دکتر احسان محجوبی

To predict body composition of growing Afshari fat-tailed lambs using the 9-11th rib composition as a predictor of whole body composition, 10 lambs were randomly selected (43.9 ± 3.9; mean shrunk body weight; mean ± SD) and harvested accordingly. After slaughter, the 9-11th rib sections were harvested from chilled carcasses for 24 h; fat, lean, fat-tail and bone were weighted separately and total separable fat (without fat-tail) and lean were grounded twice to obtain a homogenous sample for further chemical analysis. Rib dissection separable lean, fat and bone percent were (mean ± SD) 33.9 ± 6.6, 23.6 ± 6.6, and 17.3 ± 7.4, respectively. In addition, rib dissection ether extract, crude protein, moisture, and ash percent were (mean ± SD) 27.6 ± 4.1, 19.3 ± 0.7, 49.6 ± 5.3, and 1.7 ± 0.3, respectively. Except for carcass separable bone percent (with and without fat-tail), it was shown that the 9-11th physical rib composition can properly predict the carcass separable fat (adjusted R2 of 0.62 and 0.86 with and without accounting for fat-tail, respectively; P < 0.01) and lean (adjusted R2 0.77 and 0.71 with and without accounting for fat-tail, respectively; P < 0.01). As for the carcass chemical composition, with or without accounting for fat-tail, none of rib chemical commotion based on as-is analysis predicted chemical carcass composition. However, when as-is data were represented as soft tissue dry matter, only rib crude protein (%, without accounting for fat-tail) could predict carcass crude protein (adjusted R2 = 0.60; P < 0.005). In general, our results for the first time in fat-tailed sheep, showed that the 9-11th rib section can only predict physical, but not chemical, composition of fat-tailed lamb carcass.

Human demand for goat milk and its products has been growing mainly because of their exclusive nutritional properties. Goat milk is rich in functional and healthy compounds such as bioactive peptides, conjugated linoleic acids and oligosaccharides. These nutritionally important compounds offer advantages for consumers of goat dairy products. Altered climatic conditions and decreased precipitations in many regions have led goat farmers to intensify and industrialize their production systems. For goat nutrition under intensive production systems, physical form of ration would be of productive and economic significance. The objective of this study was to investigate the effect of feeding various physical forms of concentrate (mash, pelleted and textured) on milk production, nutritional behaviors, and blood parameteres of Murciano_Granadina dairy goats in Iran.

This experiment was conducted in Magsal Commercial Dairy Goat Farm (4000 dairy goats; Qazvin, Iran) from January through March 2020. Thirty second parity goats in mid lactation (Murciano_Granadina) assigned to 3 treatments (10 goats per treatment). Treatments containing concentrate with form of 1) mash, 2) pelleted, or 3) textured. Feed and milk samples (from a.m. and p.m. milkings) were collected weekly for later analytical measurements. Feed was analyzed for NDF, crude protein, ether extract, and ash. Goats were weighed weekly just before the morning feed delivery. Milk samples were analyzed for fat, protein, lactose, total solids, solids-nonfat, urea nitrogen, and total fatty acids . The data were analyzed using mixed models of SAS program.

