compared with that in the clover-fed group. Heifers fed clover had a lesser (P=0.054) conception rate and a greater (P=0.062) percentage of heifers returning to oestrus than silage-fed heifers. In conclusion, isoflavones in Berseem clover apparently disturbed hormonal balance during early pregnancy leading to a reduction in the fertility of heifers.

Posidonia oceanica banquettes as a substitute for straw in dairy goat rations: metabolic and productive effects

BACKGROUND

The marine plant Posidonia oceanica (L.) Delile can be a source of fibre to increase the efficiency of product costs. The aim of the present study was to assess the productive (milk production and performance) and metabolic (blood metabolites) effects of P. oceanica in the ration of dairy goats as a substitute for straw. Posidonia oceanica was used at 225 and 450 g day(-1) per goat in lieu of barley straw.

RESULT

Supplementation with P. oceanica had no detrimental effects on the body weight, milk production and metabolic status of goats. Goats fed P. oceanica produced more milk fat, had a lower somatic cell count in their milk and showed a decreased risk of oxidative stress.

CONCLUSION

Goats can be fed P oceanica at levels of up to 450 g day(-1) without detrimental effects on milk production and health, therefore P. oceanica can be a substitute for barley straw in the nutrition of goats.

Evaluation of the nutritive value of muiumba (Baikiaea plurijuga) seeds: chemical composition, in vitro organic matter digestibility and in vitro gas production

One of the main constraints hindering the increase of animal production in semi-arid regions of Africa is the inadequate supply of nutrients during the dry season. Incorporation of alternative feed resources in ruminant diets during this period could be a viable approach to overcome these limitations. The objective of this study was to evaluate the nutritive value of muiumba (Baikiaea plurijuga) tree seeds as an alternative nutrient source for ruminants. Muiumba seeds were compared to other eight feedstuffs including two cereal grains (corn and oat), two wheat by-products (wheat bran and distilled wheat) and four protein meals (coconut meal, sunflower meal, soybean meal and rapeseed meal) as to its chemical composition, in vitro organic matter digestibility (IVOMD) and in vitro gas production. The moderate crude protein concentrations (145 g/kg DM) of muiumba seeds indicate that this feedstuff could not be used as a protein supplement, contrarily to the majority of multipurpose tree seeds. Although the starch content was scarce (15 g/kg DM), the low neutral detergent fibre (235 g/kg DM), low molecular weight sugar (76.1 g/kg DM) and non-starch polysaccharide (510.5 g/kg DM) contents indicate that this feedstuff has potential feeding value. This was confirmed by the IVOMD (0.770) and by the data provided by the in vitro gas production showing that muiumba seeds had high (P < 0.05) maximum gas production and fractional fermentation rates, suggesting that these seeds are characterized by a highly fermentable fraction.

Diurnal variations of progesterone, testosterone, and androsta-1,4-diene-3,17-dione in the rumen and in vitro progesterone transformation by mixed rumen microorganisms of lactating dairy cows

Five Holstein lactating dairy cows fed 5 total mixed rations (TMR) with different forage combinations were used in a 5 × 5 Latin square design to investigate diurnal variations of progesterone (P4), testosterone, and androsta-1,4-diene-3,17-dione (ADD) concentrations in the rumen. Meanwhile, different P4 inclusion levels [0 (control), 2, 20, 40, 80, and 100 ng/mL in culture fluids] were incubated in vitro for 6, 12, 24, 36, 48, and 72 h together with rumen mixed microorganisms grown on a maize-rich feed mixture (maize meal:Chinese ryegrass hay = :1) with an aim to determine microbial P4 transformation into testosterone and ADD. Ruminal P4, testosterone, and ADD concentrations of lactating dairy cows were greater in the TMR with forage combination of corn silage plus alfalfa hay or Chinese wild ryegrass hay than the TMR with the corn stover-based forage combination. The diurnal fluctuation pattern showed that P4, testosterone, and ADD concentrations in the rumen were greater at nighttime than daytime and peaked 6h after feeding in the morning or afternoon. The in vitro batch cultures showed that the P4 elimination rate was highest at the P4 addition of 20 ng/mL and declined with the further increased addition of P4. The treatments after dosing P4 exhibited a shorter time than the control group until half of the initial P4 inclusion was eliminated (i.e., half time), and the lowest half time (1.46 h) occurred at the P4 addition of 20 ng/mL. In summary, the ruminal steroids concentration was affected by forage type and quality, and the rumen microorganisms exhibited great ability to transform P4 into testosterone and ADD, depending on incubation time and initial P4 addition level, suggesting that the host might affect the metabolism of its rumen microorganisms via the endogenous steroids.

Reduced cortisol and metabolic responses of thin ewes to an acute cold challenge in mid-pregnancy: implications for animal physiology and welfare

BACKGROUND

Low food availability leading to reductions in Body Condition Score (BCS; 0 indicates emaciation and 5 obesity) in sheep often coincides with low temperatures associated with the onset of winter in New Zealand. The ability to adapt to reductions in environmental temperature may be impaired in animals with low BCS, in particular during pregnancy when metabolic demand is higher. Here we assess whether BCS affects a pregnant animal's ability to cope with cold challenges.