Raw and 3.5% fat-corrected milk yields were greater (P < 0.01) for T or textured (1653 and 2074 g/d) than for P or pelleted (1372 and 1752 g/d) and M or mashed (1089 and 1439 g/d), respectively. Because of unchanged milk composition (P > 0.10), daily yields of milk fat, protein, lactose, SNF and total solids were also greater (P < 0.01) for T than for other treatments. As a result of increased total milk fat, protein, and solids yields, cheese yield estimates were greater (P < 0.01) for T than for other forms of concentrate. For example, milk fat yield was 17% and 36% greater for T than for P and M, respectively. These results demonstrated that goats fed T had better energy and nutrient balance than goats fed other treatments (Sanz Sampelayo et al., 1998). These data alongside feed sorting results suggest that feeding M (and likely P) might have adversely affected rumen conditions. Pelleting concentrate may increase the likelihood of subacute ruminal acidosis (Ebrahimi et al., 2020), and thus reduce nutrient intake and microbial protein synthesis. The present data for the first time reports that physical form of concentrate affects milk production of lactating dairy goats and that textured concentrate is superior to both pelleted and mashed concentrates.
Feeding P instead of M improved yields of fat-corrected milk and milk protein, lactose, and total solids as well as feed efficiency (P < 0.05). In addition, orts were finer containing more concentrate for M than for P (P < 0.05). These data suggest that feeding P instead of M concentrate resulted in decreased feed sorting and improved nutrient assimilation by lactating dairy goats. Notable, dry matter intake was similar between M and P (P > 0.10), emphasizing the increased orts fineness and improved feed efficiency for P vs. M. It is obvious that because of more sorting, less concentrate (than predicted) was consumed for M than for P. It is also likely that M was degraded more rapidly in the rumen, suggesting induced ruminal acidosis. This cascade could reduce nutrient efficiency in M-fed goats than in other goats.In dairy cows, feeding steam-flaked corn grains instead of ground or dry-rolled grains have improved (Cooke et al., 2008; Yu et al., 1988), tended to improve (Zhong et al., 2008), or not affected (Shen et al., 2015; Dhiman et al., 2002) milk production. Steam-flaking and texturizing are to some extent similar, as they both produce feeds with larger and more uniform particles, when compared to grinding or dry-rolling. The improved milk production of goats fed T in the current study is consistent with the above-mentioned increases in milk production of cows fed steam-flaked corn grains. Feed efficiency or FCM to DMI ratio was improved by feeding T and P instead of M, which was due to the much improved milk yield in the T and P groups than in the M group. Milk urea N was similar among the treatments, probably suggesting that rumen ammonia and splanchnic urea outputs were not significantly affected by the treatments.Blood patameters (glucose, albumin, and NEFA) were not affected by treatments.Murciano-Granadina goats separation less in textured treatment than other treatments. Under the conditions of this experiment, the use of textured concentrate in the diet of Murciano-Granadina lactating goats has more advantages for consumption of mash and pelleted concentrate and leads to increased milk production and composition and improved feed efficiency.

The commercial dairy goat production is expanding worldwide. Improving feed efficiency and farm economics is, thus, a major goal. Findings provided new information that feeding lactating Murciano-Granadina dairy goats TMR with textured concentrates instead of pelleted and mashed concentrates minimized feed sorting, increased dry matter intake and milk production, and improved cheese yield estimates and feed efficiency. Feeding pelleted vs. mashed concentrate improved milk production and feed efficiency. Blood concentrations of glucose, NEFA, albumin and total protein were not affected by the physical form of concentrate. Results confirmed that feeding textured concentrate vs. both pelleted and mashed concentrates can significantly benefit feed efficiency, milk production, and cheese yield in lactating Murciano-Granadina dairy goats. Future studies on optimizing physical form of concentrate in relation to dietary forage source are warranted.

Global demand for goat milk and its products has been growing. The decreased pasture quality has led goat producers to use intensive production systems with economical fodder resources. Goat milk contains functional compounds that enhance human immune system and overall health. Goat milk is enriched with functional peptides, conjugated linoleic acid, and healthy oligosaccharides that can immensely benefit human immunity and health. Goats are usually capable in utilizing lower quality forages. In few recent studies, alfalfa hay was compared with different by-products and local feeds with no significant effects found on rumen fermentation and milk production or composition. Murciano-Granadina goats were capable to utilize low quality fiber sources towards milk production.The objective of this study was to determine effects of feeding various forage sources on milk production, nutritional behaviors, and blood parameters of Murciano-Granadina dairy goats in Iran.

  Thirty second-parity Murciano-Granadina goats (190 ± 3 days in milk; 2 ± 0.03 kg/d milk yield) were used in a completely randomized design study with three treatments (10 goats per treatment). Treatments were diets containing 1) wheat straw (WS), 2) alfalfa hay (AH), or 3) corn silage (CS). To enable sound comparisons among forage sources, treatment diets were balanced to be isoenergetic and isonitrogenous. The concentrate portion of the rations was similarly ground for all treatments. Feed and milk (from a.m. and p.m. milking) samples were collected weekly for later analytical measurements. To determine goat behavior time; eating, ruminating, and resting times were observed and recorded by technical individuals on days 30 and 50 of the experiment in two 24-h period. Blood samples were taken at 0800 h on d 1, 30, and 56. The data were analyzed using mixed models of SAS program.

 The dry matter intake (DMI) was significantly affected by treatments (P <0.001). Body weight and its changes were similar among treatments, suggesting that nutrient partitioning towards tissue accretion or depletion was not different among treatments during the study, since goats were in late lactation. However, DMI was 228 g higher for goats received diet containing corn silage than for those received AH (P < 0.05). Decreased DMI for diets with wheat straw and alfalfa hay compared with corn silage could at least partially be related to increased dietary fat and indigestible cell wall in the former diets. Ruminating, standing, and resting times were not different among treatments (P > 0.10). These data would suggest that despite the differences in forage nutritional characteristics, digestibility, and intake, ruminating time was similar among treatments.Goats fed CS had higher milk production than the other two groups (P <0.001). The percentage of milk fat in the alfalfa hay treatment was higher than in the other treatments (p> 0.05). Similar to milk volume, daily yields of milk protein, lactose, and total solids were also higher for corn silage than for other treatments. This could be a result of increased milk volume and unchanged milk contents of protein and lactose for corn silage. Milk fat content was higher (P < 0.01) for AH treatment but milk fat yield tended (P < 0.10) to be greater for CS treatments than for other treatments.Serum concentration of glucose, albumin and non-esterified fatty acids (NEFA) were not significant among experimental treatments. Glucose and NEFA values are usually interpreted as indices for energy status of experimental animals. Similar glucose and NEFE concentrations in blood for the three forage treatments could be evaluated in light of the fact that goats were in mid and late lactation and thus were not in negative energy balance. As a result, they may have not been metabolically sensitive enough to respond to treatments at this stage of lactation. Serum concentrations of total proteins were higher for AH than for other treatments (P < 0.05). Findings  of this study suggest that lactating Murciano-Granadina goats are capable to utilize different forage sources including alfalfa hay, corn silage and wheat straw. However, corn silage leads to higher raw and fat-corrected milk yields, whereas alfalfa hay increases milk fat content. For higher feed efficiency and lower feed cost and where more available, Wheat Straw may be used in Murciano-Granadina goat diets. To improve milk yield and fat content and yield simultaneously, certain combinations of alfalfa hay and corn silage may be required. Determining this will require future experimentation. Future experiments could also investigate forage choice effects on milk fatty acids profile and other functional compounds.

In order to evaluate the effect of adding butyric acid to whole milk on growth performance and blood parameters of Holstein calves, 36 calves were used in a completely randomized design. The experimental treatments were: 1) control group without any additive (B0); 2) B0 + 4 grams per day of added butyric acid in milk (B4); and 3) B0 + 8 grams per day of added butyric acid in milk (B8). The calves had free access to feed and water during the experiment. Body weight at weaning and end of experiment tended to increase in B4 and B8 compared to B0 (P = 0.08). Average daily gain was significantly (P < 0.01) affected by treatment during the pre-weaning, so that B0 had the lowest daily gain, but no difference was observed between B4 and B8. The starter intake was less in B0 compared to the other two groups during pre-weaning period (P < 0.01), post-weaning, (P = 0.04) and throughout study (P < 0.01), but there was no difference between B4 and B8. The serum concentrations of glucose, total protein and albumin within pre-weaning were not significantly different among treatments, but BHBA concentration was lower in B0 group than in other groups (P < 0.01). There was no difference among treatments in terms of average fecal score. In general, for the first time, the results of this study showed that adding butyric acid to the whole milk can have positive effects on improving performance.