METHODS

Eighteen pregnant ewes with a BCS of 2.7±0.1 were fed to attain low (LBC: BCS2.3±0.1), medium (MBC: BCS3.2±0.2) or high BCS (HBC: BCS3.6±0.2). Shorn ewes were exposed to a 6-h acute cold challenge in a climate-controlled room (wet and windy conditions, 4.4±0.1°C) in mid-pregnancy. Blood samples were collected during the BCS change phase, acute cold challenge and recovery phase.

RESULTS

During the BCS change phase, plasma glucose and leptin concentrations declined while free fatty acids (FFA) increased in LBC compared to MBC (P<0.01, P<0.01 and P<0.05, respectively) and HBC ewes (P<0.05, P<0.01 and P<0.01, respectively). During the cold challenge, plasma cortisol concentrations were lower in LBC than MBC (P<0.05) and HBC ewes (P<0.05), and FFA and insulin concentrations were lower in LBC than HBC ewes (P<0.05 and P<0.001, respectively). Leptin concentrations declined in MBC and HBC ewes while remaining unchanged in LBC ewes (P<0.01). Glucose concentrations and internal body temperature (T(core)) increased in all treatments, although peak T(core) tended to be higher in HBC ewes (P<0.1). During the recovery phase, T4 concentrations were lower in LBC ewes (P<0.05).

CONCLUSION

Even though all ewes were able to increase T(core) and mobilize glucose, low BCS animals had considerably reduced cortisol and metabolic responses to a cold challenge in mid-pregnancy, suggesting that their ability to adapt to cold challenges through some of the expected pathways was reduced.

Prospects for using nonconventional feeds in diets for Awassi dairy sheep in Syria

High feed costs are major obstacles for resource-poor dairy sheep farmers in West Asia, along with large fluctuation in grain and straw prices. Farmers need low-cost diets using locally available feeds that can provide sufficient milk of good quality. Two experimental trials were conducted on Awassi milking ewes to evaluate nonconventional and balanced low-cost diets against the traditional unbalanced diet used by farmers (control) on the total yields (milk, fat, protein, and total solids) and milk composition (fat, protein, total solids, and lactose), an important indicator of milk quality. The first trial was conducted at the research station of the International Center for Agricultural Research in the Dry Areas (ICARDA, Aleppo, Syria) to test 6 low-cost balanced diets using locally available feeds and agro byproducts against the control diet. Each diet was tested on 8 ewes that were kept on pasture as a basal diet, but received different supplements, including barley, wheat bran and nonconventional feeds (urea-treated wheat straw, molasses, sugar beet pulp, and cotton seed cake). Five balanced diets enhanced the total yields of milk, fat, protein, and total solids, in 2 cases, significantly. These diets increased total milk yield by 17.7 to 50.2% and decreased supplement feeding costs by 43% compared with the control. However, milk composition remained unaffected. The second trial was conducted on 3 different farms in northern Syria to assess in each farm a low-cost balanced diet on milking ewes (n=15) in comparison to the farmer's control (n=15). The balanced diet was a modification requested by farmers of the best performing diet in the on-station trial. Confirming the first trial's research results, the balanced diet outperformed the control in total yields; for instance, it increased total milk yield by 28 to 40% and raised net income by 30%, without affecting milk composition. Both trials showed that using locally available nonconventional feedstuffs, such as molasses, integrated into balanced dairy sheep diets can decrease feed costs of resource-poor farmers, while enhancing total yields of milk and milk constituents without compromising milk quality components. This will greatly improve the profitability of dairy sheep production in dry areas.

Effect of concentrate supplementation on performance, ovarian response, and some biochemical profile of Malpura ewes

Effect of feed flushing on ovulation rate was investigated during the autumn seasons on 24 adult Malpura ewes (BW 34.8 ± 0.58 kg and age 4-7 years) equally divided into two groups. Ewes in G1 (group 1) were grazed 8-10 h daily on Cenchrus ciliaris pasture interspersed with seasonal shrub. In addition to grazing, concentrate was provided at 1.5% of BW to the animals in G2 (group 2) for a period of 35 days. Estrus was synchronized by a double injection schedule of PGF(2α) at 0 and 10 days of the experiment and detected by parading aproned rams at 6 h intervals. Blood samples were collected at weekly interval during the estrous cycle. A rumen fermentation study was conducted on day 23 of the experiment at 0 and 4 h post-concentrate feeding. Ovarian responses in terms of number of corpora lutea and large follicles was examined on all the ewes by laparoscopy after 3 to 6 days of each estrus and were found to be similar in both the groups. Hemoglobin and packed cell volume, total protein, albumin, and globulin were similar among the groups. Concentration of plasma glucose (12 and 22 days) was higher (P < 0.05) in G2 vis-à-vis control. Plasma urea was higher (P < 0.01) in the control than G2. Rumen liquor pH, concentration of total N, TCA-ppt N, NH(3)-N, and TVFA were significantly higher (P < 0.01) in G2 than the control. Thus, it can be concluded that concentrate supplementation in ewes prior to mating (flushing) did not enhance ovulation response during the autumn season.