Today, responding to the growing demand to food for increasing the world’s population and providing adequate food is one of the main causes of energy requirements in agriculture operations. Effective use of energy is an important condition for sustainable agricultural production which saves the cost, preserving fossil fuels and reduces air pollution. The animal husbandry sector plays an important role in providing the food security to the community by producing livestock products. Dairy farms play a significant role as the consumers and producers of energy. The livestock production is the poor converter of energy, because it is based on a double energy transformation. First, solar energy and soil nutrients are converted into biomass by green plants. Second, when crops are fed to livestock, a major share of energy intake is spent on keeping up body metabolism and only a small portion is used to produce meat and milk. Increased energy efficiency and utilization of non-renewable energy are effective to improve the air quality and also to reduce the greenhouse emissions. The aim of this study was to compare the input and consumed energy in dairy farms with different housing Systems. To carry out this research, the required information was collected from 42 dairy farms in the west of Tehran province. The studied dairy farms had an average milk yield of 31.94± 3.2 kg per day for milking cows and 195.42± 10.18 days in milk. The information included the unit consumption inputs over a one-year period aimed at comparing energy consumption and energy production between dairy farms with different housing Systems. The consumed energy included the non-renewable energy such as fuel and electricity and renewable energy such as forage, concentrate, machines, human labor, and water. Output energy included milk, meat, and manure. In order to compare energy efficiency between dairy farms, energy indices (energy ratio, net energy, energy productivity and specific energy) were used. The data were analyzed by SAS software. In this study, the average non-renewable consumed energy in dairy farms with freestall and open shed facilities per kg fat and protein corrected milk (FPCM) was 3.34 and 5.01 MJ, respectively (P=0.08). The highest share of the consumed energy in all dairy farms was related to feed energy, which had a share of 86.69% and 81.91% in the freestall and open shed, respectively. Also, the water input with consumption of 0.009 m3 per kg FPCM in freestall showed significant difference with open shed with consumption of 0.011 m3 per kg FPCM (P=0.04). Electricity consumption per kg FPCM in freestall and open shed was calculated to be 0.92 and 0.13 kWh, respectively (P=0.11). The rate of indirect energy was greater than that of direct energy consumption in both types of farms. The calculated output energy was 3.33 and 3.34 MJ per kg FPCM in freestall and open shed, respectively. The energy ratio for freestall and open shed were calculated to be 0.15 and 0.14, respectively. In addition, the energy productivity for freestall and open shed were 0.046 and 0.041, respectively. Energy indices can be improved by increasing the inputs efficiency, by reducing losses of inputs per cow or by optimizing inputs. In freestall farms, losses of inputs are lower than open shed farms. These results indicate better management of inputs in freestall farms. In freestall farms, because of the high density per unit area, consumption of inputs per head and per kilogram of FPCM was lower, indicating less waste of input and energy consumption. Considering the non-renewable consumed energy per kg FPCM, dairy farms with different housing systems (freestall vs open shed) tended to have difference. Among energy inputs, the energy of concentrate and forage (feed) consumption had the largest share of dairy farms. Also, considering the energy content of consumed feed as the main source of energy intake, special attention should be paid to prevention of energy waste throughout the suitable feed management as well as correct animal grouping. The use of proper feeding management, animal grouping, using several indicators (production, days in milk, body condition score, etc.) and breeding programs (according to production efficiency and yield traits) can improve feed consumption as the main source of energy consumption in dairy farms. Furthermore, the consumption of inputs per kg FPCM in freestall units was lower than open shed units.

The experiment designed to evaluate the effects of a glycerol based supplemental product on growth and dry matter intake (DMI) in Holstein bull calves during controlled heat stress (HS). Before the start of the experiment, bull calves (n= 14, 163.6 ± 30.1 kg BW) were allocated to thermal neutral conditions [26.5 ± 3.4°C] for 7 d (period 1; P1). During this period, productive parameters as well as DMI is measured as covariate for the subsequent HS period. Following P1, a cyclical HS pattern was implemented for 21 d (P2) where daily ambient temperatures ranged from 29.1 to 39.7°C. During P2, half of the HS calves (n=7) received a control diet (CON) and the other half received the control diet supplemented with a product containing gluconeogenic precursors (GLU, 300 g/d)). Throughout each period feed and water intake were measured daily and respiration rate and rectal temperature were recorded at 0600, 1100 and 1500 h daily. The diet had no effect on DMI. Although HS markedly reduced growth as expected, supplemental GLU did not affect body weight gain. Supplemental GLU decreased respiratory rate at 1500 h (P